feat(go-client): add ListNodes API for meta admin

Author: empiredan

go-client/admin/client.go

@@ -54,6 +54,10 @@ type Client interface {
 	// Empty `args` means "list all available tables"; Otherwise, the only parameter would
 	// specify the status of the returned tables.
 	ListTables(args ...interface{}) ([]*replication.AppInfo, error)
+
+	// Empty `args` means "list all alive nodes"; Otherwise, the only parameter would
+	// specify the status of the returned nodes.
+	ListNodes(args ...interface{}) ([]*admin.NodeInfo, error)
 }
 
 type Config struct {
@@ -234,3 +238,29 @@ func (c *rpcBasedClient) ListTables(args ...interface{}) ([]*replication.AppInfo
 	}
 	return c.listTables(args[0].(replication.AppStatus))
 }
+
+func (c *rpcBasedClient) listNodes(status admin.NodeStatus) ([]*admin.NodeInfo, error) {
+	req := &admin.ConfigurationListNodesRequest{
+		Status: status,
+	}
+
+	var nodes []*admin.NodeInfo
+	var respErr error
+	err := c.callMeta("ListNodes", req, func(iresp interface{}) {
+		resp := iresp.(*admin.ConfigurationListNodesResponse)
+		nodes = resp.Infos
+		respErr = base.GetResponseError(resp)
+	})
+	if err != nil {
+		return nodes, err
+	}
+
+	return nodes, respErr
+}
+
+func (c *rpcBasedClient) ListNodes(args ...interface{}) ([]*admin.NodeInfo, error) {
+	if len(args) == 0 {
+		return c.listNodes(admin.NodeStatus_NS_ALIVE)
+	}
+	return c.listNodes(args[0].(admin.NodeStatus))
+}

go-client/admin/client_test.go

@@ -25,6 +25,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/apache/incubator-pegasus/go-client/admin"
 	"github.com/apache/incubator-pegasus/go-client/idl/replication"
 	"github.com/apache/incubator-pegasus/go-client/pegasus"
 	"github.com/stretchr/testify/assert"
@@ -43,6 +44,22 @@ func defaultConfig() Config {
 	}
 }
 
+func defaultReplicaServers() []string {
+	return []string{"0.0.0.0:34801", "0.0.0.0:34802", "0.0.0.0:34803"}
+}
+
+func timeoutConfig() Config {
+	return Config{
+		MetaServers: []string{"0.0.0.0:123456"},
+		Timeout:     500 * time.Millisecond,
+	}
+}
+
+func testAdmin_Timeout(t *testing.T, exec func(c *admin.Client) error) {
+	c := NewClient(timeoutConfig())
+	assert.Equal(t, context.DeadlineExceeded, exec(c))
+}
+
 func TestAdmin_Table(t *testing.T) {
 	c := NewClient(defaultConfig())
 
@@ -75,13 +92,9 @@ func TestAdmin_Table(t *testing.T) {
 }
 
 func TestAdmin_ListTablesTimeout(t *testing.T) {
-	c := NewClient(Config{
-		MetaServers: []string{"0.0.0.0:123456"},
-		Timeout:     500 * time.Millisecond,
+	testAdmin_Timeout(t, func(c *admin.Client) (err, error) {
+		_, err := c.ListTables()
 	})
-
-	_, err := c.ListTables()
-	assert.Equal(t, err, context.DeadlineExceeded)
 }
 
 // Ensures after the call `CreateTable` ends, the table must be right available to access.
@@ -145,3 +158,31 @@ func TestAdmin_GetAppEnvs(t *testing.T) {
 		assert.Empty(t, tb.Envs)
 	}
 }
+
+func TestAdmin_ListNodes(t *testing.T) {
+	c := NewClient(defaultConfig())
+
+	nodes, err := c.ListNodes()
+	assert.Nil(t, err)
+
+	expectedReplicaServers := defaultReplicaServers()
+
+	// Compare slice length.
+	assert.Equal(t, len(expectedReplicaServers), len(nodes))
+
+	actualReplicaServers := make([]int, len(nodes))
+	for _, node := range nodes {
+		// Each node should be alive.
+		assert.Equal(t, admin.NodeStatus_NS_ALIVE, node.Status)
+		actualReplicaServers[i] = node.Address.GetAddress()
+	}
+
+	// Match elements without extra ordering.
+	assert.ElementsMatch(t, expectedReplicaServers, actualReplicaServers)
+}
+
+func TestAdmin_ListNodesTimeout(t *testing.T) {
+	testAdmin_Timeout(t, func(c *admin.Client) (err, error) {
+		_, err := c.ListNodes()
+	})
+}