getting started with docker-mysql-nodejs

Running a nodejs application with mysql database using docker and microservice architecture

Our end goal

• Launch mysql server in a docker container.
• Launch our simple node app in a separate container.
• Link these two containers and test our integrated mysql-nodejs app.

Youtube link-

Watch this tutorial at https://youtu.be/tIbMSqTEpfY

Prerequisite

• must have docker set up and running on your system

Launching mysql in a container

1. Create a directory for our tutorial mkdir getting-started-docker-mysql-nodejs

2. Move to this directory cd getting-started-docker-mysql-nodejs/

3. Create a directory for our mysql microservice mkdir mysql-microservice

4. Move to this directory cd mysql-microservice/

5. Create a Dockerfile with following content (name of file will be Dockerfile)

   ## Pull the mysql:5.7 image
   FROM mysql:5.7
   
   ## The maintainer name and email
   MAINTAINER Your Name <[email protected]>
   
   # database = test and password for root = password
   ENV MYSQL_DATABASE=test \
       MYSQL_ROOT_PASSWORD=password
   
   # when container will be started, we'll have `test` database created with this schema
   COPY ./test-dump.sql /docker-entrypoint-initdb.d/
   
   

6. We'll initialize our test database with a sample schema. Download test-dump.sql and put it inside mysql-microservice folder along with Dockerfile

7. Create a data directory where mysql will store its content mkdir data. We will specify this directory wile running our mysql container. On Linux default storage directory is /var/lib/mysql but in this tutorial we'll use a custom storage directory.

8. Build the image with Dockerfile docker build -t test-mysql . Note that we are inside mysql-microservice directory. test-mysql would be name of our image

9. You can check your newly built image using docker images

10. Run the newly created docker image as container

    docker run  -d \
    --publish 6603:3306 \
    --volume=/home/varunkumar/getting-started-docker-mysql-nodejs/mysql-microservice/data:/var/lib/mysql \
    --name=test-mysql-microservice test-mysql
    

11. With above command we started our container in detach mode -d and mapped host(your machine) port 6603 with container port 3306 (mysql server) --publish 6603:3306. We are also using our custom data storage directory by specifying host path volume --volume. Replace /home/varunkumar/getting-started-docker-mysql-nodejs/mysql-microservice/data path to absolute path of data directory which you created on your system. We are also naming our container as test-mysql-microservice --name

12. Check logs to see if everything went smooth docker logs test-mysql-microservice

13. Check your container state docker ps

14. We have successfully launched a mysql container

Connecting to newly launched mysql container from host (optional)

To verify that our test-mysql-microservice container is up and running, we'll connect to it. Follow below steps if you have mysql (mysql-client) installed on your system.

1. Check the ip of your system. On Linux use ifconfig. Lets say that ip is 192.168.43.147

2. Connect to test-mysql-microservice container with following params- user-root, host=192.168.43.147, port=6603, database=test and password=password. Remember that we have specified root username and password in Dockerfile. Also our container is initialized with test-dump.sql (a schema with database name test)

3. mysql -u root -p -h 192.168.43.147 -P 6603 -D test Use password=password when prompt and hit enter

4. If connected successfully you can see a sample table students show tables exit when done.

Launching nodejs app in a container

1. Right now we are in mysql-microservice directory. We go to project root directory cd ..

2. create directory for node microservice mkdir nodejs-microservice

3. Move to this directory cd nodejs-microservice/

4. Create a Dockerfile with following content (name of file will be Dockerfile)

   # Use Node v8 as the base image.
   FROM node:8
   
   # create and set app directory
   RUN mkdir -p /usr/src/app
   WORKDIR /usr/src/app
   
   # Install app dependencies
   # A wildcard is used to ensure both package.json AND package-lock.json are copied
   # where available (npm@5+)
   COPY package*.json ./
   RUN npm install
   
   # Copy app source from current host directory to container working directory
   COPY . .
   
   # Run app
   CMD ["npm", "start"]
   
   

5. We need a package.json file for our node-microservice app as well as source code. For this tutorial, I've already created one. Download package.json as well as index.js and put it inside nodejs-microservice folder along with Dockerfile.

6. Build the image with Dockerfile docker build -t test-nodejs . Note that we are inside nodejs-microservice directory. test-nodejs would be name of our image

7. You can check your newly built image using docker images

8. Run the newly created docker image as container

   docker run  -d \
   --publish 4000:4000 \
   -e MYSQL_USER='root' \
   -e MYSQL_PASSWORD='password' \
   -e MYSQL_DATABASE='test' \
   -e MYSQL_HOST='172.17.0.2' \
   --link test-mysql-microservice:db \
   --name=test-nodejs-microservice test-nodejs
   

9. Explaination of above command-

• -d run in detach mode
• --publish map the host port 4000 to the container port 4000
• -e pass environment variables to nodejs app necessary to make mysql connection (check index.js file)
• --link test-mysql-microservice:db link to the container named test-mysql-microservice and refer to it as db
• --name naming our container as test-nodejs-microservice

10. How to know your MYSQL_HOST- Note that I am using 172.17.0.2 ip-address as MYSQL_HOST. This is the IpAddress of our test-mysql-microservice container. You must replace this value to your container's ipAddress. Use docker inspect test-mysql-microservice | grep IPAddress

Testing our complete app

If everything is good so far then congratulations 😄 You have a complete app running with two microservices. To test this you can use CURL command from your host machine

1. Get homepage of your app curl -X GET localhost:4000

2. Get list of all students from test database curl -X POST 192.168.43.147:4000/get-students Here 192.168.43.147 is my host IpAddress ifconfig | grep inet

3. Add a new student to your test db curl --header "Content-Type: application/json" -d '{"rollNo": 1130360, "name": "Abhishek Goswami"}' -X POST localhost:4000/add-student

4. Again fetch all students to see updated results curl -X POST 192.168.43.147:4000/get-students

5. Modify source code of nodejs app, build image, run container and test again.

Queries/Comments

You can contact me at [email protected] or create github issues.