Rendering: Add configuration options for renderKey lifetime (#57339)

* Add configuration options for `renderKey` lifetime

* Rename config key to `render_key_lifetime`

* Update conf/defaults.ini

Co-authored-by: Joan López de la Franca Beltran <5459617+joanlopez@users.noreply.github.com>

* Add `render_key_lifetime` to sample.ini

Co-authored-by: Joan López de la Franca Beltran <5459617+joanlopez@users.noreply.github.com>

conf/defaults.ini

@@ -1134,6 +1134,11 @@ renderer_token = -
 # Concurrent render request limit affects when the /render HTTP endpoint is used. Rendering many images at the same time can overload the server,
 # which this setting can help protect against by only allowing a certain amount of concurrent requests.
 concurrent_render_request_limit = 30
+# Determines the lifetime of the render key used by the image renderer to access and render Grafana.
+# This setting should be expressed as a duration. Examples: 10s (seconds), 5m (minutes), 2h (hours). 
+# Default is 5m. This should be more than enough for most deployments.
+# Change the value only if image rendering is failing and you see `Failed to get the render key from cache` in Grafana logs.
+render_key_lifetime = 5m
 
 [panels]
 # here for to support old env variables, can remove after a few months

conf/sample.ini

@@ -1099,6 +1099,11 @@
 # Concurrent render request limit affects when the /render HTTP endpoint is used. Rendering many images at the same time can overload the server,
 # which this setting can help protect against by only allowing a certain amount of concurrent requests.
 ;concurrent_render_request_limit = 30
+# Determines the lifetime of the render key used by the image renderer to access and render Grafana.
+# This setting should be expressed as a duration. Examples: 10s (seconds), 5m (minutes), 2h (hours).
+# Default is 5m. This should be more than enough for most deployments.
+# Change the value only if image rendering is failing and you see `Failed to get the render key from cache` in Grafana logs.
+;render_key_lifetime = 5m
 
 [panels]
 # If set to true Grafana will allow script tags in text panels. Not recommended as it enable XSS vulnerabilities.
@@ -1260,4 +1265,4 @@
 # Move a specific app plugin page (referenced by its `path` field) to a specific navigation section
 [navigation.app_standalone_pages]
 # The following will move the page with the path "/a/my-app-id/starred-content" from `my-app-id` to the `starred` section
-# /a/my-app-id/starred-content = starred
+# /a/my-app-id/starred-content = starred

pkg/services/rendering/rendering.go

@@ -91,7 +91,7 @@ func ProvideService(cfg *setting.Cfg, remoteCache *remotecache.RemoteCache, rm p
 		perRequestRenderKeyProvider: &perRequestRenderKeyProvider{
 			cache:     remoteCache,
 			log:       logger,
-			keyExpiry: 5 * time.Minute,
+			keyExpiry: cfg.RendererRenderKeyLifeTime,
 		},
 		capabilities: []Capability{
 			{

pkg/setting/setting.go

@@ -247,6 +247,7 @@ type Cfg struct {
 	RendererCallbackUrl            string
 	RendererAuthToken              string
 	RendererConcurrentRequestLimit int
+	RendererRenderKeyLifeTime      time.Duration
 
 	// Security
 	DisableInitAdminCreation          bool
@@ -1486,6 +1487,7 @@ func (cfg *Cfg) readRenderingSettings(iniFile *ini.File) error {
 	}
 
 	cfg.RendererConcurrentRequestLimit = renderSec.Key("concurrent_render_request_limit").MustInt(30)
+	cfg.RendererRenderKeyLifeTime = renderSec.Key("render_key_lifetime").MustDuration(5 * time.Minute)
 	cfg.ImagesDir = filepath.Join(cfg.DataPath, "png")
 	cfg.CSVsDir = filepath.Join(cfg.DataPath, "csv")