Sample Spring-boot "MyBLOG" Project.

This is a sample Java / Maven / Spring Boot (version 2.0.4) application that exposes a few web services for sample MyBLOG project.

This application is packaged as jar file which can be run on a docker container. The tomcat is embedded in the application set-up so no need to configure it separately. In order to run the application you must need to install few things as follows.

Java 1.8 or higher
Maven
Docker

About the Service

This API exposes the following services:

Create a new blog entry.
Update a blog entry.
Delete a blog entry.
View a particular blog entry.
View all the blog entry in the database.

Sample request: For Create: http://localhost:8080/myblog/create

{
  "createBy": "string",
  "data": "string",
  "lastUpdateBy": "string"
}

For Update: http://localhost:8080/myblog/update

{
  "id": "2",
  "data": "string",
  "lastUpdateBy": "string"
}

For delete: http://localhost:8080/myblog/delete/{id}

For View particular blog: http://localhost:8080/myblog/view/{id}

For View all: http://localhost:8080/myblog/viewall

How to Run

Once the Java, maven and Docker are installed successfully you need to unzip[my-blog.jar] the source code provided in a suitable location.

Open the cmd on windows/mac OS command line with Admin Privilages.
Go to the path where you extracted the project [eg.: C:\springBoot\my-blog].
Build the project and run the tests by running mvn clean package
It will create a JAR my-blog-1.0.jar inside the target folder.

Congrats you have build your application successfully!

Next step is to create a docker container and deploy the application on it.

Open the Powershell on windows/mac OS command line with Admin Privilages.
Go to the path where you extracted the project [C:\springBoot\my-blog].

Run the following commands to set-up and start mysql in docker. It will download the mysql 5.6 image from docker hub and run for you.

docker pull mysql:5.6
docker run --name=mysql-db --env="MYSQL_ROOT_PASSWORD=root" --env="MYSQL_PASSWORD=root" --env="MYSQL_DATABASE=myblog" mysql:5.6

Now, once mysql is up and running, its time to start our REST Application. Run the following commands to start our application in a docker container: It will create a docker image of our application with the name my-blog-1.0.

docker build -f Dockerfile -t my-blog-1.0 .

It will link our application image with mysql image and start our application at PORT 8080.

docker run -t --name my-blog-1.0 --link mysql-db:mysql -p 8080:8085 my-blog-1.0

After running the above command you should see following output in the console:

2018-09-15 17:53:06.973  INFO 1 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8085 (http) with context path ''
2018-09-15 17:53:06.979  INFO 1 --- [           main] com.sb.myblog.LaunchApplication          : Started LaunchApplication in 8.054 seconds (JVM running for 9.083)

You can access the application at http://localhost:8080/swagger-ui.html#/

Afternote

You can access the mysql client with following docker command and access the database:

docker run -it --link mysql-db:mysql --rm mysql sh -c 'exec mysql -h"$MYSQL_PORT_3306_TCP_ADDR" -P"$MYSQL_PORT_3306_TCP_PORT" -uroot -proot

Troubleshoot docker

If you get an error like below while starting the docker container

Error response from daemon: Conflict. The container name "/my-blog-1.0" is already in use

Than perform following commands to forcefully kill the container.

Restart the docker engine.
docker stop mysql-db
docker rm -f mysql-db
docker stop my-blog-1.0
docker rm -f my-blog-1.0

Restart the containers:

docker pull mysql:5.6
docker run --name=mysql-db --env="MYSQL_ROOT_PASSWORD=root" --env="MYSQL_PASSWORD=root" --env="MYSQL_DATABASE=myblog" mysql:5.6
docker build -f Dockerfile -t my-blog-1.0 .
docker run -t --name my-blog-1.0 --link mysql-db:mysql -p 8080:8085 my-blog-1.0

Some additional things about Docker:

If you change the the JAR name of the application. Make sure you also update all the docker commands accordingly.

docker build -f <docker-file-name> -t <project-jar-name> .
docker run -p <physical machine port>:<docker port> <imagename>

If you change the name of mysql image. Make sure you update all the mysql related docker commands and DB properties in application.properties accordingly.

docker run --name <some-app> --link <mysql_db_name>:mysql -d <application-that-uses-mysql>
docker run -it --link <mysql_db_name>:mysql --rm mysql sh -c 'exec mysql -h"$MYSQL_PORT_3306_TCP_ADDR" -P"$MYSQL_PORT_3306_TCP_PORT" -uroot -proot

Command to forcefully kill a container

docker stop <image-name>
docker rm -f <image-name>