migrate: add back unused functionality in libsonnet

I think we could manage to get prometheus server cpu/metrics etc
presented with the same helper functions if we retain these things.

dashboards/jupyterhub.jsonnet

@@ -16,11 +16,6 @@ local jupyterhub = import 'jupyterhub.libsonnet';
 local currentActiveUsers =
   common.tsOptions
   + ts.new('Currently Active Users')
-  + ts.panelOptions.withDescription(
-    |||
-      TODO
-    |||
-  )
   + ts.standardOptions.withDecimals(0)
   + ts.fieldConfig.defaults.custom.stacking.withMode('normal')
   + ts.queryOptions.withTargets([
@@ -278,10 +273,12 @@ local hubResponseCodes =
 local allComponentsMemory = jupyterhub.memoryPanel(
   'All JupyterHub Components',
   component='singleuser-server',
+  multi=true,
 );
 local allComponentsCPU = jupyterhub.cpuPanel(
   'All JupyterHub Components',
   component='singleuser-server',
+  multi=true,
 );
 
 local hubDBUsage =

dashboards/jupyterhub.libsonnet

@@ -72,14 +72,16 @@ local prometheus = grafonnet.query.prometheus;
    * @param title The title of the timeseries panel.
    * @param metric The metric to be observed.
    * @param component The component to be measured (or excluded).
+   *     Optional if `multi=true`, in which case it is an exclusion, otherwise required.
+   * @param multi (default `false`) If true, do a multi-component chart instead of single-component.
+   *     The chart will have a legend table for each component.
    */
-  componentResourcePanel(title, metric, component)::
+  componentResourcePanel(title, metric, component, multi, namespace)::
     ts.new(title)
     // show legend as a table with current, avg, max values
     //legend_hideZero=true,
     // legend_values is required for any of the above to work
     //legend_values=true,
-    //min=0,
     + ts.options.legend.withDisplayMode('table')
     + ts.options.legend.withCalcs(['min', 'mean', 'max'])
     + ts.queryOptions.withTargets([
@@ -94,11 +96,16 @@ local prometheus = grafonnet.query.prometheus;
           |||,
           [
             metric,
-            self.onComponentLabel(component, cmp='!=', group_left='container, label_component'),
+            self.onComponentLabel(
+              component,
+              cmp=if multi then '!=' else '=',
+              group_left='container, label_component',
+              namespace=namespace,
+            ),
           ],
         )
       )
-      + prometheus.withLegendFormat('{{ label_component }}'),
+      + prometheus.withLegendFormat(if multi then '{{ label_component }}' else title),
     ]),
 
   /**
@@ -108,11 +115,16 @@ local prometheus = grafonnet.query.prometheus;
    *
    * @param name The name of the resource. Used to create the title.
    * @param component The component to be measured (or excluded).
+   *     Optional if `multi=true`, in which case it is an exclusion, otherwise required.
+   * @param multi (default `false`) If true, do a multi-component chart instead of single-component.
+   *     The chart will have a legend table for each component.
    */
-  memoryPanel(name, component)::
+  memoryPanel(name, component, multi=false, namespace='$hub')::
     self.componentResourcePanel(
       std.format('%s Memory (Working Set)', [name]),
       component=component,
+      multi=multi,
+      namespace=namespace,
       metric=|||
         # exclude name="" because the same container can be reported
         # with both no name and `name=k8s_...`,
@@ -130,11 +142,16 @@ local prometheus = grafonnet.query.prometheus;
    *
    * @param name The name of the resource. Used to create the title.
    * @param component The component to be measured (or excluded).
+   *     Optional if `multi=true`, in which case it is an exclusion, otherwise required.
+   * @param multi (default `false`) If true, do a multi-component chart instead of single-component.
+   *     The chart will have a legend table for each component.
    */
-  cpuPanel(name, component)::
+  cpuPanel(name, component, multi=false, namespace='$hub')::
     self.componentResourcePanel(
       std.format('%s CPU', [name]),
       component=component,
+      multi=multi,
+      namespace=namespace,
       metric=|||
         # exclude name="" because the same container can be reported
         # with both no name and `name=k8s_...`,

dashboards/support.jsonnet

@@ -112,6 +112,21 @@ local nfsServerReadLatency =
   ]);
 
 // Support Metrics
+
+// FIXME: Can we transition to using the function to generate the prometheus memory and cpu panels?
+//
+//        Currently held back by hardcoded label selection on the label
+//        "component" and selection on a single label instead of optionally
+//        multiple.
+//
+//local prometheusMemory = jupyterhub.memoryPanel(
+//  'Prometheus Memory (Working Set)',
+//  // app.kubernetes.io/component: server
+//  // app.kubernetes.io/name: prometheus
+//  component='singleuser-server',
+//  multi=false,
+//);
+
 local prometheusMemory =
   common.tsOptions
   + ts.new('Prometheus Memory (Working Set)')