Merge pull request #53 from vania-pooh/master

Added logfile format documentation (fixes #50)

LICENSE

@@ -374,7 +374,7 @@ Apache License
       same "printed page" as the copyright notice for easier
       identification within third-party archives.
 
-   Copyright 2016+ Alexander Andryashin and collaborators
+   Copyright 2016+ Aerokube LLC
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.

README.md

@@ -118,6 +118,48 @@ See the full history in our article - **Selenium testing: a new hope**:
 * [Part 1](https://hackernoon.com/selenium-testing-a-new-hope-7fa87a501ee9)
 * [Part 2](https://hackernoon.com/selenium-testing-a-new-hope-a00649cdb100)
 
+## Log Files
+A typical log file looks like the following:
+```
+2017/04/18 03:52:36 [12413389] [SESSION_ATTEMPTED] [my_quota] [192.168.2.3] [firefox-42.0] [firefox42-1.example.com:4444] [1]
+2017/04/18 03:52:40 [12413389] [SESSION_FAILED] [my_quota] [192.168.2.3] [firefox-42.0] [firefox42-1.example.com:4444] Error forwarding the new session Request timed out waiting for a node to become available.
+2017/04/18 03:52:40 [12413390] [SESSION_ATTEMPTED] [my_quota] [192.168.2.3] [firefox-42.0] [firefox42-5.example.com:4444] [2]
+2017/04/18 03:52:45 [12413390] [5.86s] [SESSION_CREATED] [my_quota] [192.168.2.3] [firefox-42.0] [firefox42-5.example.com:4444] [0c500a6f-98d2-4871-acb7-637d85e1416a] [2]
+....
+2017/04/18 03:53:05 [SESSION_DELETED] [192.168.2.3] [firefox42-5.example.com:4444] [0c500a6f-98d2-4871-acb7-637d85e1416a]
+```
+Every line contains:
+
+| Field | Example | Notes |
+| ----- | ------- | ----- |
+| Time | 2017/04/18 03:52:36 | - |
+| Request counter | [12413389] | Only present for new session requests. So far as session ID is unknown when doing attempts this counter is used to find all session attempts for each new session request. |
+| Status | [SESSION_ATTEMPTED] | See table below for complete list of statuses. |
+| Quota name | [my_quota] | Extracted from basic HTTP auth headers. |
+| User IP | [192.168.2.3] | IPv4 or IPv6 address |
+| Browser | [firefox-42.0] | Name and version. Only present for new session requests. |
+| Hub host | [firefox42-1.example.com:4444] | Host from quota XML file |
+| Attempt number | [1] | For SESSION_ATTEMPTED entries means current attempt number. For SESSION_CREATED entries means total number of attempts to create this session. |
+| Session ID | [0c500a6f-98d2-4871-acb7-637d85e1416a] | As arrived from hub |
+| Session start time | [5.86s] | - |
+| Error | Error forwarding the new session Request timed out waiting for a node to become available. | Only present for SESSION_FAILED |
+
+The following statuses are available:
+
+| Status | Description |
+| ------ | ----------- |
+| BAD_JSON | User request does not contain valid Selenium data |
+| BROWSER_NOT_SET | Browser name is not present or empty string |
+| CLIENT_DISCONNECTED | User disconnected and doing session attempts was interrupted |
+| INVALID_URL | Session ID does not contain information about host where it was created |
+| ROUTE_NOT_FOUND | Trying to proxy session to unknown host. Usually means quota files inconsistency between multiple Ggr instances. |
+| SESSION_ATTEMPTED | New user request for session arrived |
+| SESSION_CREATED | A new session was created and returned to user |
+| SESSION_DELETED | Existing session was deleted by user request |
+| SESSION_FAILED | Session attempt on specified host failed |
+| SESSION_NOT_CREATED | Attempts to create a new session on all hosts failed. An error was returned to user. |
+| UNSUPPORTED_BROWSER | Requested browser name and version is not present in quota |
+
 ## Development
 To build Ggr: