dockerd、docker.sock
一、docker的架构
Docker 使用客户端-服务器 (C/S) 架构模式，使用远程API来管理和创建Docker容器。
二、组件
1、rpm -ql docker-ce
/usr/bin/docker-init /usr/bin/docker-proxy /usr/bin/dockerd /usr/lib/systemd/system/docker.service /usr/lib/systemd/system/docker.socket
docker-init ：
init为true启用，旨在在容器内运行docker-init进程来处理信号转发和回收进程
docker-proxy：端口映射
ps aux | grep docker root 1420 0.0 0.6 1973052 101600 ? Ssl 6月21 0:26 /usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock root 1994 0.0 0.1 973048 17576 ? Sl 6月21 0:00 /usr/bin/docker-proxy -proto tcp -host-ip 0.0.0.0 -host-port 8080 -container-ip 172.17.0.2 -container-port 8080 root 2001 0.0 0.0 964596 14704 ? Sl 6月21 0:00 /usr/bin/docker-proxy -proto tcp -host-ip :: -host-port 8080 -container-ip 172.17.0.2 -container-port 8080 root 2017 0.0 0.0 890608 11472 ? Sl 6月21 0:00 /usr/bin/docker-proxy -proto tcp -host-ip 0.0.0.0 -host-port 3000 -container-ip 172.17.0.3 -container-port 3000 root 2024 0.0 0.0 964340 13440 ? Sl 6月21 0:00 /usr/bin/docker-proxy -proto tcp -host-ip :: -host-port 3000 -container-ip 172.17.0.3 -container-port 3000 root 2044 0.0 0.0 964340 13504 ? Sl 6月21 0:01 /usr/bin/docker-proxy -proto tcp -host-ip 0.0.0.0 -host-port 9115 -container-ip 172.17.0.4 -container-port 9115 root 2060 0.0 0.0 964340 13500 ? Sl 6月21 0:00 /usr/bin/docker-proxy -proto tcp -host-ip 0.0.0.0 -host-port 80 -container-ip 172.17.0.5 -container-port 80 root 2067 0.0 0.1 898804 17548 ? Sl 6月21 0:00 /usr/bin/docker-proxy -proto tcp -host-ip :: -host-port 80 -container-ip 172.17.0.5 -container-port 80 root 2086 0.0 0.0 964340 13436 ? Sl
dockerd：Docker守护进程（Docker daemon）
# dockerd
INFO[2022-06-23T13:52:14.105179617+08:00] Starting up
failed to start daemon: pid file found, ensure docker is not running or delete /var/run/docker.pid
[root@zjz ~]# dockerd --help
Usage: dockerd [OPTIONS]
A self-sufficient runtime for containers.
Options:
--add-runtime runtime Register an additional OCI compatible runtime (default [])
--allow-nondistributable-artifacts list Allow push of nondistributable artifacts to registry
--api-cors-header string Set CORS headers in the Engine API
--authorization-plugin list Authorization plugins to load
--bip string Specify network bridge IP
-b, --bridge string Attach containers to a network bridge
--cgroup-parent string Set parent cgroup for all containers
--config-file string Daemon configuration file (default "/etc/docker/daemon.json")
--containerd string containerd grpc address
--containerd-namespace string Containerd namespace to use (default "moby")
--containerd-plugins-namespace string Containerd namespace to use for plugins (default "plugins.moby")
--cpu-rt-period int Limit the CPU real-time period in microseconds for the parent cgroup for all containers
--cpu-rt-runtime int Limit the CPU real-time runtime in microseconds for the parent cgroup for all containers
--cri-containerd start containerd with cri
docker.service：docker 服务启动配置文件
另外还有一个 docker service，是docker服务，不同于docker容器，容器是独立的且不具备扩缩容能力，服务是集群里的容器，服务可以一键动态的扩缩容。
docker service --help Usage: docker service COMMAND Manage services Commands: create Create a new service inspect Display detailed information on one or more services logs Fetch the logs of a service or task ls List services ps List the tasks of one or more services rm Remove one or more services rollback Revert changes to a service's configuration scale Scale one or multiple replicated services update Update a service Run 'docker service COMMAND --help' for more information on a command.
/var/run/docker.sock：docker.sock 是docker client 和docker daemon 在localhost进行通信的socket文件
配置docker.sock
# cat /usr/lib/systemd/system/docker.socket [Unit] Description=Docker Socket for the API [Socket] ListenStream=/var/run/docker.sock SocketMode=0660 SocketUser=root SocketGroup=docker [Install] WantedBy=sockets.target
2、rpm -ql docker-ce-rootless-extras
/usr/bin/dockerd-rootless-setuptool.sh /usr/bin/dockerd-rootless.sh /usr/bin/rootlesskit /usr/bin/rootlesskit-docker-proxy
3、rpm -ql docker-ce-cli
/usr/bin/docker /usr/libexec/docker/cli-plugins/docker-app /usr/libexec/docker/cli-plugins/docker-buildx /usr/share/bash-completion/completions/docker /usr/share/doc/docker-ce-cli-20.10.15 /usr/share/doc/docker-ce-cli-20.10.15/LICENSE /usr/share/doc/docker-ce-cli-20.10.15/MAINTAINERS /usr/share/doc/docker-ce-cli-20.10.15/NOTICE /usr/share/doc/docker-ce-cli-20.10.15/README.md /usr/share/fish/vendor_completions.d/docker.fish /usr/share/man/man1/docker-attach.1.gz /usr/share/man/man1/docker-build.1.gz /usr/share/man/man1/docker-builder-build.1.gz /usr/share/man/man1/docker-builder-prune.1.gz /usr/share/man/man1/docker-builder.1.gz /usr/share/man/man1/docker-checkpoint-create.1.gz /usr/share/man/man1/docker-checkpoint-ls.1.gz /usr/share/man/man1/docker-checkpoint-rm.1.gz /usr/share/man/man1/docker-checkpoint.1.gz /usr/share/man/man1/docker-commit.1.gz /usr/share/man/man1/docker-config-create.1.gz /usr/share/man/man1/docker-config-inspect.1.gz /usr/share/man/man1/docker-config-ls.1.gz /usr/share/man/man1/docker-config-rm.1.gz /usr/share/man/man1/docker-config.1.gz /usr/share/man/man1/docker-container-attach.1.gz /usr/share/man/man1/docker-container-commit.1.gz /usr/share/man/man1/docker-container-cp.1.gz /usr/share/man/man1/docker-container-create.1.gz /usr/share/man/man1/docker-container-diff.1.gz /usr/share/man/man1/docker-container-exec.1.gz /usr/share/man/man1/docker-container-export.1.gz /usr/share/man/man1/docker-container-inspect.1.gz
