Kafka 0.11 on debian:stretch

[solsson]

Replaces #3 and #4.

At Yolean we recently evaluated Alpine (3.6) across our services. The small base image size and impressively fast apk saves time in development, but we had to conclude we get more glitches in production (e.g. kubernetes DNS name resolution, default shell not forwarding signals) and a bit more maintenance of our dockerfiles (e.g. 3rd party build scripts not tested with Alpine).

Before I continue with the tuning in Yolean/kubernetes-kafka#30 I wanted to minimize the gambling. To do that I've decided to look at https://github.com/confluentinc/cp-docker-images as a reference setup. We still want to maintain our own Kafka image though, compatible with Docker Hub's automated build feature.

[solsson]

Kafka docs are quite light on JVM requirements. Based on "use the latest released version of JDK 1.8" and confluentinc/cp-docker-images#21 I conclude they assume vendor is Oracle. I don't know anything about Zulu but let's do like Confluent (99f4d45).

Still deviating from Confluent's image builds in many aspects. For example they are:

• Not using the official Kafka distribution.
• Tested only with --net=host (judging by the docs) which we don't want in Kubernetes.
• Encouraging config by env, which is docker-ish but we've had to conclude in for example Multizone rack awareness Yolean/kubernetes-kafka#41 that we need .properties files modified by init containers.

[solsson]

Ouch... 99f4d45 added almost 200MB to image size. 231MB instead of 37MB for the installation layer.

[solsson]

RC build: solsson/kafka:0.11.0.0@sha256:be80af0f63b6c980d557193fec7927c3903d07ef3ab01ead6a33cff35b0440ce

TODO document

• Upgrade from previous image versions
• log4j.properties
• Pointer towards how to set up clusters

[solsson]

It would save some pull time at minor kafka upgrades if Zulu and Kafka were installed in separate layers. However due to the lack of build cache with Docker Hub automated build, the way to do this would be to maintain a Zulu image. For now let's stick with the single build strategy.

[solsson]

Interesting: https://github.com/kubernetes/contrib/tree/master/statefulsets/kafka

[solsson]

Merging this without a decision on #10. Let's keep Kafka as vanilla as possible for now (though with 2MB site-docs removed). At /opt/kafka that is.

[solsson]

Built from master: solsson/kafka@sha256:75ecbf6c7fb9f814a0ab0e44c5d48d3cb4dd688a244a377f6986eefcb1498614 and solsson/kafka:0.11.0.0@sha256:e09d493ae027bbe45d82dc5b9ceaae40adad23efb2936116b233b7dce48136ba.

[solsson]

The docs TODOs above were fixed in master, 4a7b8da.