wiki:HowTo/LoginToNodes

Version 25 (modified by nriga@bbn.com, 8 years ago) (diff)

--

This page describes how to login to hosts that you have reserved through the GENI AM API.

Login to GENI hosts

Omni Client
   
When you reserve nodes through the [http://groups.geni.net/geni/wiki/GeniApi GENI AM API], you can login to your nodes using ssh . You get access to reserved hosts only through ssh keys. This page will give you some useful tips about how to login to your nodes. In order to login to your nodes you need the following things:
  1. an ssh client
  2. your login name, and the hostname
  3. your ssh key
   

SSH Client

Depending on which OS you are using there are different ssh client options.

Linux/Mac OS

All linux and Mac distributions come with a built-in ssh client, just open a Terminal and type ssh, you should get the usage for the ssh command.

Windows OS

There are multiple windows ssh clients. A list of some popular ones can be found here. Some commonly used options are:

  • Cygwin: a complete Linux-type environment that also includes an ssh client. If you have already installed cygwin on your host then you should just run it and follow the instructions for Linux for the rest of the instructions
  • Putty: a lightweight free ssh client. Note: If you are using Putty you will also need to download puttygen to convert your private key to putty's format.

Get your Login and Host names

In order to figure out your login name the best way is to use the status command of the GENI AM API. Depending of which tool you used to reserve the resources you can get this information in different ways.

Using Flack

If you are using Flack for building your experiment then in order to get the login name you need to load your slice in Flack and press on the (i) icon that is next to the node. . On the top of the information window it has a field that says Username, and Hostname. Note: If you are on a Mac computer then you can directly use the 'SSH' button that is on the top on the information pane for the host.

Using Omni

If you are using Omni, then you can run the sliverstatus command and get back a text output. If you search within that output you should find a field about the hostname and one about the login. If you are trying to ssh to your hosts from the same machine that you used to reserve your hosts then you can use a script that comes with Omni and you can directly skip to this section.

Other tools

If you used another tool to reserve your resources, then you should figure out how to get the output of the sliverstatus command. If you can't figure this out please send us an email and let us which tool you used to reserve your resources.

Get a copy of your ssh key

When you reserve your resources, the tool that you use for the reservation also installs one or more public keys on the hosts so that you can get ssh access to the compute resources. In order to ssh to the machines you will need to get a copy of the private ssh key that correspond to the installed public keys. As before how to get a copy of the needed ssh key depends on the specific tool.

Using Flack

Flack has a list of ssh keys that it uploads to nodes during the reservation. After you login to flack, on the left pane there should be a button with your login name. If you click on that you will get a window that has different tabs. One of the tabs says SSH Keys.

In the information that will appear on the left pane there should be a private key. Press to the Save to File option and save it in your computer.

Note: If you are on a Mac computer then you can directly use the 'SSH' button that is on the top on the information pane for the host.

Using Omni

If you made your reservation with Omni then you will need to access the host where your Omni is installed to get a copy of your SSH Key. If you use the host that has Omni installed to ssh to your nodes then you skip to [ these instructions]. If you just want to get a copy of your private key and use it for logging into your nodes from another host, then you should :

  1. Login to the host where you have Omni installed
  2. Open your omni configuration file. For most users this file is located at ~/.gcf/omni_config. Also when you reserve resources using createsliver, omni prints the used configuration file towards the top.
  3. In the omni_config file there should be a section about your user that has an attribute called `keys', that has a list of all the public keys that are installed in the nodes. Usually in the same directory as the public keys there are also the private keys (a private key usually has the same name as the public key but without the '.pub' extension.
  4. Copy the private key over to your host, either by using scp or any other file transfer protocol. You can also just copy-paste the contents of the file.

Other tools

Any tool that uses the GENI AM API to reserve resources, provides the public keys to the AM to be installed on the compute resources. If you can't figure out which keys the tool you used installed on the hosts, please send an email to help@geni.net telling us which tool you used and we will be happy to help.

Omni ReadyToLogin Script

Managing SSH keys on Linux, Mac hosts

Omni Reserved Hosts

If you have reserved your nodes using Omni, you can use command-line ssh to login to your hosts. Omni comes with a script that will give you the exact ssh command you need to use to login to your nodes. To do this you need to be at the host that you used Omni to reserve your hosts and follow these steps:

  • add omni to your PYTHONPATH
  • run the script

Flack Reserved Hosts

Using other tools

Troubleshoot/Useful tips

Attachments (7)

Download all attachments as: .zip