fix: cache the instance config and api key (#1775)

We were needlessly calling the cloud-backend for data that doesn't
change and it was causing load issues on that server at scale.

This alleviates the "slow loading" problem we've been facing when
running the authenticated EM UI in the Cloud UI.

## Description:

## Is this change user facing?
NO

## References (if applicable):
<!-- Add relevant Github Issues, Discord threads, or other helpful
information. -->

enclave-manager/server/server.go

@@ -6,6 +6,7 @@ import (
 	"net/http"
 	"net/url"
 	"strings"
+	"sync"
 	"time"
 
 	"connectrpc.com/connect"
@@ -38,8 +39,12 @@ type Authentication struct {
 }
 
 type WebServer struct {
+	instanceConfigMutex *sync.RWMutex
+	apiKeyMutex         *sync.RWMutex
 	engineServiceClient *kurtosis_engine_rpc_api_bindingsconnect.EngineServiceClient
 	enforceAuth         bool
+	instanceConfig      *kurtosis_backend_server_rpc_api_bindings.GetCloudInstanceConfigResponse
+	apiKey              *string
 }
 
 func NewWebserver(enforceAuth bool) (*WebServer, error) {
@@ -50,6 +55,8 @@ func NewWebserver(enforceAuth bool) (*WebServer, error) {
 	return &WebServer{
 		engineServiceClient: &engineServiceClient,
 		enforceAuth:         enforceAuth,
+		instanceConfigMutex: &sync.RWMutex{},
+		apiKeyMutex:         &sync.RWMutex{},
 	}, nil
 }
 
@@ -408,6 +415,15 @@ func (c *WebServer) GetCloudInstanceConfig(
 	ctx context.Context,
 	apiKey string,
 ) (*kurtosis_backend_server_rpc_api_bindings.GetCloudInstanceConfigResponse, error) {
+	// Check if we have already fetched the instance config, if so return the cache
+	if c.instanceConfig != nil {
+		return c.instanceConfig, nil
+	}
+
+	// We have not yet fetched the instance configuration, so we write lock, make the external call and cache the result
+	c.instanceConfigMutex.Lock()
+	defer c.instanceConfigMutex.Unlock()
+
 	client, err := c.createKurtosisCloudBackendClient(
 		kurtosisCloudApiHost,
 		kurtosisCloudApiPort,
@@ -420,6 +436,7 @@ func (c *WebServer) GetCloudInstanceConfig(
 			ApiKey: apiKey,
 		},
 	}
+
 	getInstanceResponse, err := (*client).GetOrCreateInstance(ctx, getInstanceRequest)
 	if err != nil {
 		return nil, stacktrace.Propagate(err, "Failed to get the instance")
@@ -435,6 +452,8 @@ func (c *WebServer) GetCloudInstanceConfig(
 		return nil, stacktrace.Propagate(err, "Failed to get the instance config")
 	}
 
+	c.instanceConfig = getInstanceConfigResponse.Msg
+
 	return getInstanceConfigResponse.Msg, nil
 }
 
@@ -454,20 +473,33 @@ func (c *WebServer) ConvertJwtTokenToApiKey(
 			AccessToken: jwtToken,
 		},
 	}
-	result, err := (*client).GetOrCreateApiKey(ctx, request)
-	if err != nil {
-		return nil, stacktrace.Propagate(err, "Failed to get the API key")
-	}
 
-	if result == nil {
-		// User does not have an API key (unlikely if valid jwt token)
-		return nil, stacktrace.NewError("User does not have an API key assigned")
-	}
-	if len(result.Msg.ApiKey) > 0 {
+	if c.apiKey != nil {
 		return &Authentication{
-			ApiKey:   result.Msg.ApiKey,
+			ApiKey:   *c.apiKey,
 			JwtToken: jwtToken,
 		}, nil
+	} else {
+		c.apiKeyMutex.Lock()
+		defer c.apiKeyMutex.Unlock()
+
+		result, err := (*client).GetOrCreateApiKey(ctx, request)
+		if err != nil {
+			return nil, stacktrace.Propagate(err, "Failed to get the API key")
+		}
+
+		if result == nil {
+			// User does not have an API key (not really possible if they have a valid jwt token)
+			return nil, stacktrace.NewError("User does not have an API key assigned")
+		}
+
+		if len(result.Msg.ApiKey) > 0 {
+			c.apiKey = &result.Msg.ApiKey
+			return &Authentication{
+				ApiKey:   result.Msg.ApiKey,
+				JwtToken: jwtToken,
+			}, nil
+		}
 	}
 
 	return nil, stacktrace.NewError("an empty API key was returned from Kurtosis Cloud Backend")