Add Dockerfile

Dockerfile

@@ -0,0 +1,12 @@
+FROM golang:alpine AS builder
+WORKDIR /go/src/jrouter
+COPY . .
+RUN --mount=type=cache,target=/root/.cache/go-build \
+    --mount=type=cache,target=/go/pkg/mod \
+    apk add build-base libpcap-dev && \
+    CGO_ENABLED=1 CGO_FLAGS='-static' go build -v -o jrouter .
+
+FROM alpine:latest
+COPY --from=builder /go/src/jrouter/jrouter /usr/bin/
+RUN apk add libpcap
+ENTRYPOINT ["/usr/bin/jrouter", "-config", "/etc/jrouter/jrouter.yaml"]

README.md

@@ -49,20 +49,16 @@ First, set up a `jrouter.yaml` (use the one in this repo as an example).
 
 TODO: explain the configuration file
 
-Building and running:
+### Building and running directly
 
 1. Install [Go](https://go.dev/dl).
-
 2. Run these commands (for Debian-variety Linuxen, e.g. Ubuntu, Raspbian, Mint...):
-
   ```shell
   sudo apt install git build-essential libpcap-dev
   go install gitea.drjosh.dev/josh/jrouter@latest
   sudo setcap 'CAP_NET_BIND_SERVICE=ep CAP_NET_RAW=ep' ~/go/bin/jrouter
   ```
-
 3. Configure `jrouter.yaml`
-
 4. To run:
   ```shell
   ~/go/bin/jrouter
@@ -77,6 +73,26 @@ Notes:
 
 TODO: instructions for non-Linux / non-Debian-like machines
 
+### With Docker
+
+1.  Clone the repo and `cd` into it.
+2.  `docker build -t jrouter .`
+3.  Example `docker run` command:
+    ```shell
+    docker run \
+      -v ./cfg:/etc/jrouter \
+      --cap-add NET_RAW \
+      --net host \
+      --name jrouter \
+      jrouter
+    ```
+
+Notes:
+
+* Put `jrouter.yaml` inside a `cfg` directory (or some path of your choice and bind-mount it at `/etc/jrouter`) for it to find the config file.
+* `--cap-add NET_RAW` and `--net host` is needed for EtherTalk access to the network interface.
+* By using `--net host`, the default AURP port (387) will be bound without `-p`.
+
 ## Bug reports? Feature requests? Complaints? Praise?
 
 You can contact me on the Fediverse at @DrJosh9000@cloudisland.nz, or email me at josh.deprez@gmail.com.

main.go

@@ -30,7 +30,6 @@ import (
 	"os"
 	"os/signal"
 	"regexp"
-	"runtime/debug"
 	"slices"
 	"strings"
 	"sync"
@@ -117,7 +116,9 @@ var configFilePath = flag.String("config", "jrouter.yaml", "Path to configuratio
 
 func main() {
 	// For some reason it occasionally panics and the panics have no traceback?
-	debug.SetTraceback("all")
+	// This didn't help:
+	// debug.SetTraceback("all")
+	// I think it's calling recover in a defer too broadly.
 
 	flag.Parse()
 	log.Println("jrouter")