CODEWITHSUNDEEP
ansibleidempotent
tgcloud
tgcloud

Reputation: 887

Optimize playbook to make it idempotent with shell module

I am automating stack deployment with ansible. I am using "shell" or "command" module to execute most of the task. So In order to make playbook idempotent with shell and module, I am modifying playbook like this..

- name: Task1
  shell: 'source /etc/nova/openrc && heat stack-show myne01 | tee stack_show.log'
  args:
    creates: stack_show.log
  register: list
- debug: var=list.stdout_lines
  ignore_errors: yes

- name: Delete stack-show.log
  file: path=/home/wrsroot/stack_show.log state=absent
  when: "list.rc != 0"

- name: Failed the stack
  shell: "echo 'stack is failed'"
  when: "list.rc != 0"
  failed_when: "list.rc != 0"

Here the flow is :

1) Display stack status
2) If stack execution has failed, ignore errors and delete the "stack_show.log" file, So on the rerun anisble won't skip this task.
3) If stack execution has failed, Failed the task.

Please suggest if any better way to do this.

To add idempotency in playbook I am adding 9 lines of code for each "shell" module. It is making my playbook very big.

Upvotes: 1

Views: 7780

Answers (1)

Valeriy Solovyov
Valeriy Solovyov

Reputation: 5648

You just need changed_when: false to be idempotent. Also I think you can do this more simply:

- name: Task1
  shell: bash -c 'set -o pipefail;source /etc/nova/openrc && heat stack-show myne01 | tee stack_show.log'
  changed_when: false
  args:
    creates: stack_show.log
  register: list

- name: Delete stack-show.log
  file: path=/home/wrsroot/stack_show.log state=absent
  changed_when: false
  # You don't need this because file will deleted if exists
  #  when: "list.rc != 0"

# You don't need it because command will failed 
# set -o pipefail
#- name: Failed the stack
#  shell: "echo 'stack is failed'"
#  when: "list.rc != 0"
#  failed_when: "list.rc != 0"

You cat try Ansible 2.x Blocks

tasks:
     - block:
         - shell: bash -c 'set -o pipefail;source /etc/nova/openrc && heat stack-show myne01 | tee stack_show.log'
           changed_when: false
           args:
              creates: stack_show.log
            register: list

       always:
         - debug: msg="this always executes"    
         - name: Delete stack-show.log
              file: path=/home/wrsroot/stack_show.log state=absent
              changed_when: false

Upvotes: 1

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