Using SSH on Linux/Unix Nodes

Rundeck allows users to dispatch jobs to remote Linux/UNIX servers to manage and automate any task using Rundeck workflows. The most common protocol for connecting to Linux/Unix servers is SSH. This is an example of how to add a remote node and configure Rundeck to use SSH to connect to it.

Note: If this is the first time adding remote nodes. It is suggested to review the Rundeck Tutorial before adding remote SSH nodes. This exercise assumes some experience with Linux, SSH Keys, and Rundeck basics covered in the Tutorial.

WARNING

This documentation is for use with the Welcome Projects on non-production instances. It is strongly recommended to follow best practices when generating, managing and configuring SSH keys and access. For detailed configuration of SSH use this documentation.

Configuring Rundeck

Rundeck can store the authentication keys necessary to authenticate to our Linux example host in Rundeck’s built-in Key Storage.

1. Click on the System Menu (gear icon) and choose Key Storage.
2. Click on the Add or Upload a Key button to create a New entry in the Rundeck Key Storage.
3. For Key Type select Private Key.
4. Add Rundeck instance private key file content in Enter text. The key is located at /var/lib/rundeck/.ssh/id_rsa.
5. In the Storage path field it’s possible to define specific subfolders for the keys if needed, for this example just leave it blank.
6. In the Name textbox enter a key name that corresponds to the Rundeck host, in this example is just rundeck (now the Key Storage entry is keys/rundeck).

Adding Nodes

Now, it’s time to add the remote node.

Included in Enterprise is the Node Wizard Node Source. Use that to add a new node by following these steps:

1. Click Project Settings | Edit Nodes
   
2. Click the Modify button under the Node Wizard entry.
   
3. Click + Add Node.
   
4. Set the Node Name to node1
5. Set HostName to node1
6. Set OS Family to Unix
   
7. Click the Authentication Tab at the top.
8. Enter agent for the UserName.
   
   
9. Click Add Node to save that node entry.
10. Click the Save button under the list of nodes.
    

Rundeck Community

1. Click Project Settings | Edit Nodes
2. Click on the Add new Node Source button.
   
3. There will be a list of options, select the File Node Source.
   
4. In the drop-down menu on the right, select resourceyaml.
5. In File Path choose a path reachable by the Rundeck user - e.g: in the /var/lib/rundeck/resources.yml directory. It’s important to leave the filename at the end, otherwise, it will not be created.
6. Next, check Generate, Include Server Node and Writeable.
   
7. Finally, click on the Save button. The file will be added to the server and ready for a node entry.

Once created, the file can be edited by clicking on the "Modify" button (Edit tab) where we can add an extra entry corresponding to our remote SSH server.

Use the following resources.yaml file content:

remote-node:
  description: Remote SSH server node
  hostname: node1
  nodename: node1
  osArch: amd64
  osFamily: unix
  osName: Linux
  osVersion: 5.11.0-7612-generic
  tags: 'node1'
  username: agent
  ssh-key-storage-path: keys/rundeck

In the hostname attribute, place the DNS name of our remote node. In username the user who is trying to access the SSH server, In ssh-key-storage-path specifies the path that was created in key storage earlier.

Running Commands on Nodes

Let’s dispatch some commands!

1. Clicking on the "Nodes" tab (left menu) and using the drop-down to choose Select All Nodes will display all the nodes that have been configured. The screenshot below shows the listing with 2 nodes (the Rundeck node and the node added recently).
   
2. To select the node created earlier, put the name in Nodes textbox; In this case, node1 and press Enter key, now the node is selected.
   
3. In the Enter a command textbox put a command, e.g.: df, and click on the Run on 1 Node green button.
   

Congratulations! A remote SSH node to dispatch commands and jobs is setup in Rundeck. Stay tuned to the next blog entry where we build a job to execute on this Node.

Additional Resources

ssh-keygen command documentation (opens new window)