在Docker中使用AWS EFS

Question

在我的单个容器EB部署中，我使用了amazon提供的新的弹性文件系统。我不明白为什么安装的EFS不能映射到容器中。

EFS挂载在/efs挂载点成功地在主机上执行。

提供给Dockerrun.aws.json的是

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

然后，一旦容器开始运行，就会在容器中创建卷。然而，它已经映射了主机目录/ EFS -挂载点，而不是实际的EFS挂载点。我不知道如何让Docker映射到安装在/ EFS -挂载点而不是主机目录中的efs卷中。

NFS卷和Docker玩得好吗？

Answer 1

您需要在主机重新启动码头实例中挂载EFS卷之后进行EC2。

下面是一个例子，.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"

Answer 2

AWS有自动在弹性豆杆上创建和安装EFS的指令。他们可以找到这里

这些说明链接到两个要自定义的配置文件，并放置在部署包的.ebextensions文件夹中。

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

需要进一步修改文件storage-efs-mountfilesystem.config以处理Docker容器。添加以下命令：

02_restart:
  command: "service docker restart"

对于多容器环境，弹性集装箱服务也必须重新启动(当码头在上面重新启动时，它被杀死了)：

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

因此，storage-efs-mountfilesystem.config的完整命令部分是：

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 ]"

这不能“开箱即用”的原因是，EC2实例在运行.ebextensions中的命令之前启动了停靠守护进程。启动顺序是：

1. 启动停靠守护进程
2. 在多集装箱码头环境中启动弹性集装箱服务代理
3. 在.ebextensions中运行命令
4. 运行容器应用程序

在第一步，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，容器在将文件系统安装到主机之前就会看到一个挂载点。主机看到安装的文件系统。因此，由容器编写的文件将被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公开写入挂载目录的容器文件。

Answer 3

EFS与AWS豆柄-多集装箱码头将工作。但是许多东西将停止工作，因为您必须在挂载EFS之后重新启动docker。

实例命令

搜索周围，您可能会发现，您需要做“码头重新启动”后，安装EFS。没那么简单。当自动标号发生和/或部署新版本的应用程序时，您将遇到麻烦。

下面是一个用于将EFS安装到docker实例的脚本，其中需要执行以下步骤：

1. 停止ECS经理。需要60秒。
2. 停车码头服务
3. 杀死剩余的码头人员
4. 删除以前的网络绑定。见问题https://github.com/docker/docker/issues/7856#issuecomment-239100381
5. 山EFS
6. 启动码头服务。
7. 启动ECS服务
8. 等120秒钟。使ECS达到正确的开始/*状态。否则，就会失败。注意，这种显示是强制性的，很难找到任何文档。

这是我的剧本：

.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option_settings下面定义的VPC和子网，请查看AWS web控制台-> VPC，在那里您必须找到默认的VPC id和3个默认子网id。如果您的豆茎使用自定义VPC，您必须使用这些设置。

.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：

• 关于安装问题：https://forums.aws.amazon.com/message.jspa?messageID=730288#730555
• 对于网络端口映射问题：https://github.com/docker/docker/issues/7856
• 对于EFS挂载脚本：https://forums.aws.amazon.com/thread.jspa?messageID=733181