Add default resource generator for log entries

To accommodate invocations like:
  `syslog.entry({textPayload: 'test'})`
Create a basic class which attempts to automatically
establish resource values based on connectivity to
the metadata service and environmental variables.

This addition does not affect the existing API and
does not modify or augment user supplied resources.
The meta data class will attempt to determine if the
resource is a cloud function, app engine application
or compute engine instance. If it can't match on any
of these configurations but can still locate a project
id then it will produce a global resource id.

Author: cristiancavalli

packages/logging/package.json

@@ -54,6 +54,7 @@
   "dependencies": {
     "@google-cloud/common": "^0.8.0",
     "arrify": "^1.0.0",
+    "duplexify": "^3.5.0",
     "extend": "^3.0.0",
     "google-gax": "^0.9.1",
     "google-proto-files": "^0.8.0",

packages/logging/src/index.js

@@ -21,6 +21,7 @@
 'use strict';
 
 var arrify = require('arrify');
+var duplexify = require('duplexify');
 var common = require('@google-cloud/common');
 var extend = require('extend');
 var format = require('string-format-obj');
@@ -46,6 +47,12 @@ var Log = require('./log.js');
  */
 var Sink = require('./sink.js');
 
+/**
+ * @type {module:metdata}
+ * @private
+ */
+var Metadata = require('./metadata.js');
+
 /**
  * <p class="notice">
  *   **This is a Beta release of Stackdriver Logging.** This API is not covered
@@ -87,6 +94,19 @@ function Logging(options) {
   };
 
   common.GrpcService.call(this, config, options);
+  var requestStream = duplexify();
+  common.util.makeRequest({
+    url: 'http://metadata.google.internal/computeMetadata/v1/project/' +
+      'project-id',
+    headers: {
+      'Metadata-Flavor': 'Google'
+    }
+  },
+  {
+    stream: requestStream,
+    method: 'GET'
+  });
+  this.metadata = new Metadata(requestStream);
 }
 
 util.inherits(Logging, common.GrpcService);

packages/logging/src/log.js

@@ -52,6 +52,7 @@ var Entry = require('./entry.js');
 function Log(logging, name) {
   this.formattedName_ = Log.formatName_(logging.projectId, name);
   this.name = this.formattedName_.split('/').pop();
+  this.metadata_ = logging.metadata;
 
   var methods = {
     /**
@@ -136,6 +137,27 @@ Log.formatName_ = function(projectId, name) {
   return path + name;
 };
 
+Log.prototype.assignDefaultMetadata_ = function(entry, callback) {
+  var entryMetadata = entry.metadata;
+  // If the resource specifcally was not supplied attempt to determine it
+  // automatically
+  if (!is.object(entryMetadata) || !is.object(entryMetadata.resource)) {
+    this.metadata_.getDefaultResource(function(err, resource) {
+      if (err) {
+        callback(err);
+        return;
+      }
+      // Merge the entry's metadata with the auto generated resource; give
+      // precedence to any entry originated metadata information
+      entry.metadata = extend(true, {resource: resource}, entryMetadata);
+      callback(null);
+    });
+    return;
+  }
+  // Otherwise don't modify or augment user supplied resource data
+  callback(null);
+};
+
 /**
  * Write a log entry with a severity of "ALERT".
  *
@@ -157,7 +179,10 @@ Log.formatName_ = function(projectId, name) {
  * });
  */
 Log.prototype.alert = function(entry, options, callback) {
-  this.write(Log.assignSeverityToEntries_(entry, 'ALERT'), options, callback);
+  var self = this;
+  this.assignDefaultMetadata_(entry, function() {
+    self.write(Log.assignSeverityToEntries_(entry, 'ALERT'), options, callback);
+  });
 };
 
 /**
@@ -181,8 +206,11 @@ Log.prototype.alert = function(entry, options, callback) {
  * });
  */
 Log.prototype.critical = function(entry, options, callback) {
-  var entries = Log.assignSeverityToEntries_(entry, 'CRITICAL');
-  this.write(entries, options, callback);
+  var self = this;
+  this.assignDefaultMetadata_(entry, function() {
+    self.write(Log.assignSeverityToEntries_(entry, 'CRITICAL'), options,
+      callback);
+  });
 };
 
 /**
@@ -206,7 +234,11 @@ Log.prototype.critical = function(entry, options, callback) {
  * });
  */
 Log.prototype.debug = function(entry, options, callback) {
-  this.write(Log.assignSeverityToEntries_(entry, 'DEBUG'), options, callback);
+  var self = this;
+  this.assignDefaultMetadata_(entry, function() {
+    self.write(Log.assignSeverityToEntries_(entry, 'DEBUG'), options,
+      callback);
+  });
 };
 
 /**
@@ -230,8 +262,11 @@ Log.prototype.debug = function(entry, options, callback) {
  * });
  */
 Log.prototype.emergency = function(entry, options, callback) {
-  var entries = Log.assignSeverityToEntries_(entry, 'EMERGENCY');
-  this.write(entries, options, callback);
+  var self = this;
+  this.assignDefaultMetadata_(entry, function() {
+    self.write(Log.assignSeverityToEntries_(entry, 'EMERGENCY'), options,
+      callback);
+  });
 };
 
 /**
@@ -313,7 +348,11 @@ Log.prototype.entry = function(metadata, data) {
  * });
  */
 Log.prototype.error = function(entry, options, callback) {
-  this.write(Log.assignSeverityToEntries_(entry, 'ERROR'), options, callback);
+  var self = this;
+  this.assignDefaultMetadata_(entry, function() {
+    self.write(Log.assignSeverityToEntries_(entry, 'ERROR'), options,
+      callback);
+  });
 };
 
 /**
@@ -439,7 +478,11 @@ Log.prototype.getEntriesStream = function(options) {
  * });
  */
 Log.prototype.info = function(entry, options, callback) {
-  this.write(Log.assignSeverityToEntries_(entry, 'INFO'), options, callback);
+  var self = this;
+  this.assignDefaultMetadata_(entry, function() {
+    self.write(Log.assignSeverityToEntries_(entry, 'INFO'), options,
+      callback);
+  });
 };
 
 /**
@@ -463,7 +506,11 @@ Log.prototype.info = function(entry, options, callback) {
  * });
  */
 Log.prototype.notice = function(entry, options, callback) {
-  this.write(Log.assignSeverityToEntries_(entry, 'NOTICE'), options, callback);
+  var self = this;
+  this.assignDefaultMetadata_(entry, function() {
+    self.write(Log.assignSeverityToEntries_(entry, 'NOTICE'), options,
+      callback);
+  });
 };
 
 /**
@@ -487,7 +534,11 @@ Log.prototype.notice = function(entry, options, callback) {
  * });
  */
 Log.prototype.warning = function(entry, options, callback) {
-  this.write(Log.assignSeverityToEntries_(entry, 'WARNING'), options, callback);
+  var self = this;
+  this.assignDefaultMetadata_(entry, function() {
+    self.write(Log.assignSeverityToEntries_(entry, 'WARNING'), options,
+      callback);
+  });
 };
 
 /**