GPII-2971: Install on demand

.nycrc

@@ -2,7 +2,8 @@
     "include": [
   	  "index.js",
 	  "gpii/node_modules/*/*.js",
-	  "gpii/node_modules/*/src/*.js"
+	  "gpii/node_modules/*/src/*.js",
+	  "service/src/*.js"
     ],
     "exclude": [
 	  "!**/node_modules/"

Gruntfile.js

@@ -17,7 +17,7 @@ module.exports = function (grunt) {
         lintAll: {
             sources: {
                 md:    [ "./*.md","./gpii/*.md", "./settingsHelper/**/*.md"],
-                js:    ["./gpii/**/*.js", "./tests/**/*.js", "./*.js"],
+                js:    ["./gpii/**/*.js", "./tests/**/*.js", "./*.js", "./service/src/**/*.js", "./service/tests/**/*.js"],
                 json:  ["./gpii/**/*.json", "./tests/**/*.json", "./settingsHelper/**/*.json", "./*.json"],
                 json5: ["./gpii/**/*.json5", "./tests/**/*.json5", "./*.json5"],
                 other: ["./.*"]

gpii-service/.eslintrc.json

@@ -0,0 +1,7 @@
+{
+    "extends": "eslint-config-fluid",
+    "env": {
+        "node": true,
+        "es6": true
+    }
+}

gpii-service/README.md

@@ -0,0 +1,170 @@
+# GPII Windows Service
+
+A Windows Service that starts the GPII process (and listeners) when the user logs on, restarts it when it stops
+unexpectedly, and provides the ability to run high-privileged tasks.
+
+## Testing
+
+The service can be ran as a normal process, without installing it.
+
+Start the service via `npm start`, and the service will start GPII, and restart GPII if it dies.
+
+`npm run service-dev` will start the service in development mode. That is, without it spawning GPII and allowing new
+GPII instances to connect later without any authentication.
+
+In both cases, the service will be started as a normal process but running as Administrator. This may only work in
+vagrant boxes where UAC is at the minimal level, otherwise the commands will need to be invoked from an elevated command
+prompt.
+
+### From gpii-windows
+
+`npm start` from gpii-windows ensures the service is running (in development mode) before starting gpii. GPII only
+requires the service to be running if it applies solutions that depend on it.
+
+### Running as a Windows Service
+
+In order to use the service related functionality, such as starting GPII at the start of a Windows session, the gpii
+service needs to be installed and ran as a Windows Service. These need to be started from an elevated command prompt.
+
+Install the service: `npm run service-install`. To install the service using a config that does not start GPII, and
+allows later instances to connect, run `npm run service-install-dev`
+
+Start the service: `npm run service-start`
+
+Stop the service: `npm run service-stop`
+
+Uninstall the service: `npm run service-uninstall`
+
+### Logging
+
+When the service is being ran as a Windows service, don't expect a console window. The log will be found in
+`%ProgramData%\GPII\gpii-service.log` (`C:\ProgramData\GPII\gpii-service.log`). The service doesn't put the log in the
+same directory as GPII, because that's in the directory belonging to a user profile and the server doesn't run as a
+normal user.
+
+## Configuration
+
+### [service.json5](config/service.json5)
+
+Production config, used when being ran as `gpii-service.exe`. Starts `./gpii-app.exe` and accepts a connection from only
+that child process.
+
+### [service.dev.json5](config/service.dev.json5)
+
+Default development configuration, used when running the service from the source directory. This doesn't start a child
+gpii process, but allows any process to connect to the pipe using a known name.
+
+### [service.dev.child.json5](config/service.dev.child.json5)
+
+Starts GPII, via `node ../gpii.js` and accepts a connection only that child process.
+
+
+To specify the config file, use the `--config` option when running or installing the service.
+
+### Config options
+
+```json5
+{
+    "processes": {
+        /* A process block */
+        "gpii": { // key doesn't matter
+            /* The command to invoke. Can be undefined, to just open a pipe. */
+            "command": "gpii-app.exe", // Starts gpii
+
+            /* Provide a pipe to the process. */
+            "ipc": "gpii", // The value will be used to determine internally what the pipe does (nothing special at the moment)
+
+            /* Restart the process if it terminates. */
+            "autoRestart": true,
+        },
+
+        /* Opens a pipe (\\.\pipe\gpii-gpii), without any authentication. */
+        "gpii-dev": {
+            "ipc": "gpii",
+            "noAuth": true
+        },
+
+        /* More processes */
+        "rfid-listener": {
+            "command": "../listeners/GPII_RFIDListener.exe",
+            "autoRestart": true
+        },
+        "usb-listener": {
+            "command": "../listeners/GPII_USBListener.exe",
+            "autoRestart": true
+        }
+    },
+    "logging": {
+        /* Log level: FATAL, ERROR, WARN, INFO, or DEBUG */
+        "level": "DEBUG"
+    }
+}
+```
+
+
+## Deployment
+
+During the build process, gpii-app's Installer.ps1 will bundle the service into a standalone executable, and the
+installer will put it in the same place as gpii-app.exe.
+
+The installer will install and start the service.
+
+## Command line options
+
+`index.js` recognises the following command-line arguments 
+
+```
+ --install     Install the Windows Service.
+ --serviceArgs=ARGS
+         Comma separated arguments to pass to the service (use with --install).
+ --uninstall   Uninstall the Windows Service.
+ --service     Only used when running as a service.
+ --config=FILE Specify the config file to use (default: service.json).
+```
+
+
+## Notes
+
+## How it works
+
+Services are slightly different to normal processes, the differences are handled by
+[stegru/node-os-service#GPII-2338](https://github.com/stegru/node-os-service/tree/GPII-2338), which is a fork of
+[node-os-service](https://github.com/stephenwvickers/node-os-service), where the service-related calls are made.
+
+The service is started by Windows during the start up, then waits for a user to log in. (By listening for the
+[SERVICE_CONTROL_SESSIONCHANGE](https://msdn.microsoft.com/library/windows/desktop/ms683241.aspx)
+service control code).
+
+When a user logs on, it starts the processes listed in [service-config.json](service-config.json) as that user and will
+restart them if they die.
+
+## Debugging
+
+When installing the service, add the debug arguments using the `--nodeArgs`. For example:
+
+```
+node index.js --install --nodeArgs=--inspect-brk=0.0.0.0:1234
+sc start gpii-service
+```
+
+Then quickly attach to the service, before Windows thinks it didn't start.
+
+## IPC
+
+### Client authentication
+
+Initial research in [GPII-2399](https://issues.gpii.net/browse/GPII-2399).
+
+* Service creates pipe and listens
+* Service starts Child, passing pipe name in `GPII_SERVICE_PIPE` environment variable.
+    * pipe name isn't a secret - other processes see open pipes.
+* Child connects to pipe
+* Service creates an event
+    * [CreateEvent](https://msdn.microsoft.com/library/ms682396) (unnamed, so only the handle can be used to access it)
+    * [DuplicateHandle](https://msdn.microsoft.com/library/ms724251) creates another handle to the event that's tied to Child's process
+* Service sends the Child's handle to the event through the pipe
+    * The handle isn't a secret - it's a number that's meaningless to any process other than Child.
+* Client calls [SetEvent](https://msdn.microsoft.com/library/ms686211) on the handle.
+    * Only Child can signal that event
+* Service detects the event's signal, access is granted.
+

gpii-service/config/service.dev.child.json5

@@ -0,0 +1,14 @@
+// Development configuration, auto starts GPII.
+{
+    "processes": {
+        "gpii": {
+            "command": "node ../gpii.js",
+            "ipc": "gpii",
+            "autoRestart": true
+        }
+    },
+    "logging": {
+        "level": "DEBUG"
+    },
+    "secretFile": "test-secret.json5"
+}

gpii-service/config/service.dev.json5

@@ -0,0 +1,14 @@
+// Development configuration, opens a pipe and waits for GPII to connect.
+{
+    "processes": {
+        "gpii": {
+            "ipc": "gpii",
+            // Allow any process to connect.
+            "noAuth": true
+        }
+    },
+    "logging": {
+        "level": "DEBUG"
+    },
+    "secretFile": "test-secret.json5"
+}