Introduce SEMGREP_NETWORK_BROKER_PRIVATE_KEY env variable

pkg/config.go

@@ -321,6 +321,23 @@ func LoadConfig(configFiles []string, deploymentId int) (*Config, error) {
 
 		config.Inbound.Wireguard.LocalAddress = token.WireguardCredential.LocalAddress
 		config.Inbound.Wireguard.PrivateKey = token.WireguardCredential.PrivateKey
+		log.WithField("source", "broker_token").Info("Loaded WireGuard private key from broker token")
+	}
+
+	// Step 1a: Apply private key from environment variable if provided (takes precedence over broker token)
+	if privateKeyEnv := os.Getenv("SEMGREP_NETWORK_BROKER_PRIVATE_KEY"); privateKeyEnv != "" {
+		// Check if we're overwriting a previously set private key
+		if len(config.Inbound.Wireguard.PrivateKey) > 0 {
+			log.WithField("source", "environment_variable").Warn("SEMGREP_NETWORK_BROKER_PRIVATE_KEY environment variable taking precedence over the provided config file's private key")
+		}
+
+		privateKeyBytes, err := base64.StdEncoding.DecodeString(privateKeyEnv)
+		if err != nil {
+			return nil, fmt.Errorf("failed to decode SEMGREP_NETWORK_BROKER_PRIVATE_KEY: %v", err)
+		}
+
+		config.Inbound.Wireguard.PrivateKey = SensitiveBase64String(privateKeyBytes)
+		log.WithField("source", "environment_variable").Info("Loaded WireGuard private key from SEMGREP_NETWORK_BROKER_PRIVATE_KEY environment variable")
 	}
 
 	// Step 2: Apply config values from semgrep.dev/api/broker/{deployment_id}/default-config, if a deployment ID is provided

pkg/config_test.go

@@ -3,6 +3,7 @@ package pkg
 import (
 	"encoding/base64"
 	"fmt"
+	"os"
 	"reflect"
 	"testing"
 
@@ -135,3 +136,28 @@ func TestHttpMethodsDecodeHook(t *testing.T) {
 		t.Error(fmt.Errorf("No match: %+v != %+v", output.Methods, expected))
 	}
 }
+
+func TestPrivateKeyEnvironmentVariable(t *testing.T) {
+	// Test that SEMGREP_NETWORK_BROKER_PRIVATE_KEY environment variable is properly loaded
+	testPrivateKey := "KJR4EeL83nexOFihmdYciri7Mo7ciAq/b5/S0lREcns="
+
+	// Set the environment variable
+	os.Setenv("SEMGREP_NETWORK_BROKER_PRIVATE_KEY", testPrivateKey)
+	defer os.Unsetenv("SEMGREP_NETWORK_BROKER_PRIVATE_KEY")
+
+	// Load config
+	config, err := LoadConfig(nil, 0)
+	if err != nil {
+		t.Fatalf("Failed to load config: %v", err)
+	}
+
+	// Verify the private key was loaded correctly
+	expectedBytes, err := base64.StdEncoding.DecodeString(testPrivateKey)
+	if err != nil {
+		t.Fatalf("Failed to decode test private key: %v", err)
+	}
+
+	if !reflect.DeepEqual(config.Inbound.Wireguard.PrivateKey, SensitiveBase64String(expectedBytes)) {
+		t.Errorf("Private key not loaded correctly from environment variable")
+	}
+}