Ansible 2.7 and OEL/RHEL 5 - not mutually exclusive!

It's been quite sometime since I blogged. So, I thought, well, it should be something that helps all the folks and not just Oracle DBAs.

I have been dabbling a bit with Ansible, Python and Oracle database for a few automation tasks. During this process, I did face issues with making Ansible 2.7 work with OEL/RHEL 5.

As you all know, with the release of Ansible 2.4, the minimum version of Python required on the remote nodes is >= 2.6.

However, with OEL/RHEL 5, the default version of Python is 2.4.

So, if you are still wondering how to make the two to tango , here goes:

1. Download the latest version of Python 2.7 from here.

NOTE: At the time of writing this blog, Python 2.7.16 was the latest Python 2.7 version downloadable from here.

2. Ensure rpms zlib and zlib-devel are installed on the target node.

# rpm -qa | grep zlib

NOTE: If zlib-devel isn't installed, we'll get the below error:

myserver.domain.com | FAILED! => {

    "changed": false,

    "module_stderr": "Shared connection to myserver.domain.com closed.\r\n",

    "module_stdout": "Traceback (most recent call last):\r\n  File \"/oracle/home/oracle/.ansible/tmp/ansible-tmp-1540898245.08-275033388982084/AnsiballZ_ping.py\", line 113, in \r\n    _ansiballz_main()\r\n  File \"/oracle/home/oracle/.ansible/tmp/ansible-tmp-1540898245.08-275033388982084/AnsiballZ_ping.py\", line 105, in _ansiballz_main\r\n    invoke_module(zipped_mod, temp_path, ANSIBALLZ_PARAMS)\r\n  File \"/oracle/home/oracle/.ansible/tmp/ansible-tmp-1540898245.08-275033388982084/AnsiballZ_ping.py\", line 40, in invoke_module\r\n    f.write(z.read('__main__.py'))\r\n  File \"/opt/python2.7/lib/python2.7/zipfile.py\", line 931, in read\r\n    return self.open(name, \"r\", pwd).read()\r\n  File \"/opt/python2.7/lib/python2.7/zipfile.py\", line 1006, in open\r\n    close_fileobj=should_close)\r\n  File \"/opt/python2.7/lib/python2.7/zipfile.py\", line 526, in __init__\r\n    self._decompressor = zlib.decompressobj(-15)\r\nAttributeError: 'NoneType' object has no attribute 'decompressobj'\r\n",

    "msg": "MODULE FAILURE\nSee stdout/stderr for the exact error",

    "rc": 1

}

Reference:

1. https://stackoverflow.com/a/49680436

2. https://unix.stackexchange.com/questions/164517/nonetype-object-has-no-attribute-decompressobj-while-installing-bootstrap-se

3. Untar and unzip Python gzip tar file on the remote node.

# cd /tmp

# tar xzvf /tmp/Python-2.7.16.tgz

4. Configure Python for alternate path as below:

# cd /tmp/Python-2.7.16; ./configure --prefix=/opt/python2.7 --enable-shared

5.  Use make executable to "make" the Python folder:

# cd /tmp/Python-2.7.16; make

6. Use make altinstall to create the alternate Python:

# cd /tmp/Python-2.7.16; make altinstall

7. Now, create a shell script under $HOME (home directory) of oracle os user (or any other user that'll be used for ansible), on the target node:

 

$ cat ~/python_exec.sh

#!/bin/bash

export LD_LIBRARY_PATH="/opt/python2.7/lib":$LD_LIBRARY_PATH

exec /opt/python2.7/bin/python2.7 "$@"

$ ls -lrt ~/python_exec.sh
-rwxr-xr-x 1 myuser mygroup 113 Jul  1 04:31 python_exec.sh

NOTE: This is to avoid the below error:

 

$ ansible myremoteserver.domain.com -i inv -u oracle -m ping

myremoteserver.domain.com | FAILED! => {

    "changed": false,

    "module_stderr": "Shared connection to myremoteserver.domain.com closed.\r\n",

    "module_stdout": "/opt/python2.7/bin/python2.7: error while loading shared libraries: libpython2.7.so.1.0: cannot open shared object file: No such file or directory\r\n",

    "msg": "MODULE FAILURE\nSee stdout/stderr for the exact error",

    "rc": 127

}

 

Reference: https://github.com/ansible/ansible/issues/15239

8. Now, either in host_vars or in group_vars (depends entirely upon you), define the python interpreter as below:

 ansible_python_interpreter: ~/python_exec.sh

 9. et voilà ! ansible 2.7 works like a charm with OEL/RHEL 5.

$ ansible mytargetserver.domain.com -i hosts -m pingmytargetserver.domain.com | SUCCESS => {
    "changed": false,
    "ping": "pong"
}