Datasource: Make sure data proxy timeout applies to HTTP client (#25865)

For backend data sources executing in the backend (not through data proxy) make 
sure that the timeout applies to cached HTTP client.

Fixes #25863

Co-authored-by: Diana Payton <52059945+oddlittlebird@users.noreply.github.com>

conf/defaults.ini

@@ -126,7 +126,8 @@ connstr =
 # This enables data proxy logging, default is false
 logging = false
 
-# How long the data proxy should wait before timing out default is 30 (seconds)
+# How long the data proxy waits before timing out, default is 30 seconds.
+# This setting also applies to core backend HTTP data sources where query requests use an HTTP client with timeout set.
 timeout = 30
 
 # If enabled and user is not anonymous, data proxy will add X-Grafana-User header with username into the request, default is false.
@@ -234,7 +235,7 @@ versions_to_keep = 20
 min_refresh_interval = 5s
 
 # Path to the default home dashboard. If this value is empty, then Grafana uses StaticRootPath + "dashboards/home.json"
-default_home_dashboard_path = 
+default_home_dashboard_path =
 
 #################################### Users ###############################
 [users]

conf/sample.ini

@@ -127,7 +127,8 @@
 # This enables data proxy logging, default is false
 ;logging = false
 
-# How long the data proxy should wait before timing out default is 30 (seconds)
+# How long the data proxy waits before timing out, default is 30 seconds.
+# This setting also applies to core backend HTTP data sources where query requests use an HTTP client with timeout set.
 ;timeout = 30
 
 # If enabled and user is not anonymous, data proxy will add X-Grafana-User header with username into the request, default is false.
@@ -233,7 +234,7 @@
 ;min_refresh_interval = 5s
 
 # Path to the default home dashboard. If this value is empty, then Grafana uses StaticRootPath + "dashboards/home.json"
-;default_home_dashboard_path = 
+;default_home_dashboard_path =
 
 #################################### Users ###############################
 [users]
@@ -459,7 +460,7 @@
 ;from_name = Grafana
 # EHLO identity in SMTP dialog (defaults to instance_name)
 ;ehlo_identity = dashboard.example.com
-# SMTP startTLS policy (defaults to 'OpportunisticStartTLS') 
+# SMTP startTLS policy (defaults to 'OpportunisticStartTLS')
 ;startTLS_policy = NoStartTLS
 
 [emails]

docs/sources/administration/configuration.md

@@ -383,7 +383,9 @@ This enables data proxy logging, default is `false`.
 
 ### timeout
 
-How long the data proxy should wait before timing out. Default is `30` (seconds)
+How long the data proxy should wait before timing out. Default is 30 seconds.
+
+This setting also applies to core backend HTTP data sources where query requests use an HTTP client with timeout set.
 
 ### send_user_header
 

pkg/models/datasource_cache.go

@@ -51,7 +51,7 @@ func (ds *DataSource) GetHttpClient() (*http.Client, error) {
 	}
 
 	return &http.Client{
-		Timeout:   30 * time.Second,
+		Timeout:   time.Duration(setting.DataProxyTimeout) * time.Second,
 		Transport: transport,
 	}, nil
 }