Docker

Docker 每个命令、每个选项，都有详尽的解释。

• Why Docker?

  2013: Containers are a standardized unit of software that allows developers to isolate their app from its environment, solving the “it works on my machine” headache. Cloud Native Computing Foundation (CNCF)

Glossary

• Docker Hub 上可以找到很多 container images。
• Dockerfile
  通过 docker inspect 可以看到 dockerfile 的一些迹象。How can I see Dockerfile for each docker image?
  • CentOS Dockerfile 示例
    
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docker inspect：Return low-level information on Docker objects

• docker inspect [OPTIONS] NAME|ID [NAME|ID...]

docker run：Run a command in a new container

• $ docker run [OPTIONS] IMAGE[:TAG|@DIGEST] [COMMAND] [ARG...]
• --name : 指定 container name。Container identification 的一种。
• -v 参数 VOLUME (shared filesystems)
  --volume=[host-src:]container-dest[:]：

1. The host-src can either be an absolute path or a name value. If you supply an absolute path for the host-src, Docker bind-mounts to the path you specify. If you supply a name, Docker creates a named volume by that name.
2. The container-dest must always be an absolute path such as /src/docs.

• --mount 键值对，type 有3种值：bind, volume, tmpfs。
  • 使用 docker inspect 命令验证 bind mount 是否正确创建，查看 Mounts 部分。

bind-mount、volume、tmpfs-mount

Storage overview: Manage data in Docker

• Use bind mounts
• Use volumes
  Volumes are the preferred mechanism for persisting data generated by and used by Docker containers.
• Use tmpfs mounts
  As opposed to volumes and bind mounts, a tmpfs mount is temporary, and only persisted in the host memory. When the container stops, the tmpfs mount is removed, and files written there won’t be persisted. 用于临时存储敏感文件等。