我有机会建立一个以Docker为基础的微服务架构在我现在的工作中，很多人都会分享他们使用Docker的心得，我想我也不会例外。因此我总结了一些，可能你会在日常使用Docker的时候会用到。
1. 一台主机部署多个Docker实例如果你想运行多个Docker 容器在一台主机上，如果要设置不同的TLS设置，网络设置，日志设置和存储驱动程序特定的容器，这是特别有用的。例如，我们目前正在运行一个标准设立两个Docker守护进程。一运行consul提供DNS解析，并作为群集存储为其他Docker 容器。
For example:
# start a docker daemon and bind to a specific port docker daemon -H tcp://$IP:5000 --storage-opt dm.fs=xfs \ -p "/var/run/docker1.pid" \ -g "/var/lib/docker1" \ --exec-root="/var/run/docker1 # and start another daemon docker daemon -H tcp://$IP:5001 --storage-opt dm.fs=xfs \ -s devicemapper \ --storage-opt dm.thinpooldev=/dev/mapper/docker--vg-docker--pool \ -p "/var/run/docker2.pid" \ -g "/var/lib/docker2" --exec-root="/var/run/docker2" --cluster-store=consul://$IP:8500 \ --cluster-advertise=$IP:2376 # start a docker daemon and bind to a specific port dockerdaemon -H tcp://$IP:5000 --storage-opt dm.fs=xfs \ -p "/var/run/docker1.pid" \ -g "/var/lib/docker1" \ --exec-root="/var/run/docker1 # and start another daemon docker daemon -H tcp://$IP:5001 --storage-opt dm.fs=xfs \ -s devicemapper \ --storage-opt dm.thinpooldev=/dev/mapper/docker--vg-docker--pool \ -p "/var/run/docker2.pid" \ -g "/var/lib/docker2" --exec-root="/var/run/docker2" --cluster-store=consul://$IP:8500 \ --cluster-advertise=$IP:2376
2. Docker Exec的使用Docker Exec是一个很重要很多人都会用到的工具，也许你使用Docker不只是为你的升级，生产和测试环境，同时也对本地机器上运行的数据库，服务器密钥库等，这是能够直接运行的容器的上下文中运行的命令，非常方便。
我们做了大量的Cassandra，并检查表是否包含正确的数据。如果你只是想执行一个快速CQL查询，Docker exec 就很赞：
$ docker ps --format "table {{.ID}}\t {{.Names}}\t {{.Status}}" CONTAINER ID NAMES STATUS 682f47f97fce cassandra Up 2 minutes 4c45aea49180 consul Up 2 minutes $ docker exec -ti 682f47f97fce cqlsh --color Connected to Test Cluster at 127.0.0.1:9042. [cqlsh 5.0.1 | Cassandra 2.2.3 | CQL spec 3.3.1 | Native protocol v4] Use HELP for help. cqlsh> $ dockerps --format "table {{.ID}}\t {{.Names}}\t {{.Status}}" CONTAINERID NAMES STATUS 682f47f97fce cassandra Up 2 minutes 4c45aea49180 consul Up 2 minutes $ dockerexec -ti 682f47f97fce cqlsh --color Connectedto TestClusterat 127.0.0.1:9042. [cqlsh 5.0.1 | Cassandra 2.2.3 | CQLspec 3.3.1 | Native protocolv4] Use HELPfor help. cqlsh>
或者只是访问nodetool或镜像中可用的任何其他工具：
$ docker exec -ti 682f47f97fce nodetool status Datacenter: datacenter1 ======================= Status=Up/Down |/ State=Normal/Leaving/Joining/Moving -- Address Load Tokens Owns Host ID Rack UN 192.168.99.100 443.34 KB 256 ? 8f9f4a9c-5c4d-4453-b64b-7e01676361ff rack1 Note: Non-system keyspaces don't have the same replication settings, effective ownership information $ dockerexec -ti 682f47f97fce nodetoolstatus Datacenter: datacenter1 ======================= Status=Up/Down |/ State=Normal/Leaving/Joining/Moving -- Address Load Tokens Owns HostID Rack UN 192.168.99.100 443.34 KB 256 ? 8f9f4a9c-5c4d-4453-b64b-7e01676361ff rack1 Note: Non-systemkeyspacesdon't havethesamereplicationsettings, effectiveownershipinformation
这当然可以被应用到任何（Client）的工具捆绑在一起的镜像中。我个人觉得这样会比所有客户端和本地更新更简单。
3. Docker 的检查 和JQ与其说这是一个Docker技巧，不如说是一个JQ技巧。如果你没有听过JQ，它是一个在命令行解析JSON的伟大工具。因为我们可以不需要使用format specifier而能够查看容器里面发生的一切。
# Get network information: $ docker inspect 4c45aea49180 | jq '.[].NetworkSettings.Networks' { "bridge": { "EndpointID": "ba1b6efba16de99f260e0fa8892fd4685dbe2f79cba37ac0114195e9fad66075", "Gateway": "172.17.0.1", "IPAddress": "172.17.0.2", "IPPrefixLen": 16, "IPv6Gateway": "", "GlobalIPv6Address": "", "GlobalIPv6PrefixLen": 0, "MacAddress": "02:42:ac:11:00:02" } } # Get the arguments with which the container was started $ docker inspect 4c45aea49180 | jq '.[].Args' [ "-server", "-advertise", "192.168.99.100", "-bootstrap-expect", "1" ] # Get all the mounted volumes 11:22 $ docker inspect 4c45aea49180 | jq '.[].Mounts' [ { "Name": "a8125ffdf6c4be1db4464345ba36b0417a18aaa3a025267596e292249ca4391f", "Source": "/mnt/sda1/var/lib/docker/volumes/a8125ffdf6c4be1db4464345ba36b0417a18aaa3a025267596e292249ca4391f/_data", "Destination": "/data", "Driver": "local", "Mode": "", "RW": true } ] # Get network information: $ dockerinspect 4c45aea49180 | jq '.[].NetworkSettings.Networks' { "bridge": { "EndpointID": "ba1b6efba16de99f260e0fa8892fd4685dbe2f79cba37ac0114195e9fad66075", "Gateway": "172.17.0.1", "IPAddress": "172.17.0.2", "IPPrefixLen": 16, "IPv6Gateway": "", "GlobalIPv6Address": "", "GlobalIPv6PrefixLen": 0, "MacAddress": "02:42:ac:11:00:02" } } # Get the arguments with which the container was started $ dockerinspect 4c45aea49180 | jq '.[].Args' [ "-server", "-advertise", "192.168.99.100", "-bootstrap-expect", "1" ] # Get all the mounted volumes 11:22 $ dockerinspect 4c45aea49180 | jq '.[].Mounts' [ { "Name": "a8125ffdf6c4be1db4464345ba36b0417a18aaa3a025267596e292249ca4391f", "Source": "/mnt/sda1/var/lib/docker/volumes/a8125ffdf6c4be1db4464345ba36b0417a18aaa3a025267596e292249ca4391f/_data", "Destination": "/data", "Driver": "local", "Mode": "", "RW": true } ]