Accept file and http URI in the -f flag.

This patch was slightly modified to make it merge correctly against
master
(original patch by @jsvd is #1873)

Closes #1873

lib/logstash/agent.rb

@@ -2,7 +2,8 @@
 require "clamp" # gem 'clamp'
 require "logstash/environment"
 require "logstash/errors"
-require "logstash/environment"
+require "uri"
+require "net/http"
 LogStash::Environment.load_locale!
 
 class LogStash::Agent < Clamp::Command
@@ -286,6 +287,21 @@ class LogStash::Agent < Clamp::Command
   end # def configure_plugin_path
 
   def load_config(path)
+
+    uri = URI.parse(path)
+    case uri.scheme
+    when nil then
+      local_config(path)
+    when /http/ then
+      fetch_config(uri)
+    when "file" then
+      local_config(uri.path)
+    else
+      fail(I18n.t("logstash.agent.configuration.scheme-not-supported", :path => path))
+    end
+  end
+
+  def local_config(path)
     path = File.join(path, "*") if File.directory?(path)
 
     if Dir.glob(path).length == 0
@@ -305,4 +321,12 @@ class LogStash::Agent < Clamp::Command
     return config
   end # def load_config
 
+  def fetch_config(uri)
+    begin
+      Net::HTTP.get(uri) + "\n"
+    rescue Exception => e
+      fail(I18n.t("logstash.agent.configuration.fetch-failed", :path => uri.to_s, :message => e.message))
+    end
+  end
+
 end # class LogStash::Agent

locales/en.yml

@@ -69,6 +69,12 @@ en:
         file-not-found: |-
           No config files found: %{path}
           Can you make sure this path is a logstash config file?
+        scheme-not-supported: |-
+          URI scheme not supported: %{path}
+          Either pass a local file path or "file|http://" URI
+        fetch-failed: |-
+          Unable to fetch config from: %{path}
+          Reason: %{message}
         setting_missing: |-
           Missing a required setting for the %{plugin} %{type} plugin: