Add some documentation

Author: NautiluX

README.md

@@ -1 +1,52 @@
-# le-operator
+# le-operator
+
+This is a noperator to auomatically renew certificates of OpenShift routes.
+
+It's currently not considered production-ready and is only built to show-case how simple it is to implement such an operator with [Operator SDK](https://sdk.operatorframework.io/) and [lego](https://github.com/go-acme/lego).
+
+# Usage
+
+Install to your cluster by running `make docker-build docker-push deploy IMG=your/docker-repository`, where you specify the image registry to push to with the `IMG` variable.
+
+Create an EncryptedDomain resource to match all routes of your system for which you want to automatically renew certificates:
+
+```
+apiVersion: letsencrypt.operatingopenshift.org/v1beta1
+kind: EncryptedDomain
+metadata:
+  name: encrypteddomain-sample
+  namespace: default
+spec:
+  matchingHostnames: "^my-route.apps.mycluster.com$"
+  caDir: "https://acme-staging-v02.api.letsencrypt.org/directory"
+  RegistrationMail: "[email protected]"
+```
+
+Le-operator will find all routes matching the hostname and care for certificate renewal using the ACME protocol against the provided directory.
+
+The matchingHostnames property is a regex that you can use to customize which routes should be managed by this EncryptedDomain CR.
+Le-operator will create a separate domain for each route matching the regex.
+It as well supports managing multiple routes with the same hostname, typically used for [path-based routing](https://docs.openshift.com/container-platform/4.9/networking/routes/route-configuration.html#nw-path-based-routes_route-configuration).
+
+The above example uses the [let's encrypt staging environment](https://letsencrypt.org/docs/staging-environment/).
+
+
+# Development
+
+For development, you can deploy a [Pebble](https://github.com/letsencrypt/pebble) instance to an OpenShift cluster by applying the file in [Pebble deployment](hack/pebble.yaml).
+
+That allows as well to test the workflow with a cluster that is not publicly reachable, such as a [CRC](https://github.com/code-ready/crc) cluster.
+
+Use it's service as configuration in the `EncryptedDomain` CR:
+
+```
+apiVersion: letsencrypt.operatingopenshift.org/v1beta1
+kind: EncryptedDomain
+metadata:
+  name: encrypteddomain-sample
+  namespace: default
+spec:
+  matchingHostnames: "^my-route.apps-crc.testing$"
+  caDir: "https://pebble:14000/dir"
+  RegistrationMail: "[email protected]"
+```