根据 Docker 容器映像构建一个自定义 Clear Linux* OS¶
本指南包含构建自定义容器映像的步骤。官方基础版 Clear Linux* OS 容器映像发布在 Docker* Hub 上，而且会定期更新。
必备条件¶
- 您必须在 Clear Linux OS 系统上执行这些步骤，因为系统使用 swupd 管理容器中的捆绑包。
- 您必须在 Clear Linux OS 系统上安装
containers-basic捆绑包，否则 Docker 将无法运行。 - 您需要对 Docker 有基本了解。
构建基础容器映像¶
登录并获得 root 特权。
sudo -s
确认 Docker 已安装且正在运行。
docker info
如果 Docker 已安装且正在运行，输出类似于以下示例：
Containers: 0 Running: 0 Paused: 0 Stopped: 0 Images: 4 Server Version: 17.05.0-ce Storage Driver: overlay Backing Filesystem: extfs Supports d_type: true Logging Driver: json-file Cgroup Driver: cgroupfs Plugins: Volume: local Network: bridge host macvlan null overlay Swarm: inactive Runtimes: runc Default Runtime: runc Init Binary: docker-init containerd version: (expected: 9048e5e50717ea4497b757314bad98ea3763c145) runc version: N/A (expected: 9c2d8d184e5da67c95d601382adf14862e4f2228) init version: N/A (expected: ) Kernel Version: 4.12.7-377.native Operating System: Clear Linux OS for Intel Architecture OSType: linux Architecture: x86_64 CPUs: 4 Total Memory: 15.62GiB Name: clr-os ID: XQHJ:DYEM:3Q4D:DKLM:JOA4:RUSF:GAFR:DLPA:HOJP:W5FF:ULEE:7HZ3 Docker Root Dir: /var/lib/docker Debug Mode (client): false Debug Mode (server): false Registry: https://index.docker.io/v1/ Experimental: false Insecure Registries: 127.0.0.0/8 Live Restore Enabled: false
如果 Docker 未安装，请输入以下命令：
swupd bundle-add containers-basic systemctl start docker
使用 os-install 下载并安装捆绑包。
swupd os-install --url https://cdn.download.clearlinux.org/update --statedir "$PWD"/swupd-state --no-boot-update --version 29790 -B os-core-update,editors,network-basic base
swupd 示例使用以下标志：
- os-install 指示 swupd 执行下载和安装。
- -V / --version 指定 Clear Linux OS 捆绑包版本。
- --url 指定捆绑包存储库的 URL。
- --statedir 指定用来存储下载的捆绑包和任何状态信息的状态目录。
- --no-boot-update 指示 swupd 跳过更新引导文件，因为容器不需要引导文件。
有关 swupd 标志的详细信息，请输入 swupd os-install -h 命令。
结果示例：
swupd-client software verify 3.12.2 Copyright (C) 2012-2017 Intel Corporation Verifying version 17870 Attempting to download version string to memory Downloading packs... Extracting python-basic pack for version 17820 ...14% Extracting perl-basic pack for version 17790 ...28% Extracting openssh-server pack for version 17660 ...42% Extracting editors pack for version 17850 ...57% Extracting network-basic pack for version 17650 ...71% Extracting os-core pack for version 17870 ...85% Extracting os-core-update pack for version 17870 ...100% Adding any missing files ...88% Inspected 33982 files 33974 files were missing 33974 of 33974 missing files were replaced 0 of 33974 missing files were not replaced Calling post-update helper scripts. WARNING: boot files update skipped due to --no-boot-update argument Fix successful
注解
警告消息是意料之中的，可以忽略。
创建一个 tarball 并压缩它。
tar -C base -cf base.tar . xz -v -T0 base.tar
创建 Dockerfile 来构建映像。
cat > Dockerfile << EOF FROM scratch MAINTAINER First Last <first.last@example.com> ADD base.tar.xz / CMD ["/bin/bash"] EOF
构建 Clear Linux OS 容器映像。
docker build -t my-custom-clear-linux-container .
结果示例：
Sending build context to Docker daemon 806.5MB Step 1/4 : FROM scratch ---> Step 2/4 : MAINTAINER First Last <first.last@example.com> ---> Running in 7238f35abcd0 ---> ec5064287c60 Removing intermediate container 7238f35abcd0 Step 3/4 : ADD base.tar.xz / ---> 2723b7d20716 Removing intermediate container 16e3ed0df8da Step 4/4 : CMD /bin/bash ---> Running in efa893350647 ---> 5414c3a12993 Removing intermediate container efa893350647 Successfully built 5414c3a12993 Successfully tagged my-custom-clear-linux-container:latest
列出新创建的 Clear Linux OS 容器映像。
docker images
结果示例：
REPOSITORY TAG IMAGE ID CREATED SIZE my-custom-clear-linux-container latest 5414c3a12993 About a minute ago 616MB
启动已构建的 Clear Linux OS 容器。
docker run -it my-custom-clear-linux-container
管理容器中的捆绑包¶
您可以使用 Dockerfile 中的 RUN swupd 命令在 Clear Linux OS 容器中添加和移除捆绑包。
添加捆绑包¶
本示例 Dockerfile 将 pxe-server 捆绑添加到现有 Clear Linux OS Docker 映像：
cat > Dockerfile << EOF
FROM my-customer-clear-linux-container
MAINTAINER First Last <first.last@example.com>
RUN swupd bundle-add pxe-server
CMD ["/bin/bash/bash"]
EOF
结果示例：
docker build -t my-clearlinux-with-pxe-server-bundle .
Sending build context to Docker daemon 806.5MB
Step 1/4 : FROM my-custom-clear-linux-container
---> 5414c3a12993
Step 2/4 : MAINTAINER First Last <first.last@example.com>
---> Running in 19b4411cf4bd
---> 08d400baffde
Removing intermediate container 19b4411cf4bd
Step 3/4 : RUN swupd bundle-add pxe-server
---> Running in 3e634d6e0792
swupd-client bundle adder 3.12.2
Copyright (C) 2012-2017 Intel Corporation
Attempting to download version string to memory
Downloading packs...
Extracting pxe-server pack for version 17820
.
Installing bundle(s) files...
..............................................................................
..............................................................................
..............................................................................
..............................................................................
..............................................................................
..............................................................................
Calling post-update helper scripts.
WARNING: systemctl not operable, unable to run systemd update triggers
Bundle(s) installation done.
---> 8ead5f2c0c33
Removing intermediate container 3e634d6e0792
Step 4/4 : CMD /bin/bash
---> Running in 0ceae320279b
---> dcd9adb40611
Removing intermediate container 0ceae320279b
Successfully built dcd9adb40611
Successfully tagged my-clearlinux-with-pxe-server-bundle:latest
注解
警告消息可以忽略，因为 systemd 不在容器内运行。
移除捆绑包¶
本示例 Dockerfile 从现有的 Clear Linux OS Docker 映像中移除 pxe-server 捆绑包：
cat > Dockerfile << EOF
FROM my-clearlinux-with-pxe-server-bundle
MAINTAINER First Last <first.last@example.com>
RUN swupd bundle-remove pxe-server
CMD ["/bin/bash/bash"]
EOF
结果示例：
docker build -t my-clearlinux-remove-pxe-server-bundle .
Sending build context to Docker daemon 806.5MB
Step 1/4 : FROM my-clearlinux-with-pxe-server-bundle
---> dcd9adb40611
Step 2/4 : MAINTAINER First Last <first.last@example.com>
---> Running in 71b60f15003e
---> 742192751c1a
Removing intermediate container 71b60f15003e
Step 3/4 : RUN swupd bundle-remove pxe-server
---> Running in ad28a3390ecc
swupd-client bundle remover 3.12.2
Copyright (C) 2012-2017 Intel Corporation
Removing bundle: pxe-server
Deleting bundle files...
Total deleted files: 92
Untracking bundle from system...
Success: Bundle removed
1 bundle(s) were removed successfully
---> d6ee7903e14d
Removing intermediate container ad28a3390ecc
Step 4/4 : CMD /bin/bash
---> Running in 7694989e97de
---> ec23189ef954
Removing intermediate container 7694989e97de
Successfully built ec23189ef954
Successfully tagged my-clearlinux-remove-pxe-server-bundle:latest