From 9bfbd38431cd4fc3b2403975dd2b63841668a7f3 Mon Sep 17 00:00:00 2001
From: Paulo Canilho <paulo@canilho.net>
Date: Tue, 27 Feb 2024 21:48:10 +0100
Subject: [PATCH] feat: added a configuration key [hide_repository_metadata]
 that, if set to true, will minimize the [token.data.repositories] to
 [token.data.repositories.names] to avoid high memory consumption (#114)

---
 github/client.go      | 13 +++++++++++++
 github/config.go      | 11 +++++++++++
 github/path_config.go | 26 ++++++++++++++++++--------
 3 files changed, 42 insertions(+), 8 deletions(-)

diff --git a/github/client.go b/github/client.go
index 03b8847..14cf3d4 100644
--- a/github/client.go
+++ b/github/client.go
@@ -95,6 +95,7 @@ func NewClient(config *Config) (*Client, error) {
 	installationsURL := baseURL.ResolveReference(&url.URL{Path: "app/installations"})
 
 	return &Client{
+		Config:        config,
 		revocationURL: baseURL.ResolveReference(&url.URL{Path: "installation/token"}),
 		revocationClient: &http.Client{
 			Timeout:   reqTimeout,
@@ -221,6 +222,18 @@ func (c *Client) token(ctx context.Context, tokReq *tokenRequest) (*logical.Resp
 		return nil, fmt.Errorf("%w: %v", errUnableToDecodeAccessTokenRes, err)
 	}
 
+	// Reduce memory consumption by reducing 'repositories' metadata to simple list of repository names
+	if !c.IncludeRepositoryMetadata {
+		repositoriesKey, included := resData["repositories"]
+		if included {
+			repositories := repositoriesKey.([]any)
+			var repoNames []string
+			for _, r := range repositories {
+				repoNames = append(repoNames, r.(map[string]any)["name"].(string))
+			}
+			resData["repositories"] = repoNames
+		}
+	}
 	tokRes := &logical.Response{Data: resData}
 
 	// Enrich the response with what we know about the installation.
diff --git a/github/config.go b/github/config.go
index 3f5cac7..6f05ad8 100644
--- a/github/config.go
+++ b/github/config.go
@@ -31,6 +31,10 @@ type Config struct {
 	// BaseURL is the base URL for API requests.
 	// Defaults to GitHub's public API.
 	BaseURL string `json:"base_url"`
+
+	// IncludeRepositoryMetadata controls filtering of the 'repositories' key returned on repository-filtered tokens
+	// Defaults to returning full repository metadata; returns a minimised list of repository names if set to false
+	IncludeRepositoryMetadata bool `json:"include_repository_metadata"`
 }
 
 // NewConfig returns a pre-configured Config struct.
@@ -79,6 +83,13 @@ func (c *Config) Update(d *framework.FieldData) (bool, error) {
 		}
 	}
 
+	if includeRepositoryMetadata, ok := d.GetOk(includeRepositoryMetadataKey); ok {
+		if nv := includeRepositoryMetadata.(bool); c.IncludeRepositoryMetadata != nv {
+			c.IncludeRepositoryMetadata = nv
+			changed = true
+		}
+	}
+
 	return changed, nil
 }
 
diff --git a/github/path_config.go b/github/path_config.go
index 6595603..b9529ef 100644
--- a/github/path_config.go
+++ b/github/path_config.go
@@ -19,12 +19,15 @@ const (
 )
 
 const (
-	keyAppID    = "app_id"
-	descAppID   = "Application ID of the GitHub App."
-	keyPrvKey   = "prv_key"
-	descPrvKey  = "Private key for signing GitHub access token requests (JWTs)."
-	keyBaseURL  = "base_url"
-	descBaseURL = "Base URL for API requests (defaults to the public GitHub API)."
+	keyAppID                     = "app_id"
+	descAppID                    = "Application ID of the GitHub App."
+	keyPrvKey                    = "prv_key"
+	includeRepositoryMetadataKey = "include_repository_metadata"
+
+	descPrvKey                       = "Private key for signing GitHub access token requests (JWTs)."
+	descIncludeRepositoryMetadataKey = "If set to true, the token lease response 'data.repositories' sub-field will be minimized to 'data.repositories.*.names'"
+	keyBaseURL                       = "base_url"
+	descBaseURL                      = "Base URL for API requests (defaults to the public GitHub API)."
 )
 
 const pathConfigHelpSyn = `
@@ -51,6 +54,12 @@ func (b *backend) pathConfig() *framework.Path {
 				Description: descPrvKey,
 				Required:    true,
 			},
+			includeRepositoryMetadataKey: {
+				Type:        framework.TypeBool,
+				Description: descIncludeRepositoryMetadataKey,
+				Required:    false,
+				Default:     true,
+			},
 			keyBaseURL: {
 				Type:        framework.TypeString,
 				Description: descBaseURL,
@@ -87,8 +96,9 @@ func (b *backend) pathConfigRead(
 	}
 
 	resData := map[string]any{
-		keyAppID:   c.AppID,
-		keyBaseURL: c.BaseURL,
+		keyAppID:                     c.AppID,
+		keyBaseURL:                   c.BaseURL,
+		includeRepositoryMetadataKey: c.IncludeRepositoryMetadata,
 	}
 
 	// We don't return the key but indicate its presence for a better UX.