config tests added,

titles tests added,
.env file support added with dotenv,
README.md file updated for .evn file support,
database lost connection bug crash fixed,
session server run_session long timeout bug fixed,
links module added,
webrtc_proc json arguments added,
app_proc stdout and stderr support added,
infinity app_proc spawn freeze bug fixed

src/controller/session.js

@@ -4,7 +4,7 @@ const {get_app_path} = require('../modules/titles')
 const not_found_error = require('../../lib/src/http/errors/not_found_error')
 const server_error = require('../../lib/src/http/errors/server_error')
 const {run_webrtc, run_app} = require('../modules/run_process')
-const {external_url} = require('../../config')
+const {create_websocket_url} = require('../modules/links')
 
 
 const run_session = async (req, res, next) => {
@@ -42,8 +42,8 @@ const run_session = async (req, res, next) => {
         next(new server_error('can not add session to database'))
         return
     }
-    
-    res.json({websocket_url:`wss://${external_url}${webrtc_port}/`})
+
+    res.json({websocket_url:create_websocket_url(webrtc_port)})
 }
 
 module.exports = {

src/database/database.js

@@ -2,18 +2,21 @@ const { MongoClient } = require("mongodb")
 const { database_url, database_name } = require('../../config')
 let max_database_connection_timeout = 1000
 
+const client = new MongoClient(database_url, {
+    serverSelectionTimeoutMS: max_database_connection_timeout, 
+    useUnifiedTopology: true
+})
+
 const get_db = async () => {
-    const client = new MongoClient(database_url, {
-        serverSelectionTimeoutMS: max_database_connection_timeout, 
-        useUnifiedTopology: true
-    })
     try {
         await client.connect()
+        await client.db(database_name).command({ ping: 1 })
+        return client.db(database_name)
     } catch (err) {
-        console.log('can not connect to database')
+        console.error('can not connect to database')
+        await client.close()
         return null
     }
-    return client.db(database_name)
 }
 
 const add_running_session = async (session_id, app_pid, webrtc_pid) => {
@@ -46,7 +49,6 @@ const get_running_sessions = async () => {
     if (!db) {
         return null
     }
-
     var running_sessions = await db.collection('running_session').find().toArray()
     return (!running_sessions.length) ? null : running_sessions
 }

src/modules/links.js

@@ -0,0 +1,17 @@
+const {external_domain} = require('../../config')
+
+const create_websocket_url = (webrtc_port) => {
+    var valid_external_domain = external_domain
+
+    // if external domain contains http OR https part remove it
+    valid_external_domain = valid_external_domain.replace('http://', '').replace('https://', '')
+
+    valid_external_domain = (valid_external_domain.slice(-1) == '/') ? 
+        valid_external_domain.substring(0, valid_external_domain.length - 1) : valid_external_domain
+
+    return `wss://${valid_external_domain}/${webrtc_port}/`
+}
+
+module.exports = {
+    create_websocket_url
+}

src/modules/run_process.js

@@ -10,7 +10,7 @@ const is_proc_running = (pid) => {
     return is_running(pid)
 }
 
-const is_proc_running_async = async (pid, check_time) => {
+const is_proc_running_async = async (pid, time_ms) => {
     var timeout_count = 0
     var check_times = 10
 
@@ -22,7 +22,7 @@ const is_proc_running_async = async (pid, check_time) => {
         if (timeout_count > check_times) {
             return true
         }
-        await new Promise(resolve => setTimeout(resolve, check_time / check_times))
+        await new Promise(resolve => setTimeout(resolve, time_ms / check_times))
     }
 }
 
@@ -33,7 +33,8 @@ const run_webrtc = async (webrtc_port, app_port) => {
 
     var webrtc_proc
     try {
-        webrtc_proc = fork(webrtc_server_path, [webrtc_port.toString(), app_port.toString()], {
+        var webrtc_proc_arg = JSON.stringify({webrtc_port:webrtc_port, app_port:app_port})
+        webrtc_proc = fork(webrtc_server_path, [webrtc_proc_arg], {
             detached: true
         })
     } catch (err) {
@@ -49,9 +50,18 @@ const run_app = async (app_path, app_port) => {
     var app_proc
     try {
         app_proc = spawn(app_path, [].concat(app_args_static, 
-            [app_port_arg + app_port.toString()]), {
+            [app_port_arg + app_port.toString()], { cwd: './', stdio: ['ignore', 'pipe', 'pipe']}), {
                 detached: true
             })
+        
+        // bind some events to unfreez process
+        app_proc.stdout.on('data', data => {
+            //console.log('stdout: ' + data.toString());
+        })
+    
+        app_proc.stderr.on('data', data => {
+            //console.log('stderr: ' + data.toString());
+        })
     } catch (err) {
         return null
     }

src/modules/session_observer.js

@@ -2,8 +2,10 @@ const run_process = require('../modules/run_process')
 const database = require('../database/database')
 const {is_proc_running, kill_proc} = require('./run_process')
 const coordinator = require('./coordinator')
+const wait_list = require('./wait_list')
 
 const observer_timeout = 100
+var pending_list = new wait_list([])
 
 const start_observer = () => {
     check()
@@ -16,16 +18,22 @@ const check_sessions = async (sessions) => {
     await Promise.all(sessions.map(async (session) => {
         var webrtc_running = is_proc_running(session.webrtc_pid)
         var app_running = is_proc_running(session.app_pid)
-
+        
         if (webrtc_running && app_running) {
             return
         }
 
         // if something running kill process and skip remove from database
         if (!webrtc_running && !app_running) {
-            var close_session_result = await coordinator.close_session(session.session_id)
-            if (close_session_result) {
-                database.remove_running_session(session.session_id)
+            if (!pending_list.is_waiting(session.session_id)) {
+                pending_list.add(session.session_id)
+                var close_session_result = await coordinator.close_session(session.session_id)
+                if (close_session_result) {
+                    database.remove_running_session(session.session_id)
+                } else {
+                    pending_list.remove(session.session_id)
+                    console.log('can not connect to coordinator')
+                }
             }
         } else {
             kill_proc(session.webrtc_pid)
@@ -36,7 +44,7 @@ const check_sessions = async (sessions) => {
 
 const check = async () => {
     var sessions = await database.get_running_sessions()
-    
+
     if (!sessions) {
         return
     }

src/modules/wait_list.js

@@ -0,0 +1,20 @@
+module.exports = class wait_list {
+    constructor(list) {
+        this.list = list
+    }
+
+    is_waiting(id) {
+        return (this.list.indexOf(id) > -1)
+    }
+
+    add(id) {
+        if (this.is_waiting(id)) {
+            return
+        }
+        this.list.push(id)
+    }
+
+    remove(id) {
+        this.list.splice(this.list.indexOf(id), 1)
+    }
+}