Workflow Docker Push

In this lesson, you’ll extend your GitHub Actions CI workflow to publish a Docker image to Docker Hub. We’ll build the image for testing, verify it runs correctly, and then push it to your Docker Hub registry—all within a single workflow file.

Ensure you’ve configured the following GitHub repository secrets:

DOCKERHUB_USERNAME
DOCKERHUB_TOKEN
MONGO_URI, MONGO_USERNAME, MONGO_PASSWORD

Updated Workflow Snippet

Add these three steps to your .github/workflows/ci.yml:

# 1. Build the Docker image without pushing
- name: Docker Build for Testing
  uses: docker/build-push-action@v4
  with:
    context: .
    push: false                   # disable push during test build
    tags: ${{ vars.DOCKERHUB_USERNAME }}/solar-system:${{ github.sha }}

# 2. Run tests against the local image
- name: Docker Image Testing
  run: |
    docker images
    docker run --name solar-system-app -d \
      -p 3000:3000 \
      -e MONGO_URI=${{ secrets.MONGO_URI }} \
      -e MONGO_USERNAME=${{ secrets.MONGO_USERNAME }} \
      -e MONGO_PASSWORD=${{ secrets.MONGO_PASSWORD }} \
      ${{ vars.DOCKERHUB_USERNAME }}/solar-system:${{ github.sha }}

    # Inspect container IP and test /live endpoint
    IP=$(docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' solar-system-app)
    echo "Container IP: $IP"
    echo "Testing /live endpoint"
    wget -qO- "http://127.0.0.1:3000/live" | grep live

# 3. Push the tested image to Docker Hub
- name: Docker Push
  uses: docker/build-push-action@v4
  with:
    context: .
    push: true                    # enable push to registry
    tags: ${{ vars.DOCKERHUB_USERNAME }}/solar-system:${{ github.sha }}

After you commit and push, GitHub Actions will execute the build, test, and push steps in sequence.

Step-by-Step Breakdown

Step Name	Action	Description
Docker Build for Testing	`docker/build-push-action@v4`	Builds the image locally without pushing to the registry
Docker Image Testing	`run`	Starts a container, retrieves its IP, and tests the `/live` endpoint
Docker Push	`docker/build-push-action@v4`	Re-builds (using cache) and uploads all layers to Docker Hub

Inspecting the Push Logs

During the Docker Push step you’ll see output similar to:

/usr/bin/docker buildx build \
  --iidfile /tmp/docker-actions-toolkit/iidfile \
  --tag youruser/solar-system:e8095fb98a5b01249548095eaf3a9c371c274430 \
  --push .

This confirms that Buildx is pushing each layer of your image to Docker Hub.

Verify the Image on Docker Hub

Once the workflow completes:

Go to your repository on Docker Hub.
Look under Tags for the SHA-based tag (e.g., e8095fb98a5b01249548095eaf3a9c371c274430).

If you see authentication errors, double-check that DOCKERHUB_TOKEN is up to date and has the correct permissions.

Manual Push (Optional)

You can also push an existing local image with:

docker push youruser/solar-system:tagname

Links and References

Watch Video

Workflow Docker Build and Test

Workflow Login and Push to GHCR

Introduction

Continuous Integration with GitHub Actions

Continuous Deployment with GitHub Actions

Reusable Workflows and Reporting

Custom Actions

Self Hosted Runner

Security Guide

GitHub Actions - Core Concepts

Workflow Docker Push

Updated Workflow Snippet

Step-by-Step Breakdown

Inspecting the Push Logs

Verify the Image on Docker Hub

Manual Push (Optional)

Links and References

Watch Video

​Updated Workflow Snippet

​Step-by-Step Breakdown

​Inspecting the Push Logs

​Verify the Image on Docker Hub

​Manual Push (Optional)

​Links and References

Watch Video

Updated Workflow Snippet

Step-by-Step Breakdown

Inspecting the Push Logs

Verify the Image on Docker Hub

Manual Push (Optional)

Links and References