在Docker中运行web应用

启动一个简单的web 应用

使用社区提供的模板，启动一个简单的web应用，熟悉下各种Docker命令的使用：

1. # docker run -d -P training/webapp python app.py
2. Unable to find image 'training/webapp' locally
3. Pulling repository training/webapp
4. 31fa814ba25a: Download complete
5. 511136ea3c5a: Download complete
6. f10ebce2c0e1: Download complete
7. 82cdea7ab5b5: Download complete
8. 5dbd9cb5a02f: Download complete
9. 74fe38d11401: Download complete
10. 64523f641a05: Download complete
11. 0e2afc9aad6e: Download complete
12. e8fc7643ceb1: Download complete
13. 733b0e3dbcee: Download complete
14. a1feb043c441: Download complete
15. e12923494f6a: Download complete
16. a15f98c46748: Download complete
17. Status: Downloaded newer image for training/webapp:latest
18. d00f94a31e8767271f68ab72eab15a8e805c416b0636877f22a31572d10b718d

-d 启动一个daemon并在后台运行

-P 映射一个网络端口

training/webapp docker社区提供的，预先创建好的模板，里面包含一个简单的Python Flask web应用

1. # docker ps -l
2. CONTAINER ID        IMAGE                    COMMAND             CREATED             STATUS              PORTS                     NAMES
3. d00f94a31e87        training/webapp:latest   "python app.py"     59 seconds ago      Up 56 seconds       0.0.0.0:49153->5000/tcp   hopeful_lalande

-l 查看详细信息

PORTS显示 0.0.0.0:49153->5000/tcp

意思是将Container中的5000端口，映射到host的49153端口。5000是Python Flask 的默认端口。

也可以使用 -p container-port:host-port 命令来指定映射端口号

1. # docker run -d -p 5000:5000 training/webapp python app.py

查看web应用信息

查看名为hopeful_lalande的docker container中，5000端口的映射信息

1. # docker port hopeful_lalande 5000
2. 0.0.0.0:49153

查看web应用日志

1. # docker logs -f hopeful_lalande
2. * Running on http://0.0.0.0:5000/
3. 192.168.254.1 - - [17/Dec/2014 02:30:32] "GET / HTTP/1.1" 200 -
4. 192.168.254.1 - - [17/Dec/2014 02:30:32] "GET /favicon.ico HTTP/1.1" 404 -
5. 192.168.254.1 - - [17/Dec/2014 02:30:32] "GET /favicon.ico HTTP/1.1" 404 -

-f 持续查看container日志的标准化输出，类似tail -f

查看进程详细信息

1. # docker top hopeful_lalande
2. UID                 PID                 PPID                C                   STIME               TTY                 TIME                CMD
3. root                15189               2447                0                   10:24               ?                   00:00:00            python app.py

查看web应用容器详细信息

1. # docker inspect hopeful_lalande
2. [{
3. "AppArmorProfile": "",
4. "Args": [
5. "app.py"
6. ],
7. "Config": {
8. "AttachStderr": false,
9. "AttachStdin": false,
10. "AttachStdout": false,
11. "Cmd": [
12. "python",
13. "app.py"
14. ],
15. "CpuShares": 0,
16. "Cpuset": "",
17. "Domainname": "",
18. "Entrypoint": null,
19. "Env": [
20. "HOME=/",
21. "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
22. ],
23. "ExposedPorts": {
24. "5000/tcp": {}
25. },
26. "Hostname": "d00f94a31e87",
27. "Image": "training/webapp",
28. "Memory": 0,
29. "MemorySwap": 0,
30. "NetworkDisabled": false,
31. "OnBuild": null,
32. "OpenStdin": false,
33. "PortSpecs": null,
34. "StdinOnce": false,
35. "Tty": false,
36. "User": "",
37. "Volumes": null,
38. "WorkingDir": "/opt/webapp"
39. },
40. "Created": "2014-12-17T02:24:09.468631143Z",
41. "Driver": "devicemapper",
42. "ExecDriver": "native-0.2",
43. "HostConfig": {
44. "Binds": null,
45. "CapAdd": null,
46. "CapDrop": null,
47. "ContainerIDFile": "",
48. "Devices": [],
49. "Dns": null,
50. "DnsSearch": null,
51. "ExtraHosts": null,
52. "Links": null,
53. "LxcConf": [],
54. "NetworkMode": "bridge",
55. "PortBindings": {},
56. "Privileged": false,
57. "PublishAllPorts": true,
58. "RestartPolicy": {
59. "MaximumRetryCount": 0,
60. "Name": ""
61. },
62. "SecurityOpt": null,
63. "VolumesFrom": null
64. },
65. "HostnamePath": "/var/lib/docker/containers/d00f94a31e8767271f68ab72eab15a8e805c416b0636877f22a31572d10b718d/hostname",
66. "HostsPath": "/var/lib/docker/containers/d00f94a31e8767271f68ab72eab15a8e805c416b0636877f22a31572d10b718d/hosts",
67. "Id": "d00f94a31e8767271f68ab72eab15a8e805c416b0636877f22a31572d10b718d",
68. "Image": "31fa814ba25ae3426f8710df7a48d567d4022527ef2c14964bb8bc45e653417c",
69. "MountLabel": "",
70. "Name": "/hopeful_lalande",
71. "NetworkSettings": {
72. "Bridge": "docker0",
73. "Gateway": "172.17.42.1",
74. "IPAddress": "172.17.0.8",
75. "IPPrefixLen": 16,
76. "MacAddress": "02:42:ac:11:00:08",
77. "PortMapping": null,
78. "Ports": {
79. "5000/tcp": [
80. {
81. "HostIp": "0.0.0.0",
82. "HostPort": "49153"
83. }
84. ]
85. }
86. },
87. "Path": "python",
88. "ProcessLabel": "",
89. "ResolvConfPath": "/var/lib/docker/containers/d00f94a31e8767271f68ab72eab15a8e805c416b0636877f22a31572d10b718d/resolv.conf",
90. "State": {
91. "ExitCode": 0,
92. "FinishedAt": "0001-01-01T00:00:00Z",
93. "Paused": false,
94. "Pid": 15189,
95. "Restarting": false,
96. "Running": true,
97. "StartedAt": "2014-12-17T02:24:11.279426855Z"
98. },
99. "Volumes": {},
100. "VolumesRW": {}
101. }
102. ]

输出一个JSON格式的Docker container配置和状态。

也可以通过指定名称，获取某项信息值，如下：

1. # docker inspect -f '{{ .NetworkSettings.IPAddress }}' hopeful_lalande
2. 172.17.0.8

停止Web应用

1. # docker stop hopeful_lalande
2. hopeful_lalande

停止后，可以使用docker ps -a命令，列出之前所有docker容器

1. # docker ps -a
2. CONTAINER ID        IMAGE                    COMMAND                CREATED             STATUS                         PORTS               NAMES
3. d00f94a31e87        training/webapp:latest   "python app.py"        21 minutes ago      Exited (-1) 43 seconds ago                         hopeful_lalande
4. 7f22b335fb2c        fedora:latest            "/bin/sh -c 'while t   49 minutes ago      Exited (-1) 40 minutes ago                         silly_archimedes
5. 。。。

重启Web应用

1. # docker start hopeful_lalande
2. hopeful_lalande

删除Web应用

1. # docker rm hopeful_lalande
2. Error response from daemon: You cannot remove a running container. Stop the container before attempting removal or use -f
3. 2014/12/17 10:49:32 Error: failed to remove one or more containers

提示无法删除一个正在运行的container。

停止该container后，重新执行上条命令，成功删除container