How to migration exist service as container

如果手上有既有的服務跑在一台Linux的機器上，該怎麼打包docker images

Step1: Analysis how many serice running in exsit sever

Example:

I have a “TPS/PXE server running service” are below

• httpd (TCP/80)
• samba (TCP/139)
• tpserver/java (TCP/9000; TCP/9005)
• tftp/xinetd (UCP/69)
• nfs/portmap (TCP/111; UDP/111; TCP/2049; UDP/2049; TCP/20048; UDP/20048)

Step2: Container each service as microservice

Buildup images by Dockerfile

https://github.com/jerryk2/tps/tree/master/Dockerfile

Step3: Using docker-compose to run all of tps container images

https://docs.docker.com/compose/

Docker Compose is a tool for defining and running multi-container Docker applications.

Docker compose file

https://github.com/jerryk2/tps/blob/master/docker-compose.yml

Perform command:

/usr/bin/docker-compose -f /opt/tps/docker-compose.yml up -d

Step 4: Build-up high availability service by OS cluster or kubernets cluster

$ cat /etc/systemd/system/tps.service
[Unit]
Description=tps
Requires=docker.service
After=docker.service

[Service]
Restart=always
ExecStartPre=/usr/bin/docker-compose -f /opt/tps/docker-compose.yml down -v
ExecStartPre=/usr/bin/docker-compose -f /opt/tps/docker-compose.yml rm -v
ExecStartPre=-/bin/bash -c ‘docker rm -v $(docker ps -aq | gre tps)’
ExecStart=/usr/bin/docker-compose -f /opt/tps/docker-compose.yml up
ExecStop=/usr/bin/docker-compose -f /opt/tps/docker-compose.yml down -v

[Install]
WantedBy=multi-user.target

$ systemctl daemon-reload

$ systemctl status tps.service