shell script gives different output when invoked using Ansible shell module.

[Mohtashim S]

I have check.sh script that I wish to run on the target nodes:

cat check.sh

str=`echo $1 | sed -e 's#[\][\]n# #g'`
echo $str>check.row

It is suppose to replace \\n with a single white space from the argument and save it in check.row file.

When I run it manually on the target server i get good output results as shown below:

bash -x ./check.sh '/fin/app/01/scripts\\n/fin/app/01/sql'
++ echo '/fin/app/01/scripts\\n/fin/app/01/sql'
++ sed -e 's#[\][\]n# #g'
+ str='/fin/app/01/scripts /fin/app/01/sql'
+ echo /fin/app/01/scripts /fin/app/01/sql

Here is the check.row file output:

[user1@remotehost1 ~]$ cat check.row
/fin/app/01/scripts /fin/app/01/sql

However, when i run the same using ansible shell or command module I do not get the expected results.

Below is my playbook:

  tasks:
   - copy:
       src: "{{ playbook_dir }}/files/check.sh"
       dest: "~/"
       mode: 0754


   - set_fact:
       install_dir: "{{ hostvars[\'localhost\'][\'command_result\'].stdout.split('\t')[2] }}"


   - shell: "bash -x  ~/check.sh '{{ install_dir }}' > ~/check_rollback.log"

See ansible's debug output below:   

   

changed: [10.8.44.55] => {
    "changed": true, 
    "cmd": "bash -x  ~/check.sh '/fin/app/01/scripts\\n/fin/app/01/sql' > ~/check_rollback.log", 
    "delta": "0:00:00.118943", 
    "end": "2019-09-04 10:50:16.503745", 
    "invocation": {
        "module_args": {
            "_raw_params": "bash -x  ~/check.sh '/fin/app/01/scripts\\n/fin/app/01/sql' > ~/check_rollback.log", 
            "_uses_shell": true, 
            "argv": null, 
            "chdir": null, 
            "creates": null, 
            "executable": null, 
            "removes": null, 
            "stdin": null, 
            "stdin_add_newline": true, 
            "strip_empty_ends": true, 
            "warn": true
        }
    }, 
    "rc": 0, 
    "start": "2019-09-04 10:50:16.384802", 
    "stderr": "++ echo '/fin/app/01/scripts\\n/fin/app/01/sql'\n++ sed -e 's#[\\][\\]n# #g'\n+ str='/fin/app/01/scripts\\n/fin/app/01/sql'\n+ echo '/fin/app/01/scripts\\n/fin/app/01/sql'", 
    "stderr_lines": [
        "++ echo '/fin/app/01/scripts\\n/fin/app/01/sql'", 
        "++ sed -e 's#[\\][\\]n# #g'", 
        "+ str='/fin/app/01/scripts\\n/fin/app/01/sql'", 
        "+ echo '/fin/app/01/scripts\\n/fin/app/01/sql'"
    ], 
    "stdout": "", 
    "stdout_lines": []
}

And here is the check.row file output:

[user1@remotehost1 ~]$ cat check.row
/fin/app/01/scripts\\n/fin/app/01/sql

As you can instead of single whitespace it is now printing \\n. 

One can replicate this issue easily. Can you please suggest why am I getting this issue and how to fix this?

[Fernando Scarlazzari de Oliveira]

Mohtashim,

      Try using "echo -e".