[[PageOutline]] = GENI API Identifiers = GENI identifies objects (be it a researcher, resource, clearinghouse, or aggregate manager) with a [http://en.wikipedia.org/wiki/Uniform_Resource_Name Uniform Resource Name (URN)]. ''' The format of a GENI URN is: urn:publicid:IDN+++.''' The format is adapted from the [http://www.protogeni.net/trac/protogeni/wiki/URNs ProtoGENI URN format] and the [http://testglobalnoc.grnoc.iu.edu/gmoc/file-bin/urn-proposal3.pdf GMOC GENI URN proposal]. All sections of the URN are mandatory. Note that additional '+' characters are allowed in the section. === Public Identifiers === GENI URNs are in the [http://www.faqs.org/rfcs/rfc3151.html URN namespace for Public Identifiers]. As such, each GENI URN is of the form: `urn:publicid:{transcribed-public-identifier}`. [http://www.faqs.org/rfcs/rfc3151.html RFC 3151] describes how public identifiers are transcribed to URNs (which involves collapsing whitespace and replacing certain characters with `%` encoded values). The public identifier section of a GENI URN must begin with "IDN ". When transcribed, this means that all GENI URNs begin with "urn:publicid:IDN+". To transcribe a public ID to a URN use the following rules: || From || Transcribe to || || leading and trailing whitespace || trim || || whitespace || collapse to a single '+' || || '//' || ':' || || '::' || ';' || || '+' || '%2B' || || ":' || '%3A' || || '/' || '%2F' || || ';' || '%3B' || || '!'' || '%27' || || '?' || '%3F' || || '#' || '%23' || || '%' || '%25 || Example translations: || ''Public ID'' || ''GENI URN'' || || IDN plc//princeton authority sa || urn:publicid:IDN+plc:princeton+authority+sa || || IDN gcf//gpo//gpolab user joe || urn:publicid:IDN+gcf:gpo:gpolab+user+joe || || IDN gcf//gpo//gpolab node switch 1 port 2|| urn:publicid:IDN+gcf:gpo:gpolab+node+switch+1+port+2 || Formally, the URN format follows the following naming convention (in perl regular expression syntax for the encoding string): `“IDN [toplevelauthority][\/\/sub-authority]* resource-type resource-name”` This would lead to the following urn schema in the public id namespace (Using the transformation in [http://www.faqs.org/rfcs/rfc3151.html RFC 3151] : `“urn:publicid:IDN+toplevelauthority[:sub-authority]*\+resource-type\+resource-name”` Where: ''toplevelauthority'' is an internationalized domain name (which must match the one in the certificate of the authority which issued the object name) ''sub-authority'' is an internationalized domain name (which must match the one in the certificate of the authority which issued the object name) ''resource-type'' is a string describing the type of the named object (the set of strings is described below) ''resource-name'' should uniquely identify the object among any other resources with identical ''toplevelauthority'' and ''resource-type''. It is important to realize that the GENI API attaches no other significance to this field, and in particular, no relation is implied between objects with identical ''resource-name'' but differing ''toplevelauthority'' or ''resource-type''. However, individual authorities may choose to define additional semantics for resource names. === Examples and Usage === The following examples are borrowed from the GMOC Proposal: || '''Resource''' || '''GENI Identifier''' || || User `cviecco` at the planetlab namespace || `urn:publicid:IDN+planet-lab.org+user+cviecco` || || Planetlab node: `pl2.ucs.indiana.edu` || `urn:publicid:IDN+planet-lab.org+node+pl2.ucs.indiana.edu` || || Interface `eth0` in planetlab node `pl1.ucs.indiana.edu` || `urn:publicid:IDN+planet-lab.org+interface+pl1.ucs.indiana.edu:eth0` || Examples of additional types of objects from the ProtoGENI documentation: || '''Resource''' || '''GENI Identifier''' || || Slice `mytestslice` in the Utah Emulab slice authority || `urn:publicid:IDN+emulab.net+slice+mytestslice` || || The Utah Emulab slice authority || `urn:publicid:IDN+emulab.net+authority+sa` || || Sliver `123` in the Utah Emulab aggregate manager || `urn:publicid:IDN+emulab.net+sliver+123` || In the GENI API, URNs are used to name slices (as seen as arguments in GENI API calls), to identify users, and to label resources. URNs are also used in GENI certificates (to bind public keys to identifiers) and in Credentials (to grant permissions to source identifiers on target identifiers). === Authority String === Authorities are resource namespaces. For instance, 'plc' is the overall PlanetLab namespace and 'plc.princeton' and 'plc.bbn' are specific namespaces for the Princeton and BBN PlanetLab sites. The authority string format is `toplevelauthority:sub_authority1:...:sub_authority_n`. Only entities with URNs of type `authority` are allowed to sign credentials for a namespace (except in the case of delegation). For example, a ProtoGENI Clearinghouse with URN like protogeni.utah.... cannot issue a slice credential giving a user privileges on a PlanetLab slice (with urn plc.princeton....). Only PlanetLab can grant rights over PlanetLab slices. Essentially, to be a valid authority for a namespace, the authority name must be a prefix of the names in its namespace. EG: `a\.b` is an authority for, `a\.b.c.d`, but `a` is not an authority for, `a\.b.c.d` (the subject's name starts with `a.b`, where we've escaped the `.`). Also any authority name is an authority for itself. === Type === The string has not yet been completely specified, but is used to identify the kind of resource being identified. Many APIs require use of URNs with particular types. Use the defined types below, unless they simply do not fit for you. In which case, please contact the GPO to inform them of your new type. `authority` A GENI service (i.e. an XMLRPC server). By convention, `resource-name` is am for an aggregate manager, sa for a slice authority. In principle, other names could be used for authorities. `interface` A component which is an interface (an endpoint for links). The `toplevelauthority` must match that of the aggregate manager. `link` A component which is a network link (a connection between two or more interfaces). The `toplevelauthority` must match that of the aggregate manager. `node` A component which is a node (an abstraction for networkable resources). The `toplevelauthority` must match that of the aggregate manager. `slice` A resource container. Every valid sliver belongs to exactly one slice. The `toplevelauthority` must match that of the slice authority. `sliver` A collection of resources which has been instantiated within a slice at a single aggregate. The `toplevelauthority` must match that of the aggregate manager; the corresponding slice is not identified in the sliver URN. `user` A GENI end user. Users are associated with slice authorities, but not unique slices; the slice to user correspondence is potentially many-to-many. The `toplevelauthority` must match that of the issuing authority. Additional types may be defined in the future. ''Note: For ProtoGENI compatibility, slice credentials should be signed by an authority with name "sa", e.g., urn:publicid:IDN+gcf:gpo+authority+sa.'' === Name === The string can in general be any valid string constrained by the URN character set (e.g. no whitespace). However, names for certain URN types are restricted: '''Slice''': - Slice URN alone is a label - unique at a point in time but not over time. - Format: `urn:publicid:IDN++slice+` - Slice names are <=19 characters, only alphanumeric plus hyphen (no hyphen in first character): `'^[a-zA-Z0-9][-a-zA-Z0-9]+$'` '''Sliver''': - URN should be unique over time within an AM for record-keeping / operations purposes. - Format: `urn:publicid:IDN++sliver+` - Sliver names - Must be unique over time within that AM, and are selected by the AM. - May use only alphanumeric characters plus hyphen. '''User''': - Usernames are case-insensitive internally, though they may be case-sensitive in display. - EG !JohnSmth as a display name is johnsmth internally, and there cannot also be a user `JOHNSMTH`. - Usernames should begin with a letter and be alphanumeric or underscores - no hyphen or '.': `('^[a-zA-Z][\w]+$')`. - Usernames are limited to 8 characters. - User URNs (which contain the authority name and the username) are required to be temporally and globally unique. {{{ #!comment === Transcribing a Public Identifier for URN formatting === || From || Transcribe to || || leading and trailing whitespace || trim || || whitespace || collapse to a single '+' || || '//' || ':' || || '::' || ';' || || '+' || '%2B' || || ":' || '%3A' || || '/' || '%2F' || || ';' || '%3B' || || '!'' || '%27' || || '?' || '%3F' || || '#' || '%23' || || '%' || '%25 || === FIXME === - pointers to spots in gcf codebase }}}