Add defaultSignalSource param to set default signal source. (#1458)

Author: v-zhuravlev

common-lib/CHANGELOG.md

@@ -1,3 +1,6 @@
+# 0.4.0
+- [Signal] Add defaultSignalSource param to set default signal source.
+
 # 0.3.5
 - [Variables] Add queriesSelectorGroupOnly, queriesSelectorFilterOnly attributes
 - [Signal] Add %(queriesSelectorGroupOnly)s, %(queriesSequeriesSelectorFilterOnly)s templates

common-lib/common/signal/README.md

@@ -84,6 +84,7 @@ Init level:
 |varAdHocEnabled| Attach ad hoc labels to variables generated. |`true`,`false`|`false`|`false`|
 |varAdHocLabels| Limit ad hoc to the specific labels |*|`["environment"]`|`[]`|
 |enableLokiLogs| Add additional loki datasource to variables generation |`true`,`false`|`true`|`false`|
+|defaultSignalSource| Set default signal source (see below) | * | `prometheus` |
 
 Signal's level:
 
@@ -124,7 +125,7 @@ The following is supported in expressions and legends:
 
 ## Making signals optional
 
-When defining signals from multiple sources, you can make some of the signals optional. In this case, rendering will not throw a validation error that signal is missing for the specific source, while internal 'stub' type will be used and empty panel will be rendered instead.
+When defining signals from multiple sources, you can make some of the signals optional. In this case, rendering will not throw a validation error that signal is missing for the specific source (and also in source defined as `defaultSignalSource`), while internal 'stub' type will be used and empty panel will be rendered instead.
 
 ## Example 1: From JSON
 

common-lib/common/signal/signal.libsonnet

@@ -87,6 +87,7 @@ local xtd = import 'github.com/jsonnet-libs/xtd/main.libsonnet';
         else  //array
           type
       );
+    local defaultSignalSource = std.get(signalsJson, 'defaultSignalSource', 'prometheus');
 
     self.init(
       datasource=std.get(signalsJson, 'datasource', if std.get(signalsJson, 'enableLokiLogs', false) then 'prometheus_datasource' else 'datasource'),
@@ -96,7 +97,7 @@ local xtd = import 'github.com/jsonnet-libs/xtd/main.libsonnet';
       instanceLabels=signalsJson.instanceLabels,
       interval=std.get(signalsJson, 'interval', '$__rate_interval'),
       alertsInterval=std.get(signalsJson, 'alertsInterval', '5m'),
-      varMetric=self.getVarMetric(signalsJson, type),
+      varMetric=self.getVarMetric(signalsJson, type, defaultSignalSource),
       aggLevel=std.get(signalsJson, 'aggLevel', 'none'),
       aggFunction=std.get(signalsJson, 'aggFunction', 'avg'),
       aggKeepLabels=std.get(signalsJson, 'aggKeepLabels', []),
@@ -118,9 +119,18 @@ local xtd = import 'github.com/jsonnet-libs/xtd/main.libsonnet';
             if
               std.get(signalsJson.signals[s], 'optional', false) == false
               &&
-              !std.objectHas(signalsJson.signals[s].sources, sourceName)
+              (
+                !std.objectHas(signalsJson.signals[s].sources, sourceName)
+                &&
+                !std.objectHas(signalsJson.signals[s].sources, defaultSignalSource)
+              )
             then error 'must provide source for signal %s of type=%s' % [s, sourceName]
-            else sourceName
+            else (
+              if
+                std.objectHas(signalsJson.signals[s].sources, sourceName) then sourceName
+              else if
+                std.objectHas(signalsJson.signals[s].sources, defaultSignalSource) then defaultSignalSource
+            )
             for sourceName in typeArr
           ];
           local sourceMaps =
@@ -348,14 +358,14 @@ local xtd = import 'github.com/jsonnet-libs/xtd/main.libsonnet';
         ),
   },
 
-  getVarMetric(signalsJson, type):
+  getVarMetric(signalsJson, type, defaultSignalSource):
     if std.objectHas(signalsJson, 'discoveryMetric')
     then
       if std.type(type) == 'array' then
         std.prune(
-          [std.get(signalsJson.discoveryMetric, t, null) for t in type]
+          [std.get(signalsJson.discoveryMetric, t, std.get(signalsJson.discoveryMetric, defaultSignalSource, null)) for t in type]
         )
       else
-        std.get(signalsJson.discoveryMetric, type, 'up')
+        std.get(signalsJson.discoveryMetric, type, std.get(signalsJson.discoveryMetric, defaultSignalSource, 'up'))
     else 'up',
 }