Relative to

https://github.com/elasticsearch/elasticsearch.github.com/issues/127 :
Migrate plugins documentation to their own repos : starting with CouchDB

README.md

@@ -1,7 +1,7 @@
 CouchDB River Plugin for ElasticSearch
 ==================================
 
-The CouchDB River plugin allows to hook into couchdb `_chages` feed and automatically index it into elasticsearch.
+The CouchDB River plugin allows to hook into couchdb `_changes` feed and automatically index it into elasticsearch.
 
 In order to install the plugin, simply run: `bin/plugin -install elasticsearch/elasticsearch-river-couchdb/1.0.0`.
 
@@ -13,3 +13,93 @@ In order to install the plugin, simply run: `bin/plugin -install elasticsearch/e
     | 1.0.0            | 0.18 -> master   |
     ---------------------------------------
 
+The CouchDB River allows to automatically index couchdb and make it searchable using the excellent [_changes](http://guide.couchdb.org/draft/notifications.html) stream couchdb provides. Setting it up is as simple as executing the following against elasticsearch:
+
+	curl -XPUT 'localhost:9200/_river/my_db/_meta' -d '{
+	    "type" : "couchdb",
+	    "couchdb" : {
+	        "host" : "localhost",
+	        "port" : 5984,
+	        "db" : "my_db",
+	        "filter" : null
+	    },
+	    "index" : {
+	        "index" : "my_db",
+	        "type" : "my_db",
+	        "bulk_size" : "100",
+	        "bulk_timeout" : "10ms"
+	    }
+	}'
+
+This call will create a river that uses the **_changes** stream to index all data within couchdb. Moreover, any "future" changes will automatically be indexed as well, making your search index and couchdb synchronized at all times.
+
+The couchdb river is provided as a [plugin](https://github.com/elasticsearch/elasticsearch-river-couchdb) (including explanation on how to install it).
+
+On top of that, in case of a failover, the couchdb river will automatically be started on another elasticsearch node, and continue indexing from the last indexed seq.
+
+Bulking
+======
+
+Bulking is automatically done in order to speed up the indexing process. If within the specified **bulk_timeout** more changes are detected, changes will be bulked up to **bulk_size** before they are indexed.
+
+Filtering
+======
+
+The `changes` stream allows to provide a filter with parameters that will be used by couchdb to filter the stream of changes. Here is how it can be configured:
+
+	{
+	    "couchdb" : {
+	        "filter" : "test",
+	        "filter_params" : {
+	            "param1" : "value1",
+	            "param2" : "value2"
+	        }
+	    }
+	}
+
+Script Filters
+=========
+
+Filtering can also be performed by providing a script (default to JavaScript) that will further process each changed item within the changes stream. The json provided to the script is under a var called **ctx** with the relevant seq stream change (for example, **ctx.doc** will refer to the document, or **ctx.deleted** is the flag if its deleted or not).
+
+Note, this feature requires the `lang-javascript` plugin.
+
+The **ctx.doc** can be changed and its value can will be indexed (assuming its not a deleted change). Also, if **ctx.ignore** is set to true, the change seq will be ignore and not applied.
+
+Other possible values that can be set are **ctx.index** to control the index name to index the doc into, **ctx.type** to control the (mapping) type to index into, **ctx._parent** and **ctx._routing**.
+
+Here is an example setting that adds `field1` with value `value1` to all docs:
+
+	{
+	    "type" : "couchdb",
+	    "couchdb" : {
+	        "script" : "ctx.doc.field1 = 'value1'"
+	    }
+	}
+
+Basic Authentication
+===============
+
+Basic Authentication can be used by passing the **user** and **password** attributes.
+
+	{
+	    "type" : "couchdb",
+	    "couchdb" : {
+	        "user" : "alice",
+	        "password" : "secret"
+	    }
+	}
+
+HTTPS
+=====
+
+To use HTTPS, pass the **protocol** field. Most likely, you will also have to change the **port**. If you have unfixable problems with the servers certificates for any reason, you can disable hostname verification by passing **no_verify**.
+
+	{
+	    "type" : "couchdb",
+	    "couchdb" : {
+	        "protocol" : "https",
+	        "port" : 443,
+	        "no_verify" : "true"
+	    }
+	}