config: delegate Sigv4 validation to the inner type

This change also adds unit tests for SNS configuration.

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

config/notifiers.go

@@ -623,8 +623,5 @@ func (c *SNSConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	if (c.TargetARN == "") != (c.TopicARN == "") != (c.PhoneNumber == "") {
 		return fmt.Errorf("must provide either a Target ARN, Topic ARN, or Phone Number for SNS config")
 	}
-	if (c.Sigv4.AccessKey == "") != (c.Sigv4.SecretKey == "") {
-		return fmt.Errorf("must provide a AWS SigV4 Access key and Secret Key if credentials are specified in the SNS config")
-	}
 	return nil
 }

config/notifiers_test.go

@@ -590,6 +590,92 @@ func TestOpsgenieTypeMatcher(t *testing.T) {
 	}
 }
 
+func TestSNS(t *testing.T) {
+	for _, tc := range []struct {
+		in  string
+		err bool
+	}{
+		{
+			// Valid configuration without sigv4.
+			in:  `target_arn: target`,
+			err: false,
+		},
+		{
+			// Valid configuration without sigv4.
+			in:  `topic_arn: topic`,
+			err: false,
+		},
+		{
+			// Valid configuration with sigv4.
+			in: `phone_number: phone
+sigv4:
+    access_key: abc
+    secret_key: abc
+`,
+			err: false,
+		},
+		{
+			// at most one of 'target_arn', 'topic_arn' or 'phone_number' must be provided without sigv4.
+			in: `topic_arn: topic
+target_arn: target
+`,
+			err: true,
+		},
+		{
+			// at most one of 'target_arn', 'topic_arn' or 'phone_number' must be provided without sigv4.
+			in: `topic_arn: topic
+phone_number: phone
+`,
+			err: true,
+		},
+		{
+			// one of 'target_arn', 'topic_arn' or 'phone_number' must be provided without sigv4.
+			in:  "{}",
+			err: true,
+		},
+		{
+			// one of 'target_arn', 'topic_arn' or 'phone_number' must be provided with sigv4.
+			in: `sigv4:
+    access_key: abc
+    secret_key: abc
+`,
+			err: true,
+		},
+		{
+			// 'secret_key' must be provided with 'access_key'.
+			in: `topic_arn: topic
+sigv4:
+    access_key: abc
+`,
+			err: true,
+		},
+		{
+			// 'access_key' must be provided with 'secret_key'.
+			in: `topic_arn: topic
+sigv4:
+    secret_key: abc
+`,
+			err: true,
+		},
+	} {
+		t.Run("", func(t *testing.T) {
+			var cfg SNSConfig
+			err := yaml.UnmarshalStrict([]byte(tc.in), &cfg)
+			if err != nil {
+				if !tc.err {
+					t.Errorf("expecting no error, got %q", err)
+				}
+				return
+			}
+
+			if tc.err {
+				t.Logf("%#v", cfg)
+				t.Error("expecting error, got none")
+			}
+		})
+	}
+}
+
 func TestWeChatTypeMatcher(t *testing.T) {
 	good := []string{"text", "markdown"}
 	for _, g := range good {