rollback_migrations.yml

# This playbook will check for migrations to rollback for Django applications within a larger
# Django project. The provided input file will determine what migrations should be rolled back.
#
# The playbook uses the Django management commands found in this Django app repo:
# https://github.com/edx/edx-django-release-util
# So the Django app above needs to be installed in the Django project.
#
# Required variables for this playbook:
#
#   - APPLICATION_PATH                - the top-level path of the Django application; the application lives underneath
#                                       this directory in a directory with the same name as APPLICATION_NAME.
#                                       NOTE: It is assumed that edx-django-release-util is one of its INSTALLED_APPS.
#   - APPLICATION_NAME                - The name of the application that we are migrating.
#   - APPLICATION_USER                - user which is meant to run the application
#   - ARTIFACT_PATH                   - the path where the migration artifacts should be copied after completion
#   - initial_states                  - An array of the migrations
#   - database                        - Name of the database to run the rollback against
#
# Other variables:
#   - migration_result                - the filename where the migration output is saved
#   - SUB_APPLICATION_NAME            - used for migrations in edxapp {lms|cms}, must be specified
#                                         when APPLICATION_NAME is edxapp
#   - EDX_PLATFORM_SETTINGS           - The settings to use for the edx platform {aws|devstack} DEFAULT: aws
#   - HIPCHAT_TOKEN                   - API token to send messages to hipchat
#   - HIPCHAT_ROOM                    - ID or name of the room to send the notification
#   - HIPCHAT_URL                     - URL of the hipchat API  (defaults to v1 of the api)
#
# Example command line to run this playbook:
#    ansible-playbook \
#    -vvvv \
#    -i ../{artifact_path}/ansible_inventory \
#    --private-key=$PRIVATE_KEY \
#    --module-path=playbooks/library \
#    --user=ubuntu \
#    -e APPLICATION_PATH=$APPLICATION_PATH \
#    -e APPLICATION_NAME=$APPLICATION_NAME \
#    -e APPLICATION_USER=$APPLICATION_USER \
#    -e ARTIFACT_PATH=`/bin/pwd`/../{artifact_path}/migrations \
#    -e DB_MIGRATION_USER=$DB_MIGRATION_USER \
#    -e DB_MIGRATION_PASS=$DB_MIGRATION_PASS \
#    -e ../{artifact_path}/migration_input_file \
#    -e SUB_APPLICATION_NAME={sub_application_name} \
#    playbooks/continuous_delivery/rollback_migrations.yml

- hosts: all
  gather_facts: false
  become: true

  vars:
    COMMAND_PREFIX: ". {{ APPLICATION_PATH }}/{{ APPLICATION_NAME }}_env; DB_MIGRATION_USER={{ DB_MIGRATION_USER }} DB_MIGRATION_PASS='{{ DB_MIGRATION_PASS }}' /edx/bin/python.{{ APPLICATION_NAME }} /edx/bin/manage.{{ APPLICATION_NAME }} "
    EDX_PLATFORM_SETTINGS: "aws"
    rollback_result: rollback_result.yml
    original_state: original_state.yml
    migration_plan: migration_plan.yml
    migration_result: migration_result.yml
    database: default

  vars_files:
    - roles/edxapp/defaults/main.yml

  tasks:
    - name: Create a temporary directory for the migration output.
      command: mktemp -d
      become_user: "{{ APPLICATION_USER }}"
      register: temp_output_dir

    - name: generate current migration state
      shell: >
        {{ COMMAND_PREFIX }} show_unapplied_migrations
        --output_file '{{ temp_output_dir.stdout }}/{{ original_state }}'
      become_user: "{{ APPLICATION_USER }}"
      when: APPLICATION_NAME != "edxapp"

    - name: generate current migration state for edxapp
      shell: >
        {{ COMMAND_PREFIX }} {{ SUB_APPLICATION_NAME }} show_unapplied_migrations
        --database '{{ database }}'
        --output_file '{{ temp_output_dir.stdout }}/{{ database }}_{{ original_state }}'
        --settings '{{ EDX_PLATFORM_SETTINGS }}'
      become_user: "{{ APPLICATION_USER }}"
      when: APPLICATION_NAME == "edxapp"

    - name: migrate to original versions
      shell: >
        {{ COMMAND_PREFIX }} run_specific_migrations
        --migration '{{ item.app }}' '{{ item.migration }}'
        --output_file '{{ temp_output_dir.stdout }}/{{ migration_plan }}'
      become_user: "{{ APPLICATION_USER }}"
      with_items: "{{ initial_states }}"
      when: APPLICATION_NAME != "edxapp"

    - name: migrate to original versions for edxapp
      shell: >
        {{ COMMAND_PREFIX }} {{ SUB_APPLICATION_NAME }} run_specific_migrations
        --migration '{{ item.app }}' '{{ item.migration }}'
        --output_file '{{ temp_output_dir.stdout }}/{{ database }}_{{ migration_plan }}'
        --database '{{ database }}'
        --settings '{{ EDX_PLATFORM_SETTINGS }}'
      become_user: "{{ APPLICATION_USER }}"
      with_items: "{{ initial_states }}"
      when: APPLICATION_NAME == "edxapp"

    - name: generate post rollback migration state
      shell: >
        {{ COMMAND_PREFIX }} show_unapplied_migrations
        --output_file '{{ temp_output_dir.stdout }}/{{ migration_result }}'
      become_user: "{{ APPLICATION_USER }}"
      when: APPLICATION_NAME != "edxapp"

    - name: generate post migration state for edxapp
      shell: >
        {{ COMMAND_PREFIX }} {{ SUB_APPLICATION_NAME }} show_unapplied_migrations
        --database '{{ database }}'
        --output_file '{{ temp_output_dir.stdout }}/{{ database }}_{{ migration_result }}'
        --settings '{{ EDX_PLATFORM_SETTINGS }}'
      become_user: "{{ APPLICATION_USER }}"
      when: APPLICATION_NAME == "edxapp"

    - name: List all migration files
      action: "command ls -1 {{ temp_output_dir.stdout }}"
      register: migration_files

    - name: Transfer artifacts to the proper place.
      fetch:
        src: "{{ temp_output_dir.stdout }}/{{ item }}"
        dest: "{{ ARTIFACT_PATH }}/"
        flat: True
        fail_on_missing: True
        mode: 0700
      with_items:
        - "{{ migration_files.stdout_lines }}"

    - name: Send Hipchat notification cleanup has finished
      hipchat_2_0_0_1:
        api: "{{ HIPCHAT_URL }}"
        token: "{{ HIPCHAT_TOKEN }}"
        room: "{{ HIPCHAT_ROOM }}"
        msg: "Migrations have completed."
      ignore_errors: yes
      when: HIPCHAT_TOKEN is defined