Add s6 support

Co-authored-by: userbook <userbook@devuan>
Co-authored-by: TerminalJunki <158248817+TerminalJunki@users.noreply.github.com>
Signed-off-by: AnErrupTion <anerruption@disroot.org>

build.zig

@@ -106,6 +106,11 @@ pub fn build(b: *std.Build) !void {
     const installrunit_step = b.step("installrunit", "Install the Ly runit service");
     installrunit_step.makeFn = ServiceInstaller(.Runit).make;
     installrunit_step.dependOn(installexe_step);
+    installopenrc_step.dependOn(installexe_step);
+
+    const installs6_step = b.step("installs6", "Install the Ly s6 service");
+    installs6_step.makeFn = ServiceInstaller(.S6).make;
+    installs6_step.dependOn(installexe_step);
 
     const uninstallall_step = b.step("uninstallall", "Uninstall Ly and all services");
     uninstallall_step.makeFn = uninstallall;
@@ -123,12 +128,21 @@ const InitSystem = enum {
     Systemd,
     Openrc,
     Runit,
+    S6,
 };
 pub fn ServiceInstaller(comptime init_system: InitSystem) type {
     return struct {
         pub fn make(step: *std.Build.Step, _: ProgressNode) !void {
             const allocator = step.owner.allocator;
             switch (init_system) {
+                .Systemd => {
+                    const service_path = try std.fs.path.join(allocator, &[_][]const u8{ dest_directory, "/usr/lib/systemd/system" });
+                    std.fs.cwd().makePath(service_path) catch {};
+                    var service_dir = std.fs.cwd().openDir(service_path, .{}) catch unreachable;
+                    defer service_dir.close();
+
+                    try std.fs.cwd().copyFile("res/ly.service", service_dir, "ly.service", .{ .override_mode = 0o644 });
+                },
                 .Openrc => {
                     const service_path = try std.fs.path.join(allocator, &[_][]const u8{ dest_directory, "/etc/init.d" });
                     std.fs.cwd().makePath(service_path) catch {};
@@ -147,13 +161,22 @@ pub fn ServiceInstaller(comptime init_system: InitSystem) type {
                     try std.fs.cwd().copyFile("res/ly-runit-service/finish", service_dir, "finish", .{ .override_mode = 0o755 });
                     try std.fs.cwd().copyFile("res/ly-runit-service/run", service_dir, "run", .{ .override_mode = 0o755 });
                 },
-                .Systemd => {
-                    const service_path = try std.fs.path.join(allocator, &[_][]const u8{ dest_directory, "/usr/lib/systemd/system" });
+                .S6 => {
+                    const admin_service_path = try std.fs.path.join(allocator, &[_][]const u8{ dest_directory, "/etc/s6/adminsv/default/contents.d" });
+                    std.fs.cwd().makePath(admin_service_path) catch {};
+                    var admin_service_dir = std.fs.cwd().openDir(admin_service_path, .{}) catch unreachable;
+                    defer admin_service_dir.close();
+
+                    const file = try admin_service_dir.createFile("ly-srv", .{});
+                    file.close();
+
+                    const service_path = try std.fs.path.join(allocator, &[_][]const u8{ dest_directory, "/etc/s6/sv/ly-srv" });
                     std.fs.cwd().makePath(service_path) catch {};
                     var service_dir = std.fs.cwd().openDir(service_path, .{}) catch unreachable;
                     defer service_dir.close();
 
-                    try std.fs.cwd().copyFile("res/ly.service", service_dir, "ly.service", .{ .override_mode = 0o644 });
+                    try std.fs.cwd().copyFile("res/ly-s6/run", service_dir, "run", .{ .override_mode = 0o755 });
+                    try std.fs.cwd().copyFile("res/ly-s6/type", service_dir, "type", .{});
                 },
             }
         }
@@ -258,6 +281,16 @@ pub fn uninstallall(step: *std.Build.Step, _: ProgressNode) !void {
     std.fs.cwd().deleteTree(runit_service_path) catch {
         std.debug.print("warn: runit service not found.\n", .{});
     };
+
+    const s6_service_path = try std.fs.path.join(allocator, &[_][]const u8{ dest_directory, "/etc/s6/sv/ly-srv" });
+    std.fs.cwd().deleteTree(s6_service_path) catch {
+        std.debug.print("warn: s6 service not found.\n", .{});
+    };
+
+    const s6_admin_service_file = try std.fs.path.join(allocator, &[_][]const u8{ dest_directory, "/etc/s6/adminsv/default/contents.d/ly-srv" });
+    std.fs.cwd().deleteFile(s6_admin_service_file) catch {
+        std.debug.print("warn: s6 admin service not found.\n", .{});
+    };
 }
 
 fn getVersionStr(b: *std.Build, name: []const u8, version: std.SemanticVersion) ![]const u8 {

readme.md

@@ -132,7 +132,7 @@ then you have to disable getty, so it doesn't respawn on top of ly
 # ln -s /etc/sv/ly /var/service/
 ```
 
-By default, ly will run on tty2. To change the tty it must be set in `/etc/ly/config.ini` 
+By default, ly will run on tty2. To change the tty it must be set in `/etc/ly/config.ini`
 
 You should as well disable your existing display manager service if needed, e.g.:
 
@@ -148,6 +148,21 @@ you should disable the agetty-tty2 service like this:
 # rm /var/service/agetty-tty2
 ```
 
+### s6
+```
+# zig build installs6
+```
+
+Then, edit `/etc/s6/config/ttyX.conf` and set `SPAWN="no"`, where X is the TTY ID (e.g. `2`).
+
+Finally, enable the service:
+
+```
+# s6-service add default ly-srv
+# s6-db-reload
+# s6-rc -u change ly-srv
+```
+
 ### Updating
 You can also install Ly without copying the system service and the configuration file. That's
 called *updating*. To update, simply run:

res/ly-s6/run

@@ -0,0 +1,2 @@
+#!/bin/execlineb -P
+exec agetty -L -8 -n -l /usr/bin/ly tty2 115200

res/ly-s6/type

@@ -0,0 +1 @@
+longrun