update probez docs

probez/README.md

@@ -1 +1,79 @@
-# Kubernetes Probe Handlers
+# Kubernetes Probe Handlers
+
+This package has HTTP handlers for kubernetes liveness and readiness HTTP requests that can be easily added to any existing service. It also implements a Probe client if you want to make liveness/readiness checks against a service that implements a handler and finally it adds a server for responding to those checks for containerized applications that don't necessarily respond to HTTP requests.
+
+## Simple Usage
+
+If you have an `http.ServeMux` in your application, use that directly:
+
+```go
+package main
+
+import (
+    "net/http"
+
+    "go.rtnl.ai/x/probez"
+)
+
+
+func main() {
+    // Create the serve mux and the probe handler
+    mux := http.NewServeMux()
+    probe := probez.New()
+
+    // And the probe routes to the muxer
+    probe.Mux(mux)
+
+    // Add your other routes as necessary
+    // ...
+
+    // Serve the mux
+    http.ListenAndServe(":8080", mux)
+}
+```
+
+The probe starts in the healthy/not ready state. To modify the state of the probe, use `probe.Healthy()`, `probe.Unhealthy()`, `probe.Ready()`, `probe.NotReady()`. For example, if you have a server:
+
+```go
+type Server struct {
+    probe *probez.Handler
+}
+
+func (s *Server) Serve() {
+    // Set the probe to healthy
+    s.server.Healthy()
+
+    // Start the server up
+    // ...
+
+    // Perform database pings and other preparatory code
+    // ...
+
+    // Mark the server as ready for requests
+    s.server.Ready()
+}
+
+func (s *Server) Shutdown() {
+    // Set the server to not ready
+    s.server.NotReady()
+
+    // Perform server shutdown
+    // ...
+
+    // Mark the server as not healthy
+    s.server.NotHealthy()
+}
+```
+
+## Using with Gin
+
+Use `gin.WrapF` to utilize the probez handler with the gin web framework as follows:
+
+```go
+router := gin.Default()
+probe := probez.New()
+
+router.GET(probez.Livez, gin.Wrapf(probe.Healthz))
+router.GET(probez.Healthz, gin.Wrapf(probe.Healthz))
+router.GET(probez.Readyz, gin.Wrapf(probe.Readyz))
+```