具有ansible等待数据库的docker
我试着用ansible部署docker。我有一个docker数据库容器,另一个容器中是我的web应用程序,我尝试链接这两个容器。问题是数据库容器没有时间进行自我配置,而且web容器已经启动。我的ansible剧本看起来像:具有ansible等待数据库的docker,docker,ansible,ansible-playbook,Docker,Ansible,Ansible Playbook,我试着用ansible部署docker。我有一个docker数据库容器,另一个容器中是我的web应用程序,我尝试链接这两个容器。问题是数据库容器没有时间进行自我配置,而且web容器已经启动。我的ansible剧本看起来像: ... - name: run mysql in docker container docker: image: "mysql:5.5" name: database env: "MYSQL_ROOT_PASSWORD=password"
...
- name: run mysql in docker container
docker:
image: "mysql:5.5"
name: database
env: "MYSQL_ROOT_PASSWORD=password"
state: running
- name: run application containers
docker:
name: "application"
image: "myapp"
ports:
- "8080:8080"
links:
- "database:db"
state: running
如何确定数据库是否已启动?我尝试了等待模块,但没有成功。我不想设置超时,这对我来说不是一个好选择。使用模块。我不是MySQL方面的专家,但我假设在一些日志文件中会有一些端口或存在文件或消息等。您可以检查数据库是否启动
下面是从上面链接复制的wait_for
示例
# wait 300 seconds for port 8000 to become open on the host, don't start checking for 10 seconds
- wait_for: port=8000 delay=10
# wait 300 seconds for port 8000 of any IP to close active connections, don't start checking for 10 seconds
- wait_for: host=0.0.0.0 port=8000 delay=10 state=drained
# wait 300 seconds for port 8000 of any IP to close active connections, ignoring connections for specified hosts
- wait_for: host=0.0.0.0 port=8000 state=drained exclude_hosts=10.2.1.2,10.2.1.3
# wait until the file /tmp/foo is present before continuing
- wait_for: path=/tmp/foo
# wait until the string "completed" is in the file /tmp/foo before continuing
- wait_for: path=/tmp/foo search_regex=completed
# wait until the lock file is removed
- wait_for: path=/var/lock/file.lock state=absent
# wait until the process is finished and pid was destroyed
- wait_for: path=/proc/3466/status state=absent
# wait 300 seconds for port 22 to become open and contain "OpenSSH", don't assume the inventory_hostname is resolvable
# and don't start checking for 10 seconds
- local_action: wait_for port=22 host="{{ ansible_ssh_host | default(inventory_hostname) }}" search_regex=OpenSSH delay=10
wait_for不适用于MySQL docker容器,因为它只检查端口是否可连接(对于docker容器来说这是正确的)。但是,wait_for不会检查容器内的服务是否侦听端口并向客户端发送响应 这就是我在ansible playbook中等待MySQL服务在Docker容器中完全运行的方式:
- name: Start MySQL container
docker:
name: some-name
image: mysql:latest
state: started
ports:
- "8306:3306" # it's important to expose the port for waiting requests
env:
MYSQL_ROOT_PASSWORD: "{{ mysql_root_password }}"
- template: mode="a+rx,o=rwx" src=telnet.sh.j2 dest=/home/ubuntu/telnet.sh
# wait while MySQL is starting
- action: shell /home/ubuntu/telnet.sh
register: result
until: result.stdout.find("mysql_native_password") != -1
retries: 10
delay: 3
telnet.sh.j2是
#!/bin/bash -e
telnet localhost 8306 || true
为了避免sh和我通常没有安装telnet
- name: Wait for database to be available
shell: docker run --rm --link mysql:mysql mysql sh -c 'mysql -h"$MYSQL_PORT_3306_TCP_ADDR" -P"$MYSQL_PORT_3306_TCP_PORT" -uroot -p{{mysql_password}} || true'
register: result
until: result.stderr.find("Can't connect to MySQL") == -1
retries: 10
delay: 3
这对我来说很好:
- name: get mariadb IP address
command: "docker inspect --format '{''{ .NetworkSettings.IPAddress }''}' mariadb-container"
register: mariadb_ip_address
- name: wait for mariadb to become ready
wait_for:
host: "{{ mariadb_ip_address.stdout }}"
port: 3306
state: started
delay: 5
connect_timeout: 15
timeout: 30
作为:
wait_for不适用于MySQL docker容器,因为它只检查端口是否可连接(直接适用于docker容器)。但是,wait_for不会检查容器内的服务是否侦听端口并向客户端发送响应
使用,无需shell脚本或telnet即可等待:
- name: Wait for mariadb
command: >
docker exec {{ container|quote }}
mysqladmin ping -u{{ superuser|quote }} -p{{ superuser_password|quote }}
register: result
until: not result.rc # or result.rc == 0 if you prefer
retries: 20
delay: 3
这将运行
mysqladmin ping…
,直到成功(返回代码0)。通常超级用户是root
。我使用podman而不是docker进行了测试,但我相信不管怎样,命令都是一样的| quote
是否执行shell转义,在使用命令时也应执行此操作:
,而我也认为等待成为正确答案这会导致另一个问题:如何计算docker容器的IP地址?数据库容器没有绑定到本地主机上的端口,因此要等待它启动,我们需要docker为容器分配的IP地址。我目前正在使用docker inspect
获取IP,但这还没有提供结果。@Tobias可能会发布一个带有适当详细信息的新问题。您为什么要在单独的脚本中运行telnet命令?这对我很有效,我喜欢它避免使用脚本或telnet。我使用的变体是mysqladmin ping
和docker exec
。我使用命令模块和docker exec{{container_name}}mysqladmin ping
,然后使用,直到变成result.rc==0
。是否有一个版本不需要根MySQL用户?@JeroenDeDauw我不确定是否尝试与普通用户一起运行它,它可能会正常工作。如果没有,您可以尝试调用SELECT 1改为使用mysql
。