config: fix regression with Pager Duty (#1455)

The YAML strict mode doesn't allow mapping keys that are duplicates. If
someone wants to override one of the default keys in the Details hash,
the unmarshal function returns an error because the key is already
defined by DefaultPagerdutyConfig.

Signed-off-by: Simon Pasquier <spasquie@redhat.com>

config/notifiers.go

@@ -42,6 +42,14 @@ var (
 	// DefaultEmailSubject defines the default Subject header of an Email.
 	DefaultEmailSubject = `{{ template "email.default.subject" . }}`
 
+	// DefaultPagerdutyDetails defines the default values for PagerDuty details.
+	DefaultPagerdutyDetails = map[string]string{
+		"firing":       `{{ template "pagerduty.default.instances" .Alerts.Firing }}`,
+		"resolved":     `{{ template "pagerduty.default.instances" .Alerts.Resolved }}`,
+		"num_firing":   `{{ .Alerts.Firing | len }}`,
+		"num_resolved": `{{ .Alerts.Resolved | len }}`,
+	}
+
 	// DefaultPagerdutyConfig defines default values for PagerDuty configurations.
 	DefaultPagerdutyConfig = PagerdutyConfig{
 		NotifierConfig: NotifierConfig{
@@ -50,12 +58,6 @@ var (
 		Description: `{{ template "pagerduty.default.description" .}}`,
 		Client:      `{{ template "pagerduty.default.client" . }}`,
 		ClientURL:   `{{ template "pagerduty.default.clientURL" . }}`,
-		Details: map[string]string{
-			"firing":       `{{ template "pagerduty.default.instances" .Alerts.Firing }}`,
-			"resolved":     `{{ template "pagerduty.default.instances" .Alerts.Resolved }}`,
-			"num_firing":   `{{ .Alerts.Firing | len }}`,
-			"num_resolved": `{{ .Alerts.Resolved | len }}`,
-		},
 	}
 
 	// DefaultSlackConfig defines default values for Slack configurations.
@@ -217,6 +219,14 @@ func (c *PagerdutyConfig) UnmarshalYAML(unmarshal func(interface{}) error) error
 	if c.RoutingKey == "" && c.ServiceKey == "" {
 		return fmt.Errorf("missing service or routing key in PagerDuty config")
 	}
+	if c.Details == nil {
+		c.Details = make(map[string]string)
+	}
+	for k, v := range DefaultPagerdutyDetails {
+		if _, ok := c.Details[k]; !ok {
+			c.Details[k] = v
+		}
+	}
 	return nil
 }
 

config/notifiers_test.go

@@ -91,6 +91,63 @@ service_key: ''
 	}
 }
 
+func TestPagerdutyDetails(t *testing.T) {
+
+	var tests = []struct {
+		in      string
+		checkFn func(map[string]string)
+	}{
+		{
+			in: `
+routing_key: 'xyz'
+`,
+			checkFn: func(d map[string]string) {
+				if len(d) != 4 {
+					t.Errorf("expected 4 items, got: %d", len(d))
+				}
+			},
+		},
+		{
+			in: `
+routing_key: 'xyz'
+details:
+  key1: val1
+`,
+			checkFn: func(d map[string]string) {
+				if len(d) != 5 {
+					t.Errorf("expected 5 items, got: %d", len(d))
+				}
+			},
+		},
+		{
+			in: `
+routing_key: 'xyz'
+details:
+  key1: val1
+  key2: val2
+  firing: firing
+`,
+			checkFn: func(d map[string]string) {
+				if len(d) != 6 {
+					t.Errorf("expected 6 items, got: %d", len(d))
+				}
+			},
+		},
+	}
+	for _, tc := range tests {
+		var cfg PagerdutyConfig
+		err := yaml.UnmarshalStrict([]byte(tc.in), &cfg)
+
+		if err != nil {
+			t.Errorf("expected no error, got:%v", err)
+		}
+
+		if tc.checkFn != nil {
+			tc.checkFn(cfg.Details)
+		}
+	}
+}
+
 func TestHipchatRoomIDIsPresent(t *testing.T) {
 	in := `
 room_id: ''