Docker直接拉取的tomcat无法直接启动，所以自己封装一个镜像

1.在之前的文档中有写到过直接pull下来的tomcat直接运行会出现404的错误，因此自己封装一个tomcat，避免再次出现这样的错误。

2.通过：docker ps，查看正在运行的tomcat冗词的id

cdc@cdcs-MacBook-Pro / % docker ps
CONTAINER ID   IMAGE     COMMAND             CREATED             STATUS             PORTS                    NAMES
9fce498cd640   tomcat    "catalina.sh run"   About an hour ago   Up About an hour   0.0.0.0:3355->8080/tcp   test_tomcat

如果docker ps无法查看，可以选择通过：docker ps -a，查看运行过的容器信息

cdc@cdcs-MacBook-Pro / % docker ps -a
CONTAINER ID   IMAGE          COMMAND                  CREATED             STATUS                        PORTS                    NAMES
b210ce86a1e6   5c8857d636ba   "catalina.sh run"        9 minutes ago       Up 9 minutes                  0.0.0.0:3355->8080/tcp   my_tomcat
4d374f83236c   5c8857d636ba   "catalina.sh run"        10 minutes ago      Exited (130) 10 minutes ago                            exciting_spence
9fce498cd640   tomcat         "catalina.sh run"        About an hour ago   Exited (143) 16 minutes ago                            test_tomcat
cc2e021c959a   nginx          "/docker-entrypoint.…"   2 hours ago         Exited (0) 2 hours ago                                 test_nginx
e0108f21b135   centos         "/bin/bash"              2 hours ago         Exited (0) 2 hours ago                                 dreamy_leavitt

3.通过：docker commit -a -m id 容器名:版本信息 ，提交容器到本地信息中。

-a：作者信息

-m：描述信息

cdc@cdcs-MacBook-Pro / % docker commit -a="cdc" -m="添加webapp默认页面" 9fce498cd640 my_tomcat:1.0
sha256:5c8857d636baf7668975f956056b46c317f47601f4705bfad4f10398a74594d4

4.通过：docker images，查看刚刚的提交是否成功

cdc@cdcs-MacBook-Pro / % docker images
REPOSITORY          TAG       IMAGE ID       CREATED         SIZE
my_tomcat           1.0       5c8857d636ba   6 seconds ago   654MB
docker101tutorial   latest    bdbe87be83dd   47 hours ago    27.7MB
alpine/git          latest    ed0ba0fc6585   2 weeks ago     28.4MB
tomcat              latest    feba8d001e3f   2 weeks ago     649MB
nginx               latest    ae2feff98a0c   3 weeks ago     133MB
centos              latest    300e315adb2f   4 weeks ago     209MB
hello-world         latest    bf756fb1ae65   12 months ago   13.3kB

可以看到，第一个就是刚刚提交的信息。

5.通过：docker run，运行刚刚的容器

cdc@cdcs-MacBook-Pro / % docker run -d --name my_tomcat -p 3355:8080 5c8857d636ba
b210ce86a1e607a15acb6dcaf9928e03bc873dc54a2c2166c75921f54963c821

6.打开tomcat，查看是否可以直接运行

7.运行成功