fix: no switchover candidate found with member state "streaming" (#1992) (#2515)

* fix: no switchover candidate found with member state "streaming" (#1992)
* Add test
* Also handle "in archive recovery" state

pkg/cluster/pod.go

@@ -7,6 +7,8 @@ import (
 	"strconv"
 	"time"
 
+	"golang.org/x/exp/slices"
+
 	appsv1 "k8s.io/api/apps/v1"
 	v1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -503,7 +505,11 @@ func (c *Cluster) getSwitchoverCandidate(master *v1.Pod) (spec.NamespacedName, e
 	} else {
 		// in asynchronous mode find running replicas
 		for _, member := range members {
-			if PostgresRole(member.Role) != Leader && PostgresRole(member.Role) != StandbyLeader && member.State == "running" {
+			if PostgresRole(member.Role) == Leader || PostgresRole(member.Role) == StandbyLeader {
+				continue
+			}
+
+			if slices.Contains([]string{"running", "streaming", "in archive recovery"}, member.State) {
 				candidates = append(candidates, member)
 			}
 		}

pkg/cluster/pod_test.go

@@ -75,6 +75,13 @@ func TestGetSwitchoverCandidate(t *testing.T) {
 			expectedCandidate: spec.NamespacedName{},
 			expectedError:     fmt.Errorf("no switchover candidate found"),
 		},
+		{
+			subtest:           "replicas with streaming state",
+			clusterJson:       `{"members": [{"name": "acid-test-cluster-0", "role": "leader", "state": "running", "api_url": "http://192.168.100.1:8008/patroni", "host": "192.168.100.1", "port": 5432, "timeline": 1}, {"name": "acid-test-cluster-1", "role": "replica", "state": "streaming", "api_url": "http://192.168.100.2:8008/patroni", "host": "192.168.100.2", "port": 5432, "timeline": 1, "lag": 5}, {"name": "acid-test-cluster-2", "role": "replica", "state": "streaming", "api_url": "http://192.168.100.3:8008/patroni", "host": "192.168.100.3", "port": 5432, "timeline": 1, "lag": 2}]}`,
+			syncModeEnabled:   false,
+			expectedCandidate: spec.NamespacedName{Namespace: namespace, Name: "acid-test-cluster-2"},
+			expectedError:     nil,
+		},
 	}
 
 	for _, tt := range tests {