kbld.md

Build Container Image With kbld In Dev Environments

kbld is a CLI that automates image building, image pushing, and deployment configuration updates. kbld does this in four steps:

1. finds image references in your deployment configuration (using image keys)
2. builds images from the referenced source code (specified in a kbld config definition)
3. pushes the images to a registry (optional)
4. records the resulting image references in a yaml file

kbld will automatically give each image a unique tag, which is useful since we are not yet pushing to a remote registry. As soon as images are pushed to a remote registry, tags are converted into digest references.

Fun fact: kbld can work with multiple changing applications simultaneously, which is especially useful during local development.

Setup

• Install kbld CLI
• Install the pack CLI
• Make sure that Docker is up and running

Do

Note that in the deployment definition the container image is 'cncf-demo', and the kbld configuration points image 'cncf-demo' to our current directory, which contains our source code

cat kbld/deployment.yaml

Build an image from the referenced source code and record the resulting image ref in a new file called deployment-kbld.yaml

kbld --file kbld/deployment.yaml | tee kbld/deployment-kbld.yaml

# now in the deployment definition the container image field references our
#  newly-built container image!

# Replace `[...]` with the image tag from the output
#  (everything after 'kbld:')
export TAG=[...]

yq --inplace ".tag = \"$TAG\"" settings.yaml

docker image tag kbld:$TAG cncf-demo:$TAG

• kbld can also push images to a registry. Whether we'll do that or not depends on later choices.
• kbld can also find and update image references within your configuration. Whether we'll do that or not depends on later choices.

Continue The Adventure

• Store Container Image in a Registry