将 AWS EFS 与 Docker 结合使用

Using AWS EFS with Docker

我在我的单个容器 EB 部署中使用亚马逊提供的新弹性文件系统。我想不通为什么挂载的 EFS 不能映射到容器中。

在 /efs-mount-point 的主机上成功执行了 EFS 装载。

提供给Dockerrun.aws.json的是

{
  "AWSEBDockerrunVersion": "1"
  "Volumes": [
    {
      "HostDirectory": "/efs-mount-point",
      "ContainerDirectory": "/efs-mount-point"
    }
  ]
}

一旦容器启动,就会在容器中创建该卷 运行。但是它映射了主机目录 /efs-mount-point,而不是实际的 EFS 挂载点。我不知道如何让 Docker 映射到挂载在 /efs-mount-point 而不是主机目录的 EFS 卷中。

NFS 卷与 Docker 兼容吗?

在主机 EC2 实例中安装 EFS 卷后,您需要 restart docker

举个例子,.ebextensions/efs.config:

commands:
   01mkdir:
      command: "mkdir -p /efs-mount-point"
   02mount:
      command: "mountpoint -q /efs-mount-point || mount -t nfs4 -o nfsvers=4.1 $(curl -s http://169.254.169.254/latest/meta-data/placement/availability-zone).fs-fa35c253.efs.us-west-2.amazonaws.com:/ /efs-mount-point"
   03restart:
      command: "service docker restart"

带有 AWS Beanstalk 的 EFS - Multicontainer Docker 将起作用。但是许多事情将停止工作,因为您必须在安装 EFS 后重新启动 docker。

实例命令

四处搜索可能会发现您需要在安装 EFS 后执行 "docker restart"。没那么简单。当发生自动缩放和/或部署新版本的应用程序时,您会遇到麻烦。

下面是我用于将 EFS 挂载到 docker 实例的脚本,其中需要以下步骤:

  1. 停止 ECS 管理器。耗时 60 秒。
  2. 停止Docker服务
  3. 杀死剩下的docker个东西
  4. 删除网络以前的绑定。查看问题https://github.com/docker/docker/issues/7856#issuecomment-239100381
  5. 挂载 EFS
  6. 启动 docker 服务。
  7. 启动ECS服务
  8. 等待 120 秒。使 ECS 进入正确的 start/* 状态。否则例如00enact 脚本将失败。请注意,此显示是强制性的,并且很难找到任何文档。

这是我的脚本:

.ebextensions/commands.config:

commands:
  01stopdocker:
    command: "sudo stop ecs  > /dev/null 2>&1 || /bin/true && sudo service docker stop"
  02killallnetworkbindings:
    command: 'sudo killall docker  > /dev/null 2>&1 || /bin/true'
  03removenetworkinterface:
    command: "rm -f /var/lib/docker/network/files/local-kv.db"
    test: test -f /var/lib/docker/network/files/local-kv.db
  # Mount the EFS created in .ebextensions/media.config
  04mount:
    command: "/tmp/mount-efs.sh"
  # On new instances, delay needs to be added because of 00task enact script. It tests for start/ but it can be various states of start...
  # Basically, "start ecs" takes some time to run, and it runs async - so we sleep for some time.
  # So basically let the ECS manager take it's time to boot before going on to enact scritps and post deploy scripts.
  09restart:
    command: "service docker start && sudo start ecs && sleep 120s"

挂载脚本和环境变量

.ebextensions/mount-config.config

# efs-mount.config
# Copy this file to the .ebextensions folder in the root of your app source folder
option_settings:
  aws:elasticbeanstalk:application:environment:
    EFS_REGION: '`{"Ref": "AWS::Region"}`'
    # Replace with the required mount directory
    EFS_MOUNT_DIR: '/efs_volume'
    # Use in conjunction with efs_volume.config or replace with EFS volume ID of an existing EFS volume
    EFS_VOLUME_ID: '`{"Ref" : "FileSystem"}`'

packages:
  yum:
    nfs-utils: []
files:
  "/tmp/mount-efs.sh":
      mode: "000755"
      content : |
        #!/bin/bash

        EFS_REGION=$(/opt/elasticbeanstalk/bin/get-config environment | jq -r '.EFS_REGION')
        EFS_MOUNT_DIR=$(/opt/elasticbeanstalk/bin/get-config environment | jq -r '.EFS_MOUNT_DIR')
        EFS_VOLUME_ID=$(/opt/elasticbeanstalk/bin/get-config environment | jq -r '.EFS_VOLUME_ID')

        echo "Mounting EFS filesystem ${EFS_DNS_NAME} to directory ${EFS_MOUNT_DIR} ..."

        echo 'Stopping NFS ID Mapper...'
        service rpcidmapd status &> /dev/null
        if [ $? -ne 0 ] ; then
            echo 'rpc.idmapd is already stopped!'
        else
            service rpcidmapd stop
            if [ $? -ne 0 ] ; then
                echo 'ERROR: Failed to stop NFS ID Mapper!'
                exit 1
            fi
        fi

        echo 'Checking if EFS mount directory exists...'
        if [ ! -d ${EFS_MOUNT_DIR} ]; then
            echo "Creating directory ${EFS_MOUNT_DIR} ..."
            mkdir -p ${EFS_MOUNT_DIR}
            if [ $? -ne 0 ]; then
                echo 'ERROR: Directory creation failed!'
                exit 1
            fi
            chmod 777 ${EFS_MOUNT_DIR}
            if [ $? -ne 0 ]; then
                echo 'ERROR: Permission update failed!'
                exit 1
            fi
        else
            echo "Directory ${EFS_MOUNT_DIR} already exists!"
        fi

        mountpoint -q ${EFS_MOUNT_DIR}
        if [ $? -ne 0 ]; then
            AZ=$(curl -s http://169.254.169.254/latest/meta-data/placement/availability-zone)
            echo "mount -t nfs4 -o nfsvers=4.1 ${AZ}.${EFS_VOLUME_ID}.efs.${EFS_REGION}.amazonaws.com:/ ${EFS_MOUNT_DIR}"
            mount -t nfs4 -o nfsvers=4.1 ${AZ}.${EFS_VOLUME_ID}.efs.${EFS_REGION}.amazonaws.com:/ ${EFS_MOUNT_DIR}
            if [ $? -ne 0 ] ; then
                echo 'ERROR: Mount command failed!'
                exit 1
            fi
        else
            echo "Directory ${EFS_MOUNT_DIR} is already a valid mountpoint!"
        fi

        echo 'EFS mount complete.'

资源和配置

您必须更改下面的 option_settings。 要找到您必须在下面的 option_settings 下定义的 VPC 和子网,请查看 AWS Web控制台 -> VPC,您必须在那里找到默认 VPC id 和 3 个默认子网 id。如果你的 beantalk 使用自定义 VPC,你必须使用这些设置。

.ebextensions/efs-volume.config:

# efs-volume.config
# Copy this file to the .ebextensions folder in the root of your app source folder
option_settings:
  aws:elasticbeanstalk:customoption: 
    EFSVolumeName: "EB-EFS-Volume"
    VPCId: "vpc-xxxxxxxx"
    SubnetUSWest2a: "subnet-xxxxxxxx"
    SubnetUSWest2b: "subnet-xxxxxxxx"
    SubnetUSWest2c: "subnet-xxxxxxxx"

Resources:
  FileSystem:
    Type: AWS::EFS::FileSystem
    Properties:
      FileSystemTags:
      - Key: Name
        Value:
          Fn::GetOptionSetting: {OptionName: EFSVolumeName, DefaultValue: "EB_EFS_Volume"}
  MountTargetSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Security group for mount target
      SecurityGroupIngress:
      - FromPort: '2049'
        IpProtocol: tcp
        SourceSecurityGroupId:
          Fn::GetAtt: [AWSEBSecurityGroup, GroupId]
        ToPort: '2049'
      VpcId:
        Fn::GetOptionSetting: {OptionName: VPCId}
  MountTargetUSWest2a:
    Type: AWS::EFS::MountTarget
    Properties:
      FileSystemId: {Ref: FileSystem}
      SecurityGroups:
      - {Ref: MountTargetSecurityGroup}
      SubnetId:
        Fn::GetOptionSetting: {OptionName: SubnetUSWest2a}
  MountTargetUSWest2b:
    Type: AWS::EFS::MountTarget
    Properties:
      FileSystemId: {Ref: FileSystem}
      SecurityGroups:
      - {Ref: MountTargetSecurityGroup}
      SubnetId:
        Fn::GetOptionSetting: {OptionName: SubnetUSWest2b}
  MountTargetUSWest2c:
    Type: AWS::EFS::MountTarget
    Properties:
      FileSystemId: {Ref: FileSystem}
      SecurityGroups:
      - {Ref: MountTargetSecurityGroup}
      SubnetId:
        Fn::GetOptionSetting: {OptionName: SubnetUSWest2c}

资源:

AWS 有在 elastic beanstalk 上自动创建和安装 EFS 的说明。他们可以找到 here

这些说明 link 两个配置文件将被自定义并放置在部署包的 .ebextensions 文件夹中。

  1. storage-efs-createfilesystem.config
  2. storage-efs-mountfilesystem.config

文件 storage-efs-mountfilesystem.config 需要进一步修改才能与 Docker 容器一起使用。添加以下命令:

02_restart:
  command: "service docker restart"

并且对于 multi-container 环境 Elastic Container Service 也必须重新启动(上面 docker 重新启动时它被杀死):

03_start_eb:
  command: |
      start ecs
      start eb-docker-events
      sleep 120
  test: sh -c "[ -f /etc/init/ecs.conf ]"

所以 storage-efs-mountfilesystem.config 的完整 commands 部分是:

commands:
  01_mount:
    command: "/tmp/mount-efs.sh"
  02_restart:
    command: "service docker restart"
  03_start_eb:
    command: |
        start ecs
        start eb-docker-events
        sleep 120
    test: sh -c "[ -f /etc/init/ecs.conf ]"

这不起作用的原因 "out-of-the-box" 是因为 docker 守护程序由 EC2 实例在 .ebextensions 中的命令 运行 之前启动。启动顺序为:

  1. 启动docker守护进程
  2. 在multi-containerdocker环境中启动弹性容器服务代理
  3. 运行 .ebextensions
  4. 中的命令
  5. 运行 个容器应用

第一步,docker 守护进程提供给容器的文件系统视图是固定的。因此,在步骤 3 中对主机文件系统所做的更改不会反映在容器的视图中。

一个奇怪的效果是容器在文件系统挂载到主机之前看到一个挂载点。主机看到挂载的文件系统。因此,容器写入的文件将写入挂载目录下的主机目录,而不是挂载的文件系统。卸载 EC2 主机上的文件系统将暴露写入挂载目录的容器文件。