wiki:AaronHelsinger/GAPI_AM_API_DRAFT

Version 8 (modified by Aaron Helsinger, 7 years ago) (diff)

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GENI Aggregate Manager API Draft Revisions

This page documents DRAFT revisions to the GENI Aggregate Manager API, proposed for the next version of the API. As indicated below, some of the revisions documented here have been discussed on the GENI developer mailing list, and during at least one GEC. Other revisions are in early discussions and subject to change or abandonment.

The GENI Aggregate Manager API allows aggregates to advertise resources and to allocate resources to Slices in the form of Slivers. A Sliver is a set of resources allocated by one Aggregate to one Slice. See below for a proposed complete definition.

The current officially adopted version of the API is 2 and is documented on the main API page.

API Version 2 was adopted based on changes previously listed on this page. Those changes have been removed from this page, and are now documented on a separate page. They include:

  1. RSpec related changes, specifying that RSpecs are XML following GENI standard schemas.
    • Since June 2011, the latest software from ProtoGENI and SFA (as of code tag 1.0-24) has complied with these changes.
    • Omni version 1.3 (released June 2011) added client software support for these changes.
  2. Supporting flexible arguments and returns. Specifically, adding a property list to all calls, and making all returns be a property list.

This page documents proposed changes for AM API version 3. These changes are grouped into sets. API Version 3 will be the collection of changes from the change sets below which we next agree on. Change sets still under discussion will then be targeted at a future release.

Proposing Additional Changes

GENI community members are encouraged to propose changes to the GENI Aggregate Manager API.

Technical discussions are generally held on the Developers mailing list

Specific questions may be directed to the software team at the GPO (Tom Mitchell, Aaron Helsinger, and Sarah Edwards) at {tmitchel, ahelsing, sedwards} at geni.net

Proposed changes for GENI Aggregate Manager API version 3

This page documents a long list of proposed changes for AM API version 3. These changes provide ways for aggregates to expand GENI functionality, without requiring further API modifications.

There are many changes here. As such, aggregates may implement these to varying degrees.

  • Clients are reminded that these methods are requests - based on the AM type and resource types, these requests may fail or not make sense. Clients should watch for UNSUPPORTED returns.
  • AMs are encouraged to implement as much of this API as reasonable to provide a common front for clients. When a function is not possible, return UNSUPPORTED, document publicly what functions do work, and suggest alternative ways to get the result the client desired.

Summary

Proposed Changes

At the top level, the proposed changes for AM API v3 include:

  • Change Set C: Add the ability to UpdateSlivers to immediately modify your reservation
  • Change Set D: Slivers: Change methods to clarify that there may be multiple slivers per slice at an AM, and to allow operating on individual slivers
  • Change Set E: Tickets: Add methods using tickets to do negotiated reservations
  • Change Set F1: Superceded by F3 and F4: Define sliver states, and the state changes that various methods cause
  • Change Set F2: Superceded by F3 and F4: Add a new general ActOnSlivers method allowing AMs to support AM and resource-type specific operations
  • Change Set F3: Sliver Allocation States and methods
  • Change Set F4: Sliver Operational States and methods
  • ADOPTED: Change Set G: Generalize the credentials argument, allowing ABAC support
  • Change Set H: Clarify: A second call to CreateSlivers without an intervening DeleteSlivers is an error.
  • ADOPTED: Change Set I1: SliversStatus return structure includes sliver expiration
  • ADOPTED with changes: Change Set I2: SliversStatus return includes SSH logins/key for nodes that support SSH access
  • ADOPTED: Change Set I3: CreateSlivers return becomes a struct, adds sliver expiration
  • Change Set I4: CreateSlivers optionally does not start resources.
  • Withdrawn: Change Set J: Support proxy aggregates with 1 new option and 1 new GetVersion entry
  • ADOPTED: Change Set K: Standardize certificate contents, etc
    • Include a real serial number, holder email, holder uuid, and optionally authority URL in certificates
    • Define slice ID as the UUID plus URN in slice certificates
    • Define slice name, sliver name, and user name restrictions, and similar for URNs
    • Publish schemas for credentials and certificates
  • Postponed: Change Set L: Standardize slice credential privileges

For a full listing of the proposed API methods after all these changes, see below.

Unspecified items

  • Semantics of start/restart after UpdateSlivers
  • Define the ticket service classes
  • Publish ticket schema
  • Publish credential schema
  • Define error codes returned by new methods, conditions

Change Set C: UpdateSlivers

Add an ability for experimenters to modify their allocated resources at an aggregate without deleting (and possibly losing) existing resource allocations.

This change was briefly discussed at GEC13, and is a topic for ongoing discussion.

Motivation

A common complaint among experimenters about the current AM API is that there is no way to add or remove resources from a slice at an aggregate, without completely deleting the slice at that aggregate and recreating it, possibly losing resources to another experimenter and certainly losing state. This proposal aims to address that, by introducing a method to update the slice at an aggregate.

The SFA calls for an UpdateSlice method, "to request that additional resources—as specified in the RSpec—be allocated to the slice".

In the PlanetLab implementation of the SFA, UpdateSliver is in fact a synonym for CreateSliver - the server will ensure that your allocated resources match your request RSpec, adding, removing and modifying resources as needed. It immediately allocates and boots nodes to match the request RSpec.

The ProtoGENI CMV2 API has UpdateSliver, which is described as the way to "Request a change of resuorces for an existing sliver. The new set of resources that are desired are specified in the rspec." At ProtoGENI as at PlanetLab, this method takes the full RSpec description of resources the experimenter wants, and the server computes the difference with what the experimenter already has. At ProtoGENI though, this method returns a ticket. The experimenter must then redeem the ticket to actually acquire the resources.

This topic was discussed at the GEC12 AM API session and on the GENI dev mailing list (in October and November).

This topic was also discussed on the geni-dev mailing list here: http://lists.geni.net/pipermail/dev/2012-March/000588.html and here: http://lists.geni.net/pipermail/dev/2012-March/000643.html and elsewhere in March 2012.

A competing related proposal from Gary Wong is here: http://www.protogeni.net/trac/protogeni/wiki/AM_API_proposals

UpdateSlivers

This change would add a new method UpdateSlivers, which takes a full request RSpec of the desired final state of the slice at this aggregate. This proposal calls for adding this functionality in the context of tickets: the UpdateSlivers method returns a ticket. See Change Set E: Tickets for details.

Some points about this change:

  • The method takes a full request RSpec - not a diff.
    • Note that we want the manifest to be readily modifiable to be a request (include component_ids and sliver_ids), but it is not yet.
    • AMs may, as always, return UNSUPPORTED - EG if they are incapable of determining what changes to apply (computing a diff).
  • The request is either fully satisfied, or fails (returns an error code).
  • AMs must document the level of service they provide: will any state be lost on existing resources?
  • Options includes geni_end_time, a RFC3339 requested end time for the reservation. See below for details.
    • If omitted, the AM may reserve the resources for the default sliver duration.
    • AMs should follow the logic of RenewSlivers to determine if the requested duration of the sliver is acceptable.
    • The request should Fail (return an error code) if the resources cannot be reserved until the requested time.

Aggregates and experimenters should use an RSpec extension for specifying a guarantee on state loss per-resource: EG:

  <node ... sliver_id="urn:publicid:IDN+jonlab.tbres.emulab.net+sliver+250">
    <sliver_type name="raw-pc"/>
...
    <preserve:preserve guarantee="persistent-state" />
  </node>

This uses the RNC schema:

default namespace = "http://www.protogeni.net/resources/rspec/ext/preserve/1"

# This is meant to extend a node or link
Preserved = element preserve {
  attribute guarantee { "none" | "persistent-state" |
                        "dynamic-state" | "no-disruption" }
}

start = Preserved

In the above schema, the states represent increasing levels of state preservation guarantee.

struct UpdateSlivers(string slice_urn, string credentials[], string rspec, 
                                                 struct options)

Returns a struct:

{
  string ticket=<ticket>
  string geni_status=<sliver state - ticketed>,
 <others that are AM specific>
}

See Change Set E: Tickets for details on the ticket returned and ticket semantics.

Change Set D: Sliver-specific operations

A slice may have multiple slivers at a single AM. Experimenters can operate on slivers independently, if the AM supports it. AMs define slivers as groups of resources, and give them locally unique sliver_urns for identifying that group of resources.

This change was briefly discussed at GEC13, and remains open for discussion. Concerns include whether aggregates can support individually operating on slivers, and whether we should make this change without that functionality.

See http://lists.geni.net/pipermail/dev/2012-March/000593.html as well.

Motivation

This change set was discussed at the GEC12 AM API session.

The current AM API calls take a Slice URN, and operate on all resources under that label at the given aggregate - all the resources for that slice at the aggregate are allocated, renewed, and deleted together. There is no provision for releasing some of the resources allocated to the slice at that aggregate, or for adding new resources to the reservation for that slice at a given aggregate.

This ties closely to the precise definition of a Slice vs a Sliver. The current AM API methods imply that a sliver represents all resources at an aggregate for a given slice. However, this does not match the definition that previous GENI documents have used, nor the functionality that experimenters desire.

Previous GENI documents have used this definition: A sliver is the smallest set of resources at an aggregate that can be independently reserved and allocated. A given slice may contain multiple slivers at a single aggregate. A sliver may contain multiple components.

Given this definition, the current AM API methods in fact operate on a group of slivers.

This change set would provide a means for experimenters to operate on individual slivers within their slice at a given aggregate.

Define sliver

A Sliver is an aggregate defined grouping of resources within a slice at this aggregate, whose URN identifies the sliver, and can be used as an argument to methods such as DeleteSlivers or RenewSlivers, and whose status can be independently reported in the return from SliversStatus. The AM defines 1 or more of these groupings to satisfy a given resource request for a slice. All reserved resources are directly contained by exactly 1 such sliver container, which is in precisely 1 slice.

Slivers are identified by an aggregate selected URN. See other change proposals for details on standardizing such URNs.

Addressable Slivers

Considering the clarified sliver definition, several API names are misleading. This change proposal modifies those method names to clarify that they may work with multiple slivers. Additionally, some methods can logically operate on individual slivers: this change modifies those methods' arguments to allow specifying a particular sliver.

  1. Rename some existing methods to clarify that they act on 1+ slivers:
    • CreateSliver -> CreateSlivers
    • RenewSliver -> RenewSlivers
    • DeleteSliver -> DeleteSlivers
    • SliverStatus -> SliversStatus
  1. Some methods that take slice_urn now take a urn that may be a slice or sliver:
    • RenewSlivers, DeleteSlivers, SliversStatus
    • AMs are responsible for distinguishing whether the request operates on a slice or a sliver (see Change Set K which defines how slice and sliver URNs differ).
    • AMs are free to refuse to Renew, Delete, or provide status on an individual sliver, if the local AM or that resource type does not support it.
      • AMs should return an error message. Clients may often use UpdateSlivers instead to similar effect.

Open Question: Should the methods take a list of urns, 1 of which may be a slice_urn?

Change Set E: Tickets

AM APIv3 adds support for negotiated reservations or two-phase commit, by adding methods that allow an experimenter to reserve resources for a slice without committing to using them, or forcing the AM to incur the cost of instantiating them.

This change is actively under discussion. See for example http://lists.geni.net/pipermail/dev/2012-March/000616.html and http://lists.geni.net/pipermail/dev/2012-March/000648.html

For an alternative proposal, see: http://www.protogeni.net/trac/protogeni/wiki/AM_API_proposals

A proposal for allocation states (below) may supercede this. See Change Set F3.

Motivation

This possible change was discussed at the GEC12 AM API session.

The SFA defines the concept of a ticket. SFA1.0 section 5.3 says "A component signs an RSpec to produce a ticket, indicating a promise by the component to bind resources to the ticket-holder at some point in time." Tickets are promises to allocate resources.

Tickets are used in the ProtoGENI CMV2 interface, and are discussed on the PG wiki. Tickets with a slightly different semantics (and leases) are also used extensively in Orca. For details on the use of leases and tickets in Orca, see the Orca Book. However, each of these uses of the notion of tickets differs.

Tickets would potentially enable a number of useful and possibly critical features:

  • Coordinated or negotiated reservations: reserving resources from aggregate B only if aggregate A can give you a complementary resource. For example, a VLAN tag. This is related to stitching, both network stitching and the more general form.
  • Two phase commit reservations (similar to the above).
  • Scheduled reservations in the future.
  • Brokers: 3rd parties consolidating, scheduling and allocating resources on behalf of a number of other aggregates
  • Lending resources to other experimenters
  • Giving experimenters explicit control over when resources are started, stopped, and restarted (see the discussion on UpdateSliver).

Tickets semantics

This proposal would add tickets to the existing AM API, allowing experimenters to reserve (hold) resources temporarily and cheaply. Tickets represent a promise to the named slice to allocate the specified resources, if the ticket is 'redeemed' while the ticket is still valid. Tickets describe a complete specification of the resources that will be allocated to the slice at this aggregate, if the ticket is redeemed.

Some key properties of the tickets proposed here:

  • Tickets are IOUs from an AM to a slice (not to an experimenter - no delegation is necessary or possible).
  • Experimenters do not need to use tickets to reserve resources: existing methods without tickets still work.
  • A ticket is a promise by the AM to give the specified resources to the slice if an authorized slice member requests them.
    • The aggregate is saying they will not give away these resources to other slices, but only to this slice.
    • AMs must document how firm their promises are. See the attribute geni_ticket_service_class.
      • Some aggregates may only offer soft promises, as in PlanetLab.
  • Tickets are signed by the AM: non repudiatable.
  • Tickets are bound to a slice: they contain the slice certificate.
  • Tickets may be passed from 1 researcher on a slice to another freely - no explicit delegation is required.
    • Indeed, any experimenter with appropriate slice credentials can retrieve the ticket from the aggregate.
    • Tickets may not be delegated to another slice or other entity; these tickets do not support brokers.
  • Tickets promise a particular set of resources: they include an RSpec. Note that this may be an unbound RSpec.
    • Note that we do not currently have unbound manifest RSpecs. For now we specify only that this is an RSpec.
  • Tickets are good for a limited time.
    • They must be redeemed by a specified time, redeem_before, after which the aggregate is free to assign the resources elsewhere.
      • Aggregates determine redeem_before, which is some epsilon in the near future.
      • Aggregates may accept a new option geni_reserve_until which is a request for a particular redeem_before, but are not required to support this (they may ignore the option).
    • Tickets specify when the resources will be available from (starts, typically essentially now), and when they will be available until (typically now plus the aggregate-local default sliver expiration time).
      • The resources may be available even longer, but that would require a separate RenewSlivers call.
  • Tickets specify the full final state of the slice after applying this ticket.
    • Tickets are not incremental changes, and are not additive.
    • The implication is that there may be only 1 ticket outstanding for a slice per aggregate (except for scheduled reservations, see below).
    • This also implies that these tickets are not suitable for use by brokers.
  • Aggregates must attempt to honor their promises. As a result, aggregates must remember all outstanding tickets until they are redeemed or expire.
  • All ticket related timestamps must be in the format of RFC3339 (http://www.ietf.org/rfc/rfc3339.txt)
    • Full date and time with explicit timezone: offset from UTC or in UTC.
    • eg: 1985-04-12T23:20:50.52Z or 1996-12-19T16:39:57-08:00

Change Set F: Support AM and resource-type specific methods.

Define the control API (the AM API) as about moving slivers through various states at an AM.

The proposal here elicited concerns (the method ActOnSlivers is an ioctl, and the states mix allocation and operational states).

A later alternative proposal, see http://lists.geni.net/pipermail/dev/2012-March/000721.html

At the GEC13 coding sprint, a variant on the above was approved. It is documented here as Change Set F3.

A variant on the operational states proposal is defines as Change Set F4 and documented here: https://openflow.stanford.edu/display/FOAM/GENI+-+PerformOperationalAction

Motivation

AM API methods logically change the state of the slivers at this AM. But the API is not clear what experimenters should expect, and does not provide easy ways for experimenters to control when and how states change. There is in particular no way to move slivers through states and change them in ways otherwise undefined by the API.

Change Set F1: Define Sliver States

This change is superceded by Change Sets F3 and F4.

Currently the AM API defines several possible states as valid returns in SliversStatus: configuring, ready, unknown, and failed. This change changes and expands that list of valid states, and explicitly defines the expected states after each AM API method call. Additionally, this change provides a mechanism for aggregates to supply their own states.

The GENI AM API can be thought of as manipulating slivers. As such, each method potentially changes the state of 1 or more slivers. With the changes proposed here, several of the methods return a new geni_status field, whose value is one of the standard GENI sliver status values. Aggregates must use one of the standard GENI values for that return.

Change Set F2: ActOnSlivers

This change is superceded by Change Sets F3 and F4.

This change introduces a new method, providing a generic way to act on slivers in an AM or resource type specific way. This method shall be used to 'start' or 'stop' or 'restart' resources that have been allocated but not started by CreateSlivers or RedeemTicket. It may also be used to change the state of slivers (or their contained resources) in an aggregate or resource specific way. Some aggregates may use this method to change configuration details of allocated resources. This might include changing acceptable login keys.

Change Set F3: Sliver Allocation States and methods

This change was discussed and adopted at the GEC13 Coding Sprint.

For meeting minutes, see: the GEC13 Coding Sprint agenda page.

  • We agreed to use two kinds of states: allocation states, and operational states. We put off discussion of operational states (ie is the node booted), noting however that this is critical. See Change Set F4.
  • We debated whether the API should specify a limited number of states, or allow for aggregate or resource specific states. We agreed that for allocation states, the API should define a limited set of states, while operational states might be more permissive.
  • We discussed the pros and cons of including a single all-in-one method to change allocation states, or a single method per desired transition. There is at least 1 case where there are 2 paths between the same 2 allocation states with very different meaning. As a result, we agreed to use a separate method per allocation state change.

We agreed on 3 allocation states for slivers and an enumeration of methods for transitioning between those states.

Allocation states:

  1. geni_unallocated (alternatively called 'null'). The sliver does not exist. This is the small black circle in typical state diagrams.
  2. geni_allocated (alternatively called 'offered' or 'promised'). The sliver exists, defines particular resources, and is in a sliver. The aggregate has not (if possible) done any time consuming or expensive work to instantiate the resources, provision them, or make it difficult to revert the slice to the state prior to allocating this sliver. This state is what the aggregate is offering the experimenter.
  3. geni_provisioned. The aggregate has started instantiating resources, and otherwise making changes to resources and the slice to make the resources available to the experimenter. At this point, operational states are valid to specify further when the resources are available for experimenter use.

The key change is the addition of state 2, representing resources that have been allocated to a slice without provisioning the resources. This represents a cheap and un-doable resource allocation, such as we previously discussed in the context of tickets. This compares reasonably well to the 'transaction' proposal written up by Gary Wong (http://www.protogeni.net/trac/protogeni/wiki/AM_API_proposals). When a sliver is created and moved into state 2 (geni_allocated), the aggregate produces a manifest RSpec identifying which resources are included in the sliver. This is something like the current CreateSlivers, except that it does not provision nor start the resources. These resources are exclusively available to the containing sliver, but are not ready for use. In particular, allocating a sliver should be a cheap and quick operation, which the aggregate can readily un-do without impacting the state of slivers which are fully provisioned. For some aggregates, transitioning to this state may be a no-op.

States 2 and 3 (geni_allocated and geni_provisioned) have aggregate and possibly resource specific timeouts. By convention the geni_allocated state timeout is typically short, like the redeem_before in ProtoGENI tickets, or the commit_by in Gary's transactions proposal. The geni_provisioned state timeout is the existing sliver expiration. If the client does not transition the sliver from geni_allocated to geni_provisioned before the end of the geni_allocated state timeout, the sliver reverts to geni_unallocated. If the experimenter needs more time, the experimenter should be allowed to request a renewal of either timeout. Note that typically the sliver expiration time (timeout for state 3, geni_provisioned) will be notably longer than the timeout for state 2, geni_allocated.

State 3, geni_provisioned, is the state of the sliver allocation after the aggregate begins to instantiate the sliver. Note that fully provisioning a sliver may take noticeable time. This state also includes a timeout - the sliver expiration time (which is not necessarily related to the time it takes to provision a resource). RenewSlivers extends this timeout. For some aggregates and resource types, moving to this state from state 2 (geni_allocated) may be a no-op.

If the transition from one state to another fails, the sliver shall remain in its original state.

These are the only operational states supported by this API. Since the state transitions are finite, but include potentially multiple transitions between the same two states, this API uses separate methods to perform each state transition, rather than a single method for requesting a new state for the sliver.

  1. CreateSlivers moves 1+ slivers from geni_unallocated (state 1) to geni_allocated (state 2). This method can be described as creating an instance of the state machine for each sliver. If the aggregate cannot fully satisfy the request, the whole request fails. This is a change from the version 2 CreateSliver, which also provisioned the resources, and 'started' them. That is CreateSlivers does 1 of the 3 things that it did previously. Note the method name change, consistent with change set D.
  2. DeleteSlivers moves 1+ slivers from either state 2 or 3 (geni_allocated or geni_provisioned), back to state 1 (geni_unallocated). This is similar to the AM API version 2 DeleteSliver. Note the method name change, consistent with change set D.
  3. RenewAllocations requests an extended timeout for slivers in state 2 (geni_allocated).
  4. RenewSlivers requests an extended timeout for slivers in state 3 - the geni_provisioned state. That is, this method's semantics does not change. Note the method name change, consistent with change set D.
  5. ProvisionSlivers moves 1+ slivers from state 2 (geni_allocated) to state 3 (geni_provisioned). This is some of what version 2 CreateSliver did. Note however that this does not 'start' the resources, or otherwise change their operational state. This method only fully instantiates the resources in the slice. This may be a no-op for some aggregates or resources.

These states apply to each sliver individually. Logically, the state transition methods then take a single sliver URN. For convenience, these methods accept a list of sliver URNs, or a slice URN as a simple alias for all slivers in this slice at this aggregate.

Since each method may operate on multiple slivers, each of these methods returns a list of structs as the value:

value = [
  {
   geni_sliver_urn,
   geni_allocation_status,
   geni_expires <time when the sliver expires from its current state>,
   <others AM or method specific>
   <ProvisionSlivers returns geni_operational_status>
  },
  ...
]

CreateSlivers returns a single manifest RSpec, plus the above list of structs.

Aggregates must be consistent across all these methods whether they are all or nothing, or support partial success.

These methods all take a new option (aggregates must support it, clients do not need to supply it):

   geni_atomic = True/False, default True

If true, the client is requesting that the aggregate either fully satisfy the request, moving all listed slivers to the desired state, or fully fail the request, leaving all slivers in their original state. If the aggregate cannot guarantee all or nothing success or failure given the included slivers and resource types, the aggregate shall fail the request, returning an appropriate error code. If this option is false, then some slivers may transition to the new state, and some note. Aggregates must examine the return closely to know the state of their slivers.

[FIXME: Is this what we agreed to? Or should the default be False? Should there be a !GetVersion option for advertising the AM default?]

Note: CreateSlivers remains all or nothing (either the aggregate can allocate all desired resources as requested, or the call fails).

Note: These calls are synchronous - when they return, the slivers shall be in their final state. In particular, the transition from state 2 to 3 (geni_allocated to geni_provisioned) should be quick. The resource that is now in the 'provisioned' state may take a long time to actually be ready for operational use (e.g. imaging and booting the node) -- this remains true as in version 2 after CreateSliver.

SliverStatus, where it currently includes geni_status, shall now return geni_allocation_status with one of the above defined values, and geni_operational_status. The values of geni_operational_status are still under discussion.

Currently, SliverStatus returns a single geni_status for the entire slice at this aggregate. With this change, the top-level allocation status for the slice is not defined, and that field is not required.

Open Questions:

  • What about an UpdateAllocations method, similar to UpdateTickets or UpdateTransactions from other similar proposals, for modifying allocated resources in place, without losing allocated resources?

Change Set F4: Sliver Operational States and methods

This proposal was discussed on the geni-dev mailing list: http://lists.geni.net/pipermail/dev/2012-March/000743.html

The canonical source for documentation on this proposal is here: https://openflow.stanford.edu/display/FOAM/GENI+-+PerformOperationalAction

Open questions include:

  • Do we need a state discovery mechanism? A method? An RSpec ad extension?
  • Should the method default to all or nothing? Or to partial success?
  • What are the defined operational states, and GENI standard actions for transitions?
  • Does the API specify how operational state of slivers rolls up to the state of the slice at the aggregate?
  • Make option names and returns consistent between this change set and change set F3
PerformOperationalAction (string urn[], string credentials[], string action, struct options={})
{
  struct code = {
       int geni_code;
       [optional: string am_type;]
       [optional: int am_code;]
         }
  struct value = [ {
        'sliver_urn' : string,
        'geni_operational_status' : string,
        [optional: 'geni_resource_status' : string]
        }, ... ];
  string output;
}

Performs the given action on the given sliver_urn(s) (or slice_urn as a proxy for "all slivers"). Actions are constrained to the set of default GENI actions, as well as resource-specific actions which reasonably perform operational resource tasks as defined by the aggregate manager for the given resource type. This method is not intended to allow for reconfiguration of options found in the request rspec. Aggregate Managers SHOULD return an error code of 13 (UNSUPPORTED) if they do not support a given action for a given resource. Actions are performed on all slivers, or none - if an action cannot be performed on a sliver given, the entire operation MUST fail. Passing the option geni_best_effort allows for partial success.

An AM SHOULD constrain actions based on the current operational state of the resource, such that attempting to perform the action geni_stop on a resource that is geni_busy will fail, but SHOULD also be idempotent for all actions which result in a steady state.

geni_operational_status MUST be the current operational status of the sliver after this action (as would be returned by SliverStatus). An optional geni_resource_status field MAY be returned for each sliver which contains a resource-specific status that may be more nuanced than the options for geni_operational_status.

Calling this method with a slice_urn functions as if all the child sliver_urn had been passed in - specifically the action is performed on all slivers and all sliver_urn and their statuses are returned. No status is returned for the slice as a whole.

This is a fast synchronous operation, and MAY start long-running sliver transitions whose status can be queried using SliverStatus.

Adopted: Change Set G: Credentials are general authorization tokens.

This change was adopted at GEC13.

Motivation

Most AM API methods take a list of credentials to authorize operations. Currently the API requires credentials in a particular format, and would disallow others, such as ABAC. The API should allow for other innovative authorization tokens.

Make credentials more general

This change modifies the credentials argument to all methods. Each credential is now defined only as a signed document. A given list of credentials may contain credentials in multiple formats. The list may be empty. A given authorization policy at an AM may require 0, 1, or many credentials. Aggregates are required to allow credentials which are not used by local authorization policy or engines, using only credentials locally relevant.

  • An AM must pick credentials out of the list that it understands and be robust to receiving credentials it does not understand.
    • Current slice and user credentials will be recognizable for following the schema defined in Change Set K.
  • AMs are required to continue to accept current-format credentials.
    • In particular, a single standard slice credential remains sufficient for most authorization policies.
  • Other credential formats acceptable by some aggregates might include ABAC x509 Attribute certificates, eg.
  • AMs may get other authorization material from other sources: EG a future Credential Store service.

Advertising supported credentials

We agreed that aggregates must advertise what types of credentials they accept so clients know how to gain authorization for API methods.

Aggregates are required to return a new entry in GetVersion:

geni_credential_types = <a list of structs>: [
  {
   geni_type = <string, case insensitive>,
   geni_version = <string containing an integer>,
   <others fields optionally. EG A URL for more info, or a schema>
  }
]

We agreed that "sfa" slice credentials as defined pre AM API version 3 will have type=geni_sfa and version=2. "sfa" slice credentials as of AM API version 3 will be type=geni_sfa, version=3. ABAC credentials as of AM API version 3 will be type=geni_abac, version=1.

For example, an aggregate that accepts ABAC credentials, SFA slice credentials that were issued prior to AM API v3, and SFA slice credentials from AM API version 3, would include this in GetVersion:

geni_credential_types = [
  {
   geni_type = "geni_sfa",
   geni_version = "2"
  },
  {
   geni_type="geni_sfa",
   geni_version = "3"
  },
  {
   geni_type="geni_abac",
   geni_version="1"
  }
]

Note that there might be multiple geni_type entries to support multiple versions of SFA credentials. Note there might also be multiple kinds of ABAC credentials: identity certificates, attribute certificates, references to those certificates, bundles of those certificates. We briefly considered adding a sub_type field or a flag for 'credentials' that are really references to credentials.

Specifying Type of Supplied Credentials

For AMs to understand the type of each supplied credential, per-AM heuristics are not sufficient - they might differ at different AMs.

The API will require that credentials be explicitly typed. This change makes methods take in the credentials argument a struct:

credentials = [
   {
    geni_type = <string>, 
    geni_version = <string>,
    geni_value = <string>,
    <others>
   }
]

Note that the value may be a credential, a URL, an XLink compliant string, etc. Clients are required to identify the type of each credential they supply. Instead of requiring clients to apply similar heuristics, authorities are required to identify credentials they supply with the same type and version fields. Specifically, ProtoGENI representatives suggested that their slice authorities would issue credentials as these structures in the near future.

Changes to existing methods

Modify a few existing methods to make certain operations easier or more experimenter friendly.

Change Sets H&I: Misc other method changes

  • Change Set H: A second call to CreateSlivers without an intervening DeleteSlivers is an error.
    • This change just clarifies expected behavior that was left under-specified in AM API v1.
    • CreateSlivers takes a full Ad RSpec, it is not a way to 'add' resources.
    • Silently replacing the existing slivers with new slivers (similar to a call to UpdateSlivers) is not acceptable.
  • Adopted: Change Set I1: Add geni_expires to return from SliversStatus for whole slice and then each sliver
    • This change was adopted at GEC13
    • This change standardizes behavior necessary for experimenters to determine their sliver expiration times.
    • Format is RFC3339 (http://www.ietf.org/rfc/rfc3339.txt)
      • Full date and time with explicit timezone: offset from UTC or in UTC)
      • eg: 1985-04-12T23:20:50.52Z or 1996-12-19T16:39:57-08:00
  • Adopted: Change Set I2: Add SSH logins/keys to each node that supports SSH login in the manifest RSpec

This change standardizes behavior so experimenters can readily find how to log in to reserved resources. Aggregates that allocate resources that an experimenter can 'log in to', should use this struct to return that information. Other aggregates will not use this at all.

This change was adopted at GEC13.

Aggregates shall use a new RSpec extension to include all login information in manifest RSpecs. This extension is version controlled in the GENI RSpec git repository.

The extension adds information to the <services> tag, which already has the <login> tag.

The <login> tag tells you the kind of authentication (ssh), the port, and the username. The new extension adds an entry per login username

  • URN of the user
  • 1+ public SSH keys that can be used under that login

Note that 1 of the <user:services_user login>s in the extension duplicates the default username already in the base <login> tag. The extension allows specifying the keys usable with that login username.

EG:

.......
  <services>
    <login authentication="ssh-keys" hostname="pc27.emulab.net" port="22" username="flooby"/>
    <ssh-user:services_user login="flooby" user-urn="http://urn:publicid:IDN+jonlab.tbres.emulab.net+user+flooby">
      <ssh-user:public-key>asdfasdfasdf;lkasdf=foo@bar</ssh-user:public-key>
      <ssh-user:public-key>asdfasdfasdf;lkjasdf;lasdf=foobar@barfoo</ssh-user:public-key>
    </ssh-user:services_user>
    <ssh-user:services_user login="io" user-urn="http://urn:publicid:IDN+jonlab.tbres.emulab.net+user+io">
      <ssh-user:public-key>asdfasdfasdf;lkasdf=foo@bar</ssh-user:public-key>
      <ssh-user:public-key>asdfasdfasdf;lkjasdf;lasdf=foobar@barfoo</ssh-user:public-key>
    </ssh-user:services_user>
  </services>

And the RNC schema:

# An extension for describing user SSH login credentials in the manifest

default namespace = "http://www.protogeni.net/resources/rspec/ext/ssh_user/1"

# This is meant to extend the services element
Services = element services_user {
  attribute login { string } &
  attribute user_urn { string }? &
  element public-key { string }*
}

# Both of the above are start elements.
start = Services
  • A note on distinguishing ListResources from SliversStatus:
    • ListResources in the context of a slice URN is for listing the reserved resources. It provides mostly static information. (But if the manifest contains things which can change, then the manifest must change when those things (like say IP addresses) change.)
    • SliversStatus is for everything else: anything which the AM can change for you using API calls, or which changes over time. So it has up/down state, expiration time, and now login keys. It provides that for your whole slice at this aggregate and all contained slivers.
  • Adopted: Change Set I3: Return sliver expiration from CreateSlivers

This change was adopted at GEC13.

Experimenters currently do not know the expiration of their slivers without explicitly asking. This change makes the CreateSlivers return value become a struct:

{
 string rspec=<manifest>,
 string geni_start_time=<optional (may be omitted altogether): now if not specified>,
 string geni_expires=<RFC3339 sliver expiration, as in geni_expires from SliversStatus>,
 string geni_status=<sliver state - allocated or changing or ready>,
 <others that are AM specific>
}
  • Change Set I4: CreateSlivers optionally does not start resources.

Currently, CreateSlivers auto starts resources, moving them from allocated through changing to ready.

  • Add a new option geni_donotstart:
    • If supplied and true (boolean: 0 or 1 in XML-RPC), final state is allocated, and experimenter must explicitly start resources using ActOnSlivers.
    • If omitted or false (0) (default), AM automatically starts resources as before, and state will be changing and then ready.

Withdrawn: Change Set J

This change set has been withdrawn.

Adopted: Change Set K: Standardize certificates and credentials

This proposal was adopted at GEC13

Motivation

The current AM API specifies that certificates and credentials follow a particular format, using URNs that are based on experimenter supplied names. However that specification is not sufficiently specific, and there are currently differences in implementation among existing certificate and credential producers. This has led to errors, experimenter confusion, and messy code.

Changes

This proposal requires that certificates include a UUID and email address for the subject. It codifies restrictions on usernames, sliver names, and slice names. The proposal specifies that slices have a UUID to be used to help identify slices in a consistent way over time (slice names may be re-used).

Some overall points:

  • Aggregates are expected to fail requests that use certificates or URNs or names that violate this API.
  • Schemas for certificates & credentials will be published on geni.net.

Certificates:

  • GENI uses x509v3 identity certificates to identity users, slices, aggregates, and authorities, and these restrictions apply to all such certificates.
  • See http://groups.geni.net/geni/wiki/GeniApiCertificates.
  • Aggregates are required to properly validate all certificates to authenticate access to AM API calls, and fail calls that supply invalid certificates.

Certificate contents:

  • Version shall be properly marked: 3
  • serialNum is required to be unique within the certificate authority: each newly issued certificate must have a unique serial number.
  • The Distinguished Name should include a human readable identifier, for both subject and issuer. Details are not specified
  • Only authority certificates (but all authorities that issue certificates) shall be marked CA:TRUE in the x509 v3 basic constraints; Slices and users shall be marked FALSE.
  • The Subject Alternative Name field must include 3 pieces of information
    • Entries are comma separated (', '), and may be in any order.
    • The URN identifier, following GENI URN standards as described here: http://groups.geni.net/geni/wiki/GeniApiIdentifiers
      • The URN is identifiable by looking for the entry beginning "URI:urn:publicid:IDN", for example: URI:urn:publicid:IDN+emulab.net+user+stoller.
    • A UUID, providing a unique ID for the entity.
      • The UUID must be used with the URN to fully identify the slice or user. UUID alone should not be accepted. This ensures that the authority certifying the slice or user is always identified when referring to the slice or user.
      • In the hexadecimal digit string format given in RFC 4122
      • The UUID is identified with this prefix: "URI:urn:uuid" (as specified by RFC4122), for example: URI:urn:uuid:33178d77-a930-40b1-9469-3aae08755743.
      • The COPY tag is not supported.
    • The email address is an RFC2822 compliant and working address for contacting the subject of the certificate (experimenter, authority administrator, or slice owner).
      • The email entry is identified by the prefix "email:", for example: email:stoller@emulab.net
      • The COPY tag is not supported.
      • Note that the slice and user email addresses are addresses for contacting the responsible party - the slice owner or creator and the user. These may be aliases.
  • Recommendation: Authorities are encouraged but not required to include a URL where more information about the subject is available (eg slice authority registry URL). That URL may be included in a certificate extension, in the DN, or in the subjectAltName.

Slices:

  • Slice ID for use over time and space is the UUID plus the URN in the slice certificate.
  • Currently URNs identify slices, but they are not unique over time. This change adds UUIDs to slice identifiers. URNs remain the identifier for slices in AM API calls, and uniquely identify slices for a moment in time. UUID plus URN together uniquely identify slices over time, and can be used for forensics, or for use by authorization modules, such as ABAC. UUIDs alone should not be used to identify slices, but only in conjunction with the URN, which scopes the UUID to the authority which generated the UUID. The UUID essentially may only be used to distinguish between slices with identical URNs.
  • Slice URN alone is a label - unique at a point in time but not over time.
    • Format: urn:publicid:IDN+<SA name>+slice+<slice name>
  • Slice names are <=19 characters, only alphanumeric plus hyphen (no hyphen in first character): '^[a-zA-Z0-9][-a-zA-Z0-9]+$'
  • Aggregates are required to accept any compliant slice name and URN.
    • Note that this currently causes problems at PlanetLab/SFA aggregates, where node login names are based on slice names and are limited to 31 characters.

Slivers:

  • Have a URN (returned in manifest RSpec), determined by the aggregate.
  • This URN should be unique over time within an AM for record-keeping / operations purposes.
    • Format: urn:publicid:IDN+<AM name>+sliver+<sliver name>
  • Sliver names
    • Must be unique over time within that AM, and are selected by the AM.
    • May use only alphanumeric characters plus hyphen.

Usernames:

  • Usernames (user identifiers to the system) are set at the authority.
  • Usernames are case-insensitive internally, though they may be case-sensitive in display.
    • EG JohnSmth as a display name is johnsmth internally, and there cannot also be a user JOHNSMTH.
  • Usernames should begin with a letter and be alphanumeric or underscores - no hyphen or '.': ('^[a-zA-Z][\w]+$').
  • Usernames are limited to 8 characters.
  • User URNs (which contain the authority name and the username) are required to be temporally and globally unique.

Change Set L: Change SFA credentials' privileges

This proposal has not been fully discussed and is likely to be postponed.

Our goal is to simplify and standardize privilege strings used in SFA credentials. Currently there are wildcards, bind, embed, and others. They are confusing. We also want extensibility to use these credentials elsewhere in future.

Credentials should support these kinds of operations:

  • Learn about the slice
  • Add/Modify/Delete resources in the slice
  • Read slice details like I&M?
  • Use the slice
  • Operator shutdown

Proposal - Replace all existing privileges with only the following possible strings (case insensitive):

  • CanWrite
    • If present in a valid slice credential, aggregates may permit CreateSlivers, RenewSlivers, DeleteSlivers, Shutdown, plus new methods ActOnSlivers, UpdateSlivers, GetTicket, RedeemTicket, UpdateTicket, ReleaseTicket
    • Thus it replaces bind, embed, control, instantiate, sa, pi, or * in various places
  • CanRead
    • If present in a valid slice credential, aggregates may permit ListResources with a slice_urn, SliversStatus
    • Thus it replaces info or * in various places
  • CanReadDetails
  • CanUse

Note that those last 2 may never get used, but are there in case I&M or opt-in make those useful.

Note also that operators who wish to shut down a slice would need a slice credential with the CanWrite privilege.

Privilege and credential semantics are defined as follows:

  • Aggregates may only grant access using current SFA credentials to a method if at least one such valid credential:
    • grants the required privilege or privileges (if any)
    • to the caller of the API method
      • (identified by their SSL client certificate and the owner_gid in the credential)
    • over the slice (if any) on which they are operating
      • (target_gid in the credential).
  • Other privileges may be present in the same or other credentials, and other non-SFA credentials may be used to authorize actions (per Change Set G).
  • Local aggregate policy may grant or deny access to a particular method regardless of the presence of a valid credential granting the required privilege. This depends in part on federation policy governing aggregates.
  • Some operations (e.g. GetVersion) may either simply require a valid credential with no particular privilege, or have no credentials argument at all.

Note also that some current AMs do not require any particular privileges to do ListResources, even with a slice_urn. This change suggests that aggregates require a valid slice credential with CanRead privileges to authorize this operation using current slice credentials.


Changes Not Included

RSpec changes resulting in GENI v4 RSpecs

  • Support unbound manifests
  • Make manifest an extension of Request, so you can readily edit & resubmit a manifest
  • Make configuration information in request and manifest optional, so it can be supplied/returned separately
  • Fully implement the compute ontology from Ilia
  • Ilia's other requests (Openflow related information)
  • Document process for updates per my dev list email
  • Be consistent: ref vs idref vs href
  • Include AM name/URL in RSpecs? Experimenter who allocated it URN?
  • Incorporate stitching extension as part of the 'base' RSpec

Misc

  • Split ListResources with slice_urn from ListResources without. ListResources with slice_urn we call Resolve(slice_urn).
  • Add geni_am_info block to GetVersion return (name, id, url, location, description, is_proxy, proxy: {(a geni_am_info block)}, proxy_for[] (list of geni_am_info blocks))
  • Allow the update methods to take a generic rspec argument, allowing AMs to accept full or diff RSpecs
  • Tickets
    • Remove requestor certificate?
    • Support brokers: Make ticket methods return multiple tickets. Define tickets as optionally diffs (additive). Make RedeemTicket and UpdateTicket take a list of tickets. Tickets are delegatable via signing, but the delegated ticket must be for a strict subset of the resources in the original.
    • Drop ticket struct, not a signed document. Just reference by ID
  • Support message passing
    • Add sendMsg (and getMsgs?) methods that take a signed document, allowing freely passing messages instead of XMLRPC?

Stitching

AMs must support the stitching extension where Layer 2 connections are available:

Update stitching schema per changes here: https://geni.maxgigapop.net/twiki/bin/view/GENI/NetworkStitchingGeniApiAndRspec


Change summary - method signatures

If all change sets listed here are adopted, the final method signatures will be as follows:

GetVersion

struct GetVersion([optional: struct options])

Return struct:

      {
        int geni_api;
        struct geni_api_versions {
             URL <this API version #>; # value is a URL, name is a number
             [optional: other supported API versions and the URLs where they run]
        }
        array geni_request_rspec_versions of {
             string type;
             string version;
             string schema;
             string namespace;
             array extensions of string;
        };
        array geni_ad_rspec_versions of {
             string type;
             string version;
             string schema;
             string namespace;
             array extensions of string;
        };
      }

ListResources

struct ListResources(string credentials[], struct options)

Where options include:

{
  boolean geni_available;
  boolean geni_compressed;
  string geni_slice_urn;
  struct geni_rspec_version {
    string type;
    string version;
  };
  string geni_start_time;
  string geni_end_time;
}

Return struct:

{
   rspec (ad or Manifest - may be empty though)
   tickets[] (required but may be an empty list)
}

GetTicket

struct GetTicket (string slice_urn, string credentials[], string requestRSpec, 
                           struct options)

Options include geni_start_time and geni_end_time

Return: ticket

UpdateTicket

struct UpdateTicket(string slice_urn, string credentials[], string requestRSpec, 
                                string ticket, struct options)

Options include geni_start_time and geni_end_time

Return: ticket

RedeemTicket

struct RedeemTicket(string slice_urn, string credentials[], string ticket, 
                                 struct users[], struct options)

Options include geni_auto_start

Return struct:

{
 string rspec=<manifest>,
 geni_start_time=<optional (may be omitted altogether): now if not specified>,
 geni_expires=<RFC3339 sliver expiration>,
 string geni_status=<sliver state - allocated or changing or ready>,
 string geni_state_guarantee=<promise from AM of what experimenter state will be lost on trying to 'start' this allocation>,
 <others that are AM specific>
}

UpdateSlivers

struct UpdateSlivers(string slice_urn, string credentials[], string rspec, 
                                                 struct options)

Options include geni_start_time and geni_end_time

Return struct:

{
  string ticket=<ticket>
  string geni_status=<sliver state - ticketed>,
  string geni_state_guarantee=<promise from AM of what experimenter state will be lost on trying to 'start' this allocation>,
 <others that are AM specific>
}

ReleaseTicket

struct ReleaseTicket(string slice_urn, string credentials[], string ticket, struct options)

Return: boolean

CreateSlivers

struct CreateSlivers(string slice_urn,
                    string credentials[],
                    string rspec,
                    struct users[],
                    struct options)

Options include:

{
  boolean geni_donotstart (optional),
  string geni_start_time <datetime> (optional),
  string geni_end_time <datetime> (optional)
}

Return struct:

{
 string rspec=<manifest>,
 geni_start_time=<optional (may be omitted altogether): now if not specified>,
 geni_expires=<RFC3339 sliver expiration, as in geni_expires from SliversStatus>,
 string geni_status=<sliver state - allocated or changing or ready>,
 <others that are AM specific>
}

RenewSlivers

struct RenewSlivers(string urn,
                    string credentials[],
                    string expiration_time, 
                    struct options)

Return: boolean

SliversStatus

struct SliversStatus(string slice_urn, string credentials[], struct options)

Return:

{
  string geni_urn: <sliver URN>
  string geni_status: ready
  geni_expires: <datetime of expiration>
  struct geni_resources: [ { geni_urn: <resource URN>
                      geni_status: ready
                      geni_expires: <datetime of individual sliver expiration>
                      geni_error: ''},
                    { geni_urn: <resource URN>
                      geni_status: ready
                      geni_expires: <datetime of individual sliver expiration>
                      geni_error: ''}
                  ]
}

Where for individual resources this block may be returned:

'users' => [{'urn'   => $user1_urn.
             'login' => $login,
             'protocol' => [ssh, or ?],
             'port' => [22 or ?],
             'keys'  => [...] },
            {'urn'   => $user2_urn.
             'login' => $login,
             'protocol' => [ssh, or ?],
             'port' => [22 or ?],
             'keys'  => [...] }
           ]

ActOnSlivers

struct ActOnSlivers(string command, string credentials[], string urn, string state, struct options)

Return struct:

{
 string urn=<urn of sliver or slice>,
 string geni_status=<new state of the slivers>,
 <other entries specific to the AM or resources - specifically am_specific_status>
}

DeleteSlivers

struct DeleteSlivers(string urn, string credentials[], struct options)

Return: boolean

Shutdown

struct Shutdown(string slice_urn, string credentials[], struct options)

Return: boolean

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