Update README.md

README.md

@@ -1 +1,27 @@
-# rdsauth
+# rdsauth
+
+[![CI](https://github.com/winebarrel/rdsauth/actions/workflows/ci.yml/badge.svg)](https://github.com/winebarrel/rdsauth/actions/workflows/ci.yml)
+
+Generates an auth token used to connect to a db with IAM credentials.
+
+## Usage
+
+```sh
+$ MY_DB_HOST=database-1.cluster-abcdef012345.us-east-1.rds.amazonaws.com
+$ export PGPASSWORD=$(rdsauth postgres://scott@$MY_DB_HOST)
+$ psql -h $MY_DB_HOST -U scott
+...
+postgres=>
+```
+
+### CNAME support
+
+```sh
+$ dig +short cname my-db.example.com
+database-1.cluster-abcdef012345.us-east-1.rds.amazonaws.com
+
+$ export PGPASSWORD=$(rdsauth postgres://[email protected])
+$ psql -h my-db.example.com -U scott
+...
+postgres=>
+```