在docker宿主机上查找指定容器内运行的所有进程的PID

找到指定容器的所有进程的PID可以更方便的对容器进程进行管理，特别是在某些容器卡住无法连接的场景。

1、找出容器ID

# docker ps

2、进入相应目录

# cd /sys/fs/cgroup/memory/docker/d14e1a6182eeed7c8f2a7c0a315a790a16bfbab1fdc7a73813cdeee494e8050a/

3、进程号就存在一个文件里面

# cat cgroup.procs
1761
1869
1877
1892
1900
1903
3512
4793
4794

4、查看所有进程，找出对应的进程树分支

# ps auxwwf
...
root      1761  0.0  0.0  11360  2432 pts/13   Ss   06:40   0:00  \_ /bin/bash /root/bin/autoboot.sh
root      1869  0.0  0.0  66744  2772 ?        Ss   06:40   0:00      \_ /usr/sbin/sshd
497       1877  0.0  0.0  41396  2732 ?        Ss   06:40   0:00      \_ /usr/sbin/nrpe -c /etc/nagios/nrpe.cfg -d
root      1892 50.9  1.0 19031092 1068868 pts/13 Sl 06:40 143:06      \_ /usr/local/jdk/bin/java -Djava.util.logging.config.file=/usr/local/tomcat/conf/logging.properties -server -Xms2048m -Xmx2048m -XX:PermSize=256m -XX:MaxPermSize=256m -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/var/log/jvm/tomcat.dump -Xloggc:/var/log/jvm/tomcat_real.log -XX:+PrintGC -XX:+PrintGCDetails -XX:+PrintGCDateStamps -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djava.endorsed.dirs=/usr/local/tomcat/endorsed -classpath /usr/local/tomcat/bin/bootstrap.jar:/usr/local/tomcat/bin/tomcat-juli.jar -Dcatalina.base=/usr/local/tomcat -Dcatalina.home=/usr/local/tomcat -Djava.io.tmpdir=/usr/local/tomcat/temp org.apache.catalina.startup.Bootstrap start
root      1900  0.0  0.0  20508  2304 ?        Ss   06:40   0:00      \_ crond
root      1903  0.0  0.0  11492  2688 pts/13   S+   06:40   0:00      \_ /bin/bash
root      3512 13.5  3.9 3922968 3892780 ?     Ssl  06:46  37:15      \_ /usr/local/bin/redis-server *:6380
root      4793  0.0  0.0 109424  1880 ?        Ss   06:47   0:00      \_ nginx: master process /usr/sbin/nginx -c /etc/nginx/nginx.conf
496       4794  0.0  0.0 109888  4516 ?        S    06:47   0:00          \_ nginx: worker process
...

---

还有一种更有效的获取容器进程的方法，这种方法依赖docker程序，要是程序卡住就无法使用了。

docker top ContainerID

# docker top d14e1a6182eeed7c8f2a7c0a315a790a16bfbab1fdc7a73813cdeee494e8050a
UID                 PID                 PPID                C                   STIME               TTY                 TIME                CMD
root                1761                4765                0                   06:40               pts/13              00:00:00            /bin/bash /root/bin/autoboot.sh
root                1869                1761                0                   06:40               ?                   00:00:00            /usr/sbin/sshd
497                 1877                1761                0                   06:40               ?                   00:00:00            /usr/sbin/nrpe -c /etc/nagios/nrpe.cfg -d
root                1892                1761                50                  06:40               pts/13              02:33:35            /usr/local/jdk/bin/java -Djava.util.logging.config.file=/usr/local/tomcat/conf/logging.properties -server -Xms2048m -Xmx2048m -XX:PermSize=256m -XX:MaxPermSize=256m -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/var/log/jvm/tomcat.dump -Xloggc:/var/log/jvm/tomcat_real.log -XX:+PrintGC -XX:+PrintGCDetails -XX:+PrintGCDateStamps -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djava.endorsed.dirs=/usr/local/tomcat/endorsed -classpath /usr/local/tomcat/bin/bootstrap.jar:/usr/local/tomcat/bin/tomcat-juli.jar -Dcatalina.base=/usr/local/tomcat -Dcatalina.home=/usr/local/tomcat -Djava.io.tmpdir=/usr/local/tomcat/temp org.apache.catalina.startup.Bootstrap start
root                1900                1761                0                   06:40               ?                   00:00:00            crond
root                1903                1761                0                   06:40               pts/13              00:00:00            /bin/bash
root                3512                1761                13                  06:46               ?                   00:39:38            /usr/local/bin/redis-server *:6380
root                4793                1761                0                   06:47               ?                   00:00:00            nginx: master process /usr/sbin/nginx -c /etc/nginx/nginx.conf
496                 4794                4793                0                   06:47               ?                   00:00:00            nginx: worker process

---

还可以单独查看指定容器所属docker子进程的PID。

docker inspect -f '{{.State.Pid}}' CONTAINERID

# docker inspect -f '{{.State.Pid}}' d14e1a6182eeed7c8f2a7c0a315a790a16bfbab1fdc7a73813cdeee494e8050a
1761