Google Cloud Run docker deploy example

In this example we will deploy a simple Flask app to Google Cloud Run using Docker and the Google Arrifact Registry (which could be easily replaced by another container regigistry like Dockerhub).

Prerequisites

• Google Cloud SDK
• Docker
• Enable the Google Cloud Run API
• Enable the Google Artifact Registry API
• Set the appropriate IAM permissions

Test run app locally

Run the following commands in the root directory of the project to configure the virtual environment. Note that other versions of python should work as well, but this is what I'm using.

virtualenv -p python3.10 venv
source venv/bin/activate
pip install -r requirements.txt

The following line will start the Flask app.

python main.py

Variables

The following variables are used throughout this README and should be replaced with the appropriate values for your project.

Variable	Explanation	Example
LOCATION	The region of the Artifact Registry you created in the previous steps	us-central1
PROJECT_NAME	The name of the project you are deploying to	my-project
REPOSITORY_NAME	The name of the repository you created in the previous steps	my-repository
IMAGE_NAME	The name of the image you are building	hello-world
TAG	The version of the image	0.0.1

Create Artifact Registry repository

Do either of the following, where REPOSITORY_NAME is the name of the repository you want to create.

Command line

gcloud artifacts repositories create REPOSITORY_NAME --location=us-central1

Console

Click "+CREATE REPOSITORY" in the Artifact Registry console.

Build docker image

Now we will build the docker image. We will set the name in such way that the image can be pushed to the Artifact Registry in the next steps. MacOS M1 users will need to use a different command.

All other operating systems

docker build -t LOCATION-docker.pkg.dev/PROJECT_NAME/REPOSITORY_NAME/IMAGE_NAME:TAG .

MacOS M1

docker build --platform linux/amd64 -t LOCATION-docker.pkg.dev/PROJECT_NAME/REPOSITORY_NAME/IMAGE_NAME:TAG .

For users that are working on a MacOS M1, the --platform linux/amd64 flag is required to build the image for the x86_64 architecture, otherwise you'll get the "Failed to start and then listen on the port defined by the PORT environment variable" error when creating a Cloud Run service later on. (reference)

Run docker container of the image locally

This command will run a docker container of the image locally:

docker run --env PORT=8080 -p 8080:8080 LOCATION-docker.pkg.dev/PROJECT_NAME/REPOSITORY_NAME/IMAGE_NAME:TAG

The --env flag is used to set the environment variables for the container. Because in the Dockerfile we use the $PORT environment variable, we need to pass the PORT environment variable when running the container. When creating a Cloud Run service, the PORT environment variable is set by the Cloud Run service. The -p flag is used to map the port 8080 of the container to the port 8080 of the host.

Push docker image to Artifact Registry

This command will push the docker image to the Artifact Registry:

docker push LOCATION-docker.pkg.dev/PROJECT_NAME/REPOSITORY_NAME/IMAGE_NAME:TAG

Deploy to Cloud Run

Command line

This command will deploy the docker image to Cloud Run:

gcloud run deploy SERVICE_NAME --image LOCATION-docker.pkg.dev/PROJECT_NAME/REPOSITORY_NAME/IMAGE_NAME:TAG --platform managed --region LOCATION

Console

Click "+CREATE SERVICE" in the Cloud Run console. Fill in the appropriate values for the service and make sure to check the "Allow unauthenticated invocations" checkbox.

Now you should have a stable deployment of your app on Google Cloud Run, which you can acces through the URL generated by the Cloud Run service.