Merge pull request #3 from grishy/docs-and-refactor

Docs and clean up

.github/workflows/commit.yml

@@ -0,0 +1,41 @@
+name: commit
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+
+permissions:
+  contents: read
+
+jobs:
+  golangci:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-go@v4
+        with:
+          go-version: "1.20"
+          cache: false
+
+      - name: golangci-lint
+        uses: golangci/golangci-lint-action@v3
+        with:
+          version: v1.53
+  build_test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-go@v4
+        with:
+          go-version: "1.20"
+          cache: false
+
+      - name: Verify dependencies
+        run: go mod verify
+
+      - name: Build
+        run: go build -v ./...
+
+      - name: Test
+        run: go test -v ./...

.github/workflows/release.yml

@@ -1,4 +1,4 @@
-name: goreleaser
+name: release
 
 on:
   push:
@@ -10,7 +10,7 @@ permissions:
   contents: write
 
 jobs:
-  goreleaser:
+  release:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3

.goreleaser.yaml

@@ -12,9 +12,10 @@ builds:
       - linux
       - darwin
     goarch:
-      - amd64
-      - arm
-      - arm64
+      - "386"
+      - "amd64"
+      - "arm"
+      - "arm64"
     goarm:
       - "6"
       - "7"
@@ -34,7 +35,7 @@ release:
   target_commitish: "{{ .Commit }}"
   mode: replace
   header: |
-    ## ⚙️ The `{{ .Tag }}` release
+    ## ℹ️ For information on how to install and use please see `README.md`
   footer: |
     Your PRs & issues are welcome! Thanks 😉
   disable: false

README.md

@@ -1,10 +1,88 @@
-# go-avahi-cname
+<img src="./docs/logo_x3.png" width="350">
+
+![GitHub tag (with filter)](https://img.shields.io/github/v/tag/grishy/go-avahi-cname)
+[![Go Report Card](https://goreportcard.com/badge/github.com/grishy/go-avahi-cname)](https://goreportcard.com/report/github.com/grishy/go-avahi-cname)
+![Build Status](https://github.com/grishy/go-avahi-cname/actions/workflows/release.yml/badge.svg)
+
+## About go-avahi-cname
+
+This project publishe CNAME records pointing to the local host over multicast DNS using the **Avahi** daemon found in all major Linux distributions.
+Since Avahi is compatible with Apple's Bonjour, these names are usable from MacOS X and Windows too.
+
+### Goals
+
+- ✅ No dependencies
+- ✅ Small footprint, less than 3MB binary
+- ✅ Support x86_64 and ARM
+- ✅ Release binaries and containers
+
+### Architecture
+
+![Architecture](./docs/arch.excalidraw.svg)
+
+## Usege and installation
+
+All CNAMEs are specified as program arguments, no length limit.  
+You can use either just the name (`name1`), which will create a record as a subdomain for the current machine, or you can write the full FQDN (`name1.hostname.local.` domain with a dot on the end) format.
+
+Example output on machine with hostname `lab`:
+
+```plain
+> ./go-avahi-cname git photo.local. example.lab.local.
+2023/07/27 08:37:14 Creating publisher
+2023/07/27 08:37:14 Formating CNAMEs:
+2023/07/27 08:37:14   > 'git.lab.local.' (added current FQDN)
+2023/07/27 08:37:14   > 'photo.local.'
+2023/07/27 08:37:14   > 'example.lab.local.'
+2023/07/27 08:37:14 Publishing every 5m0s and CNAME TTL=600s.
+^C
+2023/07/27 08:37:16 Closing publisher...
+```
+
+### Installation
+
+#### Binary
+
+Binary files can be taken as artifacts for [the Release](https://github.com/grishy/go-avahi-cname/releases). In this case, it would be better to create a systemd service.
+
+#### Container
+
+The images for each version are in [the Packages section](https://github.com/grishy/go-avahi-cname/pkgs/container/go-avahi-cname).  
+You need to provide the `/var/run/dbus/system_bus_socket` file to the container to be able to communicate with the host's Avahi daemon.
+
+One-liner to run the container `v0.3.1`:
+
+```bash
+> docker run --restart=unless-stopped -d -v /var/run/dbus/system_bus_socket:/var/run/dbus/system_bus_socket ghcr.io/grishy/go-avahi-cname:v0.3.1 name1 name2.lab.local.
+5a19790e06cca93016af6651d7af4046c24095a6909ace2fe26c3451fb98ceee
+
+> docker logs 5a19790e06cca93016af6651d7af4046c24095a6909ace2fe26c3451fb98ceee
+2023/07/27 08:49:02 Creating publisher
+2023/07/27 08:49:02 Formating CNAMEs:
+2023/07/27 08:49:02   > 'name1.lab.local.' (added current FQDN)
+2023/07/27 08:49:02   > 'name2.lab.local.'
+2023/07/27 08:49:02 Publishing every 5m0s ans CNAME TTL=600s.
+```
+
+Ansible task to run the container:
+
+```yaml
+- name: go-avahi-cname | Start container
+  community.docker.docker_container:
+    name: "go-avahi-cname"
+    image: "ghcr.io/grishy/go-avahi-cname:v0.3.1"
+    restart_policy: unless-stopped
+    volumes:
+      - "/var/run/dbus/system_bus_socket:/var/run/dbus/system_bus_socket" # access to avahi-daemon
+    command: "name1 name2 git"
+```
 
 ## Source of inspiration
 
-- https://gist.github.com/gdamjan/3168336
-- https://github.com/tomoasleep/k8s-avahi
+- https://web.archive.org/web/20151016190620/http://www.avahi.org/wiki/Examples/PythonPublishAlias
+- https://pypi.org/project/mdns-publisher/
 
-## TODO
+## License
 
-- [ ] Add FreeBSD support (https://github.com/godbus/dbus/issues/315)
+Copyright © 2022 [Sergei G.](https://github.com/grishy)  
+This project is [MIT](./LICENSE) licensed.

main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"fmt"
 	"log"
 	"os"
 	"os/signal"
@@ -11,23 +12,14 @@ import (
 	"github.com/miekg/dns"
 )
 
-const TTL = uint32(60 * 10) // seconds
-
-func main() {
-	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt)
-	defer stop()
-
-	log.Println("Creating publisher")
-	publisher, err := publisher.NewPublisher()
-	if err != nil {
-		log.Fatalf("Can't create publisher: %v", err)
-	}
+const TTL = uint32(10 * 60) // in seconds
 
+func formatCname(hostnameFqdn string, cnames []string) []string {
 	log.Println("Formating CNAMEs:")
-	cnames := os.Args[1:]
+
 	for i, cname := range cnames {
 		if !dns.IsFqdn(cname) {
-			cnames[i] = dns.Fqdn(cname + "." + publisher.Fqdn())
+			cnames[i] = dns.Fqdn(cname + "." + hostnameFqdn)
 
 			log.Printf("  > '%s' (added current FQDN)", cnames[i])
 			continue
@@ -36,18 +28,27 @@ func main() {
 		log.Printf("  > '%s'", cname)
 	}
 
+	return cnames
+}
+
+func publishing(ctx context.Context, publisher *publisher.Publisher, cnames []string) {
 	resendDuration := time.Duration(TTL/2) * time.Second
-	log.Printf("Publishing every %v ans CNAME TTL=%ds.", resendDuration, TTL)
+	log.Printf("Publishing every %v and CNAME TTL=%ds.", resendDuration, TTL)
 
 	// To start publishing immediately
 	// https://github.com/golang/go/issues/17601
-	publisher.PublishCNAMES(os.Args[1:], TTL)
+	if err := publisher.PublishCNAMES(cnames, TTL); err != nil {
+		log.Fatalf("can't publish CNAMEs: %v", err)
+	}
 
 	for {
 		select {
 		case <-time.Tick(resendDuration):
-			publisher.PublishCNAMES(os.Args[1:], TTL)
+			if err := publisher.PublishCNAMES(cnames, TTL); err != nil {
+				log.Fatalf("can't publish CNAMEs: %v", err)
+			}
 		case <-ctx.Done():
+			fmt.Println()
 			log.Println("Closing publisher...")
 			if err := publisher.Close(); err != nil {
 				log.Fatalf("Can't close publisher: %v", err)
@@ -56,3 +57,17 @@ func main() {
 		}
 	}
 }
+
+func main() {
+	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt)
+	defer stop()
+
+	log.Println("Creating publisher")
+	publisher, err := publisher.NewPublisher()
+	if err != nil {
+		log.Fatalf("Can't create publisher: %v", err)
+	}
+
+	cnames := formatCname(publisher.Fqdn(), os.Args[1:])
+	publishing(ctx, publisher, cnames)
+}