PMM-1458 Create reference document (#484)

Create reference document for MongoDB exporter flags.

Author: Shashank Sinha

README.md

@@ -24,27 +24,6 @@ A flag, `--compatible-mode`, which exposes metrics with 0.1x compatible metric
 names has been implemented which simplifies migration from the old version to
 the current version.
 
-## Flags
-|Flag|Description|Example|
-|-----|-----|-----|
-|-h, \-\-help|Show context-sensitive help||
-|\-\-compatible-mode|Exposes new metrics in the new and old format at the same time||
-|\-\-discovering-mode|Enable autodiscover collections from databases which set in collstats-colls and indexstats-colls||
-|\-\-mongodb.collstats-colls|List of comma separated databases.collections to get stats|\-\-mongodb.collstats-colls=testdb.testcol1,testdb.testcol2|
-|\-\-mongodb.direct-connect|Whether or not a direct connect should be made. Direct connections are not valid if multiple hosts are specified or an SRV URI is used|\-\-mongodb.direct-connect=false|
-|\-\-mongodb.indexstats-colls|List of comma separated database.collections to get index stats|\-\-mongodb.indexstats-colls=db1.col1,db1.col2|
-|\-\-mongodb.uri|MongoDB connection URI ($MONGODB_URI)|\-\-mongodb.uri=mongodb://user:pass@127.0.0.1:27017/admin?ssl=true|
-|\-\-mongodb.global-conn-pool|Use global connection pool instead of creating new connection for each http request.||
-|\-\-web.listen-address|Address to listen on for web interface and telemetry|\-\-web.listen-address=":9216"|
-|\-\-web.telemetry-path|Metrics expose path|\-\-web.telemetry-path="/metrics"|
-|\-\-log.level|Only log messages with the given severity or above. Valid levels: [debug, info, warn, error]|\-\-log.level=error|
-|\-\-no-collector.diagnosticdata|Disable collecting metrics from getDiagnosticData||
-|\-\-no-collector.replicasetstatus|Disable collecting metrics from replSetGetStatus||
-|\-\-collector.dbstats|Enable collecting metrics from dbStats||
-|\-\-collector.topmetrics|Enable collecting metrics from top admin command||
-|\-\-metrics.overridedescendingindex| Enable descending index name override to replace -1 with _DESC ||
-|--version|Show version and exit|
-
 ### Build the exporter
 The build process uses the dockerized version of goreleaser so you don't need to install Go.
 Just run `make release` and the new binaries will be generated under the build directory.
@@ -135,6 +114,9 @@ The labels are:
 - rs_state: Replicaset state is an integer from `getDiagnosticData()` -> `replSetGetStatus.myState`. 
 Check [the official documentation](https://docs.mongodb.com/manual/reference/replica-states/) for details on replicaset status values.
 
-## Submitting Bug Reports and adding new functionality
+## Usage Reference
+
+See the [Reference Guide](REFERENCE.md) for details on using the exporter.
+## Bug Reports / Feature PR
 
-please see [Contribution Guide](CONTRIBUTING.md)
+Refer to the [Contribution Guide](CONTRIBUTING.md).

REFERENCE.md

@@ -0,0 +1,27 @@
+# Usage Reference
+
+## Flags
+|Flag|Description|Example|
+|-----|-----|-----|
+|-h, \-\-help|Show context-sensitive help||
+|--[no-]compatible-mode|Enable old mongodb-exporter compatible metrics||
+|--[no-]discovering-mode|Enable autodiscover collections||
+|--mongodb.collstats-colls|List of comma separared databases.collections to get $collStats|--mongodb.collstats-colls=db1,db2.col2|
+|--mongodb.indexstats-colls|List of comma separared databases.collections to get $indexStats|--mongodb.indexstats-colls=db1.col1,db2.col2|
+|--[no-]mongodb.direct-connect|Whether or not a direct connect should be made. Direct connections are not valid if multiple hosts are specified or an SRV URI is used||
+|--[no-]mongodb.global-conn-pool|Use global connection pool instead of creating new pool for each http request||
+|--mongodb.uri|MongoDB connection URI ($MONGODB_URI)|--mongodb.uri=mongodb://user:pass@127.0.0.1:27017/admin?ssl=true|
+|--web.listen-address|Address to listen on for web interface and telemetry|--web.listen-address=":9216"|
+|--web.telemetry-path|Metrics expose path|--web.telemetry-path="/metrics"|
+|--web.config|Path to the file having Prometheus TLS config for basic auth|--web.config=STRING|
+|--log.level|Only log messages with the given severity or above. Valid levels: [debug, info, warn, error, fatal]|--log.level="error"|
+|--collector.diagnosticdata|Enable collecting metrics from getDiagnosticData|
+|--collector.replicasetstatus|Enable collecting metrics from replSetGetStatus|
+|--collector.dbstats|Enable collecting metrics from dbStats||
+|--collector.topmetrics|Enable collecting metrics from top admin command|
+|--collector.indexstats|Enable collecting metrics from $indexStats|
+|--collector.collstats|Enable collecting metrics from $collStats|
+|--collect-all|Enable all collectors. Same as specifying all --collector.\<name\>|
+|--collector.collstats-limit=0|Disable collstats, dbstats, topmetrics and indexstats collector if there are more than \<n\> collections. 0=No limit|
+|--metrics.overridedescendingindex| Enable descending index name override to replace -1 with _DESC ||
+|--version|Show version and exit|