nitred

About

• I faced bandwidth issues between a WG Peer and a WG server. Download bandwidth when downloading from WG Server to WG peer was reduced significantly and upload bandwidth was practically non existent.
• I found a few reddit posts that said that we need to choose the right MTU. So I wrote a script to find an optimal MTU.
• Ideally I would have liked to have run all possible MTU configurations for both WG Server and WG Peer but for simplicity I choose to fix the WG Server to the original 1420 MTU and tried all MTUs from 1280 to 1500 for the WG Peer.

Testing

• On WG server, I started an iperf3 server
• On WG peer, I wrote a script that does the following:
  • wg-quick down wg0
• Edit MTU in the /etc/wireguard/wg0.conf file

bitsandbooks

Ubuntu 20.04 + Autoinstall + VirtualBox

Intro

This guide will explain how to set up a [VirtualBox][] VM running [Ubuntu 20.04][] and, using the new [autoinstall][] tool and cloud-init, install OpenSSH server, add a group and a user, who can then connect to the machine via SSH. This was done on a 2016 MacBook Pro running macOS 10.15 "Catalina" and VirtualBox 6.1.6 (with the VirtualBox Guest Additions installed).

You will also need a group name, a username, a password hash and an SSH key pair.

How Autoinstall Works

s3rj1k

# For recent versions of Ubuntu:
 - https://www.pugetsystems.com/labs/hpc/ubuntu-22-04-server-autoinstall-iso/

# Docs:
 - https://wiki.ubuntu.com/FoundationsTeam/AutomatedServerInstalls
 - https://wiki.ubuntu.com/FoundationsTeam/AutomatedServerInstalls/ConfigReference
 - https://cloudinit.readthedocs.io/en/latest/topics/datasources/nocloud.html
 - https://discourse.ubuntu.com/t/please-test-autoinstalls-for-20-04/15250/53

# Download ISO Installer:

superseb

Recover cluster.rkestate file from controlplane node

RKE

Run on controlplane node, uses any found hyperkube image

k8s 1.19 and higher

docker run --rm --net=host -v $(docker inspect kubelet --format '{{ range .Mounts }}{{ if eq .Destination "/etc/kubernetes" }}{{ .Source }}{{ end }}{{ end }}')/ssl:/etc/kubernetes/ssl:ro --entrypoint bash $(docker inspect $(docker images -q --filter=label=org.opencontainers.image.source=https://github.com/rancher/hyperkube.git) --format='{{index .RepoTags 0}}' | tail -1) -c 'kubectl --kubeconfig /etc/kubernetes/ssl/kubecfg-kube-node.yaml -n kube-system get configmap full-cluster-state -o json | jq -r .data.\"full-cluster-state\" | jq -r .' > cluster.rkestate

zytek

Terraform vs PostgreSQL RDS

Thanks to new resources (postgresql_default_priviledges) and some fixes Terraform can now add new databases and manage ownership / access to them.

This example creates new database and two users. You can use owner to create new tables and run migrations and user for normal read/write access to database.