Add structure for adding exported Ionic application to backend server

app/IonicUnit.js

@@ -0,0 +1,40 @@
+const Unit = require('libflitter/Unit')
+const cors = require('cors')
+const Express = require('express')
+const path = require('path')
+
+class IonicUnit extends Unit {
+    static get services() {
+        return [...super.services, 'configs', 'express', 'canon', 'utility']
+    }
+
+    constructor(...args) {
+        super(...args)
+
+        /**
+         * Fully qualified path to the root of the ionic app.
+         * @type {string}
+         */
+        this.directory = path.resolve(path.dirname(this.utility.root()), this.configs.get('ionic.root'))
+    }
+
+    async go(app) {
+        app.express.use(cors())
+
+        app.express.use('/i', [
+            this.canon.get('middleware::auth:UserOnly'),
+            (req, res, next) => {
+                const allowed_extensions = ['.html', '.js', '.css', '.svg', '.ttf', '.jpg', '.png', '.jpeg']
+                for ( const k1 in allowed_extensions ) {
+                    if ( req.path.endsWith(allowed_extensions[k1]) ) return next()
+                }
+
+                return res.sendFile(path.resolve(this.directory, 'index.html'))
+            },
+            Express.static(this.directory),
+        ])
+    }
+
+}
+
+module.exports = exports = IonicUnit