Managing Docker Builds

This post will cover topic related to ‘Managing Docker Builds’ with multiple docker command examples and different scenerios. So this will help you to understand the command docker and options available in it. Also this post will explain you how to use docker command.

Docker is a powerful tool for containerizing applications and managing their lifecycle. One of its essential features is the builder option, which facilitates the creation and customization of Docker images through Dockerfiles.

Example 1: Creating a Docker image using a Dockerfile named ‘Dockerfile’:

docker builder build -t myapp .

This command builds an image named ‘myapp’ using the Dockerfile in the current directory (‘.’). The -t option tags the resulting image with ‘myapp’.
To verify, check for the existence of the ‘myapp’ image in Docker:

docker image ls

Example 2: Building an image from a specific Dockerfile path:

docker builder build -t myapp -f path/to/Dockerfile .

Here, -f specifies the path to the Dockerfile relative to the current directory.
Verify the image ‘myapp’ as before.

Example 3: Building an image with build-time arguments:

docker builder build --build-arg APP_VERSION=1.0 -t myapp .

This command sets a build-time argument APP_VERSION to ‘1.0’ and builds the image ‘myapp’.
Check the details of the ‘myapp’ image to verify.

Example 4: Building without using cache:

docker builder build --no-cache -t myapp .

The --no-cache option ensures that no cached layers are used during the build, forcing all layers to be rebuilt.
Verify the absence of cached layers during the build process.

Example 5: Building and removing intermediate containers:

docker builder build --rm -t myapp .

The --rm option removes intermediate containers after a successful build, keeping the system clean.
Ensure intermediate containers are properly cleaned up after the build.

Example 6: Building with multiple Dockerfiles:

docker builder build -f path/to/Dockerfile1 -f path/to/Dockerfile2 -t myapp .

Use multiple -f options to specify different Dockerfiles for building the image ‘myapp’.
Verify the ‘myapp’ image contains the combined configurations from both Dockerfiles.

Example 7: Building with SSH key for private repositories:

docker builder build --ssh github=my_ssh_key -t myapp .

Incorporate an SSH key my_ssh_key for accessing private GitHub repositories during the build.
Ensure the SSH key is correctly configured and accessible within the Docker build environment.

Example 8: Building with secrets:

echo "my_secret_value" | docker builder build --secret id=mysecret,src=- -t myapp .

Use the --secret option to securely pass sensitive information like passwords or tokens into the Docker build context.
Verify that sensitive information is handled securely within the build process.

Example 9: Building with target stages:

docker builder build --target builder_stage -t myapp .

Specify a specific target stage builder_stage from a multi-stage Dockerfile for building the image ‘myapp’.
Verify that only the specified target stage is executed during the build.

Example 10: Building with buildkit:

DOCKER_BUILDKIT=1 docker builder build -t myapp .

Enable buildkit mode by setting DOCKER_BUILDKIT=1 to leverage advanced features and optimizations during the build process.
Verify the buildkit mode is active and observe any performance improvements or changes in behavior.

Also check similar articles.

Searching Docker Hub for Images
Logging out from Docker Registries
Logging in to Docker Registries
Listing Docker Images
Uploading Docker Images to a Registry