feature: allow server configuration, plugin configuration and default…

…s to be separate from the server install (#232)

* feature: allow server configuration, plugin configuration, defaults and samples to be separate from the server install. Allow configuration directory to be specified in an environment variable

README.md

@@ -60,9 +60,29 @@ You can also configure the path to the settings file with environment variable `
 
 The http port can be configured separately with environment variable `PORT`. You can also [run on port 80 with systemd](https://github.com/tkurki/marinepi-provisioning/blob/d3d624629799a3b96234a90fc42bc22dae4fd3a2/roles/node-app/templates/node_app_systemd_socket.j2). Environment variable NMEA0183PORT sets the NMEA 0183 tcp port.
 
+Storing Configuration Outside The Server Install Directory
+==========================================================
+You can store configuration like the settings file, plugin cofiguration, defaults.js and the mapcache in a directory outside of the server install using the `-c` option (or the `SIGNALK_NODE_CONDFIG_DIR` env variable).
+
+By default, the server will look for a `settings.json` and a `defaults.json` file in the given directory. 
+
+For example, `./bin/signalk-server -c /usr/local/etc/node_server_config`
+
+In this case, the server would look for the settings file at `/usr/local/etc/node_server_config/settings.json`
+
+You can overwrite the default settings file name by specifying the -s argument.
+
+For example, ./bin/signalk-server -c /usr/local/etc/node_server_config -s test_settings.json`
+
+In this case, the server would look for the settings file at `/usr/local/etc/node_server_config/test_settings.json`
+
+You should also put the charts mapcache directory at `/usr/local/etc/node_server_config/public/mapcache`.
+
+
 Environment variables
 ---------------------
 - `SIGNALK_NODE_SETTINGS` override the path to the settings file
+- `SIGNALK_NODE_CONDFIG_DIR` override the path to find server configuration files
 - `PORT` override the port for http/ws service
 - `EXTERNALPORT` the port used in /signalk response and Bonjour advertisement. Has precedence over configuration file.
 - `EXTERNALHOST` the host used in /signalk response and Bonjour advertisement. Has precedence over configuration file.
@@ -71,6 +91,7 @@ Environment variables
 - `TCPSTREAMADDRESS` override the address the Signal K Stream (deltas) over TCP is listening on
 - `DISABLEPLUGINS` disable all plugins so that they can not be enabled
 
+
 Real Inputs
 ---------------
 To hook the server up to your real inputs you need to create a configuration file that connects to your input source and applies the relevant parsers / converters in the provider pipeline.

lib/config/cli.js

@@ -28,9 +28,9 @@ module.exports = function(app) {
       return path.join(app.config.appPath, app.overrides.settings);
     }
 
-    var settingsFile = argv.s || 'settings/settings.json';
+    var settingsFile = argv.s || (argv.c ? 'settings.json' : 'settings/settings.json');
 
-    return path.join(app.config.appPath, settingsFile);
+    return path.join(app.config.configPath, settingsFile);
   }
 
   if(app.overrides.settings !== null && typeof app.overrides.settings === 'object') {
@@ -39,6 +39,13 @@ module.exports = function(app) {
   } else {
     app.__argv      = process.argv.slice(2);
     app.argv        = require('minimist')(app.__argv);
+
+    if(process.env.SIGNALK_NODE_CONDFIG_DIR) {
+      app.config.configPath = path.resolve(process.env.SIGNALK_NODE_CONDFIG_DIR)
+    } else {
+      app.config.configPath = app.argv.c || app.config.appPath
+    }
+
     var settings    = getSettingsFilename(app.argv);
 
     debug("Using settings file: " + settings);
@@ -51,7 +58,8 @@ module.exports = function(app) {
     }
 
     try {
-      app.config.defaults = require('../../settings/defaults.json');
+      var defaultsFile = app.argv.c ? 'defaults.json' : 'settings/defaults.json';
+      app.config.defaults = require(path.join(app.config.configPath, defaultsFile));
     } catch(e) {
       console.error("No settings/defaults.json available")
     }

lib/interfaces/charts.js

@@ -24,7 +24,8 @@ const versionPrefix = "/v1";
 const apiPathPrefix = pathPrefix + versionPrefix + "/api/";
 const parseStringAsync = Promise.promisify(require("xml2js").parseString);
 const path = require("path");
-const chartBaseDir = path.join(__dirname, "..", "..", "public", "mapcache");
+const express = require('express');
+var chartBaseDir
 
 const chartProviders = {};
 loadCharts();
@@ -35,6 +36,13 @@ module.exports = function(app) {
   api.start = function() {
     debug("Starting charts interface");
 
+    chartBaseDir = path.join(app.config.configPath, "public", "mapcache");
+
+    if ( app.config.configPath != app.config.appPath ) {
+      debug("using mapcache from config dir")
+      app.use('/mapcache', express.static(chartBaseDir));
+    }
+
     app.get(apiPathPrefix + "resources/charts/*", (req, res, next) => {
       loadCharts(app, req).then(charts => {
         var parts = req.path.split("/");

lib/interfaces/plugins.js

@@ -28,7 +28,7 @@ module.exports = function(app) {
     start: function() {
       startPlugins(app)
 
-      ensureExists(path.join(__dirname, "../../plugin-config-data"));
+      ensureExists(path.join(app.config.configPath, "plugin-config-data"));
 
       app.use('/plugins/configure', express.static(path.join(__dirname, '/../../plugin-config/public')));
 
@@ -61,7 +61,6 @@ module.exports = function(app) {
       });
     }
   }
-};
 
 function ensureExists(dir) {
   if(!fs.existsSync(dir)) {
@@ -70,7 +69,7 @@ function ensureExists(dir) {
 }
 
 function pathForPluginId(id) {
-  return path.join(__dirname, "../../plugin-config-data", id + '.json')
+  return path.join(app.config.configPath, "plugin-config-data", id + '.json')
 }
 
 function savePluginOptions(pluginId, data, callback) {
@@ -169,3 +168,5 @@ function registerPlugin(app, pluginName, metadata) {
     app.use("/signalk/v1/api", plugin.signalKApiRoutes(express.Router()))
   }
 }
+};
+

providers/filestream.js

@@ -35,6 +35,7 @@
 
 var path = require('path');
 var PassThrough = require('stream').PassThrough;
+const fs = require('fs');
 
 function EndIgnoringPassThrough() {
   PassThrough.call(this);
@@ -59,7 +60,16 @@ FileStream.prototype.pipe = function(pipeTo) {
 }
 
 FileStream.prototype.startStream = function() {
-  var filename = path.isAbsolute(this.options.filename) ? this.options.filename : path.join(__dirname, '..', this.options.filename);
+  var filename
+  if ( path.isAbsolute(this.options.filename) ) {
+    filename = this.options.filename
+  } else {
+    filename = path.join(this.options.app.config.configPath, this.options.filename)
+    if( !fs.existsSync(filename) ) {
+      filename = path.join(__dirname, '..', this.options.filename)
+    }
+  }
+
   this.filestream = require('fs').createReadStream(filename);
   if(this.keepRunning) {
     this.filestream.on('end', this.startStream.bind(this));