As I contemplate moving my “thing” into production, I’m anticipating aspects of the application that need maintenance and how this can be automated.

I’d been negligent in the maintenance of some of my container images.

I’m using mostly Go and some Rust as the basis of static(ally-compiled) binaries that run in these containers but not every container has a base image of scratch. scratch is the only base image that doesn’t change and thus the only base image that doesn’t require that container images buit FROM it, be maintained.

cAdvisor has long been a favorite monitoring tool of mine. I’m using Docker Compose for local testing and have begun including a cAdvisor in my docker-compose.yaml files.

cadvisor:
  restart: always
  image: google/cadvisor:${CADVISOR_VERSION}
  container_name: cadvisor
  # command:
  # - --prometheus_endpoint="/metrics" # Default
  volumes:
    - "/:/rootfs:ro"
    - "/var/run:/var/run:rw"
    - "/sys:/sys:ro"
    - "/var/snap/docker/current:/var/lib/docker:ro" #- "/var/lib/docker/:/var/lib/docker:ro"
  expose:
    - "8080"
  ports:
    - 8080:8080

I’d not realized until recently, that cAdvisor also surfaces a Prometheus metrics endpoint and so, if you do follow this path and you’re also using Prometheus, don’t forget to add cAdvisor to your Prometheus targets.