Implement quorum reads and merging for /v1/silences and /v1/silence/id

pkg/alertmanager/distributor.go

@@ -94,6 +94,12 @@ func (d *Distributor) isQuorumReadPath(p string) (bool, merger.Merger) {
 	if strings.HasSuffix(p, "/v2/alerts/groups") {
 		return true, merger.V2AlertGroups{}
 	}
+	if strings.HasSuffix(p, "/v1/silences") {
+		return true, merger.V1Silences{}
+	}
+	if strings.HasSuffix(path.Dir(p), "/v1/silence") {
+		return true, merger.V1SilenceID{}
+	}
 	if strings.HasSuffix(p, "/v2/silences") {
 		return true, merger.V2Silences{}
 	}
@@ -104,9 +110,7 @@ func (d *Distributor) isQuorumReadPath(p string) (bool, merger.Merger) {
 }
 
 func (d *Distributor) isUnaryReadPath(p string) bool {
-	return strings.HasSuffix(p, "/v1/silences") ||
-		strings.HasSuffix(path.Dir(p), "/v1/silence") ||
-		strings.HasSuffix(p, "/status") ||
+	return strings.HasSuffix(p, "/status") ||
 		strings.HasSuffix(p, "/receivers")
 }
 

pkg/alertmanager/distributor_test.go

@@ -119,14 +119,15 @@ func TestDistributor_DistributeRequest(t *testing.T) {
 			headersNotPreserved: true,
 			route:               "/alerts/groups",
 		}, {
-			name:               "Read /v1/silences is sent to only 1 AM",
+			name:               "Read /v1/silences is sent to 3 AMs",
 			numAM:              5,
 			numHappyAM:         5,
 			replicationFactor:  3,
 			isRead:             true,
 			expStatusCode:      http.StatusOK,
-			expectedTotalCalls: 1,
+			expectedTotalCalls: 3,
 			route:              "/v1/silences",
+			responseBody:       []byte(`{"status":"success","data":[]}`),
 		}, {
 			name:               "Read /v2/silences is sent to 3 AMs",
 			numAM:              5,
@@ -146,14 +147,15 @@ func TestDistributor_DistributeRequest(t *testing.T) {
 			expectedTotalCalls: 1,
 			route:              "/silences",
 		}, {
-			name:               "Read /v1/silence/id is sent to only 1 AM",
+			name:               "Read /v1/silence/id is sent to 3 AMs",
 			numAM:              5,
 			numHappyAM:         5,
 			replicationFactor:  3,
 			isRead:             true,
 			expStatusCode:      http.StatusOK,
-			expectedTotalCalls: 1,
+			expectedTotalCalls: 3,
 			route:              "/v1/silence/id",
+			responseBody:       []byte(`{"status":"success","data":{"id":"aaa","updatedAt":"2020-01-01T00:00:00Z"}}`),
 		}, {
 			name:               "Read /v2/silence/id is sent to 3 AMs",
 			numAM:              5,
@@ -174,15 +176,6 @@ func TestDistributor_DistributeRequest(t *testing.T) {
 			expectedTotalCalls:  0,
 			headersNotPreserved: true,
 			route:               "/silence/id",
-		}, {
-			name:               "Read /silence/id is sent to only 1 AM",
-			numAM:              5,
-			numHappyAM:         5,
-			replicationFactor:  3,
-			isRead:             true,
-			expStatusCode:      http.StatusOK,
-			expectedTotalCalls: 1,
-			route:              "/silence/id",
 		}, {
 			name:               "Delete /silence/id is sent to only 1 AM",
 			numAM:              5,

pkg/alertmanager/merger/v1_silence_id.go

@@ -0,0 +1,51 @@
+package merger
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+
+	v2_models "github.com/prometheus/alertmanager/api/v2/models"
+)
+
+// V1Silences implements the Merger interface for GET /v1/silences. This re-uses the logic for
+// merging /v2/silences, with additional handling for the enclosing status/data fields. Unlike for
+// alerts, the API definitions for silences are almost identical between v1 and v2. The differences
+// are that the fields in the JSON output are ordered differently, and the timestamps have more
+// precision in v1, but these differences should not be problematic to clients.
+type V1SilenceID struct{}
+
+func (V1SilenceID) MergeResponses(in [][]byte) ([]byte, error) {
+	type bodyType struct {
+		Status string                     `json:"status"`
+		Data   *v2_models.GettableSilence `json:"data"`
+	}
+
+	silences := make(v2_models.GettableSilences, 0)
+	for _, body := range in {
+		parsed := bodyType{}
+		if err := json.Unmarshal(body, &parsed); err != nil {
+			return nil, err
+		}
+		if parsed.Status != statusSuccess {
+			return nil, fmt.Errorf("unable to merge response of status: %s", parsed.Status)
+		}
+		silences = append(silences, parsed.Data)
+	}
+
+	merged, err := mergeV2Silences(silences)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(merged) != 1 {
+		return nil, errors.New("unexpected mismatched silence ids")
+	}
+
+	body := bodyType{
+		Status: statusSuccess,
+		Data:   merged[0],
+	}
+
+	return json.Marshal(body)
+}

pkg/alertmanager/merger/v1_silence_id_test.go

@@ -0,0 +1,110 @@
+package merger
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestV1SilenceID_ReturnsNewestSilence(t *testing.T) {
+	in := [][]byte{
+		[]byte(`{"status":"success","data":{` +
+			`"id":"77b580dd-1d9c-4b7e-9bba-13ac173cb4e5",` +
+			`"matchers":[` +
+			`{` +
+			`"name":"instance",` +
+			`"value":"prometheus-one",` +
+			`"isRegex":false,` +
+			`"isEqual":true` +
+			`}` +
+			`],` +
+			`"startsAt":"2021-04-28T17:31:01.725956017Z",` +
+			`"endsAt":"2021-04-28T20:31:01.722829007+02:00",` +
+			`"updatedAt":"2021-04-28T17:32:01.725956017Z",` +
+			`"createdBy":"",` +
+			`"comment":"The newer silence",` +
+			`"status":{"state":"active"}` +
+			`}}`),
+		[]byte(`{"status":"success","data":{` +
+			`"id":"77b580dd-1d9c-4b7e-9bba-13ac173cb4e5",` +
+			`"matchers":[` +
+			`{` +
+			`"name":"instance",` +
+			`"value":"prometheus-one",` +
+			`"isRegex":false,` +
+			`"isEqual":true` +
+			`}` +
+			`],` +
+			`"startsAt":"2021-04-28T17:31:01.725956017Z",` +
+			`"endsAt":"2021-04-28T20:31:01.722829007+02:00",` +
+			`"updatedAt":"2021-04-28T17:31:01.725956017Z",` +
+			`"createdBy":"",` +
+			`"comment":"Silence Comment #1",` +
+			`"status":{"state":"active"}` +
+			`}}`),
+	}
+
+	expected := []byte(`{"status":"success","data":{` +
+		`"id":"77b580dd-1d9c-4b7e-9bba-13ac173cb4e5",` +
+		`"status":{"state":"active"},` +
+		`"updatedAt":"2021-04-28T17:32:01.725Z",` +
+		`"comment":"The newer silence",` +
+		`"createdBy":"",` +
+		`"endsAt":"2021-04-28T20:31:01.722+02:00",` +
+		`"matchers":[` +
+		`{` +
+		`"isEqual":true,` +
+		`"isRegex":false,` +
+		`"name":"instance",` +
+		`"value":"prometheus-one"` +
+		`}` +
+		`],` +
+		`"startsAt":"2021-04-28T17:31:01.725Z"` +
+		`}}`)
+
+	out, err := V1SilenceID{}.MergeResponses(in)
+	require.NoError(t, err)
+	require.Equal(t, string(expected), string(out))
+}
+
+func TestV1SilenceID_InvalidDifferentIDs(t *testing.T) {
+	in := [][]byte{
+		[]byte(`{"status":"success","data":{` +
+			`"id":"77b580dd-1d9c-4b7e-9bba-13ac173cb4e5",` +
+			`"matchers":[` +
+			`{` +
+			`"name":"instance",` +
+			`"value":"prometheus-one",` +
+			`"isRegex":false,` +
+			`"isEqual":true` +
+			`}` +
+			`],` +
+			`"startsAt":"2021-04-28T17:31:01.725956017Z",` +
+			`"endsAt":"2021-04-28T20:31:01.722829007+02:00",` +
+			`"updatedAt":"2021-04-28T17:32:01.725956017Z",` +
+			`"createdBy":"",` +
+			`"comment":"Silence Comment #1",` +
+			`"status":{"state":"active"}` +
+			`}}`),
+		[]byte(`{"status":"success","data":{` +
+			`"id":"261248d1-4ff7-4cf1-9957-850c65f4e48b",` +
+			`"matchers":[` +
+			`{` +
+			`"name":"instance",` +
+			`"value":"prometheus-one",` +
+			`"isRegex":false,` +
+			`"isEqual":true` +
+			`}` +
+			`],` +
+			`"startsAt":"2021-04-28T17:31:01.725956017Z",` +
+			`"endsAt":"2021-04-28T20:31:01.722829007+02:00",` +
+			`"updatedAt":"2021-04-28T17:31:01.725956017Z",` +
+			`"createdBy":"",` +
+			`"comment":"Silence Comment #2",` +
+			`"status":{"state":"active"}` +
+			`}}`),
+	}
+
+	_, err := V1SilenceID{}.MergeResponses(in)
+	require.Error(t, err)
+}

pkg/alertmanager/merger/v1_silences.go

@@ -0,0 +1,45 @@
+package merger
+
+import (
+	"encoding/json"
+	"fmt"
+
+	v2_models "github.com/prometheus/alertmanager/api/v2/models"
+)
+
+// V1Silences implements the Merger interface for GET /v1/silences. Unlike for alerts, the API
+// definitions for silences are almost identical between v1 and v2. The differences are that the
+// fields in the JSON output are ordered differently, and the timestamps have more precision in v1,
+// but these differences should not be problematic to clients. Therefore, the implementation
+// re-uses the v2 types, with additional handling for the enclosing status/data fields.
+type V1Silences struct{}
+
+func (V1Silences) MergeResponses(in [][]byte) ([]byte, error) {
+	type bodyType struct {
+		Status string                     `json:"status"`
+		Data   v2_models.GettableSilences `json:"data"`
+	}
+
+	silences := make(v2_models.GettableSilences, 0)
+	for _, body := range in {
+		parsed := bodyType{}
+		if err := json.Unmarshal(body, &parsed); err != nil {
+			return nil, err
+		}
+		if parsed.Status != statusSuccess {
+			return nil, fmt.Errorf("unable to merge response of status: %s", parsed.Status)
+		}
+		silences = append(silences, parsed.Data...)
+	}
+
+	merged, err := mergeV2Silences(silences)
+	if err != nil {
+		return nil, err
+	}
+	body := bodyType{
+		Status: statusSuccess,
+		Data:   merged,
+	}
+
+	return json.Marshal(body)
+}