[WIP] a hacky implementation of services

devshell.toml

@@ -60,3 +60,11 @@ help = "golang linter"
 name = "golangci-lint"
 package = "golangci-lint"
 category = "linters"
+
+[[commands]]
+name = "hello-loop"
+command = "while true; do hello; sleep 1; done"
+
+[[services]]
+name = "hello-printer"
+command = "hello-loop"

mkDevShell/default.nix

@@ -39,6 +39,7 @@ let
       inherit (config)
         bash
         commands
+        services
         env
         motd
         name
@@ -57,9 +58,41 @@ let
                 (writeShellScriptBin name (toString command))
               ];
           in
-          (builtins.concatMap op commands) ++ packages;
+          (builtins.concatMap op commands) ++ packages ++ [ serviceViewer ];
       };
 
+      sessionName = "${name}-sessions";
+      serviceRunner = let
+        makeService = service: ''
+          echo "Starting service ${service.name}"
+          ${pkgs.tmux}/bin/tmux new-window -n '${service.name}' -t '${sessionName}' '${service.command}'
+        '';
+      in pkgs.writeShellScript "service-runner" ''
+        # In case user is running multiple terminals with the same devshell
+        ${pkgs.tmux}/bin/tmux list-sessions | grep '^${sessionName}: ' && exit 0
+
+        ${pkgs.tmux}/bin/tmux new-session -d -s '${sessionName}'
+        ${lib.strings.concatStringsSep
+          "\n"
+          (map
+            makeService
+            services
+          )
+        }
+      '';
+      serviceViewer = writeShellScriptBin "service-viewer" ''
+        serviceName="$1"
+        case "$serviceName" in
+        ${lib.strings.concatStrings (map (service: "${service.name})\n;;\n") services)}
+        *)
+          echo "Invalid service name. Choose one of ${lib.strings.concatStringsSep "\n" (map (service: service.name) services)}"
+          exit 1
+          ;;
+        esac
+
+        ${pkgs.tmux}/bin/tmux select-window -t '${sessionName}':"$serviceName" \; a -t '${sessionName}'
+      '';
+
       # write a bash profile to load
       bashrc = writeText "${name}-bashrc" ''
         # Set all the passed environment variables
@@ -73,6 +106,13 @@ let
         # Expose the path to nixpkgs
         export NIXPKGS_PATH=${toString pkgs.path}
 
+        function stopServices {
+          echo "Cleaning up services"
+          ${pkgs.tmux}/bin/tmux kill-session -t '${sessionName}'
+        }
+        trap stopServices EXIT
+        ${serviceRunner}
+
         # Load installed profiles
         for file in "$DEVSHELL_DIR/etc/profile.d/"*.sh; do
           # If that folder doesn't exist, bash loves to return the whole glob

mkDevShell/options.nix

@@ -112,6 +112,15 @@ let
       '';
     };
   };
+
+  serviceOptions = {
+    name = mkOption {
+      type = types.str;
+    };
+    command = mkOption {
+      type = types.str;
+    };
+  };
 in
 {
   options = {
@@ -160,6 +169,11 @@ in
       '';
     };
 
+    services = mkOption {
+      type = types.listOf (types.submodule { options = serviceOptions; });
+      default = [ ];
+    };
+
     bash = mkOption {
       type = types.submodule {
         options = {