078、Docker 最常用的监控方案（2019-04-25 周四）
当 Docker 部署规模逐步变大后，可视化监控容器环境的性能和健康状态会变得越来越重要。
在本章中，我们将学习几个目前比较常用的容器监控工具和方案，为以后构建自己的监控系统提供参考。
首先我们会讨论 Docker 自带的几个监控子命令：ps、top、stats。然后是几个功能更强的开源监控工具 sysdig、Weave Scope、cAdvisor 和 Prometheus 。最后我们在对这几个工具做一个对比。
docker container ps
查看当前运行的容器，下面三个命令的效果是完全一样的，加上 -a 可以查看没有运行的容器
root@host1:~# docker container ls --help
Usage: docker container ls [OPTIONS]
List containers
Aliases:
ls, ps, list
Options:
-a, --all Show all containers (default shows just running)
-f, --filter filter Filter output based on conditions provided
--format string Pretty-print containers using a Go template
-n, --last int Show n last created containers (includes all states) (default -1)
-l, --latest Show the latest created container (includes all states)
--no-trunc Don't truncate output
-q, --quiet Only display numeric IDs
-s, --size Display total file sizes
root@host1:~# docker container ps --help
Usage: docker container ls [OPTIONS]
List containers
Aliases:
ls, ps, list
Options:
-a, --all Show all containers (default shows just running)
-f, --filter filter Filter output based on conditions provided
--format string Pretty-print containers using a Go template
-n, --last int Show n last created containers (includes all states) (default -1)
-l, --latest Show the latest created container (includes all states)
--no-trunc Don't truncate output
-q, --quiet Only display numeric IDs
-s, --size Display total file sizes
root@host1:~# docker ps --help
Usage: docker ps [OPTIONS]
List containers
Options:
-a, --all Show all containers (default shows just running)
-f, --filter filter Filter output based on conditions provided
--format string Pretty-print containers using a Go template
-n, --last int Show n last created containers (includes all states) (default -1)
-l, --latest Show the latest created container (includes all states)
--no-trunc Don't truncate output
-q, --quiet Only display numeric IDs
-s, --size Display total file sizes
root@host1:~# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
b89ca1da78c3 busybox "sh" About a minute ago Up About a minute sad_sanderson
7874b10cb1d4 httpd "httpd-foreground" 2 minutes ago Up 2 minutes 80/tcp keen_yalow
root@host1:~# docker container ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
b89ca1da78c3 busybox "sh" About a minute ago Up About a minute sad_sanderson
7874b10cb1d4 httpd "httpd-foreground" 2 minutes ago Up 2 minutes 80/tcp keen_yalow
root@host1:~# docker container ls
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
b89ca1da78c3 busybox "sh" About a minute ago Up About a minute sad_sanderson
7874b10cb1d4 httpd "httpd-foreground" 2 minutes ago Up 2 minutes 80/tcp keen_yalow
root@host1:~#
root@host1:~# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
07373028ad05 busybox "sh" About a minute ago Exited (0) About a minute ago stoic_jepsen
b89ca1da78c3 busybox "sh" About a minute ago Up About a minute sad_sanderson
7874b10cb1d4 httpd "httpd-foreground" 2 minutes ago Up 2 minutes 80/tcp keen_yalow
root@host1:~# docker container ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
07373028ad05 busybox "sh" About a minute ago Exited (0) About a minute ago stoic_jepsen
b89ca1da78c3 busybox "sh" About a minute ago Up About a minute sad_sanderson
7874b10cb1d4 httpd "httpd-foreground" 2 minutes ago Up 2 minutes 80/tcp keen_yalow
root@host1:~# docker container ls -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
07373028ad05 busybox "sh" About a minute ago Exited (0) About a minute ago stoic_jepsen
b89ca1da78c3 busybox "sh" 2 minutes ago Up 2 minutes sad_sanderson
7874b10cb1d4 httpd "httpd-foreground" 2 minutes ago Up 2 minutes 80/tcp keen_yalow
docker container top container
如果想知道某容器运行了哪些进程，可以执行 docker top
还可以在最后面跟上linux中ps的参数 -aux
root@host1:~# docker top --help
Usage: docker top CONTAINER [ps OPTIONS]
Display the running processes of a container
root@host1:~# docker container top --help
Usage: docker container top CONTAINER [ps OPTIONS]
Display the running processes of a container
root@host1:~# docker run -d --name lamp mattrayner/lamp
b67aded0f855a3d02c3b19539667a76ca88fe927d5ade9322d94f7cb0a0a0d82
root@host1:~# docker container top lamp
UID PID PPID C STIME TTY TIME CMD
root 22808 22789 0 09:26 ? 00:00:00 /usr/bin/python /usr/bin/supervisord -n
root 23408 22808 0 09:27 ? 00:00:00 /bin/sh /usr/bin/mysqld_safe
root 23409 22808 0 09:27 ? 00:00:00 apache2 -D FOREGROUND
usera 23811 23409 0 09:27 ? 00:00:00 apache2 -D FOREGROUND
usera 23812 23409 0 09:27 ? 00:00:00 apache2 -D FOREGROUND
usera 23815 23409 0 09:27 ? 00:00:00 apache2 -D FOREGROUND
usera 23817 23409 0 09:27 ? 00:00:00 apache2 -D FOREGROUND
usera 23818 23409 0 09:27 ? 00:00:00 apache2 -D FOREGROUND
999 23826 23408 1 09:27 ? 00:00:00 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib/mysql/plugin --user=mysql --log-error=/var/log/mysql/error.log --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/run/mysqld/mysqld.sock --port=3306 --log-syslog=1 --log-syslog-facility=daemon --log-syslog-tag=
root@host1:~# docker top lamp
UID PID PPID C STIME TTY TIME CMD
root 22808 22789 0 09:26 ? 00:00:00 /usr/bin/python /usr/bin/supervisord -n
root 23408 22808 0 09:27 ? 00:00:00 /bin/sh /usr/bin/mysqld_safe
root 23409 22808 0 09:27 ? 00:00:00 apache2 -D FOREGROUND
usera 23811 23409 0 09:27 ? 00:00:00 apache2 -D FOREGROUND
usera 23812 23409 0 09:27 ? 00:00:00 apache2 -D FOREGROUND
usera 23815 23409 0 09:27 ? 00:00:00 apache2 -D FOREGROUND
usera 23817 23409 0 09:27 ? 00:00:00 apache2 -D FOREGROUND
usera 23818 23409 0 09:27 ? 00:00:00 apache2 -D FOREGROUND
999 23826 23408 1 09:27 ? 00:00:00 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib/mysql/plugin --user=mysql --log-error=/var/log/mysql/error.log --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/run/mysqld/mysqld.sock --port=3306 --log-syslog=1 --log-syslog-facility=daemon --log-syslog-tag=
root@host1:~# docker top lamp -aux
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 22808 0.1 0.9 51188 18704 ? Ss 09:26 0:00 /usr/bin/python /usr/bin/supervisord -n
root 23408 0.0 0.0 4504 1632 ? S 09:27 0:00 /bin/sh /usr/bin/mysqld_safe
root 23409 0.0 1.5 524236 32268 ? S 09:27 0:00 apache2 -D FOREGROUND
usera 23811 0.0 0.5 524268 10496 ? S 09:27 0:00 apache2 -D FOREGROUND
usera 23812 0.0 0.5 524268 10496 ? S 09:27 0:00 apache2 -D FOREGROUND
usera 23815 0.0 0.5 524268 10496 ? S 09:27 0:00 apache2 -D FOREGROUND
usera 23817 0.0 0.5 524268 10496 ? S 09:27 0:00 apache2 -D FOREGROUND
usera 23818 0.0 0.5 524268 10496 ? S 09:27 0:00 apache2 -D FOREGROUND
999 23826 0.1 10.1 1757648 207788 ? Sl 09:27 0:00 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib/mysql/plugin --user=mysql --log-error=/var/log/mysql/error.log --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/run/mysqld/mysqld.sock --port=3306 --log-syslog=1 --log-syslog-facility=daemon --log-syslog-tag=
docker container stats
该命令用于显示每个容器各种资源的使用情况，默认会显示一个实时变化的列表，展示每个容器的CPU、MEM的使用率和可用量，还有网络和IO的情况。
ps：容器启动时如果没有特别指定内存 limit 、stats命令会显示host的内存总量，但这并不意味着每个容器都能使用到这么多大的内存。
我们还可以查看指定容器的性能，只需在后面指定容器的名字即可，可以是一个，也可以是多个。
root@host1:~# docker stats --help
Usage: docker stats [OPTIONS] [CONTAINER...]
Display a live stream of container(s) resource usage statistics
Options:
-a, --all Show all containers (default shows just running)
--format string Pretty-print images using a Go template
--no-stream Disable streaming stats and only pull the first result
--no-trunc Do not truncate output
root@host1:~# docker container stats --help
Usage: docker container stats [OPTIONS] [CONTAINER...]
Display a live stream of container(s) resource usage statistics
Options:
-a, --all Show all containers (default shows just running)
--format string Pretty-print images using a Go template
--no-stream Disable streaming stats and only pull the first result
--no-trunc Do not truncate output
root@host1:~# docker container stats
CONTAINER ID NAME CPU % MEM USAGE / LIMIT MEM % NET I/O BLOCK I/O PIDS
b67aded0f855 lamp 0.04% 206.7MiB / 1.953GiB 10.34% 648B / 0B 4.61MB / 398MB 35
3c9c0f060dd0 admiring_bohr 0.04% 200.9MiB / 1.953GiB 10.05% 648B / 0B 60.6MB / 375MB 35
b89ca1da78c3 sad_sanderson 0.00% 56KiB / 1.953GiB 0.00% 648B / 0B 0B / 0B 1
7874b10cb1d4 keen_yalow 0.00% 7.566MiB / 1.953GiB 0.38% 1.3kB / 0B 0B / 0B 82
root@host1:~# docker container stats lamp admiring_bohr
CONTAINER ID NAME CPU % MEM USAGE / LIMIT MEM % NET I/O BLOCK I/O PIDS
b67aded0f855 lamp 0.04% 206.7MiB / 1.953GiB 10.34% 648B / 0B 4.61MB / 398MB 35
3c9c0f060dd0 admiring_bohr 0.04% 209.1MiB / 1.953GiB 10.45% 648B / 0B 60.6MB / 375MB 35
ps、top、stats这几个命令是docker 自带的，有点是运行方便，很适合想快速了解容器运行状态的场景。缺点是输出的数据有限，而且都是实时数据，无法反应历史变化和趋势。
