feat: Support configurable time zone

* Users can configure the time zone in report either by provisioning or query param

* Always create a new instance of config report handler

* Keep a singleton instance of current provisioned config

* Update docs

Signed-off-by: Mahendra Paipuri <mahendra.paipuri@gmail.com>

.ci/config/tls/app.yaml

@@ -15,6 +15,7 @@ apps:
       orientation: portrait
       layout: simple
       dashboardMode: default
+      timeZone: ''
       logo: ''
       maxRenderWorkers: 2
       persistData: false

pkg/plugin/app.go

@@ -40,6 +40,7 @@ type Config struct {
 	Orientation      string `json:"orientation"`
 	Layout           string `json:"layout"`
 	DashboardMode    string `json:"dashboardMode"`
+	TimeZone         string `json:"timeZone"`
 	EncodedLogo      string `json:"encodedLogo"`
 	MaxRenderWorkers int    `json:"maxRenderWorkers"`
 	PersistData      bool   `json:"persistData"`
@@ -79,11 +80,12 @@ func (c *Config) String() string {
 	}
 	return fmt.Sprintf(
 		"Grafana App URL: %s; Skip TLS Check: %t; Grafana Data Path: %s; "+
-			"Orientation: %s; Layout: %s; Dashboard Mode: %s; Encoded Logo: %s; Max Renderer Workers: %d; "+
-			"Persist Data: %t; Included Panel IDs: %s; Excluded Panel IDs: %s", 
-			c.AppURL, c.SkipTLSCheck, c.DataPath, c.Orientation, c.Layout,
-		c.DashboardMode, encodedLogo, c.MaxRenderWorkers, c.PersistData, includedPanelIDs,
-		excludedPanelIDs,
+			"Orientation: %s; Layout: %s; Dashboard Mode: %s; Time Zone: %s; Encoded Logo: %s; "+
+			"Max Renderer Workers: %d; "+
+			"Persist Data: %t; Included Panel IDs: %s; Excluded Panel IDs: %s",
+		c.AppURL, c.SkipTLSCheck, c.DataPath, c.Orientation, c.Layout,
+		c.DashboardMode, c.TimeZone, encodedLogo, c.MaxRenderWorkers, c.PersistData,
+		includedPanelIDs, excludedPanelIDs,
 	)
 }
 
@@ -105,20 +107,13 @@ type App struct {
 	newReport        func(logger log.Logger, grafanaClient GrafanaClient, options *ReportOptions) (Report, error)
 }
 
-// NewApp creates a new example *App instance.
-func NewApp(ctx context.Context, settings backend.AppInstanceSettings) (instancemgmt.Instance, error) {
-	var app App
+// Default config
+var defaultConfig Config
 
-	// Get context logger for debugging
-	ctxLogger := log.DefaultLogger.FromContext(ctx)
-
-	// Use a httpadapter (provided by the SDK) for resource calls. This allows us
-	// to use a *http.ServeMux for resource calls, so we can map multiple routes
-	// to CallResource without having to implement extra logic.
-	mux := http.NewServeMux()
-	app.registerRoutes(mux)
-	app.CallResourceHandler = httpadapter.New(mux)
+// Keep a state of current provisioned config
+var currentAppConfig Config
 
+func init() {
 	// Get Grafana data path based on path of current executable
 	pluginExe, err := os.Executable()
 	if err != nil {
@@ -129,14 +124,46 @@ func NewApp(ctx context.Context, settings backend.AppInstanceSettings) (instance
 	// Now we attempt to get install_dir directory which is Grafana data path
 	dataPath := filepath.Dir(filepath.Dir(filepath.Dir(pluginExe)))
 
-	// Update plugin settings defaults
-	var config = Config{
+	// Populate defaultConfig
+	defaultConfig = Config{
 		DataPath:         dataPath,
 		Orientation:      "portrait",
 		Layout:           "simple",
 		DashboardMode:    "default",
+		TimeZone:         "",
+		EncodedLogo:      "",
 		MaxRenderWorkers: 2,
 	}
+}
+
+// DefaultConfig returns an instance of default config
+func DefaultConfig() Config {
+	return defaultConfig
+}
+
+// NewAppConfig returns an instance of current app's provisioned config
+func NewAppConfig() Config {
+	return currentAppConfig
+}
+
+// NewApp creates a new example *App instance.
+func NewApp(ctx context.Context, settings backend.AppInstanceSettings) (instancemgmt.Instance, error) {
+	var app App
+
+	// Get context logger for debugging
+	ctxLogger := log.DefaultLogger.FromContext(ctx)
+
+	// Use a httpadapter (provided by the SDK) for resource calls. This allows us
+	// to use a *http.ServeMux for resource calls, so we can map multiple routes
+	// to CallResource without having to implement extra logic.
+	mux := http.NewServeMux()
+	app.registerRoutes(mux)
+	app.CallResourceHandler = httpadapter.New(mux)
+
+	// Always start with a default config so that when the plugin is not provisioned
+	// with a config, we will still have "non-null" config to work with
+	var config = DefaultConfig()
+	// Update plugin settings defaults
 	if settings.JSONData != nil && string(settings.JSONData) != "null" {
 		if err := json.Unmarshal(settings.JSONData, &config); err == nil {
 			ctxLogger.Info("provisioned config", "config", config.String())
@@ -253,6 +280,9 @@ func NewApp(ctx context.Context, settings backend.AppInstanceSettings) (instance
 		config.ChromeOptions = append(config.ChromeOptions, chromedp.ExecPath(chromeExec))
 	}
 
+	// Set current App's config
+	currentAppConfig = config
+
 	// Make config
 	app.config = &config
 

pkg/plugin/dashboard.go

@@ -284,11 +284,13 @@ func filterPanels(panels []Panel, config *Config) []Panel {
 	// Iterate over all panels and check if they should be included or not
 	var filteredPanels []Panel
 	for _, panel := range panels {
-		if len(config.IncludePanelIDs) > 0 && slices.Contains(config.IncludePanelIDs, panel.ID) && !slices.Contains(filteredPanels, panel) {
+		if len(config.IncludePanelIDs) > 0 && slices.Contains(config.IncludePanelIDs, panel.ID) &&
+			!slices.Contains(filteredPanels, panel) {
 			filteredPanels = append(filteredPanels, panel)
 		}
 
-		if len(config.ExcludePanelIDs) > 0 && !slices.Contains(config.ExcludePanelIDs, panel.ID) && !slices.Contains(filteredPanels, panel) {
+		if len(config.ExcludePanelIDs) > 0 && !slices.Contains(config.ExcludePanelIDs, panel.ID) &&
+			!slices.Contains(filteredPanels, panel) {
 			filteredPanels = append(filteredPanels, panel)
 		}
 	}

pkg/plugin/report.go

@@ -66,19 +66,28 @@ func (o ReportOptions) IsLandscapeOrientation() bool {
 
 // Get from time string
 func (o ReportOptions) From() string {
-	return o.timeRange.FromFormatted()
+	return o.timeRange.FromFormatted(o.location())
 }
 
 // Get to time string
 func (o ReportOptions) To() string {
-	return o.timeRange.ToFormatted()
+	return o.timeRange.ToFormatted(o.location())
 }
 
 // Get logo
 func (o ReportOptions) Logo() string {
 	return o.config.EncodedLogo
 }
 
+// Location of time zone
+func (o ReportOptions) location() *time.Location {
+	if location, err := time.LoadLocation(o.config.TimeZone); err != nil {
+		return time.Now().Local().Location()
+	} else {
+		return location
+	}
+}
+
 // report struct
 type report struct {
 	logger  log.Logger
@@ -266,11 +275,11 @@ func (r *report) generateHTMLFile(dash Dashboard) error {
 		return fmt.Errorf("error parsing report template: %v", err)
 	}
 
+	// Template data
+	data := templateData{dash, *r.options, time.Now().Local().In(r.options.location()).Format(time.RFC850)}
+
 	// Render the template for body of the report
-	if err = tmpl.ExecuteTemplate(
-		file,
-		"report.gohtml",
-		templateData{dash, *r.options, time.Now().Format(time.RFC850)}); err != nil {
+	if err = tmpl.ExecuteTemplate(file, "report.gohtml", data); err != nil {
 		return fmt.Errorf("error executing report template: %v", err)
 	}
 
@@ -281,10 +290,7 @@ func (r *report) generateHTMLFile(dash Dashboard) error {
 
 	// Render the template for header of the report
 	bufHeader := &bytes.Buffer{}
-	if err = tmpl.ExecuteTemplate(
-		bufHeader,
-		"header.gohtml",
-		templateData{dash, *r.options, time.Now().Format(time.RFC850)}); err != nil {
+	if err = tmpl.ExecuteTemplate(bufHeader, "header.gohtml", data); err != nil {
 		return fmt.Errorf("error executing header template: %v", err)
 	}
 	r.options.header = bufHeader.String()
@@ -296,10 +302,7 @@ func (r *report) generateHTMLFile(dash Dashboard) error {
 
 	// Render the template for footer of the report
 	bufFooter := &bytes.Buffer{}
-	if err = tmpl.ExecuteTemplate(
-		bufFooter,
-		"footer.gohtml",
-		templateData{dash, *r.options, time.Now().Format(time.RFC850)}); err != nil {
+	if err = tmpl.ExecuteTemplate(bufFooter, "footer.gohtml", data); err != nil {
 		return fmt.Errorf("error executing footer template: %v", err)
 	}
 	r.options.footer = bufFooter.String()

pkg/plugin/resources.go

@@ -93,6 +93,10 @@ func (a *App) handleReport(w http.ResponseWriter, req *http.Request) {
 	timeRange := NewTimeRange(req.URL.Query().Get("from"), req.URL.Query().Get("to"))
 	ctxLogger.Debug("time range", "range", timeRange, "user", currentUser, "dash_uid", dashboardUID)
 
+	// Always start with new instance of app config for each request
+	configInstance := NewAppConfig()
+	a.config = &configInstance
+
 	// Get custom settings if provided in Plugin settings
 	// Seems like when json.RawMessage is nil, it actually returns []byte("null"). So
 	// we need to check for both
@@ -124,6 +128,9 @@ func (a *App) handleReport(w http.ResponseWriter, req *http.Request) {
 			a.config.DashboardMode = queryDashboardMode[len(queryDashboardMode)-1]
 		}
 	}
+	if timeZone, ok := req.URL.Query()["timeZone"]; ok {
+		a.config.TimeZone = timeZone[len(timeZone)-1]
+	}
 
 	// Two special query parameters: includePanelID and excludePanelID
 	// The query parameters are self explanatory and based on the values set to them

pkg/plugin/time.go

@@ -115,15 +115,15 @@ func NewTimeRange(from, to string) TimeRange {
 }
 
 // Formats Grafana 'From' time spec into absolute printable time
-func (tr TimeRange) FromFormatted() string {
+func (tr TimeRange) FromFormatted(loc *time.Location) string {
 	n := newNow()
-	return n.parseFrom(tr.From).Format(time.UnixDate)
+	return n.parseFrom(tr.From).In(loc).Format(time.UnixDate)
 }
 
 // Formats Grafana 'To' time spec into absolute printable time
-func (tr TimeRange) ToFormatted() string {
+func (tr TimeRange) ToFormatted(loc *time.Location) string {
 	n := newNow()
-	return n.parseTo(tr.To).Format(time.UnixDate)
+	return n.parseTo(tr.To).In(loc).Format(time.UnixDate)
 }
 
 // Make current time custom struct

provisioning/plugins/app.yaml

@@ -77,6 +77,19 @@ apps:
       #
       dashboardMode: default
 
+      # Time zone to use the report. This should be provided in IANA format.
+      # More details on IANA format can be obtained from https://www.iana.org/time-zones
+      # Eg America/New_York, Asia/Singapore, Australia/Melbourne, Europe/Berlin
+      #
+      # If empty or an invalid format is provided, the plugin defaults to using local
+      # location of the Grafana server.
+      #
+      # This setting can be overridden for a particular dashboard by using query parameter
+      # ?timeZone=America%2FNew_York during report generation process. Note that we 
+      # need to escape URL characters
+      #
+      timeZone: ''
+
       # Branding logo in the report.
       #
       # A base64 encoded of the logo can be set which will be included in the footer

src/README.md

@@ -165,6 +165,10 @@ All the configuration parameters can only be modified by `Admin` role.
   Whereas in full mode, rows are un collapsed and all the panels are included in the 
   report
 
+- `Time Zone`: The time zone that will be used in the report. It has to conform to the 
+  [IANA format](https://www.iana.org/time-zones). By default, local Grafana server's 
+  time zone will be used.
+
 Although these parameters can only be changed by users with `Admin` role for whole instance
 of Grafana, it is possible to override the global defaults for a particular report
 by using query parameters. It is enough to add query parameters to dashboard report URL
@@ -179,6 +183,11 @@ to set these values.
 - Query field for dashboard mode is `dashboardMode` and it takes either `default` or `full`
   as value. Example is `<grafanaAppUrl>/api/plugins/mahendrapaipuri-dashboardreporter-app/resources/report?dashUid=<UID of dashboard>&dashboardMode=full`
 
+- Query field for dashboard mode is `timeZone` and it takes a value in [IANA format](https://www.iana.org/time-zones)
+  as value. **Note** that it should be encoded to escape URL specific characters. For example
+  to use `America/New_York` query parameter should be 
+  `<grafanaAppUrl>/api/plugins/mahendrapaipuri-dashboardreporter-app/resources/report?dashUid=<UID of dashboard>&timeZone=America%2FNew_York`
+
 Besides there are two special query parameters available namely:
 
 - `includePanelID`: This can be used to include only panels with IDs set in the query in 

src/components/AppConfig/AppConfig.tsx

@@ -26,6 +26,7 @@ export type JsonData = {
   orientation?: string;
   layout?: string;
   dashboardMode?: string;
+  timeZone?: string;
   logo?: string;
   maxRenderWorkers?: number;
   persistData?: boolean;
@@ -44,6 +45,10 @@ type State = {
   dashboardMode: string;
   // If dashboardMode has changed
   dashboardModeChanged: boolean;
+  // time zone in IANA format
+  timeZone: string;
+  // If timeZone has changed
+  timeZoneChanged: boolean;
   // base64 encoded logo
   logo: string;
   // If logo has changed
@@ -76,6 +81,8 @@ export const AppConfig = ({ plugin }: Props) => {
     layoutChanged: false,
     dashboardMode: jsonData?.dashboardMode || "default",
     dashboardModeChanged: false,
+    timeZone: jsonData?.timeZone || "",
+    timeZoneChanged: false,
     logo: jsonData?.logo || "",
     logoChanged: false,
     maxRenderWorkers: jsonData?.maxRenderWorkers || 2,
@@ -129,6 +136,15 @@ export const AppConfig = ({ plugin }: Props) => {
     });
   };
 
+  const onChangetimeZone = (event: ChangeEvent<HTMLInputElement>) => {
+    setState({
+      ...state,
+      timeZone: event.target.value,
+      timeZoneChanged: true,
+    });
+  };
+
+
   const onChangeLogo = (event: ChangeEvent<HTMLInputElement>) => {
     setState({
       ...state,
@@ -190,6 +206,7 @@ export const AppConfig = ({ plugin }: Props) => {
                     orientation: state.orientation,
                     layout: state.layout,
                     dashboardMode: state.dashboardMode,
+                    timeZone: state.timeZone,
                     logo: state.logo,
                     persistData: state.persistData,
                   },
@@ -226,6 +243,7 @@ export const AppConfig = ({ plugin }: Props) => {
                     orientation: state.orientation,
                     layout: state.layout,
                     dashboardMode: state.dashboardMode,
+                    timeZone: state.timeZone,
                     logo: state.logo,
                     persistData: state.persistData,
                   },
@@ -310,6 +328,23 @@ export const AppConfig = ({ plugin }: Props) => {
           />
         </Field>
 
+        {/* Time zone */}
+        <Field
+          label="Time Zone"
+          description="Time Zone in IANA format. By default time zone of the server will be used."
+          data-testid={testIds.appConfig.tz}
+          className={s.marginTop}
+        >
+          <Input
+            type="string"
+            width={60}
+            id="tz"
+            label={`Time Zone`}
+            value={state.timeZone}
+            onChange={onChangetimeZone}
+          />
+        </Field>
+
         {/* Branding logo */}
         <Field
           label="Branding Logo"
@@ -373,6 +408,7 @@ export const AppConfig = ({ plugin }: Props) => {
                   orientation: state.orientation,
                   layout: state.layout,
                   dashboardMode: state.dashboardMode,
+                  timeZone: state.timeZone,
                   logo: state.logo,
                   persistData: state.persistData,
                 },
@@ -389,6 +425,7 @@ export const AppConfig = ({ plugin }: Props) => {
               !state.layoutChanged &&
                 !state.orientationChanged &&
                 !state.dashboardModeChanged &&
+                !state.timeZoneChanged &&
                 !state.logoChanged &&
                 !state.maxRenderWorkersChanged &&
                 !state.persistDataChanged &&