How can I use custom Docker images in CircleCI?

How can I use custom Docker images in CircleCI?

You can use custom Docker images in CircleCI by specifying the image in your .circleci/config.yml file.

Can you give me an example of how to set that up?

Sure! In your config.yml, you can define a job like this:

version: 2.1
jobs:
  build:
    docker:
      - image: your-custom-image:latest
    steps:
      - checkout
      - run: echo 'Hello, World!'

What if I need to build my own Docker image?

You can build your own Docker image by adding a build step in your CircleCI config. Use the docker executor and a Dockerfile.

Is there a way to cache Docker layers to speed up builds?

Yes, you can use CircleCI's caching feature to cache Docker layers. Just specify the cache paths in your config.