I am deploying a Java Spring server using Docker. Here are the steps:
1. Launch a ubuntu server
In this demo, assume you have a server launched with ubuntu 14.04. Install docker via APT repository:
$ sudo apt-get update
$ sudo apt-get install apt-transport-https ca-certificates
$ sudo apt-key adv — keyserver hkp://p80.pool.sks-keyservers.net:80 — recv-keys 58118E89F3A912897C070ADBF76221572C52609D
Open /etc/apt/sources.list.d/docker.list with your favorite editor and add this line:
deb https://apt.dockerproject.org/repo ubuntu-trusty main
Install docker in the server as follow:
$ sudo apt-get update
$ sudo apt-get install docker-engine
$ sudo service docker start
2. Build Docker image
Login to Docker hub (https://hub.docker.com/) and create a new repository. Then in your terminal,
$ docker login
with your username and password.
In your local development Java spring folder, create a Dockerfile like this:
FROM frolvlad/alpine-oraclejdk8:slim
VOLUME /tmp
ADD target/fleet-beacon*.jar app.jar
EXPOSE 8080
RUN sh -c ‘touch /app.jar’
ENTRYPOINT [“java”, “-jar”,”/app.jar”]
And build the image:
$ docker build -t username/repo-name .
*where -t stands for tag,
*replace username and repo-name with your namespace.
*also don’t forget the dot .
Push the image to your remote repository:
$ docker push username/repo-name
3. Pull the docker image
In your remote ubuntu server, docker login and pull the image:
$ docker pull username/repo-name
Run it in the background
$ docker run -d -p 8080:8080 username/repo-name
*where -d means detached,
*-p means publish all exposed ports to the host interfaces, for example 8080 to 8080.
4. Nginx setup
With the vim editor, open the file in /etc/nginx/sites-available/default, and edit as follow
server {
listen 80 default_server;
listen [::]:80 default_server ipv6only=on;
root /usr/share/nginx/html;
index index.html index.htm;
server_name localhost;
location / {
proxy_set_header X-Forwarded-Host $host;
proxy_set_header X-Forwarded-Server $host;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_pass http://localhost:8080/;
}
Exit and save with :wq! that’s it. Open a browser and point to your remote server IP, you should be able to see the Java Spring page running.
5. Troubleshooting
Sometimes if you encounter a problem with the daemon connection:
Cannot connect to the Docker daemon. Is the docker daemon running on this host?
Run the command:
$ eval $(docker-machine env default)
If your are testing locally and couldn’t find your IP address, try this command to find the IP:
$ docker-machine ls
Leave a comment below if you encounter other issues as well.
Victor Leung 