Added prepull.

config/config.go

@@ -1,9 +1,12 @@
-package config;
+package config
 
 import (
-	"os"
+	"encoding/base64"
 	"encoding/json"
 	"errors"
+	"os"
+
+	"github.com/docker/docker/api/types/registry"
 );
 
 type Config struct {
@@ -15,10 +18,12 @@ type Config struct {
 	LocalBasePath string
 	BlazenaImageUrl string
 	RegistryAuth RegistryAuth
+	EncodedRegistryAuth string
 	Constants struct{
 		OverlayNetworkName string
 		HelperServiceName string
 		StorageContainerName string
+		PrepullImageServiceName string
 	}
 }
 
@@ -39,7 +44,7 @@ func GetConfig()(Config, error){
 	cfg.Constants.OverlayNetworkName = "blazenaPohar";
 	cfg.Constants.HelperServiceName = "blazenaHelper";
 	cfg.Constants.StorageContainerName = "blazenaStorage";
-	
+	cfg.Constants.PrepullImageServiceName = "blazenaPrepull";
 
 	err = json.Unmarshal(rawConfig, &cfg);
 
@@ -47,5 +52,19 @@ func GetConfig()(Config, error){
 		return cfg, errors.New("Failed to unmarshal config: " + err.Error());
 	}
 
+	authConfig := registry.AuthConfig{
+		Username: cfg.RegistryAuth.Username, 
+		Password: cfg.RegistryAuth.Password,
+	}
+
+	authJSON, err := json.Marshal(authConfig)
+
+	if err != nil {
+		panic("Failed to marshal auth config!"+ err.Error());
+	}
+
+	cfg.EncodedRegistryAuth = base64.StdEncoding.EncodeToString(authJSON);
+
+
 	return cfg, err;
 }

docker/docker.go

@@ -27,6 +27,8 @@ var scale sync.Map;
 var token string = "12345";
 var theConfig cfg.Config;
 
+var theShutdownFuncPointer *context.CancelFunc;
+
 type aService struct{
 	ServiceId string `json:"serviceId"`;
 	VolumeNames []string `json:"volumeNames"`;
@@ -39,6 +41,7 @@ func Run(Config cfg.Config){
 	theConfig = Config;
 
 	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM);
+	theShutdownFuncPointer = &stop;
 
 	var err error;
 	ApiClient, err = client.NewClientWithOpts(client.FromEnv);
@@ -62,6 +65,7 @@ func Run(Config cfg.Config){
 		Addr: ":1234",
 	}
 
+	http.HandleFunc("/prepull", prepullImage);
 	http.HandleFunc("/services", listServices);
 	http.HandleFunc("/scale/up", scaleUp);
 	http.HandleFunc("/scale/down", scaleDown);

docker/prepullImage.go

@@ -0,0 +1,78 @@
+package docker
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+	"net/http"
+	"os"
+	"time"
+
+	"github.com/docker/docker/api/types/swarm"
+)
+
+func prepullImage(w http.ResponseWriter, r *http.Request){
+	if r.Method != http.MethodPost{
+		w.WriteHeader(http.StatusMethodNotAllowed);
+		fmt.Fprint(w, "Method Not Allowed");
+		return;
+	}
+
+	if !bearerAuth(w, r){return;}
+
+	sc, err := ApiClient.ServiceCreate(context.Background(), swarm.ServiceSpec{
+		Annotations: swarm.Annotations{
+			Name: theConfig.Constants.PrepullImageServiceName, 
+			Labels: map[string]string{"blazena.prepull": "true"},
+		},
+		Mode: swarm.ServiceMode{
+			GlobalJob: &swarm.GlobalJob{},
+		},
+		TaskTemplate: swarm.TaskSpec{
+			ContainerSpec: &swarm.ContainerSpec{
+				Image: theConfig.BlazenaImageUrl, 
+				Command: []string{"sleep", "1s"},
+			},
+		},
+	}, swarm.ServiceCreateOptions{
+		QueryRegistry: true,
+		EncodedRegistryAuth: theConfig.EncodedRegistryAuth,
+	});
+
+	if err != nil {
+		slog.Error("Failed to create prepull service", slog.Any("propagatedError", err));
+		os.Exit(3);
+	}
+
+	slog.Info("Started Prepull of blazena image.");
+
+	go func(){
+	CHECKLOOP: for {
+		time.Sleep(3*time.Second);
+		tasks, err := ApiClient.TaskList(context.Background(), swarm.TaskListOptions{});
+
+		if err != nil {
+			slog.Error("Failed to list tasks.", slog.Any("propagatedError", err));
+			os.Exit(3);
+		}
+
+		for _, task := range tasks {
+			if task.ServiceID != sc.ID {continue};
+
+			if task.Status.State != "complete" {
+				time.Sleep(1*time.Second);
+				continue CHECKLOOP
+			};
+		}
+
+		err = ApiClient.ServiceRemove(context.Background(), sc.ID);
+
+		if err != nil {
+			slog.Warn("Failed to remove prepull service.", slog.Any("propagatedError", err));
+		}
+
+		slog.Info("Prepull Finished");
+		break CHECKLOOP;
+	}
+	}();
+}

host/host.go

@@ -41,6 +41,7 @@ func Run(Config cfg.Config) {
 
 	sshKeyPair := shared.GenerateSSHKeypair();
 	sshHostPkPem := exchangeKeys(Config, string(sshKeyPair.Public));
+	go prepullImage(Config);
 	createStorageContainer(Config, DockerClient, sshKeyPair.Private, sshHostPkPem);
 
 	services := getServices(Config);

host/prepullImage.go

@@ -0,0 +1,30 @@
+package host
+
+import (
+	"bytes"
+	"log/slog"
+	"net/http"
+	"os"
+
+	cfg "github.com/rony5394/blazena/config"
+);
+
+func prepullImage(Config cfg.Config){
+	rq, err := http.NewRequest("POST", Config.DockerManagerBaseUrl + "/prepull", bytes.NewBufferString("{}")); 
+
+	if err != nil{
+		slog.Error("Failed to create request", slog.Any("propagatedError", err), slog.String("note", "not send just create the object"));
+		os.Exit(1);
+	}
+
+	rq.Header.Set("Authorization", "Bearer "+ token);
+	rq.Close = true;
+	rs, err := http.DefaultClient.Do(rq);
+
+	if err != nil{
+		slog.Error("Failed to send http request", slog.Any("propagatedError", err));
+		os.Exit(1);
+	}
+
+	defer rs.Body.Close();
+}

host/scale.go

@@ -37,7 +37,9 @@ func scale(Config cfg.Config, serviceId string, up bool)bool{
 	rq.Header.Set("Authorization", "Bearer "+ token);
 	rq.Close = true;
 	rs, err := http.DefaultClient.Do(rq);
-	defer rs.Body.Close();
+	if err == nil {
+	rs.Body.Close();
+	}
 
 	if err != nil{
 		panic("Failed to send http request"+ err.Error());

main.go

@@ -47,6 +47,9 @@ func main() {
 		case "host":
 			host.Run(config);	
 		break;
+		case "pull":
+			os.Exit(0);
+		break;
 		default:
 			panic("Invalid runtime mode!");
 	}