feat: support UDP proxy of port 2022 and 2023 for P2Panda apps (#70)

# Support P2P communication between P2Panda Apps

Apps built with the set of [P2Panda](https://p2panda.org/) libraries perform P2P communication over two UDP ports. The default ports for these are 2022 and 2023.

There aren't really a lot (any?) P2Panda web apps out there, most are desktop or mobile apps.

So, this change is being specifically request by the [LoRes Tech](https://lores.tech/) project in order to support our [LoRes Node](https://github.com/local-resilience-tech/lores-node/) app. We have a recipe drafted for this [here](https://codeberg.org/lores/lores-node-coop-cloud-recipe) and we will push that to the catalogue once this change is in.

It seems better to make this kiwix change as general as possible, which is why we called the flag `P2PANDA_ENABLED` rather than `LORES_NODE_ENABLED`. In practice if there was a larger ecosystem of such apps, we'd probably need to make the actual port numbers configurable.

Reviewed-on: coop-cloud/traefik#70
Reviewed-by: p4u1 <p4u1@noreply.git.coopcloud.tech>
Co-authored-by: Jade Ambrose <jade@noreply.git.coopcloud.tech>
Co-committed-by: Jade Ambrose <jade@noreply.git.coopcloud.tech>

.drone.yml

@@ -16,7 +16,7 @@ steps:
       STACK_NAME: traefik
       LETS_ENCRYPT_ENV: production
       LETS_ENCRYPT_EMAIL: helo@autonomic.zone
-      TRAEFIK_YML_VERSION: v22
+      TRAEFIK_YML_VERSION: v26
       FILE_PROVIDER_YML_VERSION: v10
       ENTRYPOINT_VERSION: v4
 trigger:

.env.sample

@@ -131,6 +131,10 @@ COMPOSE_FILE="compose.yml"
 # COMPOSE_FILE="$COMPOSE_FILE:compose.gitea.yml"
 # GITEA_SSH_ENABLED=1
 
+## P2Panda UDP
+# COMPOSE_FILE="$COMPOSE_FILE:compose.p2panda.yml"
+# P2PANDA_ENABLED=1
+
 ## Foodsoft SMTP
 # COMPOSE_FILE="$COMPOSE_FILE:compose.foodsoft.yml"
 # FOODSOFT_SMTP_ENABLED=1

abra.sh

@@ -1,3 +1,3 @@
-export TRAEFIK_YML_VERSION=v25
+export TRAEFIK_YML_VERSION=v26
 export FILE_PROVIDER_YML_VERSION=v10
 export ENTRYPOINT_VERSION=v5

compose.p2panda.yml

@@ -0,0 +1,14 @@
+version: "3.8"
+services:
+  app:
+    environment:
+      - P2PANDA_ENABLED
+    ports:
+      - target: 2022
+        published: 2022
+        protocol: udp
+        mode: host
+      - target: 2023
+        published: 2023
+        protocol: udp
+        mode: host

traefik.yml.tmpl

@@ -37,6 +37,12 @@ entrypoints:
   gitea-ssh:
     address: ":2222"
   {{ end }}
+  {{ if eq (env "P2PANDA_ENABLED") "1" }}
+  p2panda-udp-v4:
+    address: ":2022/udp"
+  p2panda-udp-v6:
+    address: ":2023/udp"
+  {{ end }}
   {{ if eq (env "GARAGE_RPC_ENABLED") "1" }}
   garage-rpc:
     address: ":3901"