Trim contents of slack api urls from files

Signed-off-by: Sarah Brofeldt <sarah@qtr.dk>

notify/slack/slack.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"net/http"
+	"strings"
 
 	"github.com/go-kit/log"
 	"github.com/go-kit/log/level"
@@ -194,7 +195,7 @@ func (n *Notifier) Notify(ctx context.Context, as ...*types.Alert) (bool, error)
 		if err != nil {
 			return false, err
 		}
-		u = string(content)
+		u = strings.TrimSpace(string(content))
 	}
 
 	resp, err := notify.PostJSON(ctx, n.client, u, &buf)

notify/slack/slack_test.go

@@ -80,3 +80,25 @@ func TestGettingSlackURLFromFile(t *testing.T) {
 
 	test.AssertNotifyLeaksNoSecret(ctx, t, notifier, u.String())
 }
+
+func TestTrimmingSlackURLFromFile(t *testing.T) {
+	ctx, u, fn := test.GetContextWithCancelingURL()
+	defer fn()
+
+	f, err := ioutil.TempFile("", "slack_test_newline")
+	require.NoError(t, err, "creating temp file failed")
+	_, err = f.WriteString(u.String() + "\n\n")
+	require.NoError(t, err, "writing to temp file failed")
+
+	notifier, err := New(
+		&config.SlackConfig{
+			APIURLFile: f.Name(),
+			HTTPConfig: &commoncfg.HTTPClientConfig{},
+		},
+		test.CreateTmpl(t),
+		log.NewNopLogger(),
+	)
+	require.NoError(t, err)
+
+	test.AssertNotifyLeaksNoSecret(ctx, t, notifier, u.String())
+}