how to put the result of an echo command into an ansible variable

Question

I have $MY_VAR set to some value on the remote host, and I want to query it from a playbook (put it's value in an ansible variable), here's what I am seeing :

   - name: put shell var into ansible var
     command: echo $MY_VAR
     register: my_var

   - debug: var=my_var

ok: [192.168.78.10] => {
    "my_var": {
        "changed": true, 
        "cmd": [
            "echo", 
            "$my_var"
        ], 
        "delta": "0:00:00.002284", 
        "end": "2014-12-17 18:10:01.097217", 
        "invocation": {
            "module_args": "echo $my_var", 
            "module_name": "command"
        }, 
        "rc": 0, 
        "start": "2014-12-17 18:10:01.094933", 
        "stderr": "", 
        "stdout": "$my_var", 
        "stdout_lines": [
            "$my_var"
        ]
    }
}

note:

If I change the command to :

 command: pwd

then I get the expected result :

"my_var": {
  "stdout": "/home/vagrant", 
  "stdout_lines": [
      "/home/vagrant"  
  ]
}

It seems as if echo does not expand when called from ansible

Are you sure, this environment variable is accessible anytime you ssh to the remote host? If you ssh to the machine, does doing "echo $MY_VAR" print something? I mean env variables could be set per terminal instance, so is it possible that your env variable is set on one terminal, but if you start a new tab it might not be visible? — Akshar Raaj
echo $MY_VAR on the remote host prints the expected value, it is set in the ~/.profile of the user — Max L.

tedder42 tedder42 · Accepted Answer · 2014-12-17T19:57:20

The problem is that you are using the command module. Here's what the documentation says:

The given command will be executed on all selected nodes. It will not be processed through the shell, so variables like $HOME and operations like "<", ">", "|", and "&" will not work (use the shell module if you need these features).

So, use shell instead of command.

how to put the result of an echo command into an ansible variable

note:

1 Answers