165

How do I see stdout for ansible-playbook commands? -v only shows ansible output, not the individual commands. It would be great if I could figure out how to do this immediately, so if something fails or hangs I can see why.

e.g.

- name: print to stdout
  action: command echo "hello"

would print

TASK: [print variable] ******************************************************** 

hello
165

I think you can register the result to a variable, then print with debug.

- name: print to stdout
  command: echo "hello"
  register: hello

- debug: msg="{{ hello.stdout }}"

- debug: msg="{{ hello.stderr }}"
  • 26
    Additionally, you can debug a variable directly with - debug: var=hello. Sometimes this is more helpful for multiline output or Ansible module output (rather than command/shell output). – geerlingguy Mar 8 '14 at 3:03
  • 4
    I had trouble getting Java output using this. The fix is to redirect all of Java's output to stdout: shell: java -version 2>&1 – Matthias Braun Jan 6 '15 at 17:27
  • 20
    that's a lot better nothing, but you only get the stdout message after the command has successfully completed. I was having an issue where ansible would appear to hang. The reason was that I was using the wrong username for an rsync command, which spooled the interactive password request, which just hanged ansible. It was very difficult to debug - but if I could see stdout in realtime, I would have immediately realised what I'd done wrong. I would LOVE this functionality, if possible. – Michael B Feb 9 '15 at 4:31
  • 10
    while this works, it means ansible makes debugging really hard. Let's imagine the first task never terminates (perhaps it is foolishly waiting for user input)... the user would never know! Moreover, the register module, or whatever it is doesn't produce objects that have the stdout or stderr variable set.... so it's really bad that we don't just get the output by default :| – vlad-ardelean Jul 10 '15 at 10:47
96

Instead of stdout I would suggest using stdout_lines. For multiline output this is much nicer, e.g.

- hosts: all
  tasks:
    - name: Run ls.sh and output "ls /"
      script: ls.sh
      register: out

    - debug: var=out.stdout_lines

gives

TASK: [debug var=out.stdout_lines] ******************************************** 
ok: [local] => {
    "var": {
        "out.stdout_lines": [
            "total 61", 
            "lrwxrwxrwx   1 root root     7 Feb 15  2015 bin -> usr/bin", 
            "drwxr-xr-x   6 root root  1024 Aug 24 22:08 boot", 
            "drwxr-xr-x  22 root root  3580 Sep  8 18:41 dev",  
            [...] 
            "drwxr-xr-x   9 root root  4096 Aug 25 19:14 usr", 
            "drwxr-xr-x  13 root root  4096 Feb 25  2015 var"
        ]
    }
}

Regarding real time output for debugging purposes there is a closed bug report https://github.com/ansible/ansible/issues/3887#issuecomment-54672569 discussing the reasons why this is not possible and will not be implemented.

  • 16
    +1 for linking the "real time output" bug. – ntc2 Nov 26 '15 at 0:29
  • If I want to send out.stdout_lines (as body of Ansible mail task), how can I send it so it does NOT look like this when email is received? [u'total 61', u'lrwxrwxrwx 1 root root 7 Feb 15 2015 bin -> usr/bin', u'drwxr-xr-x 6 root root 1024 Aug 24 22:08 boot', u'.....'] I want it to look like this, as seen on terminal – Chris F Mar 10 '17 at 21:35
  • fatal: [127.0.0.1]: FAILED! => {"reason": "Syntax Error while loading YAML.\n did not find expected <document start>\n\nThe error appears to be in...syntax problem.\n\nThe offending line appears to be:\n\n\n- name: Run ls.sh and output \"ls /\"\n^ here\n"} – Nate Aug 15 at 16:28
20

I found using the minimal stdout_callback with ansible-playbook gave similar output to using ad-hoc ansible.

In your ansible.cfg (Note that I'm on OS X so modify the callback_plugins path to suit your install)

stdout_callback     = minimal
callback_plugins    = /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/ansible/plugins/callback

So that a task such as this

---
- hosts: example
  tasks:
   - name: Say hi
     command: echo "hi ..."

Gives output like this, like an ad-hoc command would

example | SUCCESS | rc=0 >>
hi ...

I'm using ansible-playbook 2.2.1.0

  • Nice callback plugin, simple post-processing can extract standard output only. – RichVel Jun 27 '17 at 9:43

protected by Michael Hampton Jul 25 '16 at 19:21

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