update readme

README.md

@@ -3,3 +3,37 @@
 ## Description
 Fetches IMAP inboxes via fetchmail and forwards recieved mails to a list of
 recipients.
+
+# Usage
+First you will need to write configuration files for pmml and fetchmail. Feel
+free to use the supplied examples as starting point:
+- example_configs/pmmlrc
+- example_configs/fetchmailrc
+
+## Docker
+
+```
+$ docker run -v $(pwd)/example_configs/fetchmailrc:/.fetchmailrc -v $(pwd)/example_configs/pmmlrc:/.pmmlrc -it pmml:0.1.4
+```
+
+## Kubernetes
+If using kubernetes the configuration files should be injected as secret into
+the pod executing pmml.
+
+First create the secrets:
+```
+$ kubectl create secret generic pmml-pmmlrc --from-file /Users/michaelwilson/.pmmlrc -n pmml
+$ kubectl create secret generic pmml-fetchmailrc --from-file /Users/michaelwilson/.fetchmailrc -n pmml
+```
+
+Afterwards create the deployment:
+```
+$ kubectl -n pmml apply -f example_configs/pmml_deployment.yml
+```
+
+## Updating secrets
+After updating either of the supplied secrets you will need to restart the
+pmml pod:
+```
+$ kubectl -n pmml delete pod $(kubectl -n pmml get pods | tail -1 | awk '{print $1}')
+```