chg [doc] initial README material

Author: gallypette

README.md

@@ -1,2 +1,30 @@
 # analyzer-d4-log
-Analyze logs collected though d4 to produce diverse statistics.
+This analyzer processes loglines ingested by d4 (as type 3).
+
+# Architecture
+analyzer-d4-log relies on redis to consume grokked loglines.
+
+To grok the loglines, analyzer-d4-log relies on an external tool: both logstash https://www.elastic.co/logstash
+and nifi https://nifi.apache.org/ have been tested for this purpose (using this nifi template https://github.com/D4-project/d4-nifi-templates).
+These tools poll directly the d4 server'redis server for loglines and push the results into a specific redis queue that the analyzer consumes. 
+
+![](assets/nifi.png)
+
+analyzer-d4-log polls this queue periodically to produce counts and statistics of the data. At the moment, only sshd logs are supported but more will come in the future. 
+
+# SSHD log analysis
+
+## Output generation
+Every once in a while, analyzer-d4-log compiles the result into a svg images and csv files. It will also produce a minimalist webpage to navigate the data with a datarangepicker.; 
+![](assets/analyzer-d4-log.png)
+
+## MISP export
+I addition to this graphical view, the repository contains a MISP_export folder that allows for the publication of a MISP feed of daily events. It compiles the TOP 100 usernames and sources seen in ssh login failure by D4 sensors.
+
+![](assets/dailyMISPevent.png)
+
+![](assets/d4_auth_MISPobject.png)
+
+Since MISP 2.4.128, MISP can conveniently display this data through specialized widgets.
+
+![](assets/MISP_widgets.png)