1 Containerize Applications¶

Objective:

Use GCP Cloud Source Repositories
Push Images to GCR and DockerHub
Automate local Development with Docker-Compose

Prepare the Cloud Source Repository Environment with Module 6 Assignment¶

This lab can be executed in you GCP Cloud Environment using Google Cloud Shell.

Open the Google Cloud Shell by clicking on the icon on the top right of the screen:

alt text

Once opened, you can use it to run the instructions for this lab.

Cloud Source Repositories: Qwik Start

Step 1 Locate directory where docker-compose manifest going to be stored.

cd ~/ycit019_2022/
git pull       # Pull latest Mod6_assignment

In case you don't have this folder clone it as following:

cd ~
git clone https://github.com/Cloud-Architects-Program/ycit019_2022
cd ~/ycit019_2022/Mod6_assignment/
ls

Step 2 Go into the local repository you've created:

export student_name=<write_your_name_here_and_remove_brakets>

Important

Replace above with your project_id student_name

cd ~/$student_name-notepad

Step 3 Copy Mod6_assignment folder to your repo:

git pull                              # Pull latest code from you repo
cp -r ~/ycit019_2022/Mod6_assignment/ .

Step 4 Commit Mod6_assignment folder using the following Git commands:

git status 
git add .
git commit -m "adding `Mod6_assignment` with docker-compose manifest"

Step 5 Once you've committed code to the local repository, add its contents to Cloud Source Repositories using the git push command:

git push origin master

Step 6 Review Cloud Source Repositories

Use the Google Cloud Source Repositories code browser to view repository files. You can filter your view to focus on a specific branch, tag, or comment.

Browse the Mod6_assignment files you pushed to the repository by opening the Navigation menu and selecting Source Repositories:

Click Menu -> Source Repositories > Source Code.

Result

The console shows the files in the master branch at the most recent commit.

2 Build and push Docker images to Google Container Registry (GCR)¶

2.1 Build and push `gowebapp-mysql` Image to GCR¶

Step 1 Locate folder with mysql config

cd ~/$student_name-notepad/Mod6_assignment/gowebapp-mysql

Step 2 Review the existing Dockerfile

cat Dockerfile

output:

FROM mysql:8.0

LABEL maintainer "student@mcgill.ca"
LABEL gowebapp-sql "v1"

COPY gowebapp.sql /docker-entrypoint-initdb.d/

Step 2 Set the Project ID in Environment Variable:

export PROJECT_ID=<project_id>

Here is how you can find you project_ID:

Project ID

Set the project ID as default

gcloud config set project $PROJECT_ID

Step 3 Enable the required APIs:

gcloud services enable containerregistry.googleapis.com

Step 4 Build gowebapp-mysql Docker image with GCR registry address locally

docker build -t gcr.io/${PROJECT_ID}/gowebapp-mysql:v1 .

Build the image locally. Make sure to include "." at the end. Make sure the build runs to completion without errors. You should get a success message. Run and test Docker images locally

Step 5 Push the image to gcr.io:

docker push gcr.io/${PROJECT_ID}/gowebapp-mysql:v1

Step 6 Login to GCP console -> Container Registry -> Images

Result

Docker images has been pushed to GCR registry

2.1 Build and push `gowebapp` Image to GCR¶

Step 1 Locate folder with mysql config

cd ~/$student_name-notepad/Mod6_assignment/gowebapp

Step 2 Review the existing Dockerfile

cat Dockerfile

output:

FROM golang:1.16.4

LABEL maintainer "student@mcgill.ca"
LABEL gowebapp "v1"

EXPOSE 80

ENV GO111MODULE=auto
ENV GOPATH=/go

COPY /code $GOPATH/src/gowebapp/

WORKDIR $GOPATH/src/gowebapp/

RUN go get && go install

ENTRYPOINT $GOPATH/bin/gowebapp

Note

We've updated our application to support golang version 1.16.

Step 4 Build gowebapp Docker image with GCR registry address l locally

docker build -t gcr.io/${PROJECT_ID}/gowebapp:v1 .

Build the image locally. Make sure to include "." at the end. Make sure the build runs to completion without errors. You should get a success message. Run and test Docker images locally

Step 5 Push the image to gcr.io:

docker push gcr.io/${PROJECT_ID}/gowebapp:v1

Step 6 Login to GCP console -> Container Registry -> Images

Result

Docker images has been pushed to GCR registry

Step 7 Delete locally build images, as we want to test how images will be pulled from gcr registry in the next step:

docker rmi gcr.io/$PROJECT_ID/gowebapp:v1
docker rmi gcr.io/$PROJECT_ID/gowebapp-mysql:v1

2.3 Test application by running with Docker Engine.¶

Step 1 Create Docker user-defined network

To facilitate cross-container communication, let's first define a user-defined network in which to run the frontend and backend containers:

docker network create gowebapp \
-d bridge \
--subnet 172.19.0.0/16

Step 2 Launch backend container

Next, let's launch a frontend and backend container using the Docker CLI. First, we launch the database container, as it will take a bit longer to startup, and the frontend container depends on it. Notice how we are injecting the database password into the MySQL configuration as an environment variable:

docker run --net gowebapp --name gowebapp-mysql --hostname gowebapp-mysql \
-d -e MYSQL_ROOT_PASSWORD=rootpasswd gcr.io/${PROJECT_ID}/gowebapp-mysql:v1

Step 3 Wait for mysql container to start

docker ps
docker logs <id>

You should see following output: [Server] /usr/sbin/mysqld: ready for connections

Step 3 Launch frontend container

Now launch a frontend container, mapping the container port 80 - where the web application is exposed - to port 8080 on the host machine:

docker run -p 8080:80 --net gowebapp -d --name gowebapp \
--hostname gowebapp gcr.io/${PROJECT_ID}/gowebapp:v1

Step 4 Test the application locally

Now that we've launched the application containers, let's try to test the web application locally.

You should be able to access the application at Google Cloud Web Preview Console:

alt text

Note

Web Preview using port 8080 by default. If you application using other port, you can edit this as needed.

2.4 Cleanup running applications and unused networks¶

docker ps

docker rm -f <container_id_gowebapp> <container_id_gowebapp-mysql>
docker network
docker network rm gowebapp

3 Docker Compose¶

3.1 Test application locally with Docker Compose¶

Task: Automate local testing with Docker Compose by creating docker-compose.yaml file which contains:

User-defined network gowebapp1
Service gowebapp-mysql
Service gowebapp

Reference

Docker Compose v3 documentations

Implementation

Ensure that Mysql start first and then webapp services
Ensure that Mysql database is fully up prior to start webapp services using healthcheck feature of docker compose.
Ensure that webapp-mysqland webapp build with Docker-Compose
Ensure that environment variable MYSQL_ROOT_PASSWORD is set inside of the docker compose file.

Step 1 Create compose file

cd ~/$student_name-notepad/Mod6_assignment

Edit existing docker-compose file:

edit docker-compose.yaml

Create structure as following:

version: '2.4'
services:
  gowebapp-mysql:
    build: ./gowebapp-mysql
    environment:
      MYSQL_ROOT_PASSWORD: rootpasswd
    container_name: gowebapp-mysql
    healthcheck:
      test: "/usr/bin/mysql --user=root --password=rootpasswd --execute \"SHOW DATABASES;\""
      interval: 2s
      timeout: 5s
      retries: 30
    networks:
      - gowebapp1
  gowebapp:
    build: ./gowebapp
    container_name: gowebapp
    ports:
      - "8080:80"
    depends_on:
      gowebapp-mysql:
        condition: service_healthy
    networks:
      - gowebapp1
networks:
  gowebapp1:
    driver: bridge

Step 2 Run compose file

export CLOUDSDK_PYTHON=python2  # https://github.com/google-github-actions/setup-gcloud/issues/128

docker-compose up -d

Step 3 Test the application locally

Now that we've launched the application containers, let's try to test the web application locally.

You should be able to access the application at Google Cloud Web Preview Console:

alt text

Note

Web Preview using port 8080 by default. If you application using other port, you can edit this as needed.

Step 4 Tear down environment

docker-compose down

Step 5 Cleanup created networks

docker network ls

Important

Make sure gowebapp and gowebapp1 networks has been deleted!!!

Step 1 Commit gowebapp and gowebapp-mysql folders using the following Git commands:

git add .
git commit -m "adding docker-compose.yml"

Step 2 Push commit to the Cloud Source Repositories:

git push origin master

3.3 Grant viewing permissions for a repository to Instructors/Teachers¶

Submit link to your Cloud Source Repository to LMS, replace with you values

https://source.cloud.google.com/${PROJECT_ID}/$student_name-notepad

e.g: https://source.cloud.google.com/ycit019_2022-project/ayratk-notepad

1 Containerize Applications¶

Prepare the Cloud Source Repository Environment with Module 6 Assignment¶

2 Build and push Docker images to Google Container Registry (GCR)¶

2.1 Build and push gowebapp-mysql Image to GCR¶

2.1 Build and push gowebapp Image to GCR¶

2.3 Test application by running with Docker Engine.¶

2.4 Cleanup running applications and unused networks¶

3 Docker Compose¶

3.1 Test application locally with Docker Compose¶

3.2 Commit docker-compose file to repository and share it with Instructor/Teacher¶

3.3 Grant viewing permissions for a repository to Instructors/Teachers¶

2.1 Build and push `gowebapp-mysql` Image to GCR¶

2.1 Build and push `gowebapp` Image to GCR¶