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Accepted
jdog
Asked: 2021-01-11 13:53:10 +0800 CST

Ansible run certain tasks one one group of servers, other on another

  • 772

I'm migrating a group of websites from one infrastructure to another, including a fairly slow rsync operation. The migration process includes changes to both the source and target systems.

Due to a fairly slow rsync operation that is part of the process, I am looping through a var file which contains the details for each website and then run through the tasks required to move one website at a time.

I cannot find a way to target some tasks at the source system and some at the target system. I have tried doing this by adding hosts: to each task: (all tasks are in a single role)

My playbook:

---
- hosts:
    - tag_aws_autoscaling_groupName_thename
    - tag_Name_server_name
  vars_files:
    - group_vars/all

  roles:
   - unmigratesite

unmigratesite role:

---

- include_tasks: "unmigrateonesite.yml"
  loop: "{{ wordpress_websites }}"

unmigrateonesite.yml:

- name: rsync site
  hosts: tag_aws_autoscaling_groupName_thename
  shell: rsync -avz /efs/www/{{new_folder}}/htdocs/ 172.31.18.217:/www/{{item.folder}}
  run_once: true
  register: rsync_out

- name: setup proxy host file
  template: src=proxy-host.j2 dest=/efs/nginx/sites-available/{{item.name}} owner=root group=root mode=0644
  hosts: tag_aws_autoscaling_groupName_thename
  notify:
    - restart nginx
  tags:
    - site
    - nginx-host-conf
    - nginx-temp-proxy

- name: setup wp-config.php WP_CONTENT_DIR on old server
  lineinfile: name=/www/{{ folder }}/{{ configuration_file }} regexp=WP_CONTENT_DIR line="define('WP_CONTENT_DIR', '/www/{{folder}}/app');"
  hosts: tag_Name_server_name
  ignore_errors: yes
  tags:
    - wp-config.php
    - wordpress
    - site
    - WP_CONTENT_DIR

However I'm getting an error:

    fatal: [54.219.216.237]: FAILED! => {"reason": "conflicting action statements: shell, hosts\n\nThe error appears to be in '/Users/jd/projects/bizinconline/ansible/roles/unmigratesite/tasks/unmigrateonesite.yml': line 22, column 3, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n- name: rsync site\n  ^ here\n"}
    fatal: [54.193.100.223]: FAILED! => {"reason": "conflicting action statements: shell, hosts\n\nThe error appears to be in '/Users/jd/projects/bizinconline/ansible/roles/unmigratesite/tasks/unmigrateonesite.yml': line 22, column 3, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n- name: rsync site\n  ^ here\n"}
    fatal: [13.57.52.221]: FAILED! => {"reason": "conflicting action statements: shell, hosts\n\nThe error appears to be in '/Users/jd/projects/bizinconline/ansible/roles/unmigratesite/tasks/unmigrateonesite.yml': line 22, column 3, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n- name: rsync site\n  ^ here\n"}

Exactly 3 times - as many times as there are hosts.

How can I run some tasks against one group and some against another group of servers?

ansible ansible-playbook

2 Answers

  1. Best Answer

    I cannot find a way to target some tasks at the source system and some at the target system. I have tried doing this by adding hosts: to each task: (all tasks are in a single role)

    My first idea reading this is to replace your hosts: by when: "'old_server' in group_names" or when: "'new_server' in group_names"

    If that doesn't work, I'ld give a shot at delegate_to, here's the delegation documentation

    one website at a time

    If you want to be really slow, consider using serial: 1. Or even --step in the cli.

    • 3

  2. You run tasks on different hosts by grouping the tasks into plays, each of which can define the set of hosts its tasks runs on. It's not really valid to set hosts for an individual task, which is the immediate cause of the error message.

    Here is an example, with two plays, each defining a different set of hosts. Each play defines the hosts on which its tasks will run.

     - name: configure new hosts
   hosts: tag_aws_autoscaling_groupName_thename
   strategy: free
   tasks:
    - name: rsync site
      shell: rsync -avz /efs/www/{{new_folder}}/htdocs/ 172.31.18.217:/www/{{item.folder}}
      run_once: true
      register: rsync_out
    
    - name: setup proxy host file
      template: src=proxy-host.j2 dest=/efs/nginx/sites-available/{{item.name}} owner=root group=root mode=0644
      notify:
        - restart nginx
      tags:
        - site
        - nginx-host-conf
        - nginx-temp-proxy

    Above is one play containing two tasks. Below is one play containing one task.

     - name: configure old hosts
   hosts: tag_Name_server_name
   strategy: free
   tasks:
    - name: setup wp-config.php WP_CONTENT_DIR on old server
      lineinfile: name=/www/{{ folder }}/{{ configuration_file }} regexp=WP_CONTENT_DIR line="define('WP_CONTENT_DIR', '/www/{{folder}}/app');"
      ignore_errors: yes
      tags:
        - wp-config.php
        - wordpress
        - site
        - WP_CONTENT_DIR
    • 1