Docker creates a tomcat/weblogic cluster

Install the tomcat image

Get ready for the jdk, tomcat, and other software you need to put under the home directory and start a container

docker run -t -i -v /home:/opt/data  --name mk_tomcat ubuntu /bin/bash

This command mounts the local home directory to the container's /opt/data directory, which is automatically created if it does not exist. Next is the basic configuration of tomcat, and once the jdk environment variable is set, put the tomcat program under /opt/apache-tomcat Edit the /etc/supervisor/conf.d/supervisor.conf file and add the tomcat item

[supervisord]
nodaemon=true

[program:tomcat]
command=/opt/apache-tomcat/bin/startup.sh

[program:sshd]
command=/usr/sbin/sshd -D

docker commit  ac6474aeb31d  tomcat

Create a new tomcat folder, create a new Dockerfile.

FROM mk_tomcat
EXPOSE  22 8080
CMD ["/usr/bin/supervisord"]

Create a mirror based on Dockerfile.

docker build tomcat tomcat

Install the weblogic image

The steps are basically the same as tomcat, and here's a profile

supervisor.conf
[supervisord]
nodaemon=true

[program:weblogic]
command=/opt/Middleware/user_projects/domains/base_domain/bin/startWebLogic.sh

[program:sshd]
command=/usr/sbin/sshd -D
dockerfile
FROM weblogic
EXPOSE  22 7001
CMD ["/usr/bin/supervisord"]

Use of tomcat/weblogic images

The use of storage

At startup, use the -v parameter

-v, --volume=[]            Bind mount a volume (e.g. from the host: -v /host:/container, from docker: -v /container)

Map the local disk to the inside of the container, which changes in real time between the host and the container, so we just need to update the directory of the physical host to update the program and upload the code

Implementation of tomcat and weblogic clusters

Tomcat just needs to open multiple containers

docker run -d -v -p 204:22 -p 7003:8080 -v /home/data:/opt/data --name tm1 tomcat /usr/bin/supervisord
docker run -d -v -p 205:22 -p 7004:8080 -v /home/data:/opt/data --name tm2 tomcat /usr/bin/supervisord
docker run -d -v -p 206:22 -p 7005:8080 -v /home/data:/opt/data --name tm3 tomcat /usr/bin/supervisord

Here's a look at the configuration of weblogic, and you know that weblogic has a domain concept. If you want to deploy in the regular administrator-node way, you need to write the startup scripts for administor server and node server in supervisord, respectively, which has the advantage of:

• You can use the concepts of weblogic clustering, synchronization, and so on
• Deploy a cluster application that only needs to be installed once and applied to the cluster

The disadvantages are:

• Docker's configuration is complicated
• There is no way to automatically scale the compute capacity of the cluster, so to add nodes, you need to create nodes on the administrator before configuring a new container supervisor startup script, and then start the container

Another approach is to install all the programs on top of adminiserver, and when you need to extend, start multiple nodes, which has the opposite advantages and disadvantages as the last one. (This is recommended for deploying development and test environments)

docker run -d -v -p 204:22 -p 7001:7001 -v /home/data:/opt/data --name node1 weblogic /usr/bin/supervisord
docker run -d -v -p 205:22 -p 7002:7001 -v /home/data:/opt/data --name node2 weblogic /usr/bin/supervisord
docker run -d -v -p 206:22 -p 7003:7001 -v /home/data:/opt/data --name node3 weblogic /usr/bin/supervisord

This allows the configuration to be done by using nginx for load balancing at the front end