在 Jenkins 中使用 docker 容器链接

Question

我正在尝试运行一个适用于数据库迁移脚本的 CI 系统。因此，这可能会阻止我们运行ning sql 由于语法错误而无法在迁移时运行的脚本。对于我们的本地设置，我们一次使用 docker-compose 和运行多个容器。不幸的是，这不是我们在 Jenkins 管道中的选择

我使用以下策略创建了这个 Jenkinsfile。

postgres 容器运行具有或多或少的默认参数
另一个 postgres 容器链接到第一个容器，仅使用 pg_isready 命令行等待数据库准备好进行连接
使用 flyway 容器运行针对步骤 1 中的数据库设置进行数据库迁移。最终计划运行也对 Web 应用程序进行 E2E 测试

我的实现基于 documentation here (运行ning docker sidecar)。但是，这不起作用，第一个容器（第 1 步）似乎正在停止。我添加了一些额外的调试（try catch）来查看这个容器的日志

我的 Jenkinsfile

的内容

def docker_repository = '<CUSTOM-REGISTRY>'
def docker_user_credentialsId = '<DOCKER-USER>'

pipeline {
   agent { label 'docker && linux && nonprod' }

options {
    buildDiscarder(logRotator(daysToKeepStr: '90', numToKeepStr: '20', artifactDaysToKeepStr: '90', artifactNumToKeepStr: '20'))
    timeout(time: 20, unit: 'MINUTES') 
}
stages {
    stage('build & test') {
        environment {
            POSTGRES_DB = 'mydb'
            POSTGRES_USER = 'postgres'
            POSTGRES_PASSWORD = 'postgres'                
            FLYWAY_URL = 'jdbc:postgresql://localhost:5432/mydb'
            // FLYWAY_URL = 'jdbc:postgresql://db-container:5432/mydb'
            FLYWAY_USER = 'postgres'
            FLYWAY_PASSWORD = 'postgres'
        }
        steps {
            checkout scm
            withCredentials([ usernamePassword(credentialsId: docker_user_credentialsId, passwordVariable: 'ARTIFACTORY_API_TOKEN', usernameVariable: 'ARTIFACTORY_API_USER'),]) {}                                
            script {
                docker.withRegistry(docker_repository, docker_user_credentialsId) {
                    docker.image('<REGISTRY>/postgres').withRun("--name=db-container -e POSTGRES_PASSWORD=postgres") { c ->
                        try {
                            docker.image('<REGISTRY>/postgres').inside("--link ${c.id}:db") {                                
                                sh '''
                                    while ! pg_isready -h db -p 5432
                                    do
                                         echo $
                                         echo "$(date) - waiting for database to start"
                                         sleep 10
                                    done
                                '''
                            }
                            docker.image('<REGISTRY>/flyway/flyway').inside("--link ${c.id}:db") {
                                sh 'info'
                                // sh 'migrate'
                            }
                        } catch (exc) {
                            sh "docker logs ${c.id}"
                            throw exc
                        }
                    }
                }
            }                
        }
    }
}
post {
    always {
        cleanWs()
    }
}

}

临时删除第 2 步以获取此日志，因为第 2 步在循环中等待并且 docker 日志

+ docker logs 9d9e8699b57430e288520c485c8333a0261f9283f749aec2832cfb0e5f19ef9e
 The files belonging to this database system will be owned by user "postgres".
 This user must also own the server process.
 The database cluster will be initialized with locale "en_US.utf8".
 The default database encoding has accordingly been set to "UTF8".
 The default text search configuration will be set to "english".

 Data page checksums are disabled.
 fixing permissions on existing directory /var/lib/postgresql/data ... ok
  creating subdirectories ... ok
  selecting dynamic shared memory implementation ... posix
  selecting default max_connections ... 100
  selecting default shared_buffers ... 128MB 
  selecting default time zone ... Etc/UTC
  creating configuration files ... ok
  running bootstrap script ... ok
  performing post-bootstrap initialization ... ok
  syncing data to disk ... ok
  Success. You can now start the database server using:
  pg_ctl -D /var/lib/postgresql/data -l logfile start
  initdb: warning: enabling "trust" authentication for local connections
  You can change this by editing pg_hba.conf or using the option -A, or
   --auth-local and --auth-host, the next time you run initdb.
  waiting for server to start....2021-03-31 15:21:29.923 UTC [48] LOG:  starting PostgreSQL 13.2 
  (Debian 13.2-1.pgdg100+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 8.3.0-6) 8.3.0, 64-bit
  2021-03-31 15:21:29.929 UTC [48] LOG:  listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"
  2021-03-31 15:21:29.946 UTC [49] LOG:  database system was shut down at 2021-03-31 15:21:29 UTC
  2021-03-31 15:21:29.951 UTC [48] LOG:  database system is ready to accept connections
  done

  server started

   /usr/local/bin/docker-entrypoint.sh: ignoring /docker-entrypoint-initdb.d/*
   2021-03-31 15:21:30.062 UTC [48] LOG:  received fast shutdown request
   waiting for server to shut down....2021-03-31 15:21:30.064 UTC [48] LOG:  aborting any active transactions

   2021-03-31 15:21:30.065 UTC [48] LOG:  background worker "logical replication launcher" (PID 55) 
     exited with exit code 1

    2021-03-31 15:21:30.071 UTC [50] LOG:  shutting down
    2021-03-31 15:21:30.099 UTC [48] LOG:  database system is shut down
    done

    server stopped
    PostgreSQL init process complete; ready for start up.

    2021-03-31 15:21:30.188 UTC [1] LOG:  starting PostgreSQL 13.2 (Debian 13.2-1.pgdg100+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 8.3.0-6) 8.3.0, 64-bit

    2021-03-31 15:21:30.190 UTC [1] LOG:  listening on IPv4 address "0.0.0.0", port 5432
    2021-03-31 15:21:30.190 UTC [1] LOG:  listening on IPv6 address "::", port 5432
    2021-03-31 15:21:30.196 UTC [1] LOG:  listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"
    2021-03-31 15:21:30.203 UTC [67] LOG:  database system was shut down at 2021-03-31 15:21:30 UTC
    2021-03-31 15:21:30.208 UTC [1] LOG:  database system is ready to accept connections

postgres 和 flyway 版本在这里不应发挥重要作用，但正如在日志中所见，默认标记提供的 Postgres 版本为 13.2。

这里有任何指示吗？

Answer 1

假设您使用的是 official postgres docker image，一个可能的根本原因是容器的 entrypoint 脚本失败。

来自图像的 Docker 页面：

Warning: scripts in /docker-entrypoint-initdb.d are only run if you start the container with a data directory that is empty; [...] One common problem is that if one of your /docker-entrypoint-initdb.d scripts fails (which will cause the entrypoint script to exit) and your orchestrator restarts the container with the already initialized data directory, it will not continue on with your scripts

解决方案

假设入口点进程确实失败了（可能是因为它看到一个不属于数据库并且由 entrypoint 设计来覆盖它，因为它链接到另一个 postgres 容器），你可以克服这个通过设置您自己的 entrypoint 和 cmd，从而防止图像尝试创建您无论如何都不会使用的数据库，即：

FROM postgres

#Switch back to default entrypoint
ENTRYPOINT ["/bin/sh"]

#Let the container start and do nothing until the pipeline kicks in
CMD ["-c","sleep infinity"]

根据上述 Docker 文件创建一个新镜像，推送它，并在 Jenkin 的管道中定义它而不是当前的（仅适用于 sidecar）。然后你应该有一个稳定的容器，链接到实际的数据库容器，管道可以跳入。

最后，关于在 sidecar 中启动的命令，我建议使用 localhost 而不是 db 作为目标主机，在命令问题 pg_isready -h db -p 5432 上，结果是： pg_isready -h localhost -p 5432

Answer 2

经过反复试验，以下是对我们有用的方法。尽管它与初始设置非常相似，但关键的变化在于使用 inside 和 withRun 的选择。最终的 Jenkinsfile 看起来像这样。

// credentials
def docker_user_credentialsId = '<DOCKER-USER>'
def docker_repository = '<CUSTOM-REGISTRY>'

// docker images
def pg = docker.image('postgres:12-alpine')
def flyway = docker.image('flyway/flyway:7-alpine')

pipeline {
    agent none

    options {
        buildDiscarder(logRotator(daysToKeepStr: '90', numToKeepStr: '20', artifactDaysToKeepStr: '90', artifactNumToKeepStr: '20'))
        timeout(time: 120, unit: 'MINUTES') 
    }

    stages {
        stage('db migration test') {
            agent { 
                label 'docker && linux'
            }

            environment {
                PGHOST = 'db'
                PGPORT = '5432'
                PGDATABASE = 'postgres'
                PGUSER = 'postgres'
                PGPASSWORD = 'postgres'
            }

            steps {
                script {
                    docker.withRegistry(docker_repository, docker_user_credentialsId) {
                        def db = pg.withRun(
                            "-v ${WORKSPACE}/docker/init-user-db.sh:/docker-entrypoint-initdb.d/init-user-db.sh -e POSTGRES_USER=${env.PGUSER} -e POSTGRES_PASSWORD=${env.PGPASSWORD} -e POSTGRES_DB=${env.PGDATABASE}"
                        ) { db ->
                            pg.inside("--link ${db.id}:${env.PGHOST}") {                                
                                sh '''
                                    echo "$(date) - waiting for database to start"
                                    while ! pg_isready
                                    do
                                        sleep 10
                                    done
                                '''
                            }
                            flyway.withRun("-e FLYWAY_LOCATIONS=filesystem:/tmp/database/server,filesystem:/tmp/database/local -e FLYWAY_URL=jdbc:postgresql://${PGHOST}:${env.PGPORT}/${env.PGDATABASE} -e FLYWAY_USER=${env.PGUSER} -e FLYWAY_PASSWORD=${env.PGPASSWORD} -v ${WORKSPACE}/database/local:/tmp/database/local -v ${WORKSPACE}/database/server:/tmp/database/server --link ${db.id}:db", "migrate") { f ->
                                sh "docker logs -f ${f.id}"
                                def output = sh script: "docker inspect ${f.id} --format='{{.State.ExitCode}}'", returnStdout: true
                                sh "exit ${output}"
                            }
                        }
                    }
                }
            }
        }
    }
 }

在 Jenkins 中使用 docker 容器链接

Using docker Container links in Jenkins

postgresql

jenkins

flyway

docker

jenkins-pipeline

解决方案