Adds support for cold migration to drain script

Author: jovial

etc/kayobe/ansible/nova-compute-drain.yml

@@ -5,68 +5,39 @@
   tags:
     - nova-compute-drain
   vars:
-    venv: "{{ virtualenv_path }}/openstack"
-    live_migration_fatal: true
+    nova_compute_migration_fatal: true
   tasks:
-    - name: Set up openstack cli virtualenv
-      pip:
-        virtualenv: "{{ venv }}"
-        name:
-          - python-openstackclient
-        state: latest
-        extra_args: "{% if pip_upper_constraints_file %}-c {{ pip_upper_constraints_file }}{% endif %}"
+    - include_role:
+        name: nova-compute-drain
+        tasks_from: setup.yml
       run_once: true
-      delegate_to: "{{ groups['controllers'][0] }}"
 
-    - block:
-        - name: Query instances
-          command: >
-            {{ venv }}/bin/openstack
-            server list --host {{ ansible_facts.nodename }}
-            --all-projects
-            --status ACTIVE
-            --format json
-          register: instances
+    - include_role:
+        name: nova-compute-drain
+        tasks_from: instance-info.yml
 
-        - name: Live migrate instances
-          command: >
-            {{ venv }}/bin/openstack
-            --os-compute-api-version 2.25
-            server migrate
-            {{ instance_uuid }}
-            --live-migration
-            --wait
-          loop: "{{ instances.stdout | from_json }}"
-          loop_control:
-            label: "{{ instance_uuid }}"
-          vars:
-            instance_uuid: "{{ item.ID | default }}"
-          register: result
-          failed_when:
-            - live_migration_fatal | bool
-            - result is failed
+    - include_role:
+        name: nova-compute-drain
+        tasks_from: live-migrate.yml
+      loop: "{{ nova_compute_drain_instance_info | selectattr('Status', 'equalto', 'ACTIVE') | list }}"
+      loop_control:
+        label: "{{ item.ID | default }}"
 
-        - name: Query instances
-          command: >
-            {{ venv }}/bin/openstack
-            server list --host {{ ansible_facts.nodename }}
-            --all-projects
-            --status ACTIVE
-            --format json
-          register: instances
+    - include_role:
+        name: nova-compute-drain
+        tasks_from: cold-migrate.yml
+      loop: "{{ nova_compute_drain_instance_info | selectattr('Status', 'equalto', 'SHUTOFF') | list }}"
+      loop_control:
+        label: "{{ item.ID | default }}"
 
-        - name: Fail if there are instances still on the host
-          fail:
-            msg: >
-              Instances still on {{ inventory_hostname }}: {{ instances.stdout | from_json }}
-          when:
-            - live_migration_fatal | bool
-            - instances.stdout | from_json | length > 0
+    - include_role:
+        name: nova-compute-drain
+        tasks_from: instance-info.yml
 
-      delegate_to: "{{ groups['controllers'][0] }}"
-      environment: "{{ openstack_auth_env }}"
+    - name: Fail if there are instances still on the host
+      fail:
+        msg: >
+          Instances still on {{ inventory_hostname }}: {{ instances.stdout | from_json }}
       when:
-        - "'compute' in group_names"
-        - groups['compute'] | length > 1
-      vars:
-        ansible_host: "{{ hostvars[groups['controllers'][0]].ansible_host }}"
+        - nova_compute_migration_fatal | bool
+        - nova_compute_drain_instance_info | length > 0

etc/kayobe/ansible/roles/nova-compute-drain/defaults/main.yml

@@ -0,0 +1,4 @@
+---
+
+nova_compute_drain_venv: "{{ virtualenv_path }}/openstack"
+nova_compute_drain_delegate_host: "{{ groups['controllers'][0] }}"

etc/kayobe/ansible/roles/nova-compute-drain/tasks/cold-migrate.yml

@@ -0,0 +1,38 @@
+---
+
+- block:
+  - name: "Cold migrate instance: {{ instance_uuid }}"
+    command: >
+      {{ nova_compute_drain_venv }}/bin/openstack
+      --os-compute-api-version 2.25
+      server migrate
+      {{ instance_uuid }}
+      --wait
+    register: result
+
+  - name: "Wait for VERIFY_RESIZE: {{ instance_uuid }}"
+    command: >
+      {{ nova_compute_drain_venv }}/bin/openstack server show {{ instance_uuid }} -f value -c status
+    register: result
+    until: result.stdout == 'VERIFY_RESIZE' or result.stdout == 'SHUTOFF'
+    retries: 10
+    delay: 30
+
+  - name: "Confirm resize: {{ instance_uuid }}"
+    command: >
+      {{ nova_compute_drain_venv }}/bin/openstack server migrate confirm {{ instance_uuid }}
+    when: result.stdout == 'VERIFY_RESIZE'
+
+  - name: "Wait for SHUTOFF: {{ instance_uuid }}"
+    command: >
+      {{ nova_compute_drain_venv }}/bin/openstack server show {{ instance_uuid }} -f value -c status
+    register: result
+    until: result.stdout == 'SHUTOFF'
+    retries: 10
+    delay: 30
+  environment: "{{ openstack_auth_env }}"
+  vars:
+    ansible_host: "{{ hostvars[nova_compute_drain_delegate_host].ansible_host }}"
+    instance_uuid: "{{ item.ID | default }}"
+  rescue:
+    - meta: noop

etc/kayobe/ansible/roles/nova-compute-drain/tasks/instance-info.yml

@@ -0,0 +1,15 @@
+---
+- name: Query instances
+  command: >
+    {{ nova_compute_drain_venv }}/bin/openstack
+    server list --host {{ ansible_facts.fqdn }}
+    --all-projects
+    --format json
+  register: instances
+  environment: "{{ openstack_auth_env }}"
+  vars:
+    ansible_host: "{{ hostvars[nova_compute_drain_delegate_host].ansible_host }}"
+
+- name: Set fact containing list of instances
+  set_fact:
+    nova_compute_drain_instance_info: "{{ instances.stdout | from_json }}"

etc/kayobe/ansible/roles/nova-compute-drain/tasks/live-migrate.yml

@@ -0,0 +1,17 @@
+---
+
+- name: "Live migrate instance: {{ instance_uuid }}"
+  command: >
+    {{ nova_compute_drain_venv }}/bin/openstack
+    --os-compute-api-version 2.25
+    server migrate
+    {{ instance_uuid }}
+    --live-migration
+    --wait
+  environment: "{{ openstack_auth_env }}"
+  vars:
+    instance_uuid: "{{ item.ID | default }}"
+    ansible_host: "{{ hostvars[nova_compute_drain_delegate_host].ansible_host }}"
+  register: result
+  failed_when:
+    - result is failed

etc/kayobe/ansible/roles/nova-compute-drain/tasks/setup.yml

@@ -0,0 +1,29 @@
+---
+
+- name: Initiate openstack cli virtualenv
+  pip:
+    virtualenv: "{{ nova_compute_drain_venv }}"
+    name:
+      - pip
+      - setuptools
+    state: latest
+    virtualenv_command: /usr/bin/python3.6 -m venv
+  run_once: true
+  delegate_to: "{{ nova_compute_drain_delegate_host }}"
+  vars:
+    # NOTE: Without this, the delegate ansible_host variable will not
+    # be respected when using delegate_to.
+    ansible_host: "{{ hostvars[nova_compute_drain_delegate_host].ansible_host | default(nova_compute_drain_delegate_host) }}"
+
+- name: Install openstack CLI tools in virtualenv
+  pip:
+    virtualenv: "{{ nova_compute_drain_venv }}"
+    name:
+      - python-openstackclient
+
+  run_once: true
+  delegate_to: "{{ nova_compute_drain_delegate_host }}"
+  vars:
+    # NOTE: Without this, the delegate's ansible_host variable will not
+    # be respected when using delegate_to.
+    ansible_host: "{{ hostvars[nova_compute_drain_delegate_host].ansible_host | default(nova_compute_drain_delegate_host) }}"