Add stuff from askiiart/pc-configs

docs/Debian/find-fastest-apt-mirror.md

@@ -0,0 +1,39 @@
+# Find Fastest Mirror
+
+You can find the fastest apt mirror using `netselect-apt`. Install it with:
+
+```bash
+sudo apt install netselect-apt
+```
+
+Then run it:
+
+```bash
+sudo netselect-apt -c US -a amd64 -n stable
+```
+
+You should get something like this:
+
+```text
+Running netselect to choose 10 out of 33 addresses.     
+..............................................................................................................................................................................................................................
+The fastest 10 servers seem to be:
+
+	http://mirror.dal.nexril.net/debian/
+	http://mirror.us.oneandone.net/debian/
+	http://mirrors.gigenet.com/debian/
+	http://mirror.steadfast.net/debian/
+	http://mirrors.xtom.com/debian/
+	http://la.mirrors.clouvider.net/debian/
+	http://mirror.keystealth.org/debian/
+	http://mirror.clarkson.edu/debian/
+	http://ftp.us.debian.org/debian/
+	http://mirror.cogentco.com/debian/
+
+Of the hosts tested we choose the fastest valid for http:
+        http://mirror.dal.nexril.net/debian/
+
+Writing sources.list.
+sources.list exists, moving to sources.list.1672257815
+Done.
+```

docs/Debian/port-53-in-use.md

@@ -0,0 +1,39 @@
+# Port in use (connman)
+
+## Problem
+
+When trying to run DNS thing, `connman` is already using port 53.
+
+```bash
+docker compose up --detach --build --remove-orphans
+[+] Running 0/1
+ ⠿ Container pihole  Starting                                                       0.2s
+Error response from daemon: driver failed programming external connectivity on endpoint pihole (bc535387671f0d471f11f8ade5eedc4771126c057e2099931e8ef49461111149): Error starting userland proxy: listen tcp4 0.0.0.0:53: bind: address already in use
+```
+
+## Solution
+
+- Find the `connman.service` file:
+
+```bash
+grep -Ril "connman" /etc/systemd/
+```
+
+- Add `--nodnsproxy` to the `ExecStart` line:
+
+```bash
+ExecStart=/usr/sbin/connmand -n --nodnsproxy
+```
+
+- Reload and restart stuff:
+
+```bash
+systemctl daemon-reload
+systemctl restart connman.service
+```
+
+- Try your thing again. For example:
+
+```bash
+docker compose up -d --remove-orphans
+```

docs/Debian/privilged-ports.md

@@ -0,0 +1,15 @@
+# Port is privileged, cannot be used
+
+When running a container that uses a priviledged port, AKA anything less than 1024, you will get the following error:
+
+```text
+Error starting userland proxy: error while calling PortManager.AddPort(): cannot expose privileged port 80, you can add 'net.ipv4.ip_unprivileged_port_start=80' to /etc/sysctl.conf
+```
+
+To fix this, you need to add the following to your `/etc/sysctl.conf` file:
+
+```conf
+net.ipv4.ip_unprivileged_port_start=0
+```
+
+Then, you can just run the container again.