Change behavior for installing plugin with missing .prov file (now warns and continues instead of failing)

Signed-off-by: Scott Rigby <scott@r6by.com>

internal/plugin/installer/http_installer.go

@@ -184,20 +184,15 @@ func (i *HTTPInstaller) PrepareForVerification() (string, func(), error) {
 		return "", nil, fmt.Errorf("failed to write plugin file: %w", err)
 	}
 
-	// Download signature file
-	provData, err := g.Get(i.Source+".prov", getter.WithURL(i.Source+".prov"))
-	if err != nil {
-		cleanup()
-		return "", nil, fmt.Errorf("failed to download plugin signature: %w", err)
-	}
-
-	if err := os.WriteFile(pluginFile+".prov", provData.Bytes(), 0644); err != nil {
-		cleanup()
-		return "", nil, fmt.Errorf("failed to write signature file: %w", err)
+	// Try to download signature file - don't fail if it doesn't exist
+	if provData, err := g.Get(i.Source+".prov", getter.WithURL(i.Source+".prov")); err == nil {
+		if err := os.WriteFile(pluginFile+".prov", provData.Bytes(), 0644); err == nil {
+			// Store the provenance data so we can save it after installation
+			i.provData = provData.Bytes()
+		}
 	}
-
-	// Store the provenance data so we can save it after installation
-	i.provData = provData.Bytes()
+	// Note: We don't fail if .prov file can't be downloaded - the verification logic
+	// in InstallWithOptions will handle missing .prov files appropriately
 
 	return pluginFile, cleanup, nil
 }

internal/plugin/installer/installer.go

@@ -100,20 +100,32 @@ func InstallWithOptions(i Installer, opts Options) (*VerificationResult, error)
 			defer cleanup()
 		}
 
-		// Verify the plugin
-		verification, err := plugin.VerifyPlugin(pluginPath, opts.Keyring)
-		if err != nil {
-			return nil, fmt.Errorf("plugin verification failed: %w", err)
-		}
+		// Check if provenance file exists
+		provFile := pluginPath + ".prov"
+		if _, err := os.Stat(provFile); err != nil {
+			if os.IsNotExist(err) {
+				// No .prov file found - emit warning but continue installation
+				fmt.Fprintf(os.Stderr, "WARNING: No provenance file found for plugin. Plugin is not signed and cannot be verified.\n")
+			} else {
+				// Other error accessing .prov file
+				return nil, fmt.Errorf("failed to access provenance file: %w", err)
+			}
+		} else {
+			// Provenance file exists - verify the plugin
+			verification, err := plugin.VerifyPlugin(pluginPath, opts.Keyring)
+			if err != nil {
+				return nil, fmt.Errorf("plugin verification failed: %w", err)
+			}
 
-		// Collect verification info
-		result = &VerificationResult{
-			SignedBy:    make([]string, 0),
-			Fingerprint: fmt.Sprintf("%X", verification.SignedBy.PrimaryKey.Fingerprint),
-			FileHash:    verification.FileHash,
-		}
-		for name := range verification.SignedBy.Identities {
-			result.SignedBy = append(result.SignedBy, name)
+			// Collect verification info
+			result = &VerificationResult{
+				SignedBy:    make([]string, 0),
+				Fingerprint: fmt.Sprintf("%X", verification.SignedBy.PrimaryKey.Fingerprint),
+				FileHash:    verification.FileHash,
+			}
+			for name := range verification.SignedBy.Identities {
+				result.SignedBy = append(result.SignedBy, name)
+			}
 		}
 	}
 

internal/plugin/installer/local_installer.go

@@ -190,15 +190,14 @@ func (i *LocalInstaller) PrepareForVerification() (string, func(), error) {
 		return "", nil, fmt.Errorf("verification not supported for directories")
 	}
 
-	// For local files, we just need to check that the .prov file exists
+	// For local files, try to read the .prov file if it exists
 	provFile := i.Source + ".prov"
-	provData, err := os.ReadFile(provFile)
-	if err != nil {
-		return "", nil, fmt.Errorf("signature file %s not found: %w", provFile, err)
+	if provData, err := os.ReadFile(provFile); err == nil {
+		// Store the provenance data so we can save it after installation
+		i.provData = provData
 	}
-
-	// Store the provenance data so we can save it after installation
-	i.provData = provData
+	// Note: We don't fail if .prov file doesn't exist - the verification logic
+	// in InstallWithOptions will handle missing .prov files appropriately
 
 	// Return the source path directly, no cleanup needed
 	return i.Source, nil, nil

internal/plugin/installer/oci_installer.go

@@ -288,21 +288,18 @@ func (i *OCIInstaller) PrepareForVerification() (pluginPath string, cleanup func
 		return "", nil, fmt.Errorf("failed to save plugin tarball: %w", err)
 	}
 
-	// Download the provenance file
+	// Try to download the provenance file - don't fail if it doesn't exist
 	provSource := i.Source + ".prov"
-	provData, err := i.getter.Get(provSource)
-	if err != nil {
-		cleanup()
-		return "", nil, fmt.Errorf("failed to pull provenance from %s: %w", provSource, err)
-	}
-
-	// Save provenance to temp directory
-	provFile := filepath.Join(tempDir, filename+".prov")
-	if err := os.WriteFile(provFile, provData.Bytes(), 0644); err != nil {
-		cleanup()
-		return "", nil, fmt.Errorf("failed to save provenance file: %w", err)
+	if provData, err := i.getter.Get(provSource); err == nil {
+		// Save provenance to temp directory
+		provFile := filepath.Join(tempDir, filename+".prov")
+		if err := os.WriteFile(provFile, provData.Bytes(), 0644); err == nil {
+			slog.Debug("prepared plugin for verification", "plugin", pluginTarball, "provenance", provFile)
+		}
 	}
+	// Note: We don't fail if .prov file can't be downloaded - the verification logic
+	// in InstallWithOptions will handle missing .prov files appropriately
 
-	slog.Debug("prepared plugin for verification", "plugin", pluginTarball, "provenance", provFile)
+	slog.Debug("prepared plugin for verification", "plugin", pluginTarball)
 	return pluginTarball, cleanup, nil
 }