Some logging added.

This change is untested!

config/config.go

@@ -3,6 +3,7 @@ package config;
 import (
 	"os"
 	"encoding/json"
+	"errors"
 );
 
 type Config struct {
@@ -26,14 +27,15 @@ type RegistryAuth struct {
 	Password string
 }
 
-func GetConfig() Config {
+func GetConfig()(Config, error){
 	var cfg Config;
 
 	rawConfig, err := os.ReadFile("/config.json");
 	if err != nil{
-		panic("Failed it load config file." + err.Error());
+		return cfg, errors.New("Failed it load config file." + err.Error());
 	}
 
+	// Set defaults
 	cfg.Constants.OverlayNetworkName = "blazenaPohar";
 	cfg.Constants.HelperServiceName = "blazenaHelper";
 	cfg.Constants.StorageContainerName = "blazenaStorage";
@@ -42,8 +44,8 @@ func GetConfig() Config {
 	err = json.Unmarshal(rawConfig, &cfg);
 
 	if err != nil{
-		panic("Failed to unmarshal config." + err.Error())
+		return cfg, errors.New("Failed to unmarshal config: " + err.Error());
 	}
 
-	return cfg;
+	return cfg, err;
 }

docker/docker.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"log/slog"
 	"os"
 	"os/signal"
 	"strings"
@@ -32,22 +33,27 @@ type aService struct{
 }
 
 func Run(Config cfg.Config){
-	theConfig = Config; 
+	// Before touching the line below think.
+	theConfig = Config;
+
 	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM);
 
 	var err error;
 	ApiClient, err = client.NewClientWithOpts(client.FromEnv);
 	if(err != nil){
-		panic("Docker client was not able to init from env!" + err.Error());
+		slog.Error("Failed to create docker client!", slog.String("note", "Try to look into DOCKER_HOST env var or check if socket exists and works"));
+		os.Exit(1);
 	}
 
 	info, err := ApiClient.Info(context.Background())
 	if(err != nil){
-		panic("Error getting info!" + err.Error());
+		slog.Error("Error getting info from docker socket!", slog.String("note", "This is kind of ping."));
+		os.Exit(1);
 	}
 
 	if(!info.Swarm.ControlAvailable){
-		panic("Node is not a swarm manager.");
+		slog.Error("This node is not a swarm manager!");
+		os.Exit(1);
 	}
 
 	server := &http.Server{
@@ -68,7 +74,7 @@ func Run(Config cfg.Config){
 		stop();
 	});
 
-	ApiClient.NetworkCreate(context.Background(), theConfig.Constants.OverlayNetworkName, network.CreateOptions{
+	ApiClient.NetworkCreate(context.Background(), Config.Constants.OverlayNetworkName, network.CreateOptions{
 		Attachable: true,
 		// Internal: true,
 		Driver: "overlay",
@@ -84,7 +90,8 @@ func Run(Config cfg.Config){
 
 		}
 		if(err != nil){
-			panic("Unable to start http server!" + err.Error());
+			slog.Error("Unable to start http server!", slog.Any("propagatedError", err));
+			os.Exit(1);
 		}
 
 	}();
@@ -96,7 +103,7 @@ func Run(Config cfg.Config){
 	fmt.Println("Stopping http server.");
 	server.Close();
 
-	ApiClient.NetworkRemove(context.Background(), theConfig.Constants.OverlayNetworkName);
+	ApiClient.NetworkRemove(context.Background(), Config.Constants.OverlayNetworkName);
 	ApiClient.ConfigRemove(context.Background(), "blazenaSSHPublicKey")
 	ApiClient.SecretRemove(context.Background(), "blazenaSSHHostPrivateKey");
 
@@ -110,6 +117,7 @@ func bearerAuth(w http.ResponseWriter, r *http.Request)bool {
 	if authHeader != expected {
 		w.WriteHeader(http.StatusUnauthorized)
 		fmt.Fprintln(w, "Unauthorized")
+		slog.Warn("Unauthorized request received", slog.Any("request", *r));
 		return false;
 	}
 	return true;
@@ -131,6 +139,16 @@ func listServices(w http.ResponseWriter, r *http.Request){
 
 	var services []aService;
 
+
+	nodes, err := ApiClient.NodeList(context.Background(), swarm.NodeListOptions{});
+
+	var validNodeHostnames []string;
+
+	for _, node := range nodes{
+		validNodeHostnames = append(validNodeHostnames, node.Description.Hostname);
+	}
+
+
 	for _, service := range list{
 		var settings map[string]string = service.Spec.Labels; 
 		
@@ -141,6 +159,12 @@ func listServices(w http.ResponseWriter, r *http.Request){
 
 		targetVolumes := strings.Split(settings["blazena.volumes"], ",");
 
+		if !contains(validNodeHostnames, settings["blazena.node"]) {
+			errMsg := "node with hostname:'"+ settings["blazena.node"] +"' does not exist.";
+			slog.Warn("Invalid Service Config!", slog.String("serviceId", service.ID), slog.String("errMessage", errMsg));
+			continue;
+		}
+
 		services = append(services, aService{
 			ServiceId: service.ID,
 			VolumeNames: targetVolumes,
@@ -152,7 +176,8 @@ func listServices(w http.ResponseWriter, r *http.Request){
 	bytes, err := json.Marshal(services);
 
 	if err != nil{
-		panic("Error during response encoding!" + err.Error());
+		slog.Error("Error during response encoding!", slog.Any("propagatedError", err));
+		os.Exit(1);
 	}
 
 	fmt.Fprint(w, string(bytes));

docker/prepare.go

@@ -2,17 +2,17 @@ package docker
 
 import (
 	"context"
+	"encoding/base64"
 	"encoding/json"
 	"fmt"
 	"io"
 	"net/http"
-	"encoding/base64"
 	"time"
 
-	"github.com/docker/docker/api/types/mount"
-	"github.com/docker/docker/api/types/swarm"
-	"github.com/docker/docker/api/types/registry"
 	"github.com/docker/docker/api/types/image"
+	"github.com/docker/docker/api/types/mount"
+	"github.com/docker/docker/api/types/registry"
+	"github.com/docker/docker/api/types/swarm"
 	"github.com/docker/docker/client"
 
 	cfg "github.com/rony5394/blazena/config"

go.mod

@@ -19,6 +19,7 @@ require (
 	github.com/felixge/httpsnoop v1.0.4 // indirect
 	github.com/go-logr/logr v1.4.3 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
+	github.com/google/uuid v1.6.0 // indirect
 	github.com/moby/docker-image-spec v1.3.1 // indirect
 	github.com/moby/sys/atomicwriter v0.1.0 // indirect
 	github.com/moby/term v0.5.2 // indirect

host/host.go

@@ -8,6 +8,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"log/slog"
 	"net/http"
 	"os"
 	"time"
@@ -44,18 +45,24 @@ func Run(Config cfg.Config) {
 	services := getServices(Config);
 
 	for _, service := range services {
-		fmt.Println("Scaling Down: "+service.ServiceId)
-		scale(Config, service.ServiceId, false);
-		fmt.Println("Done!");
-		for _, volume := range service.VolumeNames{
-			fmt.Println("Preparing: " + service.ServiceId + " volume: " + volume);
-			if !prepareService(Config, service, volume) {continue}
-			fmt.Println("Done!");
 
-			storagePath, _ := generateStoragePath(Config, service.Node, volume, DockerClient);
+		slog.Info("Scaling Down", slog.String("serviceId", service.ServiceId));
-			fmt.Println(storagePath);
+		scale(Config, service.ServiceId, false);
+		slog.Info("Done");
+
+		for _, volume := range service.VolumeNames{
+			slog.Info("Preparing", slog.String("serviceId", service.ServiceId), slog.String("volumeId", volume));
+			if !prepareService(Config, service, volume) {continue}
+			slog.Info("Done");
+
+			targetStoragePath, _ := generateStoragePath(Config, service.Node, volume, DockerClient);
+			sourceStoragePath := "root@tasks."+ Config.Constants.HelperServiceName +":/volume";
+
+			slog.Debug("targetStoragePath", slog.String("value", targetStoragePath), slog.String("serviceId", service.ServiceId));
+			slog.Debug("sourceStoragePath", slog.String("value", sourceStoragePath), slog.String("serviceId", service.ServiceId));
+
 			command := `rsync -avz --delete -e "ssh -i /ssh-key -p 2222 -o StrictHostKeyChecking=yes -o UserKnownHostsFile=/expected-host-key" \
-				root@tasks.`+ Config.Constants.HelperServiceName +`:/volume/ ` +storagePath;
+				`+ sourceStoragePath +" "+ targetStoragePath;
 
 			exec, err := DockerClient.ContainerExecCreate(context.Background(), Config.Constants.StorageContainerName, container.ExecOptions{
 				Cmd: []string{"sh", "-c", command},
@@ -64,30 +71,37 @@ func Run(Config cfg.Config) {
 				Tty: false,
 			});
 			if err != nil {
-				panic("Failed to create rsync exec!"+err.Error());
+				slog.Error("Failed to create rsync exec!", slog.Any("propagatedError", err));
+				os.Exit(1);
 			}
 
 
 			resp, err := DockerClient.ContainerExecAttach(context.Background(), exec.ID, container.ExecStartOptions{});
+			if err != nil {
+				slog.Error("Failed to create container exec!", slog.Any("propagatedError", err));
+			}
 			defer resp.Close();
 
 			io.Copy(os.Stdout, resp.Reader)
 
 			time.Sleep(30*time.Second);
-			fmt.Println("Cleaning Up: " + service.ServiceId);
+			slog.Info("Cleaning Up", slog.String("serviceId", service.ServiceId), slog.String("volumeId", volume));
 			cleanupService(Config, service);
-			fmt.Println("Done!");
+			slog.Info("Done!");
 		}
-		fmt.Println("Scaling up: "+service.ServiceId);
+		slog.Info("Scaling Up", slog.String("serviceId", service.ServiceId));
 		scale(Config, service.ServiceId, true);
-		fmt.Println("Done!");
+		slog.Info("Done!");
 	}
 
 	DockerClient.ContainerRemove(context.Background(), Config.Constants.StorageContainerName, container.RemoveOptions{
 		Force: true,
 	});
 
-	if !shutdown(Config){panic("Failed to shutdown docker api!");}
+	if !shutdown(Config){
+		slog.Error("Failed to shutdown docker api!");
+		os.Exit(1);
+	}
 }
 
 func getServices(Config cfg.Config)[]aService{

main.go

@@ -5,6 +5,7 @@ import (
 	"github.com/rony5394/blazena/docker"
 	"github.com/rony5394/blazena/host"
 	cfg "github.com/rony5394/blazena/config"
+	"log/slog"
 );
 
 func main() {
@@ -12,7 +13,19 @@ func main() {
 		panic("Usage: blazena <mode>");
 	}
 
-	var config = cfg.GetConfig();
+	logger := slog.New(slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{
+		Level: slog.LevelDebug,
+	}));
+	slog.SetDefault(logger);
+
+	config, err := cfg.GetConfig();
+
+	if(err != nil){
+		slog.Error("Failed to load config!", slog.Any("propagatedError", err.Error()));
+		os.Exit(1);
+	}
+
+	slog.Debug("Config", slog.Any("Value", config));
 
 	mode := os.Args[1];
 	switch mode {

shared/trace.go

@@ -0,0 +1,28 @@
+package shared
+
+import (
+	"log/slog"
+
+	"github.com/google/uuid"
+);
+
+func NewTraceId()string{
+	return uuid.New().String();
+}
+
+func helper(name string, id *string)slog.Attr{
+	if id == nil{
+		return slog.String(name, NewTraceId());
+	}
+
+	return  slog.String(name, *id);
+}
+
+func NewSlogTrace(id *string)slog.Attr{
+	return helper("trace", id);
+}
+
+func NewSlogOperation(id *string)slog.Attr{
+	return helper("operation", id);
+}
+