build, etc: Add systemd units and ufw rules for relay and discovery (fixes #5115) (#5350)

build.go

@@ -57,11 +57,13 @@ type target struct {
 	name              string
 	debname           string
 	debdeps           []string
+	debpre            string
 	debpost           string
 	description       string
 	buildPkg          string
 	binaryName        string
 	archiveFiles      []archiveFile
+	systemdServices   []string
 	installationFiles []archiveFile
 	tags              []string
 }
@@ -128,6 +130,7 @@ var targets = map[string]target{
 		name:        "stdiscosrv",
 		debname:     "syncthing-discosrv",
 		debdeps:     []string{"libc6"},
+		debpre:      "cmd/stdiscosrv/scripts/preinst",
 		description: "Syncthing Discovery Server",
 		buildPkg:    "github.com/syncthing/syncthing/cmd/stdiscosrv",
 		binaryName:  "stdiscosrv", // .exe will be added automatically for Windows builds
@@ -137,12 +140,17 @@ var targets = map[string]target{
 			{src: "LICENSE", dst: "LICENSE.txt", perm: 0644},
 			{src: "AUTHORS", dst: "AUTHORS.txt", perm: 0644},
 		},
+		systemdServices: []string{
+			"cmd/stdiscosrv/etc/linux-systemd/stdiscosrv.service",
+		},
 		installationFiles: []archiveFile{
 			{src: "{{binary}}", dst: "deb/usr/bin/{{binary}}", perm: 0755},
 			{src: "cmd/stdiscosrv/README.md", dst: "deb/usr/share/doc/syncthing-discosrv/README.txt", perm: 0644},
 			{src: "LICENSE", dst: "deb/usr/share/doc/syncthing-discosrv/LICENSE.txt", perm: 0644},
 			{src: "AUTHORS", dst: "deb/usr/share/doc/syncthing-discosrv/AUTHORS.txt", perm: 0644},
 			{src: "man/stdiscosrv.1", dst: "deb/usr/share/man/man1/stdiscosrv.1", perm: 0644},
+			{src: "cmd/stdiscosrv/etc/linux-systemd/default", dst: "deb/etc/default/syncthing-discosrv", perm: 0644},
+			{src: "cmd/stdiscosrv/etc/firewall-ufw/stdiscosrv", dst: "deb/etc/ufw/applications.d/stdiscosrv", perm: 0644},
 		},
 		tags: []string{"purego"},
 	},
@@ -150,6 +158,7 @@ var targets = map[string]target{
 		name:        "strelaysrv",
 		debname:     "syncthing-relaysrv",
 		debdeps:     []string{"libc6"},
+		debpre:      "cmd/strelaysrv/scripts/preinst",
 		description: "Syncthing Relay Server",
 		buildPkg:    "github.com/syncthing/syncthing/cmd/strelaysrv",
 		binaryName:  "strelaysrv", // .exe will be added automatically for Windows builds
@@ -160,6 +169,9 @@ var targets = map[string]target{
 			{src: "LICENSE", dst: "LICENSE.txt", perm: 0644},
 			{src: "AUTHORS", dst: "AUTHORS.txt", perm: 0644},
 		},
+		systemdServices: []string{
+			"cmd/strelaysrv/etc/linux-systemd/strelaysrv.service",
+		},
 		installationFiles: []archiveFile{
 			{src: "{{binary}}", dst: "deb/usr/bin/{{binary}}", perm: 0755},
 			{src: "cmd/strelaysrv/README.md", dst: "deb/usr/share/doc/syncthing-relaysrv/README.txt", perm: 0644},
@@ -167,6 +179,8 @@ var targets = map[string]target{
 			{src: "LICENSE", dst: "deb/usr/share/doc/syncthing-relaysrv/LICENSE.txt", perm: 0644},
 			{src: "AUTHORS", dst: "deb/usr/share/doc/syncthing-relaysrv/AUTHORS.txt", perm: 0644},
 			{src: "man/strelaysrv.1", dst: "deb/usr/share/man/man1/strelaysrv.1", perm: 0644},
+			{src: "cmd/strelaysrv/etc/linux-systemd/default", dst: "deb/etc/default/syncthing-relaysrv", perm: 0644},
+			{src: "cmd/strelaysrv/etc/firewall-ufw/strelaysrv", dst: "deb/etc/ufw/applications.d/strelaysrv", perm: 0644},
 		},
 	},
 	"strelaypoolsrv": {
@@ -555,9 +569,15 @@ func buildDeb(target target) {
 	for _, dep := range target.debdeps {
 		args = append(args, "-d", dep)
 	}
+	for _, service := range target.systemdServices {
+		args = append(args, "--deb-systemd", service)
+	}
 	if target.debpost != "" {
 		args = append(args, "--after-upgrade", target.debpost)
 	}
+	if target.debpre != "" {
+		args = append(args, "--before-install", target.debpre)
+	}
 	runPrint("fpm", args...)
 }
 

cmd/stdiscosrv/etc/firewall-ufw/stdiscosrv

@@ -0,0 +1,4 @@
+[stdiscosrv]
+title=Syncthing discovery server
+description=Lets syncthing clients discover each other
+ports=8443/tcp

cmd/stdiscosrv/etc/linux-systemd/default

@@ -0,0 +1,3 @@
+# Default settings for syncthing-relaysrv (strelaysrv).
+## Add Options here:
+DISCOSRV_OPTS=

cmd/stdiscosrv/etc/linux-systemd/stdiscosrv.service

@@ -0,0 +1,25 @@
+[Unit]
+Description=Syncthing Discovery Server
+After=network.target
+Documentation=man:stdiscosrv(1)
+
+[Service]
+WorkingDirectory=/var/lib/syncthing-discosrv
+EnvironmentFile=/etc/default/syncthing-discosrv
+ExecStart=/usr/bin/stdiscosrv $DISCOSRV_OPTS
+
+# Hardening
+User=syncthing-discosrv
+Group=syncthing
+ProtectSystem=strict
+ReadWritePaths=/var/lib/syncthing-discosrv
+NoNewPrivileges=true
+PrivateTmp=true
+PrivateDevices=true
+ProtectHome=true
+SystemCallArchitectures=native
+MemoryDenyWriteExecute=true
+
+[Install]
+WantedBy=multi-user.target
+Alias=syncthing-discosrv.service

cmd/stdiscosrv/scripts/preinst

@@ -0,0 +1,4 @@
+#!/bin/bash
+
+addgroup --system syncthing
+adduser --system --home /var/lib/syncthing-discosrv --ingroup syncthing syncthing-discosrv

cmd/strelaysrv/etc/firewall-ufw/strelaysrv

@@ -0,0 +1,9 @@
+[strelaysrv]
+title=Syncthing relay server
+description=Proxies traffic of syncthing client behind firewalls
+ports=22067/tcp
+
+[strelaysrv-metrics]
+title=Syncthing relay metrics
+description=Provides metrics about the syncthing relay server
+ports=22070/tcp

cmd/strelaysrv/etc/linux-systemd/default

@@ -0,0 +1,5 @@
+# Default settings for syncthing-relaysrv (strelaysrv).
+NAT=true
+
+## Add Options here:
+RELAYSRV_OPTS=

cmd/strelaysrv/etc/linux-systemd/strelaysrv.service

@@ -1,17 +1,25 @@
 [Unit]
-Description=Syncthing relay server
+Description=Syncthing Relay Server
 After=network.target
+Documentation=man:strelaysrv(1)
 
 [Service]
-User=strelaysrv
-Group=strelaysrv
-ExecStart=/usr/bin/strelaysrv
-WorkingDirectory=/var/lib/strelaysrv
+WorkingDirectory=/var/lib/syncthing-relaysrv
+EnvironmentFile=/etc/default/syncthing-relaysrv
+ExecStart=/usr/bin/strelaysrv -nat=${NAT} $RELAYSRV_OPTS
 
+# Hardening
+User=syncthing-relaysrv
+Group=syncthing
+ProtectSystem=strict
+ReadWritePaths=/var/lib/syncthing-relaysrv
+NoNewPrivileges=true
 PrivateTmp=true
-ProtectSystem=full
+PrivateDevices=true
 ProtectHome=true
-NoNewPrivileges=true
+SystemCallArchitectures=native
+MemoryDenyWriteExecute=true
 
 [Install]
 WantedBy=multi-user.target
+Alias=syncthing-relaysrv.service

cmd/strelaysrv/scripts/preinst

@@ -0,0 +1,4 @@
+#!/bin/bash
+
+addgroup --system syncthing
+adduser --system --home /var/lib/syncthing-relaysrv --ingroup syncthing syncthing-relaysrv