Deploy Java Spring server with Docker container

June 02, 2016

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](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

    $ 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/](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.