Image

Image

Without image you rely on the default container image

Our runner configuration defaults to alpine

Choose which container image is used for your jobs

Each job can have its own container image

Use official images

Do not use community images

Avoid maintaining custom image

Hands-On

See chapter Image

Pro tip: Using private registries

Private container registries are supported

Credentials must be provided in variable DOCKER_AUTH_CONFIG

• Either defined in pipeline/job
• Or defined globally in runner

Fill DOCKER_AUTH_CONFIG

Variable context matches ~/.docker/config.json

{ "auths": { "reg.comp.org": { "auth": "<user:pass-base64-encoded>" } } }

Fill from environment variables:

jq --null-input \
    --arg host "${REG_HOST}" \
    --arg auth "$(echo "${REG_USER}:${REG_PASS}" | base64 -w0)" \
    '{"auths": {$host:{"auth": $auth}}}'