Inside my playbook I'd like to create a variable holding the output of an external command. Afterwards I want to make use of that variable in a couple of templates.
Here are the relevant parts of the playbook:
tasks:
- name: Create variable from command
command: "echo Hello"
register: command_output
- debug: msg="{{command_output.stdout}}"
- name: Copy test service
template: src=../templates/test.service.j2 dest=/tmp/test.service
- name: Enable test service
shell: systemctl enable /tmp/test.service
- name: Start test service
shell: systemctl start test.service
and let's say this is my template:
[Unit]
Description=MyApp
After=docker.service
Requires=docker.service
[Service]
TimeoutStartSec=0
ExecStartPre=-/usr/bin/docker kill busybox1
ExecStartPre=-/usr/bin/docker rm busybox1
ExecStartPre=/usr/bin/docker pull busybox
ExecStart=/usr/bin/docker run --name busybox1 busybox /bin/sh -c "while true; do echo {{ string_to_echo }}; sleep 1; done"
[Install]
WantedBy=multi-user.target
(Notice the {{ string_to_echo }})
So what I'm basically looking for is a way to store the contents of command_output.stdout (which is generated/retrieved during the first task) in a new variable string_to_echo.
That variable I'd like to use in multiple templates afterwards.
I guess I could just use {{command_output.stdout}} in my templates, but I want to get rid of that .stdout for readability.
You have to store the content as a fact:
- set_fact:
string_to_echo: "{{ command_output.stdout }}"
There's no need to set a fact.
- shell: cat "hello"
register: cat_contents
- shell: echo "I cat hello"
when: cat_contents.stdout == "hello"
A slight modification beyond @udondan's answer. I like to reuse the registered variable names with the set_fact to help keep the clutter to a minimum.
So if I were to register using the variable, psk, I'd use that same variable name with creating the set_fact.
Example
- name: generate PSK
shell: openssl rand -base64 48
register: psk
delegate_to: 127.0.0.1
run_once: true
- set_fact:
psk={{ psk.stdout }}
- debug: var=psk
run_once: true
Then when I run it:
$ ansible-playbook -i inventory setup_ipsec.yml
PLAY [all] *************************************************************************************************************************************************************************
TASK [Gathering Facts] *************************************************************************************************************************************************************
ok: [hostc.mydom.com]
ok: [hostb.mydom.com]
ok: [hosta.mydom.com]
TASK [libreswan : generate PSK] ****************************************************************************************************************************************************
changed: [hosta.mydom.com -> 127.0.0.1]
TASK [libreswan : set_fact] ********************************************************************************************************************************************************
ok: [hosta.mydom.com]
ok: [hostb.mydom.com]
ok: [hostc.mydom.com]
TASK [libreswan : debug] ***********************************************************************************************************************************************************
ok: [hosta.mydom.com] => {
"psk": "6Tx/4CPBa1xmQ9A6yKi7ifONgoYAXfbo50WXPc1kGcird7u/pVso/vQtz+WdBIvo"
}
PLAY RECAP *************************************************************************************************************************************************************************
hosta.mydom.com : ok=4 changed=1 unreachable=0 failed=0
hostb.mydom.com : ok=2 changed=0 unreachable=0 failed=0
hostc.mydom.com : ok=2 changed=0 unreachable=0 failed=0
I'm a newbie in Ansible, but I would suggest next solution:
playbook.yml
...
vars:
command_output_full:
stdout: will be overriden below
command_output: {{ command_output_full.stdout }}
...
...
...
tasks:
- name: Create variable from command
command: "echo Hello"
register: command_output_full
- debug: msg="{{ command_output }}"
It should work (and works for me) because Ansible uses lazy evaluation. But it seems it checks validity before the launch, so I have to define command_output_full.stdout in vars.
And, of course, if it is too many such vars in vars section, it will look ugly.
In case than you want to store a complex command to compare text result, for example to compare the version of OS, maybe this can help you:
tasks:
- shell: echo $(cat /etc/issue | awk {'print $7'})
register: echo_content
- shell: echo "It works"
when: echo_content.stdout == "12"
register: out
- debug: var=out.stdout_lines
