Cinq

This presentation from Google Next 2018 is very good to understand how to use Vault in Kubernetes:

The details of the demos are available on GitHub:

https://github.com/sethvargo/vault-on-gke

The details shown on how to run Vault in Kubernetes and how to get application in Kubernetes to use Vault are very good and help understand how we can deploy our own.

Some applications started to require a newer version of the bash shell on my Mac. Apple ships a version of 3.2 but Bash is up to version 4.4 and Apple is not able to ship a newer version because Bash 4 uses a GPLv3 license.

I found this quick solution where you use homebrew to install the latest Bash version and changing the terminal configuration to use this new shell.

If you don’t have homebrew it is quite easy with this one command:

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

Then you simply have to execute:

brew install bash

Changing the terminal configuration is easy because it is on te first tab of the preferences. Where it says “Shells open with” change from “Default login shell” to “Command (complete path)” and enter this string:

/usr/local/Cellar/bash/4.4.19/bin/bash

Obviously your version may vary depending on what is the latest one available.

 

Reference:
https://apple.stackexchange.com/questions/193411/update-bash-to-version-4-0-on-osx
https://brew.sh/

We have been seeing this intermittently in our different kubernetes clusters, kube-dns is not resolving some hosts names and it is causing failures with some batch jobs or containers that are dependent on others to start.

We know that the networking is working because we are able to reach services or containers with IPs. So I had to stop blaming flannel.

Our Linux architect noticed that br_netfilter module was loaded but not the xt_physdev one.

On each node he fixed it with these commands (first and last ones to verify the loaded modules and second to load the missing module):

[root@server ~]# lsmod | grep br_
br_netfilter 22209 0
bridge 136173 1 br_netfilter

[root@server ~]# modprobe xt_physdev

[root@server ~]# lsmod | grep br_
br_netfilter 22209 1 xt_physdev
bridge 136173 1 br_netfilter

Everything started to work perfectly after that little fix.

I have been working on deploying Kafka on a Kubernetes cluster using the Confluent platform and it has been much harder than I expected.

Deploying their zookeeper in a StatefulSet seemed impossible so I had to switch to using the Google version of zookeeper. I just could not get it to deploy with a serverId that was unique and the Google example made this trivial.

Kafka was easily deployed once Zookeeper was working.

Kafka Connect has been very difficult and I have tried quite a few combinations. Nothing seems to work. Basically, it times out.

If you want to see the latest update to the YAML and some notes to this struggle I have it on Github: https://github.com/cinq/confluent-kafka-k8s