example.java.helloworld

This is "Hello World" Example for Java.

Compile class

For compile the main class for package, execute the follow command: ::

javac HelloWorld/Main.java

This generate the Main.class file into HelloWorld directory.

Run class

For run the main class for package, execute the follow command: ::

java -cp . HelloWorld.Main

This show the Hello world message. Ctrl + c to interrupt

Create a JAR file

For pack the main class for package as a JAR file, execute the follow command: ::

jar cfm Main.jar Manifest.txt HelloWorld/Main.class

Run a JAR file

For run the JAR file packed, execute the follow command: ::

java -jar Main.jar

This show the Hello world message and type that it's alive. Ctrl + c to interrupt

Docker build

To build local docker image run: docker build app

Where app is the directory, where Dockerfile is located.

Sending build context to Docker daemon  4.096kB
Step 1/4 : FROM openjdk:8
 ---> c14ba9d23b3a
Step 2/4 : ADD Main.jar Main.jar
 ---> Using cache
 ---> cd01ac514fc0
Step 3/4 : EXPOSE 8080
 ---> Using cache
 ---> 2184856efa48
Step 4/4 : ENTRYPOINT java -jar Main.jar
 ---> Using cache
 ---> ca4f636e0e79
Successfully built ca4f636e0e79

After this wee can tag the local image ( change ID!) : docker tag ca4f636e0e79 javahelloworld

Now we can run container from local image javahelloworld (ctrl +c to interrupt): :: docker run javahelloworld

To run container in detached mode: :: docker run --name javahelloworldapp -d javahelloworld:latest

Where javahelloworldapp is the container name

Look at the status:

docker ps
CONTAINER ID        IMAGE                   COMMAND                CREATED             STATUS              PORTS               NAMES
5c7e34ff4460        javahelloworld:latest   "java -jar Main.jar"   43 seconds ago      Up 42 seconds       8080/tcp            javahelloworldapp

In order to stop running container: :: docker stop javahelloworldapp or :: docker stop 5c7e34ff4460 Where 5c7e34ff4460 is the container ID

To see log output of running container: :: docker logs javahelloworldapp

To follow the log (ctrl +c to interrupt): :: docker logs -f 5c7e34ff4460 or :: docker logs -f javahelloworldapp

Docker hub

Create dockerhub account. Run docker login and enter credentials.

Create a tag by running docker tag LOCALIMAGE:VERSION DOCKERHUBUSER/DOCKERHUNREPO:VERSION:

docker tag javahelloworld aliaskov/javahelloworld:latest Push image to dockerhub: :: docker push aliaskov/javahelloworld

Also possible: :: docker build -t aliaskov/javahelloworld:latest app

Get full image info : :: docker inspect aliaskov/javahelloworld

Run Mysql container

docker run -p 3306:3306 --name mysqlDB -e MYSQL_ROOT_PASSWORD=my-secret-pw -v /opt/mysql-data:/var/lib/mysql -d mysql:latest Where: some-mysql is the container name -e MYSQL_ROOT_PASSWORD - environment variable my-secret-pw - mysql root password -d - detached mode mysql:latest - image name and version tag -v /opt/mysql-data:/var/lib/mysql volume mount to save DB files, where /opt/mysql-data - host dir and /var/lib/mysql - container dir

Stop mysql container docker stop some-mysql

Start mysql container docker start some-mysql

Docker-compose

#docker-compose version
version: '3.3'

#Services we configure to run
services:

# Database service name.
# This name is used to refer this "service" inside of this docker-compose.yml configuration file
# When docker-compose will be started, db container will be visible to other containers of this file by name "db"
  db:

#   By this name db container will be accessible, using docker commands, intead of container name,
#   like, docker logs -f db
    container_name: db

#    Image, we want to build container from
    image: mysql:5.7

#   Environment variables we pass inside of the container, like JAVA_HOME
    environment:
      - MYSQL_ROOT_PASSWORD=r00t

#   Ports we want to bind our container with host OS
    ports:
      - "3306:3306"

# Java application service name.
# This name is used to refer this "service" inside of this docker-compose.yml configuration file
# When docker-compose will be started, web container will be visible to other containers of this file by name "web"
  app:

#   By this name "web" container will be accessible, using docker commands, instead of container name,
#   like: docker logs -f db
    container_name: app

#   We define, how we want to build our container.
#   Here, we are providing configuration to build, using Dockerfile
    build:

#     Dockerfile location
      dockerfile: app/Dockerfile

#     Dockerfile context. Like "working directory" or "workspace" of Dockerfile.
#     This configuration provides so-called "base path" for Dockerfile
      context: app/

#   Ports we want to bind our container with host OS
    ports:
    - "8080:8080"

#   Environment variables we pass inside of the container, like JAVA_HOME
    environment:
    - MYSQL_ROOT_PASSWORD=r00t
    - MYSQL_ROOT_USERNAME=root
    - START_DELAY=20000

#   This container (web) will start only, after "db" starts.
#   There is no reason to start web, if db is not started
    depends_on:
      - db

Reference

• java - [How to run a JAR file - Stack Overflow] [http://stackoverflow.com/questions/1238145/how-to-run-a-jar-file]