dleske

Hopefully helped another k8s newbie with the following. The question was, how do you update a single key in a secret in k8s? I don't know anything about secrets but I will probably want to know this in the future, so here we go.

First, to create a dummy secret:

apiVersion: v1
kind: Secret
metadata:
  name: test-secret
data:

dleske

Basic guide to deploying a simple three-node Lustre cluster on Centos 7.

Updated fork of joshuar/Three-Node-LustreFS-Cluster-Quickstart.md, which was based on Intel's How to Create and Mount a Lustre Filesystem.

Overview

(Note: I am a newbie to Lustre so this overview is extremely light and hopefully what depth there is isn't full of mistakes!)

Note on changes

dleske

diff -uNr harbor.orig/install.sh harbor/install.sh
--- harbor.orig/install.sh	2023-06-02 11:46:12.000000000 +0000
+++ harbor/install.sh	2023-07-26 18:04:48.666624099 +0000
@@ -19,6 +19,8 @@
 with_clair=$false
 # trivy is not enabled by default
 with_trivy=$false
+# assume no systemd for now
+have_systemd=$false

dleske

#!/usr/bin/env python3
#
# Reads certificate information from Terraform output and creates certificate
# files ready for use.
#
# If Terraform variable for certificates is defined like:
#
#   variable certificates {
#     type = map(string)
#     default = {}

dleske

docs/%.md: myapp/%.py misc/pdoc-templates/text.mako
        @pdoc3 --template-dir=misc/pdoc-templates myapp.$* > $@

docs: docs/mymodule.md docs/othermodule.md

dleske

#!/bin/sh
#
# Checks if upstream image has been updated, and if so, triggers automatic build
# on Dockerhub.  Use this for official images, which are no longer directly supported
# by Dockerhub's automatic builds.
#
# Assumes presence of "notify" script which takes a title, message, and optional
# reference URL.
#
# Create a build trigger in your Docker Hub repository via

dleske

class DirtyDict(dict):
  """
  DirtyDict behaves (hopefully) like a regular dict but overrides mutator
  methods to mark the dictionary dirty.  In this way changes to the data are
  tracked in order to, for example, keep related database objects in sync.
  """

  def __init__(self, *args, **kwargs):
    self._dirty = False
    self._created = []

dleske

Original message in kubernetes-novice Slack:

I am using Container Linux with Kubespray and I have found that after a short while new deployments all fail due to pod errors with: Pod sandbox changed, it will be killed and re-created. and subsequently, Failed create pod sandbox. This happens repeatedly. It appears that the issue is due to Container Linux automatically updating itself and rebooting the node. In the end, deployments only work on the masters, which have a No reboots update strategy, but in my understanding this only means the masters will not reboot automatically--the update is still downloaded and if/when the masters are rebooted, they will also be in the same state. I have compared a node that hasn’t yet updated to an updated node and can’t find any differences. Has anybody else seen this?

Took it to #kubespray on advice of a friendly user. Others have seen it but were messing about with routing and such. Furth

dleske

Kubernetes Cheat Sheet

kubectl

get OS information about all nodes

Or use as a pattern for other queries. Replace the OS image JSON path with whatever you want.

$ kubectl get nodes -o custom-columns='NAME:.metadata.name,OS:.status.nodeInfo.osImage'

dleske

E0220 06:48:00.109771       1 event.go:209] Unable to write event: 'Post https://localhost:6443/api/v1/namespaces/default/events: dial tcp 127.0.0.1:6443: getsockopt: connection refused' (may retry after sleeping)
E0220 06:48:00.109837       1 reflector.go:205] k8s.io/kubernetes/pkg/client/informers/informers_generated/internalversion/factory.go:85: Failed to list *core.Service: Get https://localhost:6443/api/v1/services?limit=500&resourceVersion=0: dial tcp 127.0.0.1:6443: getsockopt: connection refused
E0220 06:48:00.109978       1 reflector.go:205] k8s.io/kubernetes/pkg/client/informers/informers_generated/internalversion/factory.go:85: Failed to list *core.Endpoints: Get https://localhost:6443/api/v1/endpoints?limit=500&resourceVersion=0: dial tcp 127.0.0.1:6443: getsockopt: connection refused
E0220 06:48:01.110568       1 reflector.go:205] k8s.io/kubernetes/pkg/client/informers/informers_generated/internalversion/factory.go:85: Failed to list *core.Service: Get https://localhost:6443/api/v1/services?lim