AnsibleでMariaDBサービスのアップグレードを安全に実行：停止とアップグレードを自動化
Ansible で MariaDB サービスをアップグレードが必要な場合にのみ停止する方法
事前準備
以下の要件を満たしていることを確認してください。
- Ansible がインストールおよび設定されている
- MariaDB が CentOS 7 システムにインストールされている
root権限を持つユーザーとして Ansibleを実行できる
Playbookの作成
以下の内容を含む Ansible playbook を作成します。
---
- name: Check if MariaDB upgrade is required
hosts: all
become: true
tasks:
- name: Get MariaDB version
shell: rpm -q --queryformat '%{version}' mariadb-server
register: mariadb_version
- name: Check if upgrade is available
yum:
name: mariadb-server
state: latest
update_cache: yes
register: mariadb_update
- name: Stop MariaDB service if upgrade is required
service:
name: mariadb
state: stopped
when: mariadb_update.updated
以下のコマンドを実行して、Playbook を実行します。
ansible-playbook mariadb_upgrade.yml
この Playbook は以下の処理を実行します。
rpmコマンドを使用して、現在の MariaDB バージョンを取得します。yumモジュールを使用して、利用可能な MariaDB アップグレードがあるかどうかを確認します。- アップグレードが利用可能な場合、
serviceモジュールを使用して MariaDB サービスを停止します。
注意事項
- この Playbook は、MariaDB サービスが実行されていることを前提としています。サービスが停止している場合は、手動で起動する必要があります。
- Playbook を実行する前に、Ansible 変数を適切に設定していることを確認してください。
- この Playbook は、あくまでも例であり、本番環境で使用される前に十分にテストする必要があります。
---
- name: Check if MariaDB upgrade is required
hosts: all
become: true
tasks:
- name: Get MariaDB version
shell: rpm -q --queryformat '%{version}' mariadb-server
register: mariadb_version
- name: Check if upgrade is available
yum:
name: mariadb-server
state: latest
update_cache: yes
register: mariadb_update
- name: Stop MariaDB service if upgrade is required
service:
name: mariadb
state: stopped
when: mariadb_update.updated
Explanation:
How to use:
ansible-playbook mariadb_upgrade.yml
This will check if there is an available MariaDB upgrade for the hosts in the inventory file. If an upgrade is available, it will stop the MariaDB service before installing the upgrade. Once the upgrade is installed, it will start the MariaDB service again.
Notes:
- This playbook assumes that the MariaDB service is running. If the service is not running, you will need to start it manually before running the playbook.
- This is just an example, and you may need to modify it to fit your specific needs.
I hope this helps!
Method 1: Using the when conditional with the yum module
Instead of using the service module to stop the MariaDB service, you can use the when conditional with the yum module to stop the service only if the updated flag is set to true. This approach is more concise and avoids the need for an additional task.
---
- name: Check if MariaDB upgrade is required and stop service if necessary
hosts: all
become: true
tasks:
- name: Check if upgrade is available and stop MariaDB service if required
yum:
name: mariadb-server
state: latest
update_cache: yes
notify: restart_mariadb
when: updated
- name: Restart MariaDB service
service:
name: mariadb
state: started
notify: restart_mariadb
In this example, the restart_mariadb handler is used to restart the MariaDB service after the upgrade is installed. The handler is only executed if the updated flag is set to true.
Method 2: Using a custom filter
You can create a custom filter to check if a MariaDB upgrade is available and then use the filter in the when conditional of the service module. This approach gives you more control over the logic for checking for upgrades.
---
- name: Check if MariaDB upgrade is required and stop service if necessary
hosts: all
become: true
filters:
mariadb_upgrade_available:
filter: "{{ mariadb_version | version_compare(mariadb_latest_version, '<') }}"
tasks:
- name: Get MariaDB version
shell: rpm -q --queryformat '%{version}' mariadb-server
register: mariadb_version
- name: Get latest MariaDB version
shell: yum info mariadb-server | grep Version: | awk '{ print $2 }'
register: mariadb_latest_version
- name: Stop MariaDB service if upgrade is available
service:
name: mariadb
state: stopped
when: mariadb_upgrade_available | bool
In this example, the mariadb_upgrade_available filter is defined to compare the current MariaDB version to the latest version. The filter returns true if an upgrade is available and false otherwise. The filter is then used in the when conditional of the service module to stop the MariaDB service only if an upgrade is available.
Method 3: Using a conditional playbook
You can create two separate playbooks: one for checking if a MariaDB upgrade is available and one for stopping the MariaDB service and installing the upgrade. You can then use the conditional playbook directive to run the appropriate playbook based on the results of the first playbook.
---
- name: Check if MariaDB upgrade is required
hosts: all
become: true
tasks:
- name: Get MariaDB version
shell: rpm -q --queryformat '%{version}' mariadb-server
register: mariadb_version
- name: Get latest MariaDB version
shell: yum info mariadb-server | grep Version: | awk '{ print $2 }'
register: mariadb_latest_version
- name: Set upgrade_required variable
set_fact:
upgrade_required: "{{ mariadb_version | version_compare(mariadb_latest_version, '<') }}"
- name: Stop MariaDB service and install upgrade (if required)
hosts: all
become: true
vars:
upgrade_required: "{{ lookup('host_vars', 'localhost', 'upgrade_required', default=false) }}"
when: upgrade_required
tasks:
- name: Stop MariaDB service
service:
name: mariadb
state: stopped
- name: Install MariaDB upgrade
yum:
name: mariadb-server
state: latest
update_cache: yes
- name: Start MariaDB service
service:
name: mariadb
state: started
In this example, the first playbook checks if a MariaDB upgrade is available and sets the upgrade_required variable accordingly. The second playbook is only run if the upgrade_required variable is set to true. This ensures that the service is only stopped and the upgrade
ansible mariadb centos7
