Allow filtering silences by createdBy author

This commit adds a `--created-by` argument to the `amtool silence
query` command so that silences can be filtered by the author they
were created with in `amtool silence add --author=<name>`.

Signed-off-by: nre <nre@ableton.com>

cli/silence_query.go

@@ -28,10 +28,11 @@ import (
 )
 
 type silenceQueryCmd struct {
-	expired  bool
-	quiet    bool
-	matchers []string
-	within   time.Duration
+	expired   bool
+	quiet     bool
+	createdBy string
+	matchers  []string
+	within    time.Duration
 }
 
 const querySilenceHelp = `Query Alertmanager silences.
@@ -84,6 +85,7 @@ func configureSilenceQueryCmd(cc *kingpin.CmdClause) {
 
 	queryCmd.Flag("expired", "Show expired silences instead of active").BoolVar(&c.expired)
 	queryCmd.Flag("quiet", "Only show silence ids").Short('q').BoolVar(&c.quiet)
+	queryCmd.Flag("created-by", "Only show silences created by this author").StringVar(&c.createdBy)
 	queryCmd.Arg("matcher-groups", "Query filter").StringsVar(&c.matchers)
 	queryCmd.Flag("within", "Show silences that will expire or have expired within a duration").DurationVar(&c.within)
 	queryCmd.Action(execWithTimeout(c.query))
@@ -127,6 +129,10 @@ func (c *silenceQueryCmd) query(ctx context.Context, _ *kingpin.ParseContext) er
 		if c.expired && int64(c.within) > 0 && time.Time(*silence.EndsAt).Before(time.Now().UTC().Add(-c.within)) {
 			continue
 		}
+		// skip silences if the author doesn't match
+		if c.createdBy != "" && *silence.CreatedBy != c.createdBy {
+			continue
+		}
 
 		displaySilences = append(displaySilences, *silence)
 	}