DOCKER学习_008:Docker容器的运行最佳实践

一容器分类

容器按用途大致可分为两类:

服务类容器，如 web server、 database等

工具类容器，如cur容器， Iredis-cli容器

通常而言，服务类容器需要长期运行，所以使用 daemon的方式运行;而工作类环境通常是给我们提供一个临时的工作环境，所以一般以runt的方式在前台运行

容器的短任务和长任务

长任务就是长期执行的任务，比如容器监听在某个端口上，只要放在后台运行即可（http,nginx,myslq等）

二工具类容器

2.1 简单实验

如执行一个docker run centos:7 /bin/bash,就是一个短任务，结束终端退出，容器就关闭了

[root@docker-server3 ~]# docker run -it centos:7 /bin/bash

Unable to find image 'centos:7' locally

: Pulling from library/centos

ab5ef0e58194: Pull complete

Digest: sha256:4a701376d03f6b39b8c2a8f4a8e499441b0d567f9ab9d58e4991de4472fb813c

Status: Downloaded newer image for centos:7
[root@5e82ea0e65f0 /]#

[root@5e82ea0e65f0 /]# exit
exit
[root@docker-server3 ~]# docker ps -a

CONTAINER ID        IMAGE               COMMAND             CREATED              STATUS                     PORTS               NAMES

5e82ea0e65f0        centos:            "/bin/bash"         About a minute ago   Exited ()  seconds ago                       romantic_lewin

执行完成就退出

在退出后，容器不会删除，start后依然可以做操作

[root@docker-server3 ~]# docker start 5e82ea0e65f0

[root@docker-server3 ~]# docker ps -a

CONTAINER ID        IMAGE               COMMAND             CREATED              STATUS              PORTS               NAMES

5e82ea0e65f0        centos:            "/bin/bash"         About a minute ago   Up  second                             romantic_lewin

再次进入容器进行操作

[root@docker-server3 ~]# docker exec -it 5e82ea0e65f0 /bin/bash

注意有的容器可能没有bash终端，可以尝试使用shell终端，即docker exec -it 5e82ea0e65f0 /bin/sh

就可以正在容器内进行一些测试操作

[root@5e82ea0e65f0 /]# ps -ef

UID         PID   PPID  C STIME TTY          TIME CMD

root                   : pts/    :: /bin/bash

root                  : pts/    :: /bin/bash

root                 : pts/    :: ps -ef

[root@5e82ea0e65f0 /]# curl www.baidu.com

<!DOCTYPE html>

<!--STATUS OK--><html> <head><meta http-equiv=content-type content=text/html;charset=utf-><meta http-equiv=X-UA-Compatible content=IE=Edge><meta content=always name=referrer><link rel=stylesheet type=text/css href=http://s1.bdstatic.com/r/www/cache/bdorz/baidu.min.css><title>百度一下，你就知</title></head> <body link=#0000cc> <div id=wrapper> <div id=head> <div class=head_wrapper> <div class=s_form> <div class=s_form_wrapper> <div id=lg> <img hidefocus=true src=//www.baidu.com/img/bd_logo1.png width=270 height=129> </div> <form id=form name=f action=//www.baidu.com/s class=fm> <input type=hidden name=bdorz_come value=1> <input type=hidden name=ie value=utf-8> <input type=hidden name=f value=8> <input type=hidden name=rsv_bp value=1> <input type=hidden name=rsv_idx value=1> <input type=hidden name=tn value=baidu><span class="bg s_ipt_wr"><input id=kw name=wd class=s_ipt value maxlength=255 autocomplete=off autofocus></span><span class="bg s_btn_wr"><input type=submit id=su value=百度一下 class="bg s_btn"></span> </form> </div> </div> <div id=u1> <a href=http://news.baidu.com name=tj_trnews class=mnav>新闻</a> <a href=http://www.hao123.com name=tj_trhao123 class=mnav>hao123</a> <a href=http://map.baidu.com name=tj_trmap class=mnav>地图</a> <a href=http://v.baidu.com name=tj_trvideo class=mnav>视频</a> <a href=http://tieba.baidu.com name=tj_trtieba class=mnav>贴吧</a> <noscript> <a href=http://www.baidu.com/bdorz/login.gif?login&amp;tpl=mn&amp;u=http%3A%2F%2Fwww.baidu.com%2f%3fbdorz_come%3d1 name=tj_login class=lb>登录</a> </noscript> <script>document.write('<a href="http://www.baidu.com/bdorz/login.gif?login&tpl=mn&u='+ encodeURIComponent(window.location.href+ (window.location.search === "" ? "?" : "&")+ "bdorz_come=1")+ '" name="tj_login" class="lb">登录</a>');</script> <a href=//www.baidu.com/more/ name=tj_briicon class=bri style="display: block;">更多产品</a> </div> </div> </div> <div id=ftCon> <div id=ftConw> <p id=lh> <a href=http://home.baidu.com>关于百度</a> <a href=http://ir.baidu.com>About Baidu</a> </p> <p id=cp>&copy;2017&nbsp;Baidu&nbsp;<a href=http://www.baidu.com/duty/>使用百度前必读</a>&nbsp; <a href=http://jianyi.baidu.com/ class=cp-feedback>意见反馈</a>&nbsp;京ICP证030173号&nbsp; <img src=//www.baidu.com/img/gs.gif> </p> </div> </div> </div> </body> </html>

[root@5e82ea0e65f0 /]# yum -y install net-tools

[root@5e82ea0e65f0 /]# ifconfig

eth0: flags=<UP,BROADCAST,RUNNING,MULTICAST>  mtu

        inet 192.168.0.2  netmask 255.255.255.0  broadcast 192.168.0.255

        ether ::c0:a8::  txqueuelen   (Ethernet)

        RX packets   bytes  (24.7 MiB)

        RX errors   dropped   overruns   frame

        TX packets   bytes  (113.1 KiB)

        TX errors   dropped  overruns   carrier   collisions 

lo: flags=<UP,LOOPBACK,RUNNING>  mtu

        inet 127.0.0.1  netmask 255.0.0.0

        loop  txqueuelen   (Local Loopback)

        RX packets   bytes  (0.0 B)

        RX errors   dropped   overruns   frame

        TX packets   bytes  (0.0 B)

        TX errors   dropped  overruns   carrier   collisions

发现ip的网段是192.168.0.0/16

查看dockers配置

[root@5e82ea0e65f0 /]# exit

[root@docker-server3 ~]# cat /etc/docker/daemon.json

{

"log-driver":"journald",

"bip":"192.168.0.1/24"

}

2.2 docker的终端运行进程

每个docker容器都有一个默认的进程，但是这个进程拥有最低权限，可以覆盖掉

例如安装httpd测试

[root@docker-server3 ~]# docker run -d httpd:2.4

c57bbb0cae70ea529fbddec7de895cfd8865a55fd1cafb39e81e144dbccceb47

[root@docker-server3 ~]# docker run -it httpd:2.4 /bin/bash

root@11494f95ef19:/usr/local/apache2#

另开一个终端查看

[root@docker-server3 ~]# docker ps -a

CONTAINER ID        IMAGE               COMMAND                  CREATED              STATUS                      PORTS               NAMES

11494f95ef19        httpd:2.4           "/bin/bash"               seconds ago       Up  seconds               /tcp              serene_cannon

c57bbb0cae70        httpd:2.4           "httpd-foreground"        seconds ago       Up  seconds               /tcp              serene_williamson

COMMAND就是容器的终端进程，但是看到第一个进程是我们指定的/bin/bash，覆盖了默认进程httpd-foreground

2.3 运行一个redis测试

[root@docker-server3 ~]# docker run -d redis:4.0

Unable to find image 'redis:4.0' locally

4.0: Pulling from library/redis

8ec398bc0356: Pull complete

da01136793fa: Pull complete

cf1486a2c0b8: Pull complete

94baf980b8df: Pull complete

08ee3ec1a85f: Pull complete

9990996bca2f: Pull complete

Digest: sha256:e4adaff7466861d44c2d21178c5b8e8fa7d812172b9747071b08502b37e6ea2a

Status: Downloaded newer image for redis:4.0

acd538e93dec6de676610894ee5733caf7f23793d9b15ad72c2447c7436eabd2

[root@docker-server3 ~]# docker ps -a

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS               NAMES

acd538e93dec        redis:4.0           "docker-entrypoint.s…"    seconds ago      Up  seconds       /tcp            zen_raman

5e82ea0e65f0        centos:            "/bin/bash"               minutes ago      Up  minutes                           romantic_lewin

[root@docker-server3 ~]# docker inspect acd538e93dec|grep IP

"LinkLocalIPv6Address": "",

            "LinkLocalIPv6PrefixLen": ,

            "SecondaryIPAddresses": null,

            "SecondaryIPv6Addresses": null,

            "GlobalIPv6Address": "",

            "GlobalIPv6PrefixLen": ,

            "IPAddress": "192.168.0.3",

            "IPPrefixLen": ,

            "IPv6Gateway": "",

                    "IPAMConfig": null,

                    "IPAddress": "192.168.0.3",

                    "IPPrefixLen": ,

                    "IPv6Gateway": "",

                    "GlobalIPv6Address": "",

                    "GlobalIPv6PrefixLen": ,

安装一个redis-cli客户端的容器

进入查看操作

https://hub.docker.com/r/goodsmileduck/redis-cli

[root@docker-server3 ~]# docker run -it goodsmileduck/redis-cli:latest /bin/sh

Unable to find image 'goodsmileduck/redis-cli:latest' locally

latest: Pulling from goodsmileduck/redis-cli

: Pull complete

ff9fae49e01a: Pull complete

Digest: sha256:dbe86d99f417fd3d18c06ecdadc6f473300e365c711de6b3da7f4598ee6feb1f

Status: Downloaded newer image for goodsmileduck/redis-cli:latest

/ # redis-cli -h 192.168.0.3 -p 6379 info

# Server

redis_version:4.0.

redis_git_sha1:

redis_git_dirty:

redis_build_id:198fbb2e6c7e2b25

redis_mode:standalone

os:Linux 3.10.-957.27..el7.x86_64 x86_64

arch_bits:

multiplexing_api:epoll

atomicvar_api:atomic-builtin

gcc_version:8.3.

process_id:

run_id:659feb59d1a9210008d21e67952b9c018cb14a46

tcp_port:

uptime_in_seconds:

uptime_in_days:

hz:

lru_clock:

executable:/data/redis-server

config_file:

# Clients

connected_clients:

client_longest_output_list:

client_biggest_input_buf:

blocked_clients:

# Memory

used_memory:

used_memory_human:.45K

used_memory_rss:

used_memory_rss_human:7.61M

used_memory_peak:

used_memory_peak_human:.45K

used_memory_peak_perc:100.12%

used_memory_overhead:

used_memory_startup:

used_memory_dataset:

used_memory_dataset_perc:21.04%

total_system_memory:

total_system_memory_human:.78G

used_memory_lua:

used_memory_lua_human:.00K

maxmemory:

maxmemory_human:0B

maxmemory_policy:noeviction

mem_fragmentation_ratio:9.39

mem_allocator:jemalloc-4.0.

active_defrag_running:

lazyfree_pending_objects:

# Persistence

loading:

rdb_changes_since_last_save:

rdb_bgsave_in_progress:

rdb_last_save_time:

rdb_last_bgsave_status:ok

rdb_last_bgsave_time_sec:-

rdb_current_bgsave_time_sec:-

rdb_last_cow_size:

aof_enabled:

aof_rewrite_in_progress:

aof_rewrite_scheduled:

aof_last_rewrite_time_sec:-

aof_current_rewrite_time_sec:-

aof_last_bgrewrite_status:ok

aof_last_write_status:ok

aof_last_cow_size:

# Stats

total_connections_received:

total_commands_processed:

instantaneous_ops_per_sec:

total_net_input_bytes:

total_net_output_bytes:

instantaneous_input_kbps:0.00

instantaneous_output_kbps:0.00

rejected_connections:

sync_full:

sync_partial_ok:

sync_partial_err:

expired_keys:

expired_stale_perc:0.00

expired_time_cap_reached_count:

evicted_keys:

keyspace_hits:

keyspace_misses:

pubsub_channels:

pubsub_patterns:

latest_fork_usec:

migrate_cached_sockets:

slave_expires_tracked_keys:

active_defrag_hits:

active_defrag_misses:

active_defrag_key_hits:

active_defrag_key_misses:

# Replication

role:master

connected_slaves:

master_replid:2f59d8dd98d882302c7da6d302faa6aa0857979a

master_replid2:

master_repl_offset:

second_repl_offset:-

repl_backlog_active:

repl_backlog_size:

repl_backlog_first_byte_offset:

repl_backlog_histlen:

# CPU

used_cpu_sys:1.25

used_cpu_user:1.14

used_cpu_sys_children:0.00

used_cpu_user_children:0.00

# Cluster

cluster_enabled:

也可以在外面执行，指令执行完容器就退出

[root@docker-server3 ~]# docker run -it goodsmileduck/redis-cli:latest redis-cli -h 192.168.0.3 -p 6379 info

会得到上面一个相同的结果，但是容器执行完，得到结果后，容器就退出

[root@docker-server3 ~]# docker ps -a

CONTAINER ID        IMAGE                            COMMAND                  CREATED              STATUS                          PORTS               NAMES

66886f9eca2f        goodsmileduck/redis-cli:latest   "redis-cli -h 192.16…"   About a minute ago   Exited () About a minute ago                       cocky_cerf

d798dd31871d        goodsmileduck/redis-cli:latest   "redis-cli -h 192.16…"   About a minute ago   Exited () About a minute ago                       zealous_jackson

281468c747b3        goodsmileduck/redis-cli:latest   "/bin/sh"                 minutes ago        Exited () About a minute ago                       musing_wiles

acd538e93dec        redis:4.0                        "docker-entrypoint.s…"    minutes ago       Up  minutes                   /tcp            zen_raman

5e82ea0e65f0        centos:                         "/bin/bash"               minutes ago       Up  minutes                                       romantic_lewin

删除掉不必要的容器

[root@docker-server3 ~]# docker rm 66886f9eca2f d798dd31871d 281468c747b3

[root@docker-server3 ~]# docker ps -a

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS               NAMES

acd538e93dec        redis:4.0           "docker-entrypoint.s…"    minutes ago      Up  minutes       /tcp            zen_raman

5e82ea0e65f0        centos:            "/bin/bash"               minutes ago      Up  minutes                           romantic_lewin

短任务执行后，退出就删除容器

[root@docker-server3 ~]# docker run -it --rm goodsmileduck/redis-cli:latest redis-cli -h 192.168.0.3 -p 6379 info

[root@docker-server3 ~]# docker ps -a

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS               NAMES

acd538e93dec        redis:4.0           "docker-entrypoint.s…"    minutes ago      Up  minutes       /tcp            zen_raman

5e82ea0e65f0        centos:            "/bin/bash"               minutes ago      Up  minutes                           romantic_lewin

容器执行完，已经被删除

博主声明：本文的内容来源主要来自誉天教育晏威老师，由本人实验完成操作验证，需要的博友请联系誉天教育（http://www.yutianedu.com/），获得官方同意或者晏老师（https://www.cnblogs.com/breezey/）本人同意即可转载，谢谢！