So you build a GitLab project, you created a pipeline and then a scheduler to run every week your pipeline.

And then you realize that you are polluting the internet with deprecated (garbage) things, at some point you have a debug option on, bla bla bla… etc etc.

It is time to clean up your mess!

Create a GitLab API Token

aka Personal Access Tokens

Select scopes: api.

Verify API token

run something like this

export GITLAB_API="glpat-HldkXzyurwBmroAdQCMo"

curl -sL --header "PRIVATE-TOKEN: ${GITLAB_API}" "https://gitlab.com/api/v4/projects?owned=true" | jq .[].path_with_namespace

you should see your projects.

Get your Project ID

create a new bash variable:

export PROJECT="terraform-provider/terraform-provider-hcloud-ci"

and then use the get rest api call

curl -sL --header "PRIVATE-TOKEN: ${GITLAB_API}" "https://gitlab.com/api/v4/projects?owned=true&search=${PROJECT}&search_namespaces=true" | jq -r .[].id

or you can also put the id into a new bash variable:

export ID=$(curl -sL --header "PRIVATE-TOKEN: ${GITLAB_API}" "https://gitlab.com/api/v4/projects?owned=true&search=${PROJECT}&search_namespaces=true" | jq -r .[].id)

View the previous pipelines

curl -sL \
  --header "PRIVATE-TOKEN: ${GITLAB_API}" \
  https://gitlab.com/api/v4/projects/${ID}/pipelines | jq .

Remove deprecated pipelines

just delete them via the API

curl -sL --header "PRIVATE-TOKEN: ${GITLAB_API}"   "https://gitlab.com/api/v4/projects/${ID}/pipelines?per_page=150"  \
 | jq  -r .[].id    \
 | awk '{print "curl -sL --header \"PRIVATE-TOKEN: ${GITLAB_API}\" --request DELETE https://gitlab.com/api/v4/projects/${ID}/pipelines/"$1}'   \
 | sh -x

that’s it !

WackoWiki is the wiki of my choice and one of the first opensource project I’ve ever contributed. I still use wackowiki for personal use!

A few days ago, wackowiki released version 6.0.25. In this blog post, I will try to share my experience of installing wackowiki on a new VM ubuntu 20.04 LTS.

Ansible Role

I have updated the WackoWiki Ansible Role on my personal github account to represent all necessary steps of this article.

Terraform files

In order to test/verify wackowiki installation and ansible role, I use a virtual machine on my home lab. To make this fast and reproducable, I have uploaded my terraform files that I used on my lab here: GitHub

Requirements

Ubuntu 20.04 LTS

apt-get update
apt -y install /
       php /
       php-common /
       php-bcmath /
       php-ctype /
       php-gd /
       php-iconv /
       php-json /
       php-mbstring /
       php-mysql /
       apache2 /
       libapache2-mod-php /
       mariadb-server /
       unzip

Apache2

We need to enable mod_reqwrite in apache2 but also to add the appropiate configuration in the default conf in VirtualHost

sudo -i
a2enmod rewrite

vim /etc/apache2/sites-available/000-default.conf

<VirtualHost *:80>
...
    # enable.htaccess
    <Directory /var/www/html/>
        Options Indexes FollowSymLinks MultiViews
        AllowOverride All
        Require all granted
    </Directory>
...
</VirtualHost>

MySQL

wacko.sql

CREATE DATABASE IF NOT EXISTS wacko;
CREATE USER IF NOT EXISTS 'wacko'@'localhost' IDENTIFIED BY 'YOURNEWPASSWORD';
GRANT  ALL PRIVILEGES ON wacko.* TO 'wacko'@'localhost';
FLUSH  PRIVILEGES;

sudo -i
mysql < wacko.sql

Get WackoWiki

curl -sLO https://downloads.sourceforge.net/wackowiki/wacko.6.0.25.zip
unzip wacko.6.0.25.zip
mv wackowiki-6.0.25/wacko /var/www/html/wacko/
chown -R www-data:www-data /var/www/html/wacko/

Web Installation

Post Install

Last, we need to remove write permission for the wackowiki configuration file and remove setup folder

sudo -i
chmod -w /var/www/html/wacko/config/config.php
rm -rf   /var/www/html/wacko/setup/

Simple WackoWiki Walkthrough

WireGuard: fast, modern, secure VPN tunnel. WireGuard securely encapsulates IP packets over UDP.

Goal

What I would like to achieve, in this article, is to provide a comprehensive guide for a redirect-gateway vpn using wireguard with a twist. The client machine should reach internet through the wireguard vpn server. No other communications should be allowed from the client and that means if we drop the VPN connection, client can not go to the internet.

Intro - Lab Details

Here are my lab details. This blog post will help you understand all the necessary steps and provide you with a guide to replicate the setup. You should be able to create a wireguard VPN server-client between two points. I will be using ubuntu 20.04 as base images for both virtual machines. I am also using LibVirt and Qemu/KVM running on my archlinux host.

Wireguard Generate Keys

and the importance of them!

Before we begin, give me a moment to try explaining how the encryption between these two machines, in a high level design works.

Each linux machines creates a pair of keys.

• Private Key
• Public Key

These keys have a unique relationship. You can use your public key to encrypt something but only your private key can decrypt it. That mean, you can share your public keys via an cleartext channel (internet, email, slack). The other parties can use your public key to encrypt traffic towards you, but none other decrypt it. If a malicious actor replace the public keys, you can not decrypt any incoming traffic thus make it impossible to connect to VPN server!

Public - Private Keys

Now each party has the other’s public keys and they can encrypt traffic for each other, BUT only you can decrypt your traffic with your private key. Your private key never leaves your computer.

Hopefully you get the idea.

Wireguard Server - Ubuntu 20.04 LTS

In order to make the guide easy to follow, I will start with the server part.

Server Key Generation

Generate a random private and public key for the server as-root

wg genkey | tee /etc/wireguard/privatekey | wg pubkey > /etc/wireguard/publickey

Make the keys read-only

chmod 0400 /etc/wireguard/*key

List keys

ls -l /etc/wireguard/

total 8
-r-------- 1 root root 45 Jul 12 20:29 privatekey
-r-------- 1 root root 45 Jul 12 20:29 publickey

UDP Port & firewall

In order to run a VPN service, you need to choose a random port that wireguard VPN server can listen to it.

eg.

61194

open firewall

ufw allow 61194/udp

Rule added
Rule added (v6)

view more info

ufw status verbose

Status: active
Logging: on (low)
Default: deny (incoming), allow (outgoing), disabled (routed)
New profiles: skip

To             Action      From
--             ------      ----
22/tcp         ALLOW IN    Anywhere
61194          ALLOW IN    Anywhere
22/tcp (v6)    ALLOW IN    Anywhere (v6)
61194 (v6)     ALLOW IN    Anywhere (v6)

So you see, only SSH and our VPN ports are open.
Default Incoming Policy is: DENY.

Wireguard Server Configuration File

Now it is time to create a basic configuration wireguard-server file.

Naming the wireguard interface

Clarification the name of our interface does not matter, you can choose any name. Gets it’s name from the configuration filename! But in order to follow the majority of guides try to use something from wg+. For me it is easier to name wireguard interface:

• wg0

but you may seen it also as

• wg

without a number. All good!

Making a shell script for wireguard server configuration file

Running the below script will create a new configuration file /etc/wireguard/wg0.conf

PRIVATE_KEY=$(cat /etc/wireguard/privatekey)
NETWORK=10.0.8

cat > /etc/wireguard/wg0.conf <<EOF
[Interface]
Address = ${NETWORK}.1/24
ListenPort = 61194
PrivateKey = ${PRIVATE_KEY}

EOF

ls -l /etc/wireguard/wg0.conf
cat   /etc/wireguard/wg0.conf

Note I have chosen the network 10.0.8.0/24 for my VPN setup, you can choose any Private Network

10.0.0.0/8     - Class A
172.16.0.0/12  - Class B
192.168.0.0/16 - Class C

I chose a Class C (256 IPs) from a /8 (Class A) private network, do not be confused about this. It’s just a Class-C /24 private network.

Let’s make our first test with the server

wg-quick up wg0

[#] ip link add wg0 type wireguard
[#] wg setconf wg0 /dev/fd/63
[#] ip -4 address add 10.0.8.1/24 dev wg0
[#] ip link set mtu 1420 up dev wg0

It’s Alive!

Kernel Module

Verify that wireguard is loaded as a kernel module on your system.

lsmod | grep wireguard

wireguard             212992  0
ip6_udp_tunnel         16384  1 wireguard
udp_tunnel             16384  1 wireguard

Wireguard is in the Linux kernel since March 2020.

Show IP address

ip address show dev wg0

3: wg0: <POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1420
qdisc noqueue state UNKNOWN group default qlen 1000
    link/none
    inet 10.0.8.1/24 scope global wg0
       valid_lft forever preferred_lft forever

Listening Connections

Verify that wireguard server listens to our specific UDP port

ss -nulp '( sport = :61194 )' | column -t

State   Recv-Q  Send-Q  Local Address:Port  Peer Address:Port  Process
UNCONN  0       0           0.0.0.0:61194       0.0.0.0:*
UNCONN  0       0              [::]:61194          [::]:*

Show wg0

wg show wg0

interface: wg0
  public key: <public key>
  private key: (hidden)
  listening port: 61194

Show Config

wg showconf wg0

[Interface]
ListenPort = 61194
PrivateKey = <private key>

Close wireguard

wg-quick down wg0

What is IP forwarding

In order for our VPN server to forward our client’s network traffic from the internal interface wg0 to it’s external interface and on top of that, to separate it’s own traffic from client’s traffic, the vpn server needs to masquerade all client’s traffic in a way that knows who to forward and send back traffic to the client. In a nuthshell this is IP forwarding and perhaps the below diagram can explain it a little better.

To do that, we need to enable the IP forward feature on our linux kernel.

sysctl -w net.ipv4.ip_forward=1

The above command does not persist the change across reboots. To persist this setting we need to add it, to sysctl configuration. And although many set this option global, we do not need to have to do that!

Wireguard provides four (4) stages, to run our own scripts.

Wireguard stages

• PreUp
• PostUp
• PreDown
• PostDown

So we can choose to enable IP forwarding at wireguard up and disable it on wireguard down.

IP forwarding in wireguard configuration file

PRIVATE_KEY=$(cat /etc/wireguard/privatekey)
NETWORK=10.0.8

cat > /etc/wireguard/wg0.conf <<EOF

[Interface]
Address    = ${NETWORK}.1/24
ListenPort = 61194
PrivateKey = ${PRIVATE_KEY}

PreUp    = sysctl -w net.ipv4.ip_forward=1
PostDown = sysctl -w net.ipv4.ip_forward=0
EOF

verify above configuration

wg-quick up wg0

[#] sysctl -w net.ipv4.ip_forward=1
net.ipv4.ip_forward = 1
[#] ip link add wg0 type wireguard
[#] wg setconf wg0 /dev/fd/63
[#] ip -4 address add 10.0.8.1/24 dev wg0
[#] ip link set mtu 1420 up dev wg0

Verify system control setting for IP forward:

sysctl net.ipv4.ip_forward

net.ipv4.ip_forward = 1

Close wireguard

wg-quick down wg0

[#] wg showconf wg0
[#] ip link delete dev wg0
[#] sysctl -w net.ipv4.ip_forward=0
net.ipv4.ip_forward = 0

Verify that now IP Forward is not enabled.

sysctl net.ipv4.ip_forward

net.ipv4.ip_forward = 0

Routing via firewall rules

Next on our agenda, is to add some additional rules on our firewall. We already enabled IP Forward feature with the above and now it is time to update our firewall so it can masquerade our client’s network traffic.

Default Route

We need to identify the default external network interface on the ubuntu server.

DEF_ROUTE=$(ip -4 -json route list default | jq  -r .[0].dev)

usually is eth0 or ensp3 or something similar.

firewall rules

1. We need to forward traffic from the internal interface to the external interface
2. We need to masquerade the traffic of the client.

iptables -A FORWARD -i %i -o ${DEF_ROUTE} -s ${NETWORK}.0/24 -j ACCEPT

iptables -t nat -A POSTROUTING -s ${NETWORK}.0/24 -o ${DEF_ROUTE} -j MASQUERADE

and also we need to drop these rules when we stop wireguard service

iptables -D FORWARD -i %i -o ${DEF_ROUTE} -s ${NETWORK}.0/24 -j ACCEPT

iptables -t nat -D POSTROUTING -s ${NETWORK}.0/24 -o ${DEF_ROUTE} -j MASQUERADE

See the -D after iptables.

iptables is a CLI (command line interface) for netfilters. So think the above rules as filters on our network traffic.

WG Server Conf

To put everything all together and also use wireguard PostUp and PreDown to

wg genkey | tee /etc/wireguard/privatekey | wg pubkey > /etc/wireguard/publickey

chmod 0400 /etc/wireguard/*key

PRIVATE_KEY=$(cat /etc/wireguard/privatekey)
NETWORK=10.0.8
DEF_ROUTE=$(ip -4 -json route list default | jq  -r .[0].dev)
WG_PORT=61194

cat > /etc/wireguard/wg0.conf <<EOF
[Interface]
Address    = ${NETWORK}.1/24
ListenPort = ${WG_PORT}
PrivateKey = ${PRIVATE_KEY}

PreUp    = sysctl -w net.ipv4.ip_forward=1
PostDown = sysctl -w net.ipv4.ip_forward=0

PostUp  = iptables -A FORWARD -i %i -o ${DEF_ROUTE} -s ${NETWORK}.0/24 -j ACCEPT ; iptables -t nat -A POSTROUTING -s ${NETWORK}.0/24 -o ${DEF_ROUTE} -j MASQUERADE
PreDown = iptables -D FORWARD -i %i -o ${DEF_ROUTE} -s ${NETWORK}.0/24 -j ACCEPT ; iptables -t nat -D POSTROUTING -s ${NETWORK}.0/24 -o ${DEF_ROUTE} -j MASQUERADE

EOF

testing up

wg-quick up wg0

[#] sysctl -w net.ipv4.ip_forward=1
net.ipv4.ip_forward = 1
[#] ip link add wg0 type wireguard
[#] wg setconf wg0 /dev/fd/63
[#] ip -4 address add 10.0.8.1/24 dev wg0
[#] ip link set mtu 1420 up dev wg0
[#] iptables -A FORWARD -i wg0 -o ens3 -s 10.0.8.0/24 -j ACCEPT ; iptables -t nat -A POSTROUTING -s 10.0.8.0/24 -o ens3 -j MASQUERADE

testing down

wg-quick down wg0

[#] iptables -D FORWARD -i wg0 -o ens3 -s 10.0.8.0/24 -j ACCEPT ; iptables -t nat -D POSTROUTING -s 10.0.8.0/24 -o ens3 -j MASQUERADE
[#] ip link delete dev wg0
[#] sysctl -w net.ipv4.ip_forward=0
net.ipv4.ip_forward = 0

Start at boot time

systemctl enable wg-quick@wg0

and status

systemctl status wg-quick@wg0

Get the wireguard server public key

We have NOT finished yet with the server !

Also we need the output of:

cat /etc/wireguard/publickey

output should be something like this:

wr3jUAs2qdQ1Oaxbs1aA0qrNjogY6uqDpLop54WtQI4=

Wireguard Client - Ubuntu 20.04 LTS

Now we need to move to our client virtual machine.
It is a lot easier but similar with above commands.

Client Key Generation

Generate a random private and public key for the client

wg genkey | tee /etc/wireguard/privatekey | wg pubkey > /etc/wireguard/publickey

Make the keys read-only

chmod 0400 /etc/wireguard/*key

Wireguard Client Configuration File

Need to replace <wireguard server public key> with the output of the above command.

Configuration is similar but simpler from the server

PRIVATE_KEY=$(cat /etc/wireguard/privatekey)
NETWORK=10.0.8
WG_PORT=61194
WGS_IP=$(ip -4 -json route list default | jq -r .[0].prefsrc)
WSG_PUBLIC_KEY="<wireguard server public key>"

cat > /etc/wireguard/wg0.conf <<EOF
[Interface]
Address    = ${NETWORK}.2/24
PrivateKey = ${PRIVATE_KEY}

[Peer]
PublicKey  = ${WSG_PUBLIC_KEY}
Endpoint   = ${WGS_IP}:${WG_PORT}
AllowedIPs = 0.0.0.0/0

EOF

verify

wg-quick up wg0

[#] ip link add wg0 type wireguard
[#] wg setconf wg0 /dev/fd/63
[#] ip -4 address add 10.0.8.2/24 dev wg0
[#] ip link set mtu 1420 up dev wg0
[#] wg set wg0 fwmark 51820
[#] ip -4 route add 0.0.0.0/0 dev wg0 table 51820
[#] ip -4 rule add not fwmark 51820 table 51820
[#] ip -4 rule add table main suppress_prefixlength 0
[#] sysctl -q net.ipv4.conf.all.src_valid_mark=1
[#] iptables-restore -n

start client at boot

systemctl enable wg-quick@wg0

Get the wireguard client public key

We have finished with the client, but we need the output of:

cat /etc/wireguard/publickey

Wireguard Server - Peers

As we mentioned above, we need to exchange public keys of server & client to the other machines in order to encrypt network traffic.

So as we get the client public key and run the below script to the server

WSC_PUBLIC_KEY="<wireguard client public key>"
NETWORK=10.0.8

wg set wg0 peer ${WSC_PUBLIC_KEY} allowed-ips ${NETWORK}.2

after that we can verify that our wireguard server and connect to the wireguard client

wireguard server ping to client

$ ping -c 5 10.0.8.2

PING 10.0.8.2 (10.0.8.2) 56(84) bytes of data.
64 bytes from 10.0.8.2: icmp_seq=1 ttl=64 time=0.714 ms
64 bytes from 10.0.8.2: icmp_seq=2 ttl=64 time=0.456 ms
64 bytes from 10.0.8.2: icmp_seq=3 ttl=64 time=0.557 ms
64 bytes from 10.0.8.2: icmp_seq=4 ttl=64 time=0.620 ms
64 bytes from 10.0.8.2: icmp_seq=5 ttl=64 time=0.563 ms

--- 10.0.8.2 ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4103ms
rtt min/avg/max/mdev = 0.456/0.582/0.714/0.084 ms

wireguard client ping to server

$ ping -c 5 10.0.8.1

PING 10.0.8.1 (10.0.8.1) 56(84) bytes of data.
64 bytes from 10.0.8.1: icmp_seq=1 ttl=64 time=0.752 ms
64 bytes from 10.0.8.1: icmp_seq=2 ttl=64 time=0.639 ms
64 bytes from 10.0.8.1: icmp_seq=3 ttl=64 time=0.622 ms
64 bytes from 10.0.8.1: icmp_seq=4 ttl=64 time=0.625 ms
64 bytes from 10.0.8.1: icmp_seq=5 ttl=64 time=0.597 ms

--- 10.0.8.1 ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4093ms
rtt min/avg/max/mdev = 0.597/0.647/0.752/0.054 ms

wireguard server - Peers at configuration file

Now the final things is to update our wireguard server with the client Peer (or peers).

wg showconf wg0

the output should be something like that:

[Interface]
ListenPort = 61194
PrivateKey = <server: private key>

[Peer]
PublicKey = <client: public key>
AllowedIPs = 10.0.8.2/32
Endpoint = 192.168.122.68:52587

We need to append the peer section to our configuration file.

so /etc/wireguard/wg0.conf should look like this:

[Interface]
Address    = 10.0.8.1/24
ListenPort = 61194
PrivateKey = <server: private key>

PreUp    = sysctl -w net.ipv4.ip_forward=1
PostDown = sysctl -w net.ipv4.ip_forward=0

PostUp  = iptables -A FORWARD -i %i -o ens3 -s 10.0.8.0/24 -j ACCEPT ; iptables -t nat -A POSTROUTING -s 10.0.8.0/24 -o ens3 -j MASQUERADE
PreDown = iptables -D FORWARD -i %i -o ens3 -s 10.0.8.0/24 -j ACCEPT ; iptables -t nat -D POSTROUTING -s 10.0.8.0/24 -o ens3 -j MASQUERADE

[Peer]
PublicKey = <client: public key>
AllowedIPs = 10.0.8.2/32
Endpoint = 192.168.122.68:52587

SaveConfig

In None of server or client wireguard configuration file, we didn’t declare this option. If set, then the configuration is saved on the current state of wg0 interface. Very useful !

SaveConfig = true

client firewall

It is time to introduce our twist!

If you mtr or traceroute our traffic from our client, we will notice that in need our network traffic goes through the wireguard vpn server !

               My traceroute  [v0.93]
wgc (10.0.8.2)                        2021-07-21T22:41:44+0300

                          Packets               Pings
 Host                Loss%   Snt   Last   Avg  Best  Wrst StDev
 1. 10.0.8.1         0.0%    88    0.6   0.6   0.4   0.8   0.1
 2. myhomepc         0.0%    88    0.8   0.8   0.5   1.0   0.1
 3. _gateway         0.0%    88    3.8   4.0   3.3   9.6   0.8
 ...

The first entry is:

1. 10.0.8.1  

if we drop our vpn connection.

wg-quick down wg0

We still go to the internet.

                     My traceroute  [v0.93]
wgc (192.168.122.68)                     2021-07-21T22:45:04+0300

                            Packets               Pings
 Host                   Loss%   Snt   Last   Avg  Best  Wrst StDev
 1. myhomepc             0.0%     1    0.3   0.3   0.3   0.3   0.0
 2. _gateway             0.0%     1    3.3   3.3   3.3   3.3   0.0

This is important because in some use cases, we do not want our client to directly or unsupervised talk to the internet.

UFW alternative for the client

So to avoid this issue, we will re-rewrite our firewall rules.

A simple script to do that is the below. Declares the default policy to DENY for everything and only accepts ssh incoming traffic and outgoing traffic through the vpn.

DEF_ROUTE=$(ip -4 -json route list default | jq -r .[0].dev)
WGS_IP=192.168.122.69
WG_PORT=61194

## reset
ufw --force reset

## deny everything!

ufw default deny incoming
ufw default deny outgoing
ufw default deny forward

## allow ssh
ufw allow 22/tcp

## enable
ufw --force enable

## allow traffic out to the vpn server
ufw allow out on ${DEF_ROUTE} to ${WGS_IP} port ${WG_PORT}

## allow tunnel traffic out
ufw allow out on wg+

# ufw status verbose

Status: active
Logging: on (low)
Default: deny (incoming), deny (outgoing), disabled (routed)
New profiles: skip

To                         Action      From
--                         ------      ----
22/tcp                     ALLOW IN    Anywhere
22/tcp (v6)                ALLOW IN    Anywhere (v6)             

192.168.122.69 61194       ALLOW OUT   Anywhere on ens3
Anywhere                   ALLOW OUT   Anywhere on wg+
Anywhere (v6)              ALLOW OUT   Anywhere (v6) on wg+

DNS

There is caveat. Please bare with me.

Usually and especially in virtual machines they get DNS setting through a local LAN. We can either allow traffic on the local vlan or update our local DNS setting so it can go only through our VPN

cat > /etc/systemd/resolved.conf <<EOF
[Resolve]
DNS=88.198.92.222

EOF

systemctl restart systemd-resolved

let’s try this

# ping google.com
ping: google.com: Temporary failure in name resolution

Correct, fire up wireguard vpn client

wg-quick up wg0

ping -c4 google.com

PING google.com (142.250.185.238) 56(84) bytes of data.
64 bytes from fra16s53-in-f14.1e100.net (142.250.185.238): icmp_seq=1 ttl=115 time=43.5 ms
64 bytes from fra16s53-in-f14.1e100.net (142.250.185.238): icmp_seq=2 ttl=115 time=44.9 ms
64 bytes from fra16s53-in-f14.1e100.net (142.250.185.238): icmp_seq=3 ttl=115 time=43.8 ms
64 bytes from fra16s53-in-f14.1e100.net (142.250.185.238): icmp_seq=4 ttl=115 time=43.0 ms

--- google.com ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3004ms
rtt min/avg/max/mdev = 42.990/43.795/44.923/0.707 ms

mtr shows:

mtr google.com

                My traceroute  [v0.93]
wgc (10.0.8.2)                          2021-07-21T23:01:16+0300

                                        Packets               Pings
 Host                                 Loss%   Snt   Last   Avg  Best  Wrst StDev
 1. 10.0.8.1                           0.0%     2    0.6   0.7   0.6   0.7   0.1
 2. _gateway                           0.0%     1    0.8   0.8   0.8   0.8   0.0
 3. 192.168.1.1                        0.0%     1    3.8   3.8   3.8   3.8   0.0

drop vpn connection

# wg-quick down wg0 

[#] ip -4 rule delete table 51820
[#] ip -4 rule delete table main suppress_prefixlength 0
[#] ip link delete dev wg0
[#] iptables-restore -n

# ping -c4 google.com
ping: google.com: Temporary failure in name resolution

and that is perfect !

No internet access for our client. Only when our vpn connection is up!

WireGuard: fast, modern, secure VPN tunnel

That’s it!

Below my personal settings -as of today- for LibreDNS using systemd-resolved service for DNS resolution.

sudo vim /etc/systemd/resolved.conf

basic settings

[Resolve]
DNS=116.202.176.26:854#dot.libredns.gr
DNSOverTLS=yes
FallbackDNS=88.198.92.222
Cache=yes

apply

sudo systemctl restart systemd-resolved.service

verify

resolvectl query analytics.google.com

analytics.google.com: 0.0.0.0                  -- link: eth0

-- Information acquired via protocol DNS in 144.7ms.
-- Data is authenticated: no; Data was acquired via local or encrypted transport: yes
-- Data from: network

Explain Settings

DNS setting

DNS=116.202.176.26:854#dot.libredns.gr

We declare the IP of our DoT service. Using : as a separator we add the no-ads TCP port of DoT, 854. We also need to add our domain in the end to tell systemd-resolved that this IP should respond to dot.libredns.gr

Dns Over TLS

DNSOverTLS=yes

The usually setting is yes. In older systemd versions you can also select opportunistic.
As we are using Lets Encrypt systemd-resolved can not verify (by default) the IP inside the certificate. The type of certificate can verify the domain dot.libredns.gr but we are asking the IP: 116.202.176.26 and this is another type of certificate that is not free. In order to “fix” this , we added the #dot.libredns.gr in the above setting.

FallBack

Yes not everything has Five nines so you may need a fall back dns to .. fall. Be aware this is cleartext traffic! Not encrypted.

FallbackDNS=88.198.92.222

Cache

Last but not least, caching your queries can give provide you with an additional speed when browsing the internet ! You already asked this a few seconds ago, why not caching it on your local system?

Cache=yes

to give you an example

resolvectl query analytics.google.com

analytics.google.com: 0.0.0.0                  -- link: eth0

-- Information acquired via protocol DNS in 144.7ms.
-- Data is authenticated: no; Data was acquired via local or encrypted transport: yes
-- Data from: network

second time:

resolvectl query analytics.google.com
analytics.google.com: 0.0.0.0                  -- link: eth0

-- Information acquired via protocol DNS in 2.3ms.
-- Data is authenticated: no; Data was acquired via local or encrypted transport: yes
-- Data from: cache

One of the most well-known k8s memes is the below image that represent the effort and complexity on building a kubernetes cluster just to run a simple blog. So In this article, I will take the opportunity to install a simple blog engine on kubernetes using k3s!

terraform - libvirt/qemu - ubuntu

For this demo, I will be workinig on my local test lab. A libvirt /qemu ubuntu 20.04 virtual machine via terraform. You can find my terraform notes on my github repo tf/0.15/libvirt/0.6.3/ubuntu/20.04.

k3s

k3s is a lightweight, fully compliant kubernetes distribution that can run on a virtual machine, single node.

login to your machine and became root

$ ssh 192.168.122.42 -l ubuntu
$ sudo -i
#

install k3s with one command

curl -sfL https://get.k3s.io | sh -

output should be something like this

[INFO]  Finding release for channel stable

[INFO]  Using v1.21.1+k3s1 as release
[INFO]  Downloading hash https://github.com/k3s-io/k3s/releases/download/v1.21.1+k3s1/sha256sum-amd64.txt
[INFO]  Downloading binary https://github.com/k3s-io/k3s/releases/download/v1.21.1+k3s1/k3s
[INFO]  Verifying binary download
[INFO]  Installing k3s to /usr/local/bin/k3s
[INFO]  Creating /usr/local/bin/kubectl symlink to k3s
[INFO]  Creating /usr/local/bin/crictl symlink to k3s
[INFO]  Creating /usr/local/bin/ctr symlink to k3s
[INFO]  Creating killall script /usr/local/bin/k3s-killall.sh
[INFO]  Creating uninstall script /usr/local/bin/k3s-uninstall.sh
[INFO]  env: Creating environment file /etc/systemd/system/k3s.service.env
[INFO]  systemd: Creating service file /etc/systemd/system/k3s.service
[INFO]  systemd: Enabling k3s unit
Created symlink /etc/systemd/system/multi-user.target.wants/k3s.service → /etc/systemd/system/k3s.service.
[INFO]  systemd: Starting k3s

Firewall Ports

I would propose to open the below network ports so k3s can run smoothly.

Inbound Rules for K3s Server Nodes

PROTOCOL	PORT	SOURCE	DESCRIPTION
TCP	6443	K3s agent nodes	Kubernetes API Server
UDP	8472	K3s server and agent nodes	Required only for Flannel VXLAN
TCP	10250	K3s server and agent nodes	Kubelet metrics
TCP	2379-2380	K3s server nodes	Required only for HA with embedded etcd

Typically all outbound traffic is allowed.

ufw allow

ufw allow 6443/tcp
ufw allow 8472/udp
ufw allow 10250/tcp
ufw allow 2379/tcp
ufw allow 2380/tcp

full output

# ufw allow 6443/tcp
Rule added
Rule added (v6)

# ufw allow 8472/udp
Rule added
Rule added (v6)

# ufw allow 10250/tcp
Rule added
Rule added (v6)

# ufw allow 2379/tcp
Rule added
Rule added (v6)

# ufw allow 2380/tcp
Rule added
Rule added (v6)

k3s Nodes / Pods / Deployments

verify nodes, roles, pods and deployments

# kubectl get nodes -A
NAME         STATUS   ROLES                  AGE   VERSION
ubuntu2004   Ready    control-plane,master   11m   v1.21.1+k3s1

# kubectl get pods -A
NAMESPACE     NAME                                      READY   STATUS      RESTARTS   AGE
kube-system   helm-install-traefik-crd-8rjcf            0/1     Completed   2          13m
kube-system   helm-install-traefik-lwgcj                0/1     Completed   3          13m
kube-system   svclb-traefik-xtrcw                       2/2     Running     0          5m13s
kube-system   coredns-7448499f4d-6vrb7                  1/1     Running     5          13m
kube-system   traefik-97b44b794-q294l                   1/1     Running     0          5m14s
kube-system   local-path-provisioner-5ff76fc89d-pq5wb   1/1     Running     6          13m
kube-system   metrics-server-86cbb8457f-n4gsf           1/1     Running     6          13m

# kubectl get deployments -A
NAMESPACE     NAME                     READY   UP-TO-DATE   AVAILABLE   AGE
kube-system   coredns                  1/1     1            1           17m
kube-system   traefik                  1/1     1            1           8m50s
kube-system   local-path-provisioner   1/1     1            1           17m
kube-system   metrics-server           1/1     1            1           17m

Helm

Next thing is to install helm. Helm is a package manager for kubernetes, it will make easy to install applications.

curl -sL https://raw.githubusercontent.com/helm/helm/master/scripts/get-helm-3 | bash

output

Downloading https://get.helm.sh/helm-v3.6.0-linux-amd64.tar.gz
Verifying checksum... Done.
Preparing to install helm into /usr/local/bin
helm installed into /usr/local/bin/helm

helm version

version.BuildInfo{Version:"v3.6.0", GitCommit:"7f2df6467771a75f5646b7f12afb408590ed1755", GitTreeState:"clean", GoVersion:"go1.16.3"}

repo added

As a package manager, you can install k8s packages, named charts and you can find a lot of helm charts here https://artifacthub.io/. You can also add/install a single repo, I will explain this later.

# helm repo add nicholaswilde https://nicholaswilde.github.io/helm-charts/

"nicholaswilde" has been added to your repositories

# helm repo update
Hang tight while we grab the latest from your chart repositories...

Successfully got an update from the "nicholaswilde" chart repository
Update Complete. ⎈Happy Helming!⎈

hub Vs repo

basic difference between hub and repo is that hub is the official artifacthub. You can search charts there

helm search hub blog

URL                                                 CHART VERSION   APP VERSION DESCRIPTION
https://artifacthub.io/packages/helm/nicholaswi...  0.1.2           v1.3        Lightweight self-hosted facebook-styled PHP blog.
https://artifacthub.io/packages/helm/nicholaswi...  0.1.2           v2021.02    An ultra-lightweight blogging engine, written i...
https://artifacthub.io/packages/helm/bitnami/dr...  10.2.23         9.1.10      One of the most versatile open source content m...
https://artifacthub.io/packages/helm/bitnami/ghost  13.0.13         4.6.4       A simple, powerful publishing platform that all...
https://artifacthub.io/packages/helm/bitnami/jo...  10.1.10         3.9.27      PHP content management system (CMS) for publish...
https://artifacthub.io/packages/helm/nicholaswi...  0.1.1           0.1.1       A Self-Hosted, Twitter™-like Decentralised micr...
https://artifacthub.io/packages/helm/nicholaswi...  0.1.1           900b76a     A self-hosted well uh wiki engine or content ma...
https://artifacthub.io/packages/helm/bitnami/wo...  11.0.13         5.7.2       Web publishing platform for building blogs and ...

using a repo, means that you specify charts sources from single (or multiple) repos, usally outside of hub.

helm search repo blog

NAME                        CHART VERSION   APP VERSION DESCRIPTION
nicholaswilde/blog          0.1.2           v1.3        Lightweight self-hosted facebook-styled PHP blog.
nicholaswilde/chyrp-lite    0.1.2           v2021.02    An ultra-lightweight blogging engine, written i...
nicholaswilde/twtxt         0.1.1           0.1.1       A Self-Hosted, Twitter™-like Decentralised micr...
nicholaswilde/wiki          0.1.1           900b76a     A self-hosted well uh wiki engine or content ma...

Install a blog engine via helm

before we continue with the installation of our blog engine, we need to set the kube config via a shell variable

kube configuration yaml file

export KUBECONFIG=/etc/rancher/k3s/k3s.yaml

kubectl-k3s, already knows where to find this yaml configuration file. kubectl is a link to k3s in our setup

# whereis kubectl
kubectl: /usr/local/bin/kubectl

# ls -l /usr/local/bin/kubectl
lrwxrwxrwx 1 root root 3 Jun  4 23:20 /usr/local/bin/kubectl -> k3s

but not helm that we just installed.

After that we can install our blog engine.

helm install chyrp-lite              \
  --set env.TZ="Europe/Athens"  \
  nicholaswilde/chyrp-lite

output

NAME: chyrp-lite
LAST DEPLOYED: Fri Jun  4 23:46:04 2021
NAMESPACE: default
STATUS: deployed
REVISION: 1
TEST SUITE: None
NOTES:
Get the application URL by running these commands:
  http://chyrp-lite.192.168.1.203.nip.io/

for the time being, ignore nip.io and verify the deployment

# kubectl get deployments
NAME         READY   UP-TO-DATE   AVAILABLE   AGE
chyrp-lite   1/1     1            1           2m15s

# kubectl get pods
NAME                          READY   STATUS    RESTARTS   AGE
chyrp-lite-5c544b455f-d2pzm   1/1     Running   0          2m18s

Port Forwarding

as this is a pod running through k3s inside a virtual machine on our host operating system, in order to visit the blog and finish the installation we need to expose the port.

Let’s find out if there is a service running

kubectl get service chyrp-lite

output

NAME         TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)   AGE
chyrp-lite   ClusterIP   10.43.143.250   <none>        80/TCP    11h

okay we have a cluster ip.

you can also verify that our blog engine is running

curl -s 10.43.143.250/install.php | head

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title>Chyrp Lite Installer</title>
        <meta name="viewport" content="width = 800">
        <style type="text/css">
            @font-face {
                font-family: 'Open Sans webfont';
                src: url('./fonts/OpenSans-Regular.woff') format('woff');

and then port forward the pod tcp port to our virtual machine

kubectl port-forward service/chyrp-lite 80

output

Forwarding from 127.0.0.1:80 -> 80
Forwarding from [::1]:80 -> 80

k3s issue with TCP Port 80

Port 80 used by build-in load balancer by default

That means service port 80 will become 10080 on the host, but 8080 will become 8080 without any offset.

So the above command will not work, it will give you an 404 error.
We can disable LoadBalancer (we do not need it for this demo) but it is easier to just forward the service port to 10080

kubectl port-forward service/chyrp-lite 10080:80

Forwarding from 127.0.0.1:10080 -> 80
Forwarding from [::1]:10080 -> 80
Handling connection for 10080
Handling connection for 10080

from our virtual machine we can verify

curl -s http://127.0.0.1:10080/install.php  | head

it will produce

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title>Chyrp Lite Installer</title>
        <meta name="viewport" content="width = 800">
        <style type="text/css">
            @font-face {
                font-family: 'Open Sans webfont';
                src: url('./fonts/OpenSans-Regular.woff') format('woff');

ssh port forward

So now, we need to forward this TCP port from the virtual machine to our local machine. Using ssh, you should be able to do it like this from another terminal

ssh 192.168.122.42 -l ubuntu -L8080:127.0.0.1:10080

verify it

$ sudo ss -n -t -a 'sport = :10080'

State           Recv-Q          Send-Q                   Local Address:Port                    Peer Address:Port         Process
LISTEN          0               128                          127.0.0.1:10080                        0.0.0.0:*
LISTEN          0               128                              [::1]:10080                           [::]:*

$ curl -s http://localhost:10080/install.php | head

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title>Chyrp Lite Installer</title>
        <meta name="viewport" content="width = 800">
        <style type="text/css">
            @font-face {
                font-family: 'Open Sans webfont';
                src: url('./fonts/OpenSans-Regular.woff') format('woff');

I am forwarding to a high tcp port (> 1024) so my user can open a tcp port, eitherwise I need to be root.

finishing the installation

To finish the installation of our blog engine, we need to visit the below url from our browser

http://localhost:10080/install.php

Database Setup

Admin Setup

Installation Completed

First blog post

that’s it !

I am using archlinux in my WSL for the last two (2) years and the whole experience is quite smooth. I wanted to test native docker will run within WSL and not with the windows docker/container service, so I installed docker. My main purpose is building packages so (for now) I do not need networking/routes or anything else.

WSL

ebal@myworklaptop:~$ uname -a
Linux myworklaptop 4.19.128-microsoft-standard #1 SMP Tue Jun 23 12:58:10 UTC 2020 x86_64 GNU/Linux

ebal@myworklaptop:~$ cat /etc/os-release
NAME="Arch Linux"
PRETTY_NAME="Arch Linux"
ID=arch
BUILD_ID=rolling
ANSI_COLOR="38;2;23;147;209"
HOME_URL="https://www.archlinux.org/"
DOCUMENTATION_URL="https://wiki.archlinux.org/"
SUPPORT_URL="https://bbs.archlinux.org/"
BUG_REPORT_URL="https://bugs.archlinux.org/"
LOGO=archlinux

Docker Install

$ sudo pacman -S docker

$ sudo pacman -Q docker
docker 1:20.10.6-1

$ sudo dockerd -v
Docker version 20.10.6, build 8728dd246c

Run docker

sudo dockerd -D

-D is for debug

and now pull an alpine image

ebal@myworklaptop:~$ docker images
REPOSITORY   TAG       IMAGE ID   CREATED   SIZE

ebal@myworklaptop:~$ docker pull alpine:latest
latest: Pulling from library/alpine
540db60ca938: Pull complete
Digest: sha256:69e70a79f2d41ab5d637de98c1e0b055206ba40a8145e7bddb55ccc04e13cf8f
Status: Downloaded newer image for alpine:latest
docker.io/library/alpine:latest

ebal@myworklaptop:~$ docker images
REPOSITORY   TAG       IMAGE ID       CREATED       SIZE
alpine       latest    6dbb9cc54074   2 weeks ago   5.61MB

Test alpine image

docker run -ti alpine:latest ash

perform a simple update

# apk update

fetch https://dl-cdn.alpinelinux.org/alpine/v3.13/main/x86_64/APKINDEX.tar.gz
fetch https://dl-cdn.alpinelinux.org/alpine/v3.13/community/x86_64/APKINDEX.tar.gz
v3.13.5-71-gfcabe3349a [https://dl-cdn.alpinelinux.org/alpine/v3.13/main]
v3.13.5-65-g28e7396caa [https://dl-cdn.alpinelinux.org/alpine/v3.13/community]

OK: 13887 distinct packages available

okay, seems that it is working.

Genie Systemd

as many already know, we can not run systemd inside WSL, at least not by default. So here comes genie !

A quick way into a systemd “bottle” for WSL

WSLv2 ONLY.

wsl.exe -l -v

  NAME            STATE           VERSION
* Archlinux       Running         2
  Ubuntu-20.04    Stopped         1

It will work on my arch.

Install Genie

genie comes by default with an archlinux artifact from github

curl -sLO https://github.com/arkane-systems/genie/releases/download/v1.40/genie-systemd-1.40-1-x86_64.pkg.tar.zst

sudo pacman -U genie-systemd-1.40-1-x86_64.pkg.tar.zst

$ pacman -Q genie-systemd
genie-systemd 1.40-1

daemonize

Genie has a dependency of daemonize.

In Archlinux, you can find the latest version of daemonize here:

https://gitlab.com/archlinux_build/daemonize

$ sudo pacman -U daemonize-1.7.8-1-x86_64.pkg.tar.zst

loading packages...
resolving dependencies...
looking for conflicting packages...

Package (1)  New Version  Net Change
daemonize    1.7.8-1        0.03 MiB
Total Installed Size:  0.03 MiB

:: Proceed with installation? [Y/n] y

$ pacman -Q daemonize
daemonize 1.7.8-1

Is genie running ?

We can start as-root genie with a new shell:

# genie --version
1.40

# genie -s
Waiting for systemd....!

# genie -r
running

okay !

Windows Terminal

In order to use systemd-genie by default, we need to run our WSL Archlinux with an initial command.

I use aka.ms/terminal to start/open my WSLv2 Archlinux so I had to edit the “Command Line” Option to this:

wsl.exe -d Archlinux genie -s

You can also verify that your WSL distro is down, with this

wsl.exe --shutdown

then fire up a new WSL distro!

Systemd Service

you can enable & start docker service unit,

$ sudo systemctl enable docker

$ sudo systemctl start  docker

so next time will auto-start:

$ docker images
REPOSITORY   TAG       IMAGE ID       CREATED       SIZE
alpine       latest    6dbb9cc54074   2 weeks ago   5.61MB

systemd

$ ps -e fuwwww | grep -i systemd
root           1  0.1  0.2  21096 10748 ?        Ss   14:27   0:00 systemd
root          29  0.0  0.2  30472 11168 ?        Ss   14:27   0:00 /usr/lib/systemd/systemd-journald
root          38  0.0  0.1  25672  7684 ?        Ss   14:27   0:00 /usr/lib/systemd/systemd-udevd
dbus          63  0.0  0.1  12052  5736 ?        Ss   14:27   0:00 /usr/bin/dbus-daemon --system --address=systemd: --nofork --nopidfile --systemd-activation --syslog-only
root          65  0.0  0.1  14600  7224 ?        Ss   14:27   0:00 /usr/lib/systemd/systemd-logind
root         211  0.0  0.1  14176  6872 ?        Ss   14:27   0:00 /usr/lib/systemd/systemd-machined
ebal         312  0.0  0.0   3164   808 pts/1    S+   14:30   0:00  _ grep -i systemd
ebal         215  0.0  0.2  16036  8956 ?        Ss   14:27   0:00 /usr/lib/systemd/systemd --user

$ systemctl status docker
* docker.service - Docker Application Container Engine
     Loaded: loaded (/usr/lib/systemd/system/docker.service; enabled; vendor preset: disabled)
     Active: active (running) since Sat 2021-05-01 14:27:12 EEST; 3min 22s ago
TriggeredBy: * docker.socket
       Docs: https://docs.docker.com
   Main PID: 64 (dockerd)
      Tasks: 17 (limit: 4715)
     Memory: 167.9M
     CGroup: /system.slice/docker.service
             |-64 /usr/bin/dockerd -H fd://
             `-80 containerd --config /var/run/docker/containerd/containerd.toml --log-level info

May 01 14:27:12 myworklaptop-wsl systemd[1]: Started Docker Application Container Engine.
May 01 14:27:12 myworklaptop-wsl dockerd[64]: time="2021-05-01T14:27:12.303580300+03:00" level=info msg="AP>

that’s it !

I am an archlinux user using Sony WH-1000XM3 bluetooth noise-cancellation headphones. I am also using pulseaudio and it took me a while to switch the bluetooth headphones to HSP/HFP profile so the microphone can work too. Switching the bluetooth profile of your headphones to HeadSet Audio works but it is only monophonic audio and without noise-cancellation and I had to switch to piperwire also. But at least now the microphone works!

I was wondering how distros that by default have already switched to pipewire deal with this situation. So I started a fedora 34 (beta) edition and attached both my bluetooth adapter TP-LINK UB400 v1 and my web camera Logitech HD Webcam C270.

The test should be to open a jitsi meet and a zoom test meeting and verify that my headphones can work without me doing any stranger CLI magic.

tldr; works out of the box !

lsusb

[root@fedora ~]# lsusb 

Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 004: ID 046d:0825 Logitech, Inc. Webcam C270
Bus 001 Device 003: ID 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode)
Bus 001 Device 002: ID 0627:0001 Adomax Technology Co., Ltd QEMU USB Tablet
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

as you can see both usb devices have properly attached to fedora34

kernel

we need Linux kernel > 5.10.x to have a proper support

[root@fedora ~]# uname -a
Linux fedora 5.11.10-300.fc34.x86_64 #1 SMP Thu Mar 25 14:03:32 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux 

pipewire

and of-course piperwire installed

[root@fedora ~]# rpm -qa | grep -Ei 'blue|pipe|pulse' 

libpipeline-1.5.3-2.fc34.x86_64
pulseaudio-libs-14.2-3.fc34.x86_64
pulseaudio-libs-glib2-14.2-3.fc34.x86_64
pipewire0.2-libs-0.2.7-5.fc34.x86_64
bluez-libs-5.56-4.fc34.x86_64
pipewire-libs-0.3.24-4.fc34.x86_64
pipewire-0.3.24-4.fc34.x86_64
bluez-5.56-4.fc34.x86_64
bluez-obexd-5.56-4.fc34.x86_64
pipewire-gstreamer-0.3.24-4.fc34.x86_64
pipewire-pulseaudio-0.3.24-4.fc34.x86_64
gnome-bluetooth-libs-3.34.5-1.fc34.x86_64
gnome-bluetooth-3.34.5-1.fc34.x86_64
bluez-cups-5.56-4.fc34.x86_64
NetworkManager-bluetooth-1.30.2-1.fc34.x86_64
pipewire-alsa-0.3.24-4.fc34.x86_64
pipewire-jack-audio-connection-kit-0.3.24-4.fc34.x86_64
pipewire-utils-0.3.24-4.fc34.x86_64

screenshots

Bluetooth Profiles

Online Meetings

In WSLv2 there is a way to limit the resources of your linux distro (cpu/memory) to have a better performance on you win10.

To give you an example, this is how it starts on my HP-G5

~$ free -m
               total        used        free      shared  buffcache   available
Mem:           12659          68       12555           0          34       12425
Swap:           4096           0        4096

~$ grep -Ec proc /proc/cpuinfo
8

8 CPU threads, 12G

wslconfig

To define your specs, open cmd and change to your user profile directory

~> cd %UserProfile%

Verify that your WSL distros are stopped:

~> wsl.exe -l -v
  NAME            STATE           VERSION
* Archlinux       Running         2
  Ubuntu-20.04    Stopped         1

~> wsl.exe -t Archlinux -v

~> wsl.exe -l -v
  NAME            STATE           VERSION
* Archlinux       Stopped         2
  Ubuntu-20.04    Stopped         1

and terminate wsl

~> wsl.exe --shutdown

Create a new (or edit your previous) wsl config file

~> notepad.exe .wslconfig

My current setup is

~> type .wslconfig

[wsl2]
memory=4GB   # Limits VM memory in WSL 2 to 4 GB
processors=2 # Makes the WSL 2 VM use two virtual processors
swap=2GB     # How much swap space to add to the WSL2 VM. 0 for no swap file.
swapFile=C:\wsl2-swap.vhdx

as you can see, I want 4GB of RAM and 2 CPU , but also I want a 2GB swap file.

Edit this file according to your needs. The full settings can be found here wsl/wsl-config.

Reminder: you have to shutdown WSL

wsl.exe --shutdown

WSLv2 Limited

Now start your fav linux distro and verify

~$ grep -Ec proc /proc/cpuinfo
2

~$ grep -Ei MemTotal /proc/meminfo
MemTotal:        4028776 kB

~$ free
               total        used        free      shared  buffcache   available
Mem:         4028776       46348     3947056          64       35372     3848616
Swap:        2097152           0     2097152

that’s it !

I upgraded my home internet connection and as a result I had to give up my ~15y Static IP. Having an ephemeral Dynamic IP means I need to use a dynamic dns service to access my homepc. Although the ISP’s CPE (router) has a few public dynamic dns services, I chose to create a simple solution on my own self-hosted DNS infra.

There are a couple of ways to do that, PowerDNS supports Dynamic Updates but I do not want to open PowerDNS to the internet for this kind of operations. I just want to use cron with a simple curl over https.

PowerDNS WebAPI

to enable and use the Built-in Webserver and HTTP API we need to update our configuration:

/etc/pdns/pdns.conf

api-key=0123456789ABCDEF
api=yes

and restart powerdns auth server.

verify it

ss -tnl 'sport = :8081'

State   Recv-Q  Send-Q  Local Address:Port  Peer Address:Port
LISTEN      0       10      127.0.0.1:8081             *:*

WebServer API in PHP

Next to build our API in PHP

Basic Auth

By using https means that the transport layer is encrypted so we only need to create a basic auth mechanism.

<?php
  if ( !isset($_SERVER["PHP_AUTH_USER"]) ) {
      header("WWW-Authenticate: Basic realm='My Realm'");
      header("HTTP/1.0 401 Unauthorized");
      echo "Restricted area: Only Authorized Personnel Are Allowed to Enter This Area";
      exit;
  } else {
    // code goes here
  }
?>

by sending Basic Auth headers, the _SERVER php array variable will contain two extra variables

$_SERVER["PHP_AUTH_USER"]
$_SERVER["PHP_AUTH_PW"]

We do not need to setup an external IDM/LDAP or any other user management system just for this usecase (single user access).

and we can use something like:

<?php
  if (($_SERVER["PHP_AUTH_USER"] == "username") && ($_SERVER["PHP_AUTH_PW"] == "very_secret_password")){
    // code goes here
  }
?>

RRSet Object

We need to create the RRSet Object

here is a simple example

<?php
  $comments = array(
  );

  $record = array(
      array(
          "disabled"  => False,
          "content"   => $_SERVER["REMOTE_ADDR"]
      )
  );

  $rrsets = array(
      array(
          "name"          => "dyndns.example.org.",
          "type"          => "A",
          "ttl"           => 60,
          "changetype"    => "REPLACE",
          "records"       => $record,
          "comments"      => $comments
      )
  );

  $data = array (
      "rrsets" => $rrsets
  );

?>

by running this data set to json_encode should return something like this

{
  "rrsets": [
    {
      "changetype": "REPLACE",
      "comments": [],
      "name": "dyndns.example.org.",
      "records": [
        {
          "content": "1.2.3.4",
          "disabled": false
        }
      ],
      "ttl": 60,
      "type": "A"
    }
  ]
}

be sure to verify that records, comments and rrsets are also arrays !

Stream Context

Next thing to create our stream context

$API_TOKEN = "0123456789ABCDEF";
$URL = "http://127.0.0.1:8081/api/v1/servers/localhost/zones/example.org";

$stream_options = array(
    "http" => array(
        "method"    => "PATCH",
        "header"    => "Content-type: application/json \r\n" .
                        "X-API-Key: $API_TOKEN",
        "content"   => json_encode($data),
        "timeout"   => 3
    )
);

$context = stream_context_create($stream_options);

Be aware of " \r\n" . in header field, this took me more time than it should ! To have multiple header fiels into the http stream, you need (I don’t know why) to carriage return them.

Get Zone details

Before continue, let’s make a small script to verify that we can successfully talk to the PowerDNS HTTP API with php

<?php
  $API_TOKEN = "0123456789ABCDEF";
  $URL = "http://127.0.0.1:8081/api/v1/servers/localhost/zones/example.org";

  $stream_options = array(
      "http" => array(
          "method"    => "GET",
          "header"    => "Content-type: application/jsonrn".
                          "X-API-Key: $API_TOKEN"
      )
  );

  $context = stream_context_create($stream_options);

  echo file_get_contents($URL, false, $context);
?>

by running this:

php get.php | jq .

we should get the records of our zone in json format.

Cron Entry

you should be able to put the entire codebase together by now, so let’s work on the last component of our self-hosted dynamic dns server, how to update our record via curl

curl -sL https://username:very_secret_password@example.org/dyndns.php

every minute should do the trick

# dyndns
* * * * * curl -sL https://username:very_secret_password@example.org/dyndns.php

That’s it !