Is your image really distroless?

Laurent Goderre from Docker. The entire talk was very short, but it was a nice demo of init containers

Baseline

• Security is hard - distroless sounds like a nice helper
• Basic Challenge: Usability-Security Dilemma -> But more usability doesn’t mean less secure, but more updating
• Distro: Kernel + Software Packages + Package manager (optional) -> In Containers just without the kernel
• Distroless: No package manager, no shell, no web client (curl/wget) - only minimal software bundles

Tools for distroless image creation

• Multi-Stage Builds: No cleanup needed and better caching
• Buildkit: More complex, but a pluggable build architecture

The title question

• Well many images don’t include a package manager, but a shell and some tools (busybox)
• Tools are usually included as config-time tools (init) -> They just stay around after init - unused
• Solution: Our lord and savior init containers without any inbound traffic that just does config stuff

Demo

• A (rough) distroless Postgres with alpine build step and scratch final step
• A basic pg:alpine container used for init with a shared data volume
• The init uses the pg admin user to initialize the pg server (you don’t need the admin credentials after this)

Kube

• K apply failed b/c no internet, but was fixed by connecting to Wi-Fi
• Without the init container the pod just crashes, with the init container the correct config gets created

Docker compose

• Just use service_completed_successfully condition in depends on