From 2c4b6cd96dd45d52065431ad97a034d0444100a7 Mon Sep 17 00:00:00 2001
From: Staffan Olsson <staffan@repos.se>
Date: Tue, 27 Jun 2017 13:08:54 +0200
Subject: [PATCH] Adds probes, but for Kafka I don't think it indicates
 readiness...

which might not matter because we no longer have a loadbalancing service.

These probes won't catch all failure modes,
but if they fail we're pretty sure the container is malfunctioning.

I found some sources recommending ./bin/kafka-topics.sh for probes
but to me it looks risky to introduce a dependency to some other service for such things.
One such source is https://github.com/kubernetes/charts/pull/144

The zookeeper probe is from
https://kubernetes.io/docs/tasks/configure-pod-container/configure-liveness-readiness-probes/
An issue is that zookeeper's logs are quite verbose for every probe.
---
 50kafka.yml          |  6 ++++++
 zookeeper/50pzoo.yml | 12 ++++++++++++
 zookeeper/51zoo.yml  | 12 ++++++++++++
 3 files changed, 30 insertions(+)

diff --git a/50kafka.yml b/50kafka.yml
index 4a57f3d3..862cbe0b 100644
--- a/50kafka.yml
+++ b/50kafka.yml
@@ -47,6 +47,12 @@ spec:
           requests:
             cpu: 100m
             memory: 512Mi
+        livenessProbe:
+          exec:
+            command:
+            - /bin/sh
+            - -c
+            - 'echo "" | nc -w 1 127.0.0.1 9092'
         volumeMounts:
         - name: data
           mountPath: /var/lib/kafka/data
diff --git a/zookeeper/50pzoo.yml b/zookeeper/50pzoo.yml
index 7b949ce6..c8e35426 100644
--- a/zookeeper/50pzoo.yml
+++ b/zookeeper/50pzoo.yml
@@ -60,6 +60,18 @@ spec:
           requests:
             cpu: 10m
             memory: 100Mi
+        livenessProbe:
+          exec:
+            command:
+            - /bin/sh
+            - -c
+            - '[ "imok" == $(echo "ruok" | nc -w 1 127.0.0.1 2181) ]'
+        readinessProbe:
+          exec:
+            command:
+            - /bin/sh
+            - -c
+            - '[ "imok" == $(echo "ruok" | nc -w 1 127.0.0.1 2181) ]'
         volumeMounts:
         - name: config
           mountPath: /usr/local/kafka/config
diff --git a/zookeeper/51zoo.yml b/zookeeper/51zoo.yml
index b73db298..50be93d9 100644
--- a/zookeeper/51zoo.yml
+++ b/zookeeper/51zoo.yml
@@ -60,6 +60,18 @@ spec:
           requests:
             cpu: 10m
             memory: 100Mi
+        livenessProbe:
+          exec:
+            command:
+            - /bin/sh
+            - -c
+            - '[ "imok" == $(echo "ruok" | nc -w 1 127.0.0.1 2181) ]'
+        readinessProbe:
+          exec:
+            command:
+            - /bin/sh
+            - -c
+            - '[ "imok" == $(echo "ruok" | nc -w 1 127.0.0.1 2181) ]'
         volumeMounts:
         - name: config
           mountPath: /usr/local/kafka/config