Add 'silenced' query param to /alerts endpoint

This adds the silenced query parameter to the /alerts API endpoint. In
addition it changes the default in the UI. Previously silenced alerts
were displayed by default. This PR hides silenced alerts by default.

api/api.go

@@ -256,8 +256,9 @@ func (api *API) listAlerts(w http.ResponseWriter, r *http.Request) {
 		err error
 		// Initialize result slice to prevent api returning `null` when there
 		// are no alerts present
-		res      = []*APIAlert{}
-		matchers = []*labels.Matcher{}
+		res          = []*APIAlert{}
+		matchers     = []*labels.Matcher{}
+		showSilenced = true
 	)
 
 	if filter := r.FormValue("filter"); filter != "" {
@@ -271,6 +272,21 @@ func (api *API) listAlerts(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
+	if silencedParam := r.FormValue("silenced"); silencedParam != "" {
+		if silencedParam == "false" {
+			showSilenced = false
+		} else if silencedParam != "true" {
+			respondError(w, apiError{
+				typ: errorBadData,
+				err: fmt.Errorf(
+					"parameter 'silenced' can either be 'true' or 'false', not '%v'",
+					silencedParam,
+				),
+			}, nil)
+			return
+		}
+	}
+
 	alerts := api.alerts.GetPending()
 	defer alerts.Close()
 
@@ -286,6 +302,10 @@ func (api *API) listAlerts(w http.ResponseWriter, r *http.Request) {
 
 		status := api.getAlertStatus(a.Fingerprint())
 
+		if !showSilenced && len(status.SilencedBy) != 0 {
+			continue
+		}
+
 		apiAlert := &APIAlert{
 			Alert:  &a.Alert,
 			Status: status,

ui/app/src/Utils/Filter.elm

@@ -48,7 +48,7 @@ generateQueryString { receiver, showSilenced, text, group } =
     let
         -- TODO: Re-add receiver once it is parsed on the server side.
         parts =
-            [ ( "silenced", Maybe.map (toString >> String.toLower) showSilenced )
+            [ ( "silenced", Maybe.withDefault False showSilenced |> toString |> String.toLower |> Just )
             , ( "filter", emptyToNothing text )
             , ( "group", group )
             ]

ui/app/src/Views/AlertList/Filter.elm

@@ -1,4 +1,4 @@
-module Views.AlertList.Filter exposing (silenced, matchers)
+module Views.AlertList.Filter exposing (matchers)
 
 import Alerts.Types exposing (Alert, AlertGroup, Block)
 import Utils.Types exposing (Matchers)
@@ -15,30 +15,6 @@ matchers matchers alerts =
             alerts
 
 
-silenced : Maybe Bool -> List Alert -> List Alert
-silenced maybeShowSilenced alerts =
-    let
-        showSilenced =
-            Maybe.withDefault False maybeShowSilenced
-    in
-        if showSilenced then
-            alerts
-        else
-            List.filter (.silenced >> not) alerts
-
-
-filterAlertGroup : (String -> Bool) -> AlertGroup -> Maybe AlertGroup
-filterAlertGroup fn alertGroup =
-    let
-        blocks =
-            List.filter (\b -> fn b.routeOpts.receiver) alertGroup.blocks
-    in
-        if not <| List.isEmpty blocks then
-            Just { alertGroup | blocks = blocks }
-        else
-            Nothing
-
-
 alertsFromBlock : (Alert -> Bool) -> Block -> Maybe Block
 alertsFromBlock fn block =
     let
@@ -95,28 +71,6 @@ filterAlertGroupLabels matchers alertGroup =
             Nothing
 
 
-matchersToLabels : Utils.Types.Matchers -> Utils.Types.Labels
-matchersToLabels matchers =
-    List.map (\m -> ( m.name, m.value )) matchers
-
-
-alertGroupsSilenced : AlertGroup -> Maybe AlertGroup
-alertGroupsSilenced alertGroup =
-    let
-        blocks =
-            List.filterMap filterSilencedAlerts alertGroup.blocks
-    in
-        if not <| List.isEmpty blocks then
-            Just { alertGroup | blocks = blocks }
-        else
-            Nothing
-
-
-filterSilencedAlerts : Block -> Maybe Block
-filterSilencedAlerts block =
-    alertsFromBlock (.silenced >> not) block
-
-
 by : (a -> Maybe a) -> List a -> List a
 by fn groups =
     List.filterMap fn groups

ui/app/src/Views/AlertList/Views.elm

@@ -11,7 +11,7 @@ import Utils.Types exposing (ApiResponse(Initial, Success, Loading, Failure), La
 import Utils.Views exposing (buttonLink, listButton)
 import Utils.List
 import Views.AlertList.AlertView as AlertView
-import Views.AlertList.Filter exposing (silenced, matchers)
+import Views.AlertList.Filter exposing (matchers)
 import Views.GroupBar.Types as GroupBar
 import Utils.Views exposing (buttonLink, listButton)
 import Views.AlertList.Types exposing (AlertListMsg(MsgForFilterBar, MsgForGroupBar, SetTab, ToggleSilenced), Model, Tab(..))
@@ -94,7 +94,6 @@ alertGroups filter groupBar alerts =
     let
         grouped =
             alerts
-                |> silenced filter.showSilenced
                 |> Utils.List.groupBy
                     (.labels >> List.filter (\( key, _ ) -> List.member key groupBar.fields))
     in

ui/app/src/Views/Silence/Updates.elm

@@ -34,7 +34,7 @@ update msg model =
                 | silence = Success { silence | silencedAlerts = Loading }
               }
             , Alerts.Api.fetchAlerts
-                ({ nullFilter | text = Just (Utils.List.mjoin silence.matchers) })
+                ({ nullFilter | text = Just (Utils.List.mjoin silence.matchers), showSilenced = Just True })
                 |> Cmd.map (AlertGroupsPreview >> MsgForSilence)
             )
 

ui/app/tests/Filter.elm

@@ -38,17 +38,21 @@ parseMatcher =
 generateQueryString : Test
 generateQueryString =
     describe "generateQueryString"
-        [ test "should not render keys with Nothing value" <|
+        [ test "should default silenced parameter to false if showSilenced is Nothing" <| 
             \() ->
-                Expect.equal ""
+                Expect.equal "?silenced=false"
+                    (Utils.Filter.generateQueryString { receiver = Nothing, group = Nothing, text = Nothing, showSilenced = Nothing })
+        , test "should not render keys with Nothing value except the silenced parameter" <|
+            \() ->
+                Expect.equal "?silenced=false"
                     (Utils.Filter.generateQueryString { receiver = Nothing, group = Nothing, text = Nothing, showSilenced = Nothing })
         , test "should not render filter key with empty value" <|
             \() ->
-                Expect.equal ""
+                Expect.equal "?silenced=false"
                     (Utils.Filter.generateQueryString { receiver = Nothing, group = Nothing, text = Just "", showSilenced = Nothing })
         , test "should render filter key with values" <|
             \() ->
-                Expect.equal "?filter=%7Bfoo%3D%22bar%22%2C%20baz%3D~%22quux.*%22%7D"
+                Expect.equal "?silenced=false&filter=%7Bfoo%3D%22bar%22%2C%20baz%3D~%22quux.*%22%7D"
                     (Utils.Filter.generateQueryString { receiver = Nothing, group = Nothing, text = Just "{foo=\"bar\", baz=~\"quux.*\"}", showSilenced = Nothing })
         , test "should render silenced key with bool" <|
             \() ->