Amtool: Implement filter by receiver fixes:#937 (#1402)

* Amtool: Implement filter by receiver

* Adds receiver flag to amtool alert query
* Adds receiver argument to alert http client
* Updates http client tests for added argument

Also works: scpecifying `receiver: "receiver-123"` in config file
automaticly filters all alerts shown

* Include receiver in amtool config docs

Now that I've implemented the receiver in amtool I should add the new
feature to the documentation.

*  #937 Add mention of supporting regex syntax to receiver flag

README.md

@@ -281,6 +281,9 @@ comment_required: true
 
 # Set a default output format. (unset defaults to simple)
 output: extended
+
+# Set a default receiver
+receiver: team-X-pager
 ```
 
 ## High Availability

cli/alert.go

@@ -29,8 +29,8 @@ import (
 
 type alertQueryCmd struct {
 	inhibited, silenced, active, unprocessed bool
-
-	matcherGroups []string
+	receiver                                 string
+	matcherGroups                            []string
 }
 
 const alertHelp = `View and search through current alerts.
@@ -71,6 +71,7 @@ func configureAlertCmd(app *kingpin.Application) {
 	queryCmd.Flag("silenced", "Show silenced alerts").Short('s').BoolVar(&a.silenced)
 	queryCmd.Flag("active", "Show active alerts").Short('a').BoolVar(&a.active)
 	queryCmd.Flag("unprocessed", "Show unprocessed alerts").Short('u').BoolVar(&a.unprocessed)
+	queryCmd.Flag("receiver", "Show alerts matching receiver (Supports regex syntax)").Short('r').StringVar(&a.receiver)
 	queryCmd.Arg("matcher-groups", "Query filter").StringsVar(&a.matcherGroups)
 	queryCmd.Action(a.queryAlerts)
 }
@@ -100,7 +101,7 @@ func (a *alertQueryCmd) queryAlerts(ctx *kingpin.ParseContext) error {
 	if !a.silenced && !a.inhibited && !a.active && !a.unprocessed {
 		a.active = true
 	}
-	fetchedAlerts, err := alertAPI.List(context.Background(), filterString, a.silenced, a.inhibited, a.active, a.unprocessed)
+	fetchedAlerts, err := alertAPI.List(context.Background(), filterString, a.receiver, a.silenced, a.inhibited, a.active, a.unprocessed)
 	if err != nil {
 		return err
 	}

client/client.go

@@ -154,7 +154,7 @@ func (h *httpStatusAPI) Get(ctx context.Context) (*ServerStatus, error) {
 // AlertAPI provides bindings for the Alertmanager's alert API.
 type AlertAPI interface {
 	// List returns all the active alerts.
-	List(ctx context.Context, filter string, silenced, inhibited, active, unprocessed bool) ([]*ExtendedAlert, error)
+	List(ctx context.Context, filter, receiver string, silenced, inhibited, active, unprocessed bool) ([]*ExtendedAlert, error)
 	// Push sends a list of alerts to the Alertmanager.
 	Push(ctx context.Context, alerts ...Alert) error
 }
@@ -194,7 +194,7 @@ type httpAlertAPI struct {
 	client api.Client
 }
 
-func (h *httpAlertAPI) List(ctx context.Context, filter string, silenced, inhibited, active, unprocessed bool) ([]*ExtendedAlert, error) {
+func (h *httpAlertAPI) List(ctx context.Context, filter, receiver string, silenced, inhibited, active, unprocessed bool) ([]*ExtendedAlert, error) {
 	u := h.client.URL(epAlerts, nil)
 	params := url.Values{}
 	if filter != "" {
@@ -204,6 +204,7 @@ func (h *httpAlertAPI) List(ctx context.Context, filter string, silenced, inhibi
 	params.Add("inhibited", fmt.Sprintf("%t", inhibited))
 	params.Add("active", fmt.Sprintf("%t", active))
 	params.Add("unprocessed", fmt.Sprintf("%t", unprocessed))
+	params.Add("receiver", receiver)
 	u.RawQuery = params.Encode()
 
 	req, _ := http.NewRequest(http.MethodGet, u.String(), nil)

client/client_test.go

@@ -118,7 +118,7 @@ func TestAPI(t *testing.T) {
 	}
 	doAlertList := func() (interface{}, error) {
 		api := httpAlertAPI{client: client}
-		return api.List(context.Background(), "", false, false, false, false)
+		return api.List(context.Background(), "", "", false, false, false, false)
 	}
 	doAlertPush := func() (interface{}, error) {
 		api := httpAlertAPI{client: client}