Running Commands
Difficulty: Basic
Time: Approximately 5 minutes
You can use Bolt to run arbitrary commands on a set of remote hosts. Let’s see that in practice before we move on to more advanced features. Choose the exercise based on the operating system of your test nodes.
Prerequisites
Complete the following before you start this lesson:
Running shell commands on Linux nodes
Bolt by default uses SSH for transport. If you can connect to systems remotely, you can use Bolt to run shell commands. It reuses your existing SSH configuration for authentication, which is typically provided in ~/.ssh/config.
To run a command against a remote Linux node, use the following command syntax:
bolt command run <command> --nodes <nodes>
To run a command against a remote node using a username and password rather than keys use the following syntax:
bolt command run <command> --nodes <nodes> --user <user> --password <password>
Run the uptime command to view how long the system has been running. If you are using existing nodes on your system, replace node1 with the address for your node.
bolt command run uptime --nodes node1
The result:
Started on node1...
Finished on node1:
STDOUT:
22:42:18 up 16 min, 0 users, load average: 0.00, 0.01, 0.03
Successful on 1 node: node1
Ran on 1 node in 0.42 seconds
Tip: If you receive the error Host key verification failed make sure the correct host keys are in your known_hosts file or pass --no-host-key-check to future Bolt commands. Bolt will not honor StrictHostKeyChecking in your SSH configuration.
Run the ‘uptime’ command on multiple nodes by passing a comma-separated list. If you are using existing nodes on your system, replace node1,node2,node3 with addresses for your nodes. If you get an error about Host key verification run the rest of the examples with the --no-host-key-check flag to disable host key verification.
bolt command run uptime --nodes node1,node2,node3
The result:
Started on node1...
Started on node3...
Started on node2...
Finished on node2:
STDOUT:
21:03:37 up 2:06, 0 users, load average: 0.00, 0.01, 0.03
Finished on node3:
STDOUT:
21:03:37 up 2:05, 0 users, load average: 0.08, 0.03, 0.05
Finished on node1:
STDOUT:
21:03:37 up 2:07, 0 users, load average: 0.00, 0.01, 0.05
Successful on 3 nodes: node1,node2,node3
Ran on 3 nodes in 0.52 seconds
Create an inventory file to store information about your nodes and refer to them as a group. Later exercises will refer to the default group all. For more information on how to set up other named groups, see the Inventory File docs.
For example, if you are using the provided Vagrant configuration file, save the following to ~/.puppetlabs/bolt/inventory.yaml:
---
nodes: [node1, node2, node3]
config:
ssh:
host-key-check: false
Running PowerShell commands on Windows nodes
Bolt can communicate over WinRM and execute PowerShell commands when running Windows nodes. To run a command against a remote Windows node, use the following command syntax:
bolt command run <command> --nodes winrm://<node> --user <user> --password <password>
Note the winrm:// prefix for the node address. Also note the --username and --password flags for passing authentication information. In addition, unless you have set up SSL for WinRM communication, you must supply the --no-ssl flag. Otherwise running a Bolt command will result in an unknown protocol error.
bolt command run <command> --no-ssl --nodes winrm://<node>,winrm://<node> --user <user> --password <password>
Set a variable with the list of nodes. Later exercises will refer to this variable. You can incorporate the username and password into the node address. For example, if you are using the provided Vagrant configuration file, set the following:
WINNODE=winrm://vagrant:vagrant@localhost:55985
On Windows, you can do the same thing with Powershell:
$WINNODE="winrm://vagrant:vagrant@localhost:55985"
Run the following command to list all of the processes running on a remote machine.
bolt command run "gps | select ProcessName" --nodes $WINNODE --no-ssl
Use following syntax to list all of the processes running on multiple remote machines.
bolt command run <command> --nodes winrm://<node>,winrm://<node> --user <user> --password <password>
Next steps
Now that you know how to use Bolt to run adhoc commands you can move on to: