From e2a91aa06d9cf0817877a190e625d25088923b76 Mon Sep 17 00:00:00 2001
From: Jussi Maki <jussi@isovalent.com>
Date: Mon, 18 Mar 2024 09:53:26 +0100
Subject: [PATCH] Add http handlers

Signed-off-by: Jussi Maki <jussi@isovalent.com>
---
 demo/handlers.go | 28 ++++++++++++++++++++++++++++
 demo/main.go     | 40 +++++++++++++++++++++++++++++++++++++---
 2 files changed, 65 insertions(+), 3 deletions(-)
 create mode 100644 demo/handlers.go

diff --git a/demo/handlers.go b/demo/handlers.go
new file mode 100644
index 0000000..b1a0b25
--- /dev/null
+++ b/demo/handlers.go
@@ -0,0 +1,28 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+	"text/tabwriter"
+	"time"
+
+	"github.com/cilium/statedb"
+	v1 "k8s.io/api/core/v1"
+)
+
+func registerStateDBHTTPHandler(mux *http.ServeMux, db *statedb.DB) {
+	mux.Handle("/statedb", db)
+}
+
+func registerPodHTTPHandler(mux *http.ServeMux, db *statedb.DB, pods statedb.Table[*Pod]) {
+	mux.HandleFunc("/pods/running", func(w http.ResponseWriter, req *http.Request) {
+		txn := db.ReadTxn()
+		iter, _ := pods.Get(txn, PodPhaseIndex.Query(v1.PodRunning))
+		t := tabwriter.NewWriter(w, 10, 4, 2, ' ', 0)
+		fmt.Fprintf(t, "NAME\tSTARTED\tPOD IP\tSTATUS\n")
+		for pod, _, ok := iter.Next(); ok; pod, _, ok = iter.Next() {
+			fmt.Fprintf(t, "%s/%s\t%s ago\t%s\t%s\n", pod.Namespace, pod.Name, time.Since(pod.Status.StartTime.Time), pod.Status.PodIP, pod.ReconciliationStatus())
+		}
+		t.Flush()
+	})
+}
diff --git a/demo/main.go b/demo/main.go
index cd7df2b..be55c84 100644
--- a/demo/main.go
+++ b/demo/main.go
@@ -1,6 +1,8 @@
 package main
 
 import (
+	"log/slog"
+	"net/http"
 	"path"
 	"time"
 
@@ -21,20 +23,37 @@ var Hive = hive.New(
 	statedb.Cell,
 	cell.SimpleHealthCell,
 
+	// Kubernetes client
 	cell.Provide(
-		NewPodTable,
 		newClientset,
+	),
+
+	// HTTP server
+	cell.Provide(
+		http.NewServeMux,
+	),
+	cell.Invoke(
+		registerHTTPServer,
+		registerStateDBHTTPHandler,
+	),
+
+	// Pod tables and the reconciler
+	cell.Provide(
+		NewPodTable,
+		statedb.RWTable[*Pod].ToTable,
 		podReflectorConfig,
 		podReconcilerConfig,
 	),
 
+	reflector.KubernetesCell[*Pod](),
+
 	cell.Invoke(
 		statedb.RegisterTable[*Pod],
 
 		reconciler.Register[*Pod],
-	),
 
-	reflector.KubernetesCell[*Pod](),
+		registerPodHTTPHandler,
+	),
 )
 
 func main() {
@@ -66,3 +85,18 @@ func newClientset() (*kubernetes.Clientset, error) {
 
 	return kubernetes.NewForConfig(cfg)
 }
+
+func registerHTTPServer(log *slog.Logger, mux *http.ServeMux, lc cell.Lifecycle) {
+	s := &http.Server{Addr: ":8080", Handler: mux}
+	lc.Append(cell.Hook{
+		OnStart: func(cell.HookContext) error {
+			log.Info("Serving HTTP", "addr", s.Addr)
+			go s.ListenAndServe()
+			return nil
+		},
+		OnStop: func(ctx cell.HookContext) error {
+			return s.Shutdown(ctx)
+		},
+	})
+
+}