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# Install these packages (use your favorite AUR tool here)
yay -S minikube kubectl docker-machine-driver-kvm2 libvirt qemu-headless ebtables

# Get libvirt going
sudo systemctl enable libvirtd.service
sudo usermod -a -G libvirt $(whoami)

# This fix thanks to http://blog.programmableproduction.com/2018/03/08/Archlinux-Setup-Minikube-using-KVM/
sudo virsh net-autostart default

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Using the kubectl run command can help in generating a YAML template

Reference: https://kubernetes.io/docs/reference/kubectl/conventions/

Create an NGINX Pod

kubectl run --generator=run-pod/v1 nginx --image=nginx

Generate POD Manifest YAML file (-o yaml). Don't create it(--dry-run)

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How to conditionally choose an image in Helm

If you want to choose an image based on a condition, you can do it with the following example:

values.yaml

image:
  repository: my-docker-repo/my-image
  tag: "latest"
  pullPolicy: Always

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Profiling JVM on Kubernetes using VisualVM

Enable JMX server

Edit Dockerfile to enable JMX server and change the hostname with the IP where the container will run:

FROM openjdk:8-jre-alpine
ADD ./target/app.jar app.jar
EXPOSE 8080
ENTRYPOINT java -Dcom.sun.management.jmxremote.rmi.port=9090 -Dcom.sun.management.jmxremote=true -Dcom.sun.management.jmxremote.port=9090 -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.local.only=false -Djava.rmi.server.hostname=192.168.1.2 -jar app.jar

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Linux useful commands

Print file with line number:

cat -n notes.sh

Write to file replacing all content:

echo "foo" > teste.txt

Write to file appending the content:

echo "foo" >> teste.txt

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1. How to install virtualenv:

1.1. Install pip

  sudo apt install python3-pip

1.2. Install virtualenv:

 pip3 install virtualenv