Docker简单安装和命令使用 dockerdocker容器可在一次构建后多次运行dcoker和虚拟机的对比:通常我们是硬件上跑linux系统，在系统上做linux虚拟化，在虚拟主机中跑各种应用，而此各个虚拟机是完全隔离，而docker则是在硬件层次上跑linux系统，在系统上做docker engine,在docker engine上直接跑各种应用，在底层是容器。目前docker只能在64位操作系统运行，在windows是无法运行，只能在windowns虚拟机下运行。docker上c/s结构，分客户端和服务端，，在docker组件中，镜像通常是一个完整的操作系统，并且镜像上只读的，应用通常运行在容器中，在可写的情况下才能运行。docker仓库是集中存放镜像 1,docker安装和简单命令使用tee /etc/yum.repos.d/docker.repo <<-'EOF' [dockerrepo] name=Docker Repository baseurl=https://yum.dockerproject.org/repo/main/centos/7/ enabled=1 gpgcheck=1 gpgkey=https://yum.dockerproject.org/gpg EOF 2，yum安装[root@zabbix-3 ~]# yum install docker-engine util-linux [root@zabbix-3 ~]# systemctl start docker [root@zabbix-3 ~]# docker search centos 搜索镜像 [root@zabbix-3 ~]# docker pull centos 获取镜像 Using default tag: latest latest: Pulling from library/centos a3ed95caeb02: Pull complete da71393503ec: Pull complete Digest: sha256:1a62cd7c773dd5c6cf08e2e28596f6fcc99bd97e38c9b324163e0da90ed27562 Status: Downloaded newer image for centos:latest 查看镜像[root@zabbix-3 ~]# docker images 查看镜像 REPOSITORY TAG IMAGE ID CREATED SIZE centos latest 904d6c400333 3 weeks ago 196.7 MB 删除镜像[root@zabbix-3 ~]# docker rmi 删除镜像尝试运行：[root@zabbix-3 ~]# docker run centos /bin/echo 'hello world' hello world [root@zabbix-3 ~]# docker run centos /bin/ls /etc/ |wc -l 117 [root@zabbix-3 ~]# ps -a可查看详细的操作信息[root@zabbix-3 ~]# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES aacbb56b34f0 centos "/bin/ls /etc/" 51 seconds ago Exited (0) 50 seconds ago big_khorana 0aaac85decee centos "/bin/ls /etc/" About a minute ago Exited (0) 59 seconds ago compassionate_fermi 971692c3b076 centos "/bin/echo 'hello wor" About a minute ago Exited (0) About a minute ago sharp_wozniak 进入docker,--name 名称 -it 镜像名 /bin/bash-i:保持终端打开-t:开启tty绑定到此标准输入如果不存在此镜像，则会自动pull[root@zabbix-3 ~]# docker run --name mydocker -it centos /bin/bash [root@de5276472785 /]# 退出容器则服务器中断，重新连接如下：找到需要重新连接的id[root@zabbix-3 ~]# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES de5276472785 centos "/bin/bash" 3 hours ago Exited (0) 33 minutes ago mydocker aacbb56b34f0 centos "/bin/ls /etc/" 3 hours ago Exited (0) 3 hours ago big_khorana 0aaac85decee centos "/bin/ls /etc/" 3 hours ago Exited (0) 3 hours ago compassionate_fermi 971692c3b076 centos "/bin/echo 'hello wor" 3 hours ago Exited (0) 3 hours ago sharp_wozniak start 此id[root@zabbix-3 ~]# docker start de5276472785 de5276472785 [root@zabbix-3 ~]# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES de5276472785 centos "/bin/bash" 3 hours ago Up 16 seconds mydocker aacbb56b34f0 centos "/bin/ls /etc/" 3 hours ago Exited (0) 3 hours ago big_khorana 0aaac85decee centos "/bin/ls /etc/" 3 hours ago Exited (0) 3 hours ago compassionate_fermi 971692c3b076 centos "/bin/echo 'hello wor" 3 hours ago Exited (0) 3 hours ago sharp_wozniak [root@zabbix-3 ~]# 后台运行-d，当在后台运行时会返回一个id[root@zabbix-3 ~]# docker run -d --name mark centos bash 3b51dff90eb1e76a21a54def1f6e813505951cad1bb5a644abff7e27561be94d [root@zabbix-3 ~]# docker删除容器先停止[root@zabbix-3 ~]# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 3b51dff90eb1 centos "bash" 4 hours ago Exited (0) 4 hours ago mark 删除[root@zabbix-3 ~]# docker rm 3b51dff90eb1 3b51dff90eb1 [root@zabbix-3 ~]# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES [root@zabbix-3 ~]# yum install util-linux进入后台容器，先将nginx pull下来[root@zabbix-3 ~]# docker run -d --name mynginx nginx attach：在某些场景下使用attach可能会导致容器退出我们安装另外一个工具nsenter，这个工具可以访问容器空间安装此工具：yum install util-linux我们先获取此容器的pid[root@zabbix-3 ~]# docker inspect --format "{{.State.Pid}}" mynginx 8085 而后挂载，接挂载参数进入此容器[root@zabbix-3 ~]# nsenter --target 8085 --mount --uts --ipc --net --pid root@5643fa5e6925:/# ps aux USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND root 1 0.0 0.0 31680 2872 ? Ss 17:28 0:00 nginx: master process nginx -g daemon off; nginx 6 0.0 0.0 32072 1700 ? S 17:28 0:00 nginx: worker process root 7 0.0 0.0 20256 1912 ? S 17:50 0:00 -bash root 11 0.0 0.0 17492 1160 ? R+ 17:50 0:00 ps aux root@5643fa5e6925:/# root@5643fa5e6925:/etc/nginx# ls /etc/nginx/nginx.conf /etc/nginx/nginx.conf root@5643fa5e6925:/etc/nginx# ls /etc/nginx/conf.d/default.conf /etc/nginx/conf.d/default.conf root@5643fa5e6925:/etc/nginx# 但是官方的镜像非常简单，很多常用命令都没有，进入docker的脚本如下[root@zabbix-3 ~]# cat in.sh #!/bin/bash CNAME=$1 CPID=$(docker inspect --format "{{.State.Pid}}" $CNAME) nsenter --target "$CPID" --mount --uts --ipc --net --pid [root@zabbix-3 ~]# [root@zabbix-3 ~]# chmod +x in.sh [root@zabbix-3 ~]# ./in.sh mynginx root@5643fa5e6925:/# ps aux|grep nginx root 1 0.0 0.0 31680 2872 ? Ss 17:28 0:00 nginx: master process nginx -g daemon off; nginx 6 0.0 0.0 32072 1700 ? S 17:28 0:00 nginx: worker process root 29 0.0 0.0 10988 452 ? R+ 18:00 0:00 grep nginx root@5643fa5e6925:/# 在创建好容器后，iptables会添加一段nat表规则