Docker 使用详解看了挺开悟的

对于运行在Docker环境的容器，有时我们想查询它们的一些基本信息，例如环境变量、hostname、ip地址等，接下来我们以一个tomcat容器为例，看看有哪些方式来取得这些信息；

在docker环境下执行如下命令，即可创建一个名为tomcat001的tomcat容器：

docker run --name tomcat001 -idt tomcat

执行docker ps检查一下，容器创建成功：

root@maven:~# docker ps
CONTAINER ID	IMAGE	COMMAND				CREATED			STATUS			PORTS		NAMES
98d119ed4c73	tomcat	"catalina.sh run"	10 minutes ago	Up 10 minutes	8080/tcp	tomcat001

获取信息常用的方式有如下三种：

1. 进入容器内部获取信息；
2. 执行docker exec命令；
3. 执行docker inspect -f命令（推荐方式）；

执行以下命令可进入容器内部：

docker exec -it tomcat001 /bin/bash

此时已进入容器内部，所以分别执行hostname、ip addr、env这三个命令可以获取相关信息，如下：

root@98d119ed4c73:/usr/local/tomcat# hostname
98d119ed4c73
root@98d119ed4c73:/usr/local/tomcat# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00inet 127.0.0.1/8 scope host lovalid_lft forever preferred_lft foreverinet6 ::1/128 scope host valid_lft forever preferred_lft forever
17: eth0@if18: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default link/ether 02:42:ac:11:00:05 brd ff:ff:ff:ff:ff:ff link-netnsid 0inet 172.17.0.5/16 scope global eth0valid_lft forever preferred_lft foreverinet6 fe80::42:acff:fe11:5/64 scope link valid_lft forever preferred_lft forever
root@98d119ed4c73:/usr/local/tomcat# env
LD_LIBRARY_PATH=/usr/local/tomcat/native-jni-lib
CATALINA_HOME=/usr/local/tomcat
LANG=C.UTF-8
HOSTNAME=98d119ed4c73
OPENSSL_VERSION=1.1.0f-3+deb9u1
TOMCAT_VERSION=8.5.24
GPG_KEYS=05AB33110949707C93A279E3D3EFE6B686867BA6 07E48665A34DCAFAE522E5E6266191C37C037D42 47309207D818FFD8DCD3F83F1931D684307A10A5 541FBE7D8F78B25E055DDEE13C370389288584E7 61B832AC2F1C5A90F0F9B00A1C506407564C17A3 713DA88BE50911535FE716F5208B0AB1D63011C7 79F7026C690BAA50B92CD8B66A3AD3F4F22C4FED 9BA44C2621385CB966EBA586F72C284D731FABEE A27677289986DB50844682F8ACB77FC2E86E29AC A9C5DF4D22E99998D9875A5110C01C5A2F6059E7 DCFD35E0BF8CA7344752DE8B6FB21E8933C60243 F3A04C595DB5B6A5F1ECA43E3B7BBB100D811BBE F7DA48BB64BCB84ECBA7EE6935CD23C10D498E23
JAVA_HOME=/docker-java-home/jre
TOMCAT_NATIVE_LIBDIR=/usr/local/tomcat/native-jni-lib
JAVA_VERSION=8u151
PWD=/usr/local/tomcat
HOME=/root
CA_CERTIFICATES_JAVA_VERSION=20170531+nmu1
TOMCAT_MAJOR=8
JAVA_DEBIAN_VERSION=8u151-b12-1~deb9u1
TOMCAT_SHA1=9e26ba61c5665aafc849073edeb769be555283cd
TERM=xterm
SHLVL=1
TOMCAT_ASC_URLS=https://www.apache.org/dyn/closer.cgi?action=download&filename=tomcat/tomcat-8/v8.5.24/bin/apache-tomcat-8.5.24.tar.gz.asc      https://www-us.apache.org/dist/tomcat/tomcat-8/v8.5.24/bin/apache-tomcat-8.5.24.tar.gz.asc    https://www.apache.org/dist/tomcat/tomcat-8/v8.5.24/bin/apache-tomcat-8.5.24.tar.gz.asc       https://archive.apache.org/dist/tomcat/tomcat-8/v8.5.24/bin/apache-tomcat-8.5.24.tar.gz.asc
PATH=/usr/local/tomcat/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
TOMCAT_TGZ_URLS=https://www.apache.org/dyn/closer.cgi?action=download&filename=tomcat/tomcat-8/v8.5.24/bin/apache-tomcat-8.5.24.tar.gz  https://www-us.apache.org/dist/tomcat/tomcat-8/v8.5.24/bin/apache-tomcat-8.5.24.tar.gz        https://www.apache.org/dist/tomcat/tomcat-8/v8.5.24/bin/apache-tomcat-8.5.24.tar.gz   https://archive.apache.org/dist/tomcat/tomcat-8/v8.5.24/bin/apache-tomcat-8.5.24.tar.gz
_=/usr/bin/env

不用进入容器，直接在docker环境执行docker exec 容器名 容器内命令的方式也可以获取相关信息，举例如下：

1. 获取容器的hostname：docker exec tomcat001 hostname
2. 获取容器ip地址：docker exec tomcat001 ip addr
3. 获取容器环境变量：docker exec tomcat001 env

执行结果如下所示:

root@maven:~# docker exec tomcat001 hostname
98d119ed4c73
root@maven:~# docker exec tomcat001 ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00inet 127.0.0.1/8 scope host lovalid_lft forever preferred_lft foreverinet6 ::1/128 scope host valid_lft forever preferred_lft forever
17: eth0@if18: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default link/ether 02:42:ac:11:00:05 brd ff:ff:ff:ff:ff:ff link-netnsid 0inet 172.17.0.5/16 scope global eth0valid_lft forever preferred_lft foreverinet6 fe80::42:acff:fe11:5/64 scope link valid_lft forever preferred_lft forever
root@maven:~# docker exec tomcat001 env
PATH=/usr/local/tomcat/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
HOSTNAME=98d119ed4c73
LANG=C.UTF-8
JAVA_HOME=/docker-java-home/jre
JAVA_VERSION=8u151
JAVA_DEBIAN_VERSION=8u151-b12-1~deb9u1
CA_CERTIFICATES_JAVA_VERSION=20170531+nmu1
CATALINA_HOME=/usr/local/tomcat
TOMCAT_NATIVE_LIBDIR=/usr/local/tomcat/native-jni-lib
LD_LIBRARY_PATH=/usr/local/tomcat/native-jni-lib
OPENSSL_VERSION=1.1.0f-3+deb9u1
GPG_KEYS=05AB33110949707C93A279E3D3EFE6B686867BA6 07E48665A34DCAFAE522E5E6266191C37C037D42 47309207D818FFD8DCD3F83F1931D684307A10A5 541FBE7D8F78B25E055DDEE13C370389288584E7 61B832AC2F1C5A90F0F9B00A1C506407564C17A3 713DA88BE50911535FE716F5208B0AB1D63011C7 79F7026C690BAA50B92CD8B66A3AD3F4F22C4FED 9BA44C2621385CB966EBA586F72C284D731FABEE A27677289986DB50844682F8ACB77FC2E86E29AC A9C5DF4D22E99998D9875A5110C01C5A2F6059E7 DCFD35E0BF8CA7344752DE8B6FB21E8933C60243 F3A04C595DB5B6A5F1ECA43E3B7BBB100D811BBE F7DA48BB64BCB84ECBA7EE6935CD23C10D498E23
TOMCAT_MAJOR=8
TOMCAT_VERSION=8.5.24
TOMCAT_SHA1=9e26ba61c5665aafc849073edeb769be555283cd
TOMCAT_TGZ_URLS=https://www.apache.org/dyn/closer.cgi?action=download&filename=tomcat/tomcat-8/v8.5.24/bin/apache-tomcat-8.5.24.tar.gz  https://www-us.apache.org/dist/tomcat/tomcat-8/v8.5.24/bin/apache-tomcat-8.5.24.tar.gz        https://www.apache.org/dist/tomcat/tomcat-8/v8.5.24/bin/apache-tomcat-8.5.24.tar.gz   https://archive.apache.org/dist/tomcat/tomcat-8/v8.5.24/bin/apache-tomcat-8.5.24.tar.gz
TOMCAT_ASC_URLS=https://www.apache.org/dyn/closer.cgi?action=download&filename=tomcat/tomcat-8/v8.5.24/bin/apache-tomcat-8.5.24.tar.gz.asc      https://www-us.apache.org/dist/tomcat/tomcat-8/v8.5.24/bin/apache-tomcat-8.5.24.tar.gz.asc    https://www.apache.org/dist/tomcat/tomcat-8/v8.5.24/bin/apache-tomcat-8.5.24.tar.gz.asc       https://archive.apache.org/dist/tomcat/tomcat-8/v8.5.24/bin/apache-tomcat-8.5.24.tar.gz.asc
HOME=/root

推荐使用docker inspect来获取信息，这个命令会返回一个json字符串，里面以key-value的格式准备了该容器相关的信息，内容十分丰富，可以一次性取得全部内容，也可以返回指定key对应的信息；

我们先来看看所有内容，执行命令docker inspect tomcat001，可以看到如下信息：

root@maven:~# docker inspect tomcat001
[{"Id": "98d119ed4c73c750e53353e77f7c6942803809a9d5dedc28d8b0f41ce58b8b17","Created": "2018-05-06T07:39:45.464492435Z","Path": "catalina.sh","Args": ["run"],"State": {"Status": "running","Running": true,"Paused": false,"Restarting": false,"OOMKilled": false,"Dead": false,"Pid": 22468,"ExitCode": 0,"Error": "","StartedAt": "2018-05-06T07:39:46.143092505Z","FinishedAt": "0001-01-01T00:00:00Z"},"Image": "sha256:3dcfe809147daf54fbdbe1f6886b4c49df63f28e2b3c8ac119fef6a7f7490d3c","ResolvConfPath": "/var/lib/docker/containers/98d119ed4c73c750e53353e77f7c6942803809a9d5dedc28d8b0f41ce58b8b17/resolv.conf","HostnamePath": "/var/lib/docker/containers/98d119ed4c73c750e53353e77f7c6942803809a9d5dedc28d8b0f41ce58b8b17/hostname","HostsPath": "/var/lib/docker/containers/98d119ed4c73c750e53353e77f7c6942803809a9d5dedc28d8b0f41ce58b8b17/hosts","LogPath": "/var/lib/docker/containers/98d119ed4c73c750e53353e77f7c6942803809a9d5dedc28d8b0f41ce58b8b17/98d119ed4c73c750e53353e77f7c6942803809a9d5dedc28d8b0f41ce58b8b17-json.log","Name": "/tomcat001","RestartCount": 0,"Driver": "aufs","MountLabel": "","ProcessLabel": "","AppArmorProfile": "","ExecIDs": ["cffec99f38514024f6a6e31e0e160d37d295041e4813a2245466be2dbc9c4037"],"HostConfig": {"Binds": null,"ContainerIDFile": "","LogConfig": {"Type": "json-file","Config": {}},"NetworkMode": "default","PortBindings": {},"RestartPolicy": {"Name": "no","MaximumRetryCount": 0},"AutoRemove": false,"VolumeDriver": "","VolumesFrom": null,"CapAdd": null,"CapDrop": null,"Dns": [],"DnsOptions": [],"DnsSearch": [],"ExtraHosts": null,"GroupAdd": null,"IpcMode": "","Cgroup": "","Links": null,"OomScoreAdj": 0,"PidMode": "","Privileged": false,"PublishAllPorts": false,"ReadonlyRootfs": false,"SecurityOpt": null,"UTSMode": "","UsernsMode": "","ShmSize": 67108864,"Runtime": "runc","ConsoleSize": [0,0],"Isolation": "","CpuShares": 0,"Memory": 0,"NanoCpus": 0,"CgroupParent": "","BlkioWeight": 0,"BlkioWeightDevice": null,"BlkioDeviceReadBps": null,"BlkioDeviceWriteBps": null,"BlkioDeviceReadIOps": null,"BlkioDeviceWriteIOps": null,"CpuPeriod": 0,"CpuQuota": 0,"CpuRealtimePeriod": 0,"CpuRealtimeRuntime": 0,"CpusetCpus": "","CpusetMems": "","Devices": [],"DiskQuota": 0,"KernelMemory": 0,"MemoryReservation": 0,"MemorySwap": 0,"MemorySwappiness": -1,"OomKillDisable": false,"PidsLimit": 0,"Ulimits": null,"CpuCount": 0,"CpuPercent": 0,"IOMaximumIOps": 0,"IOMaximumBandwidth": 0},"GraphDriver": {"Name": "aufs","Data": null},"Mounts": [],"Config": {"Hostname": "98d119ed4c73","Domainname": "","User": "","AttachStdin": false,"AttachStdout": false,"AttachStderr": false,"ExposedPorts": {"8080/tcp": {}},"Tty": true,"OpenStdin": true,"StdinOnce": false,"Env": ["PATH=/usr/local/tomcat/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin","LANG=C.UTF-8","JAVA_HOME=/docker-java-home/jre","JAVA_VERSION=8u151","JAVA_DEBIAN_VERSION=8u151-b12-1~deb9u1","CA_CERTIFICATES_JAVA_VERSION=20170531+nmu1","CATALINA_HOME=/usr/local/tomcat","TOMCAT_NATIVE_LIBDIR=/usr/local/tomcat/native-jni-lib","LD_LIBRARY_PATH=/usr/local/tomcat/native-jni-lib","OPENSSL_VERSION=1.1.0f-3+deb9u1","GPG_KEYS=05AB33110949707C93A279E3D3EFE6B686867BA6 07E48665A34DCAFAE522E5E6266191C37C037D42 47309207D818FFD8DCD3F83F1931D684307A10A5 541FBE7D8F78B25E055DDEE13C370389288584E7 61B832AC2F1C5A90F0F9B00A1C506407564C17A3 713DA88BE50911535FE716F5208B0AB1D63011C7 79F7026C690BAA50B92CD8B66A3AD3F4F22C4FED 9BA44C2621385CB966EBA586F72C284D731FABEE A27677289986DB50844682F8ACB77FC2E86E29AC A9C5DF4D22E99998D9875A5110C01C5A2F6059E7 DCFD35E0BF8CA7344752DE8B6FB21E8933C60243 F3A04C595DB5B6A5F1ECA43E3B7BBB100D811BBE F7DA48BB64BCB84ECBA7EE6935CD23C10D498E23","TOMCAT_MAJOR=8","TOMCAT_VERSION=8.5.24","TOMCAT_SHA1=9e26ba61c5665aafc849073edeb769be555283cd","TOMCAT_TGZ_URLS=https://www.apache.org/dyn/closer.cgi?action=download&filename=tomcat/tomcat-8/v8.5.24/bin/apache-tomcat-8.5.24.tar.gz \thttps://www-us.apache.org/dist/tomcat/tomcat-8/v8.5.24/bin/apache-tomcat-8.5.24.tar.gz \thttps://www.apache.org/dist/tomcat/tomcat-8/v8.5.24/bin/apache-tomcat-8.5.24.tar.gz \thttps://archive.apache.org/dist/tomcat/tomcat-8/v8.5.24/bin/apache-tomcat-8.5.24.tar.gz","TOMCAT_ASC_URLS=https://www.apache.org/dyn/closer.cgi?action=download&filename=tomcat/tomcat-8/v8.5.24/bin/apache-tomcat-8.5.24.tar.gz.asc \thttps://www-us.apache.org/dist/tomcat/tomcat-8/v8.5.24/bin/apache-tomcat-8.5.24.tar.gz.asc \thttps://www.apache.org/dist/tomcat/tomcat-8/v8.5.24/bin/apache-tomcat-8.5.24.tar.gz.asc \thttps://archive.apache.org/dist/tomcat/tomcat-8/v8.5.24/bin/apache-tomcat-8.5.24.tar.gz.asc"],"Cmd": ["catalina.sh","run"],"ArgsEscaped": true,"Image": "tomcat","Volumes": null,"WorkingDir": "/usr/local/tomcat","Entrypoint": null,"OnBuild": null,"Labels": {}},"NetworkSettings": {"Bridge": "","SandboxID": "50244517221e6faff4217ff5453919f0c297b10434812ecfbf3decb3ce9860f6","HairpinMode": false,"LinkLocalIPv6Address": "","LinkLocalIPv6PrefixLen": 0,"Ports": {"8080/tcp": null},"SandboxKey": "/var/run/docker/netns/50244517221e","SecondaryIPAddresses": null,"SecondaryIPv6Addresses": null,"EndpointID": "e9336feece03b1c87e6724253575ee50963e9bdc1f9618609fe641a8a939b87a","Gateway": "172.17.0.1","GlobalIPv6Address": "","GlobalIPv6PrefixLen": 0,"IPAddress": "172.17.0.5","IPPrefixLen": 16,"IPv6Gateway": "","MacAddress": "02:42:ac:11:00:05","Networks": {"bridge": {"IPAMConfig": null,"Links": null,"Aliases": null,"NetworkID": "87eb4d08d408c08489db4460915aabed59210d04f8193364420d3719cd308d83","EndpointID": "e9336feece03b1c87e6724253575ee50963e9bdc1f9618609fe641a8a939b87a","Gateway": "172.17.0.1","IPAddress": "172.17.0.5","IPPrefixLen": 16,"IPv6Gateway": "","GlobalIPv6Address": "","GlobalIPv6PrefixLen": 0,"MacAddress": "02:42:ac:11:00:05"}}}}
]

可见内容十分丰富；

如果我们只对其中的一些感兴趣，例如hostname、ip地址、环境变量，该如何查看呢？

1. hostname：在返回值中，hostname的位置如下图红框所示，

由上图可见，hostname位于Config.Hostname这个节点位置，所以执行命令docker inspect -f {{.Config.Hostname}} tomcat001即可获取到hostname，如下所示：

root@maven:~# docker inspect -f {{.Config.Hostname}} tomcat001
98d119ed4c73

ip地址：执行命令docker inspect -f {{.NetworkSettings.IPAddress}} tomcat001即可获取到ip地址：

root@maven:~# docker inspect -f {{.NetworkSettings.IPAddress}} tomcat001
172.17.0.5

环境变量：从完整的inspect信息中可以看到环境变量Config.Env的内容是个json数组，所以除了用docker inspect -f {{.Config.Env}} tomcat001获取所有环境变量信息，还可以用docker inspect -f ‘{{index .Config.Env 1}}’ tomcat001命令获取数组中的某一条记录，如下：

root@maven:~# docker inspect -f '{{index .Config.Env 1}}' tomcat001
LANG=C.UTF-8
root@maven:~# docker inspect -f '{{index .Config.Env 2}}' tomcat001 
JAVA_HOME=/docker-java-home/jre

至此，三种获取容器信息的方式已经全部列出，之所以在本文中推荐第三种，是因为有时我们会在shell脚本中获取容器信息，这时候用这种方式最为简单；

一种是基于创建一个容器并启动

docker create 
docker start 

另一种 使用 run 创建自动启动；
是状态下的停止 启动

docker start nginx1

docker stop NAMES     # 停止
docker restart NAMES  # 启动

# service docker start# docker run - 运行(创建)一个容器 

docker run -d -p 0.0.0.0:18080:8080 --name nginx1 nginx
-d： 让容器在后台运行
-P： 将容器内部使用的网络端口映射到我们使用的主机上
-p： 指定端口
--name ：设置容器命名
nginx 是容器镜像
docker pull nginx  拉取镜像；

进入一个 nginx1 容器

docker exec -it nginx1 /bin/bash
-d : 分离模式: 在后台运行
-i : 交互模式 即使没有附加也保持STDIN 打开
-t : 分配一个伪终端
/bin/bash ： 运行命令 bash shell

另一种进入方式：

docker attach centos6.3

docker 启动所有的容器
docker start $(docker ps -a | awk '{ print $1}' | tail -n +2)docker 关闭所有的容器
docker stop $(docker ps -a | awk '{ print $1}' | tail -n +2)docker 删除所有的容器
docker rm $(docker ps -a | awk '{ print $1}' | tail -n +2)docker 删除所有的镜像
docker rmi $(docker images | awk '{print $3}' |tail -n +2)

如何查看docker容器运行状态？有时候，我们需要进入运行的docker容器，查看容器运行情况，查看 docker 容器的状态信息。

查看容器状态：

docker stats nginx1

查看进程信息：

docker top nginx1

使用 docker inspect 来查看Docker的底层信息。它会返回一个 JSON 文件记录着 Docker 容器的配置和状态信息

docker 容器默认的目录：

/var/lib/docker/containers

目录下 12 位开头的 就是 容器ID
inspect 内容就是 config.v2.json 文件

cat/var/lib/docker/containers/23defb07e362b81fa9d282382dfb5101e7a269f97b3d167493a5b1e031d15120/config.v2.json

inspect 查看容器的配置信息，包含容器名、环境变量、运行命令、主机配置、网络配置和数据卷配置

docker inspect nginx1 查看容器所有状态；

root@rbtnode1: ~# docker inspect --format='{{.NetworkSettings.IPAddress}}' nginx1
172.16.57.5root@rbtnode1: ~# docker inspect --format '{{.Name}} {{.State.Running}}' nginx1
/nginx1 true