From 964057cd52eb0983bbbfbd36d17f1a5396e04709 Mon Sep 17 00:00:00 2001 From: Jerome Petazzoni Date: Fri, 1 Mar 2019 19:04:39 -0600 Subject: [PATCH] Add troubleshooting instructions to Helm exercise When following all the instructions, the Helm Chart that we create is buggy, and the app shows up but with a zero hash rate. This explains why, and how to fix it. Fixes #432 --- slides/k8s/namespaces.md | 41 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 40 insertions(+), 1 deletion(-) diff --git a/slides/k8s/namespaces.md b/slides/k8s/namespaces.md index a2ec544f..68261602 100644 --- a/slides/k8s/namespaces.md +++ b/slides/k8s/namespaces.md @@ -189,7 +189,46 @@ we created our Helm chart before. ] -Note: it might take a minute or two for the app to be up and running. +If the graph shows up but stays at zero, check the next slide! + +--- + +## Troubleshooting + +If did the exercices from the chapter about labels and selectors, +the app that you just created may not work, because the `rng` service +selector has `enabled=yes` but the pods created by the `rng` daemon set +do not have that label. + +How can we troubleshoot that? + +- Query individual services manually + + → the `rng` service will time out + +- Inspect the services with `kubectl describe service` + + → the `rng` service will have an empty list of backends + +--- + +## Fixing the broken service + +The easiest option is to add the `enabled=yes` label to the relevant pods. + +.exercise[ + +- Add the `enabled` label to the pods of the `rng` daemon set: + ```bash + kubectl label pods -l app=rng enabled=yes + ``` + +] + +The *best* option is to change either the service definition, or the +daemon set definition, so that their respective selectors match correctly. + +*This is left as an exercise for the reader!* ---