From 40ac6af15644acc2ab6d4e89ecd42ce57bbb23db Mon Sep 17 00:00:00 2001
From: Mateusz Charytoniuk <mateusz.charytoniuk@protonmail.com>
Date: Tue, 30 Jul 2024 20:28:13 +0200
Subject: [PATCH] feat: health status of individual agents

---
 agent/RespondToHealth.go           | 26 +++++++++++++++++++++
 agent/StatusServer.go              | 37 ++++++++++++++++++++++++++++++
 agent/StatusServerConfiguration.go |  7 ++++++
 cmd/Agent.go                       | 10 ++++++++
 main.go                            | 30 ++++++++++++++++++++----
 5 files changed, 106 insertions(+), 4 deletions(-)
 create mode 100644 agent/RespondToHealth.go
 create mode 100644 agent/StatusServer.go
 create mode 100644 agent/StatusServerConfiguration.go

diff --git a/agent/RespondToHealth.go b/agent/RespondToHealth.go
new file mode 100644
index 0000000..7493720
--- /dev/null
+++ b/agent/RespondToHealth.go
@@ -0,0 +1,26 @@
+package agent
+
+import (
+	"net/http"
+
+	"github.com/distantmagic/paddler/goroutine"
+)
+
+type RespondToHealth struct {
+	ServerEventsChannel chan<- goroutine.ResultMessage
+}
+
+func (self *RespondToHealth) ServeHTTP(response http.ResponseWriter, request *http.Request) {
+	response.Header().Set("Content-Type", "text/plain")
+	response.WriteHeader(http.StatusOK)
+
+	_, err := response.Write([]byte("OK"))
+
+	if err != nil {
+		self.ServerEventsChannel <- goroutine.ResultMessage{
+			Error: err,
+		}
+
+		return
+	}
+}
diff --git a/agent/StatusServer.go b/agent/StatusServer.go
new file mode 100644
index 0000000..cd93a32
--- /dev/null
+++ b/agent/StatusServer.go
@@ -0,0 +1,37 @@
+package agent
+
+import (
+	"net/http"
+
+	"github.com/distantmagic/paddler/goroutine"
+	"github.com/hashicorp/go-hclog"
+)
+
+type StatusServer struct {
+	StatusServerConfiguration *StatusServerConfiguration
+	Logger                    hclog.Logger
+	RespondToHealth           http.Handler
+}
+
+func (self *StatusServer) Serve(serverEventsChannel chan<- goroutine.ResultMessage) {
+	self.Logger.Debug(
+		"listen",
+		"host", self.StatusServerConfiguration.HttpAddress.GetHostWithPort(),
+	)
+
+	mux := http.NewServeMux()
+
+	mux.Handle("/health", self.RespondToHealth)
+
+	err := http.ListenAndServe(
+		self.StatusServerConfiguration.HttpAddress.GetHostWithPort(),
+		mux,
+	)
+
+	if err != nil {
+		serverEventsChannel <- goroutine.ResultMessage{
+			Comment: "failed to listen",
+			Error:   err,
+		}
+	}
+}
diff --git a/agent/StatusServerConfiguration.go b/agent/StatusServerConfiguration.go
new file mode 100644
index 0000000..c983879
--- /dev/null
+++ b/agent/StatusServerConfiguration.go
@@ -0,0 +1,7 @@
+package agent
+
+import "github.com/distantmagic/paddler/netcfg"
+
+type StatusServerConfiguration struct {
+	HttpAddress *netcfg.HttpAddressConfiguration
+}
diff --git a/cmd/Agent.go b/cmd/Agent.go
index 95d828f..be68f3c 100644
--- a/cmd/Agent.go
+++ b/cmd/Agent.go
@@ -17,6 +17,7 @@ type Agent struct {
 	LocalLlamaCppConfiguration    *llamacpp.LlamaCppConfiguration
 	Logger                        hclog.Logger
 	ManagementServerConfiguration *management.ManagementServerConfiguration
+	StatusServerConfiguration     *agent.StatusServerConfiguration
 }
 
 func (self *Agent) Action(cliContext *cli.Context) error {
@@ -38,7 +39,16 @@ func (self *Agent) Action(cliContext *cli.Context) error {
 		},
 	}
 
+	statusServer := &agent.StatusServer{
+		Logger: self.Logger.Named("StatusServer"),
+		RespondToHealth: &agent.RespondToHealth{
+			ServerEventsChannel: serverEventsChannel,
+		},
+		StatusServerConfiguration: self.StatusServerConfiguration,
+	}
+
 	go llamaCppObserver.ObserveAndReport(serverEventsChannel)
+	go statusServer.Serve(serverEventsChannel)
 
 	for serverEvent := range serverEventsChannel {
 		self.Logger.Info(
diff --git a/main.go b/main.go
index 591077a..248f6ae 100644
--- a/main.go
+++ b/main.go
@@ -44,6 +44,9 @@ func main() {
 		ManagementServerConfiguration: &management.ManagementServerConfiguration{
 			HttpAddress: &netcfg.HttpAddressConfiguration{},
 		},
+		StatusServerConfiguration: &agent.StatusServerConfiguration{
+			HttpAddress: &netcfg.HttpAddressConfiguration{},
+		},
 	}
 
 	balancer := &cmd.Balancer{
@@ -60,10 +63,6 @@ func main() {
 		},
 	}
 
-	// buffer := &cmd.Buffer{
-	// 	Logger:                    logger.Named("Buffer"),
-	// }
-
 	app := &cli.App{
 		Name:  "paddler",
 		Usage: "llama.cpp load balaner and reverse proxy server",
@@ -100,6 +99,14 @@ func main() {
 
 					agent.ManagementServerConfiguration.HttpAddress.Host = host
 
+					host, err = hostResolver.ResolveHost(backgroundContext, agent.StatusServerConfiguration.HttpAddress.Host)
+
+					if err != nil {
+						return err
+					}
+
+					agent.StatusServerConfiguration.HttpAddress.Host = host
+
 					return nil
 				},
 				Flags: []cli.Flag{
@@ -153,6 +160,21 @@ func main() {
 						Value:       DefaultManagementScheme,
 						Destination: &agent.ManagementServerConfiguration.HttpAddress.Scheme,
 					},
+					&cli.StringFlag{
+						Name:        "status-server-host",
+						Value:       "127.0.0.1",
+						Destination: &agent.StatusServerConfiguration.HttpAddress.Host,
+					},
+					&cli.UintFlag{
+						Name:        "status-server-port",
+						Value:       8087,
+						Destination: &agent.StatusServerConfiguration.HttpAddress.Port,
+					},
+					&cli.StringFlag{
+						Name:        "status-server-scheme",
+						Value:       "http",
+						Destination: &agent.StatusServerConfiguration.HttpAddress.Scheme,
+					},
 				},
 			},
 			{