Add opt-in auto-update from Gitea releases

The program now lives in /usr/local/lib/blacktip and is owned by its service user so it can replace itself.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

.env.example

@@ -18,3 +18,7 @@ BLACKTIP_TOKEN=
 #BLACKTIP_TRAEFIK=/usr/local/lib/blacktip/traefik
 #BLACKTIP_ACME_DNS=cloudflare
 #CF_DNS_API_TOKEN=
+
+# Check for new releases every few hours and update and restart by itself (Linux and macOS).
+# setup.sh turns this on; remove it to update by hand.
+#BLACKTIP_AUTO_UPDATE=1

README.md

@@ -54,6 +54,10 @@ sudo systemctl start blacktip
 
 Use `linux_arm64` or `linux_arm` for Raspberry Pi and other ARM machines. To upgrade, repeat the same steps: your settings and data are kept. `sudo ./install.sh --uninstall` removes the service and binary but leaves `/etc/blacktip` and `/var/lib/blacktip` alone. `blacktip -version` tells you which build is running.
 
+**Updates**
+
+Set `BLACKTIP_AUTO_UPDATE=1` (or pass `-auto-update`) and Blacktip checks this server for a newer release every few hours, verifies it against `SHA256SUMS`, checks that the new binary runs, swaps it in and restarts itself. It only follows full releases (never pre-releases), never downgrades, and keeps the old binary if anything looks wrong. `setup.sh` turns it on. It is not available on Windows, and it is for the systemd and plain-binary installs: with Docker, pull a new image instead.
+
 **With Docker**
 
 ```

cmd/blacktip/main.go

@@ -11,6 +11,7 @@ import (
 
 	"git.veillax.com/Veillax/blacktip"
 	"git.veillax.com/Veillax/reef/dotenv"
+	"git.veillax.com/Veillax/reef/selfupdate"
 )
 
 // version is set at build time (deploy/build.sh).
@@ -38,6 +39,7 @@ func main() {
 	acmeDNS := flag.String("acme-dns", os.Getenv("BLACKTIP_ACME_DNS"), "with -traefik: DNS-challenge provider (e.g. cloudflare) for wildcard certificates; its credentials go in this process's environment")
 	noACME := flag.Bool("no-acme", false, "with -traefik: serve Traefik's self-signed certificate instead of requesting Let's Encrypt ones")
 	flag.String("env", ".env", "file to read secrets and settings from")
+	autoUpdate := flag.Bool("auto-update", os.Getenv("BLACKTIP_AUTO_UPDATE") == "1", "check for new releases every few hours and update and restart by itself (Linux and macOS)")
 	showVersion := flag.Bool("version", false, "print the version and exit")
 	flag.Parse()
 	if *showVersion {
@@ -58,6 +60,9 @@ func main() {
 	log.Printf("blacktip %s starting", version)
 	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt)
 	defer stop()
+	if *autoUpdate {
+		go selfupdate.Run(ctx, selfupdate.Config{Server: "https://git.veillax.com", Repo: "Veillax/blacktip", App: "blacktip", Current: version, Logf: log.Printf})
+	}
 	if err := b.Run(ctx); err != nil {
 		log.Fatal(err)
 	}

deploy/blacktip.service

@@ -10,7 +10,7 @@ Group=blacktip
 # The Traefik that ships with Blacktip; set BLACKTIP_TRAEFIK= (empty) in the env file for the built-in proxy.
 Environment=BLACKTIP_TRAEFIK=/usr/local/lib/blacktip/traefik
 EnvironmentFile=-/etc/blacktip/blacktip.env
-ExecStart=/usr/local/bin/blacktip -data /var/lib/blacktip
+ExecStart=/usr/local/lib/blacktip/blacktip -data /var/lib/blacktip
 WorkingDirectory=/var/lib/blacktip
 Restart=on-failure
 RestartSec=3
@@ -22,7 +22,7 @@ AmbientCapabilities=CAP_NET_BIND_SERVICE
 CapabilityBoundingSet=CAP_NET_BIND_SERVICE
 NoNewPrivileges=true
 ProtectSystem=strict
-ReadWritePaths=/var/lib/blacktip
+ReadWritePaths=/var/lib/blacktip /usr/local/lib/blacktip
 ProtectHome=true
 PrivateTmp=true
 ProtectKernelTunables=true

deploy/install.sh

@@ -5,7 +5,7 @@
 #   sudo ./install.sh --start      the same, then start (or restart) the service
 #   sudo ./install.sh --uninstall  remove the service and binary (keeps the settings and data)
 #
-# Files: /usr/local/bin/blacktip, /etc/systemd/system/blacktip.service,
+# Files: /usr/local/lib/blacktip/blacktip (linked from /usr/local/bin/blacktip), /etc/systemd/system/blacktip.service,
 #        /etc/blacktip/blacktip.env (your settings and secrets), /var/lib/blacktip (data).
 # Set DESTDIR=/some/dir to stage everything there without touching the system.
 set -eu
@@ -17,6 +17,7 @@ UNIT=$ROOT/etc/systemd/system/$NAME.service
 CONF=$ROOT/etc/$NAME
 ENVFILE=$CONF/$NAME.env
 DATA=$ROOT/var/lib/$NAME
+LIB=$ROOT/usr/local/lib/$NAME # the program lives here, owned by the service, so auto-update can replace it
 
 say() { printf '%s\n' "$*"; }
 real() { [ -z "${DESTDIR:-}" ]; } # are we touching the real system?
@@ -30,7 +31,7 @@ if [ "${1:-}" = "--uninstall" ]; then
 	if real; then
 		systemctl disable --now "$NAME" > /dev/null 2>&1 || true
 	fi
-	rm -f "$UNIT" "$BIN" "$ROOT/usr/local/lib/$NAME/traefik"
+	rm -f "$UNIT" "$BIN" "$LIB/$NAME" "$ROOT/usr/local/lib/$NAME/traefik"
 	if real; then
 		systemctl daemon-reload || true
 	fi
@@ -46,8 +47,11 @@ if real && ! id "$NAME" > /dev/null 2>&1; then
 fi
 
 mkdir -p "$ROOT/usr/local/lib/$NAME" "$ROOT/usr/local/bin" "$ROOT/etc/systemd/system" "$CONF" "$DATA"
-install -m 0755 "$HERE/$NAME" "$BIN.new"
-mv -f "$BIN.new" "$BIN" # atomic, so upgrading a running service is safe
+mkdir -p "$LIB"
+install -m 0755 "$HERE/$NAME" "$LIB/$NAME.new"
+mv -f "$LIB/$NAME.new" "$LIB/$NAME" # atomic, so upgrading a running service is safe
+rm -f "$BIN"
+ln -s "/usr/local/lib/$NAME/$NAME" "$BIN"
 if [ -f "$HERE/traefik" ]; then
 	install -m 0755 "$HERE/traefik" "$ROOT/usr/local/lib/$NAME/traefik.new"
 	mv -f "$ROOT/usr/local/lib/$NAME/traefik.new" "$ROOT/usr/local/lib/$NAME/traefik"
@@ -58,7 +62,7 @@ if [ ! -f "$ENVFILE" ]; then
 	say "Created $ENVFILE. Edit it before starting."
 fi
 if real; then
-	chown -R "$NAME:$NAME" "$DATA"
+	chown -R "$NAME:$NAME" "$DATA" "$LIB"
 fi
 
 if real; then
@@ -70,7 +74,7 @@ if real; then
 	fi
 fi
 
-say "Installed $("$BIN" -version 2> /dev/null || echo "$NAME")."
+say "Installed $("$LIB/$NAME" -version 2> /dev/null || echo "$NAME")."
 say "Next:"
 say "  1. edit $ENVFILE"
 say "  2. systemctl start $NAME      (or run this again with --start)"

go.mod

@@ -3,7 +3,7 @@ module git.veillax.com/Veillax/blacktip
 go 1.27.3
 
 require (
-	git.veillax.com/Veillax/reef v0.1.0
+	git.veillax.com/Veillax/reef v0.1.3
 	github.com/emersion/go-msgauth v0.7.0
 	golang.org/x/crypto v0.58.0
 )

go.sum

@@ -1,5 +1,7 @@
 git.veillax.com/Veillax/reef v0.1.0 h1:O0OhEKFx2CsvACJ20sfzJNjGsngomtfDdKdxu4ROpCs=
 git.veillax.com/Veillax/reef v0.1.0/go.mod h1:ZBUd/BARO5kkpUNTP81TTY1aQXLHFR6bKDhCxckjHso=
+git.veillax.com/Veillax/reef v0.1.3 h1:RxSq2xwaup1+MieAkhlvOTZnYwPf19thFHEAe/7VxsI=
+git.veillax.com/Veillax/reef v0.1.3/go.mod h1:ZBUd/BARO5kkpUNTP81TTY1aQXLHFR6bKDhCxckjHso=
 github.com/Microsoft/go-winio v0.6.4 h1:kJF2pamtYCWXf0xAT8sAkwKC0pMl2HYBrRPHAqyUc+g=
 github.com/Microsoft/go-winio v0.6.4/go.mod h1:1xl5JXG4ze/m74GH6Dc4Mwxfc3VL5siRVQjIAlHH07U=
 github.com/emersion/go-msgauth v0.7.0 h1:vj2hMn6KhFtW41kshIBTXvp6KgYSqpA/ZN9Pv4g1INc=