从零开始搭建服务器之更加优雅地部署项目（1）https://developer.aliyun.com/article/1542857
自我介绍
用法介绍的第一段就是自我介绍,用法是: docker [OPTIONS] COMMAND ,即 docker + 可选选项 + 必选命令.
表示的含义就是 A self-sufficient runtime for containers 为容器提供一个自包含的运行环境!
Usage: docker [OPTIONS] COMMAND A self-sufficient runtime for containers
Docker 类似于生活中超级货轮,运输着统一规格的集装箱,而集装箱装着各种各样的货物,开往不同的目的地.
容器则是集装箱,货轮为集装箱提供了自包含的环境,集装箱之间是相互独立的,这也是对第一段话的简单解释.
选项配置
下面我们继续看第二段内容,主要解释了有哪些配置项以及这些配置项背后表示的具体含义.
Options: --config string Location of client config files (default "/root/.docker") -c, --context string Name of the context to use to connect to the daemon (overrides DOCKER_HOST env var and default context set with "docker context use") -D, --debug Enable debug mode -H, --host list Daemon socket(s) to connect to -l, --log-level string Set the logging level ("debug"|"info"|"warn"|"error"|"fatal") (default "info") --tls Use TLS; implied by --tlsverify --tlscacert string Trust certs signed only by this CA (default "/root/.docker/ca.pem") --tlscert string Path to TLS certificate file (default "/root/.docker/cert.pem") --tlskey string Path to TLS key file (default "/root/.docker/key.pem") --tlsverify Use TLS and verify the remote -v, --version Print version information and quit
只要有一定英语基础的人应该都能看懂其中的意思,如果对个人细节不是很清楚的话,可以复制粘贴到浏览器在线翻译,这里就不全文解释了.
不消息看到了最后一个 -v, --version 选项,表示的意思是打印版本信息并且退出.
看到这里我们就明白了,原来之前运行的 docker version 和这里的 --version 并不是一回事啊!
[root@snowdreams1006 ~]# docker -v Docker version 19.03.5, build 633a0ea [root@snowdreams1006 ~]# docker --version Docker version 19.03.5, build 633a0ea
单纯从输出结果来说,docker --version 更加简洁,如果只是验证环境安装是否成功,还是运行docker --version 比较简单明了.
管理命令
第三部分是 Docker 支持的管理命令,现在不去深究细节,只要有印象就行,注意这里有个关于镜像的命令 docker image
Management Commands: builder Manage builds config Manage Docker configs container Manage containers context Manage contexts engine Manage the docker engine image Manage images network Manage networks node Manage Swarm nodes plugin Manage plugins secret Manage Docker secrets service Manage services stack Manage Docker stacks swarm Manage Swarm system Manage Docker trust Manage trust on Docker images volume Manage volumes
因为自我介绍中关于用法是 docker [OPTIONS] COMMAND ,而中括号 [] 表示该内容是可选的,所以不加任何选项的基本用法就是 docker COMMAND ,因此其中关于 image 命令的完整用法就是: docker image .
[root@snowdreams1006 ~]# docker image Usage: docker image COMMAND Manage images Commands: build Build an image from a Dockerfile history Show the history of an image import Import the contents from a tarball to create a filesystem image inspect Display detailed information on one or more images load Load an image from a tar archive or STDIN ls List images prune Remove unused images pull Pull an image or a repository from a registry push Push an image or a repository to a registry rm Remove one or more images save Save one or more images to a tar archive (streamed to STDOUT by default) tag Create a tag TARGET_IMAGE that refers to SOURCE_IMAGE Run 'docker image COMMAND --help' for more information on a command.
别有洞天,管理命令中还有子命令,大概用法和之前介绍的内容大致相同,基本用法是: docker image COMMAND .
其中支持的命令中有 ls ,因此调用 ls 命令的最终完整命令就是: docker image ls .
# docker image ls REPOSITORY TAG IMAGE ID CREATED SIZE hello-world latest fce289e99eb9 11 months ago 1.84kB
服务器已安装的 image 中就包括我们熟悉的 hello-world ,至于什么是 REPOSITORY ,什么是 IMAGE 暂时也不用深究,只需要知道如何无文档使用这些命令即可!
如果用心留意的话,可以看到 Run 'docker image COMMAND --help' for more information on a command. 这么一句话,看来我们有现成的帮助文档供我们学习啊!
还是以 ls 命令为例,演示一下如何使用 docker image COMMAND --help 查看帮助文档.
[root@snowdreams1006 ~]# docker image ls --help Usage: docker image ls [OPTIONS] [REPOSITORY[:TAG]] List images Aliases: ls, images, list Options: -a, --all Show all images (default hides intermediate images) --digests Show digests -f, --filter filter Filter output based on conditions provided --format string Pretty-print images using a Go template --no-trunc Don't truncate output -q, --quiet Only show numeric IDs
麻雀虽小五脏俱全,没想到 ls 命令还有更加细粒度的用法说明,支持可选参数和 [REPOSITORY[:TAG]] ,除此之外还有 ls, images, list 别名!
如果 ls 有 images 和 list 别名,那么岂不是意味着 docker image ls 等价于 docker image images 和 docker image list ?
[root@snowdreams1006 ~]# docker image list REPOSITORY TAG IMAGE ID CREATED SIZE hello-world latest fce289e99eb9 11 months ago 1.84kB [root@snowdreams1006 ~]# docker image images REPOSITORY TAG IMAGE ID CREATED SIZE hello-world latest fce289e99eb9 11 months ago 1.84kB
从上述输出结果来看,三者的运行效果确实是一样的,看来又发现了新大陆!
普通命令
回到 docker 命令的主线,除了管理命令外还是普通命令,这部分命令也是经常性使用到的命令也是重点学习掌握的命令!
Commands: attach Attach local standard input, output, and error streams to a running container build Build an image from a Dockerfile commit Create a new image from a container's changes cp Copy files/folders between a container and the local filesystem create Create a new container diff Inspect changes to files or directories on a container's filesystem events Get real time events from the server exec Run a command in a running container export Export a container's filesystem as a tar archive history Show the history of an image images List images import Import the contents from a tarball to create a filesystem image info Display system-wide information inspect Return low-level information on Docker objects kill Kill one or more running containers load Load an image from a tar archive or STDIN login Log in to a Docker registry logout Log out from a Docker registry logs Fetch the logs of a container pause Pause all processes within one or more containers port List port mappings or a specific mapping for the container ps List containers pull Pull an image or a repository from a registry push Push an image or a repository to a registry rename Rename a container restart Restart one or more containers rm Remove one or more containers rmi Remove one or more images run Run a command in a new container save Save one or more images to a tar archive (streamed to STDOUT by default) search Search the Docker Hub for images start Start one or more stopped containers stats Display a live stream of container(s) resource usage statistics stop Stop one or more running containers tag Create a tag TARGET_IMAGE that refers to SOURCE_IMAGE top Display the running processes of a container unpause Unpause all processes within one or more containers update Update configuration of one or more containers version Show the Docker version information wait Block until one or more containers stop, then print their exit codes
命令虽好但不可贪多,还是找到最简单刚刚用过的 docker run 和 docker version 命令吧!
docker run:Run a command in a new container
表示在新的容器内运行命令,翻译成生活语言就是在集装箱内做着不可告人的神秘操作!
docker version:Show the Docker version information
显示 Docker 版本信息,还记得 docker --version 吗?
忘记了的话,往上翻翻看,--version 的描述是 Print version information and quit ,是一种更加简单的版本信息.
无论是管理命令还是普通命令,直接输入命令后都会有相应的用法说明以及帮助信息,同样地追加 --help 即可!
[root@snowdreams1006 ~]# docker run "docker run" requires at least 1 argument. See 'docker run --help'. Usage: docker run [OPTIONS] IMAGE [COMMAND] [ARG...] Run a command in a new container
帮助信息
最后的才是亮点,在命令结尾处追加 --help 可以获取更加详细的帮助信息,这一点不仅适合一级命令 docker image --help 还适合二级子命令 docker image ls --help .
Run 'docker COMMAND --help' for more information on a command.
所以,遇到不懂的或者陌生的命令请一定要记住 --help 帮助命令,这是 docker 全部命令中最重要的一点!
回忆总结
Docker 是一种规范化的部署运维新方式,相对于传统打包部署的来说,更加统一规范化,货物是各种各样的正如开发语言的多样性一样,但是集装箱的出现却颠覆了物流运输,带来了巨大的进步!
如果你是 Java 后台开发,或多或少肯定有着自己独立部署项目的经历,先登录服务器装个 Java 环境再装个 Tomcat 环境,最后在上传自己的 War 包到 Tomcat 部署目录,如此重复繁琐的劳动还不一定能保证一次性成功!
因为有时你的代码中很有可能有些绝对路径,部署到服务器肯定会报错,如果缺少了个人文件也会报错等等,这时候就出现了经典的对话:明明在我的电脑运行地好好的啊!
Docker 的出现在一定程度上解决了这种问题,将应用打包到集装箱,Docker 作为超级货轮承载着集装箱安全快速地运送到目的地,集装箱内的环境是自给自足的封闭环境,所有的相关依赖一次性全部都给你.
无论是本机运输这个封闭的集装箱还是远程服务器运输这个集装箱结果都是一样的,再也不会出现环境不一致而导致的相互埋怨情况的发生了!
那么问题来了,如果给你一个集装箱,你能安全快速运输到目的地吗?如果你手头上已经有一批货需要这种集装箱服务,如何快速封装成集装箱呢?
对于第一个问题,本文已经给出答案,那就是 docker + docker COMMAND --help 查询支持的命令以及查看命令的帮助文档.
[root@snowdreams1006 ~]# docker Usage: docker [OPTIONS] COMMAND A self-sufficient runtime for containers Options: --config string Location of client config files (default "/root/.docker") -c, --context string Name of the context to use to connect to the daemon (overrides DOCKER_HOST env var and default context set with "docker context use") -D, --debug Enable debug mode -H, --host list Daemon socket(s) to connect to -l, --log-level string Set the logging level ("debug"|"info"|"warn"|"error"|"fatal") (default "info") --tls Use TLS; implied by --tlsverify --tlscacert string Trust certs signed only by this CA (default "/root/.docker/ca.pem") --tlscert string Path to TLS certificate file (default "/root/.docker/cert.pem") --tlskey string Path to TLS key file (default "/root/.docker/key.pem") --tlsverify Use TLS and verify the remote -v, --version Print version information and quit Management Commands: builder Manage builds config Manage Docker configs container Manage containers context Manage contexts engine Manage the docker engine image Manage images network Manage networks node Manage Swarm nodes plugin Manage plugins secret Manage Docker secrets service Manage services stack Manage Docker stacks swarm Manage Swarm system Manage Docker trust Manage trust on Docker images volume Manage volumes Commands: attach Attach local standard input, output, and error streams to a running container build Build an image from a Dockerfile commit Create a new image from a container's changes cp Copy files/folders between a container and the local filesystem create Create a new container diff Inspect changes to files or directories on a container's filesystem events Get real time events from the server exec Run a command in a running container export Export a container's filesystem as a tar archive history Show the history of an image images List images import Import the contents from a tarball to create a filesystem image info Display system-wide information inspect Return low-level information on Docker objects kill Kill one or more running containers load Load an image from a tar archive or STDIN login Log in to a Docker registry logout Log out from a Docker registry logs Fetch the logs of a container pause Pause all processes within one or more containers port List port mappings or a specific mapping for the container ps List containers pull Pull an image or a repository from a registry push Push an image or a repository to a registry rename Rename a container restart Restart one or more containers rm Remove one or more containers rmi Remove one or more images run Run a command in a new container save Save one or more images to a tar archive (streamed to STDOUT by default) search Search the Docker Hub for images start Start one or more stopped containers stats Display a live stream of container(s) resource usage statistics stop Stop one or more running containers tag Create a tag TARGET_IMAGE that refers to SOURCE_IMAGE top Display the running processes of a container unpause Unpause all processes within one or more containers update Update configuration of one or more containers version Show the Docker version information wait Block until one or more containers stop, then print their exit codes Run 'docker COMMAND --help' for more information on a command.
对于第二个问题,请先预习 docker 相关命令,下一次将实例分享如何使用 docker 运输集装箱,感谢你的阅读!
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