Merge pull request #1947 from hashicorp/f-server-members-rpc

Add an RPC endpoint for server members

CHANGELOG.md

@@ -43,6 +43,7 @@ IMPROVEMENTS:
   * driver/lxc: Support for LXC containers [GH-1699]
   * driver/rkt: Support network configurations [GH-1862]
   * driver/rkt: Support rkt volumes (rkt >= 1.0.0 required) [GH-1812]
+  * server/rpc: Added an RPC endpoint for retreiving server members [GH-1947]
 
 BUG FIXES:
   * core: Fix case where dead nodes were not properly handled by System

api/agent.go

@@ -131,8 +131,8 @@ func (a *Agent) Join(addrs ...string) (int, error) {
 }
 
 // Members is used to query all of the known server members
-func (a *Agent) Members() ([]*AgentMember, error) {
-	var resp []*AgentMember
+func (a *Agent) Members() (*ServerMembers, error) {
+	var resp *ServerMembers
 
 	// Query the known members
 	_, err := a.client.query("/v1/agent/members", &resp, nil)
@@ -217,6 +217,13 @@ type joinResponse struct {
 	Error     string `json:"error"`
 }
 
+type ServerMembers struct {
+	ServerName string
+	Region     string
+	DC         string
+	Members    []*AgentMember
+}
+
 // AgentMember represents a cluster member known to the agent
 type AgentMember struct {
 	Name        string

command/agent/agent_endpoint.go

@@ -88,17 +88,13 @@ func (s *HTTPServer) AgentMembersRequest(resp http.ResponseWriter, req *http.Req
 	if req.Method != "GET" {
 		return nil, CodedError(405, ErrInvalidMethod)
 	}
-	srv := s.agent.Server()
-	if srv == nil {
-		return nil, CodedError(501, ErrInvalidMethod)
+	args := &structs.GenericRequest{}
+	var out structs.ServerMembersResponse
+	if err := s.agent.RPC("Status.Members", args, &out); err != nil {
+		return nil, err
 	}
 
-	serfMembers := srv.Members()
-	members := make([]Member, len(serfMembers))
-	for i, mem := range serfMembers {
-		members[i] = nomadMember(mem)
-	}
-	return members, nil
+	return out, nil
 }
 
 func (s *HTTPServer) AgentForceLeaveRequest(resp http.ResponseWriter, req *http.Request) (interface{}, error) {

command/server_members.go

@@ -64,17 +64,22 @@ func (c *ServerMembersCommand) Run(args []string) int {
 	}
 
 	// Query the members
-	mem, err := client.Agent().Members()
+	srvMembers, err := client.Agent().Members()
 	if err != nil {
 		c.Ui.Error(fmt.Sprintf("Error querying servers: %s", err))
 		return 1
 	}
 
+	if srvMembers == nil {
+		c.Ui.Error("Agent doesn't know about server members")
+		return 0
+	}
+
 	// Sort the members
-	sort.Sort(api.AgentMembersNameSort(mem))
+	sort.Sort(api.AgentMembersNameSort(srvMembers.Members))
 
 	// Determine the leaders per region.
-	leaders, err := regionLeaders(client, mem)
+	leaders, err := regionLeaders(client, srvMembers.Members)
 	if err != nil {
 		c.Ui.Error(fmt.Sprintf("Error determining leaders: %s", err))
 		return 1
@@ -83,9 +88,9 @@ func (c *ServerMembersCommand) Run(args []string) int {
 	// Format the list
 	var out []string
 	if detailed {
-		out = detailedOutput(mem)
+		out = detailedOutput(srvMembers.Members)
 	} else {
-		out = standardOutput(mem, leaders)
+		out = standardOutput(srvMembers.Members, leaders)
 	}
 
 	// Dump the list

nomad/status_endpoint.go

@@ -61,3 +61,32 @@ func (s *Status) Peers(args *structs.GenericRequest, reply *[]string) error {
 	*reply = peers
 	return nil
 }
+
+// Members return the list of servers in a cluster that a particular server is
+// aware of
+func (s *Status) Members(args *structs.GenericRequest, reply *structs.ServerMembersResponse) error {
+	serfMembers := s.srv.Members()
+	members := make([]*structs.ServerMember, len(serfMembers))
+	for i, mem := range serfMembers {
+		members[i] = &structs.ServerMember{
+			Name:        mem.Name,
+			Addr:        mem.Addr,
+			Port:        mem.Port,
+			Tags:        mem.Tags,
+			Status:      mem.Status.String(),
+			ProtocolMin: mem.ProtocolMin,
+			ProtocolMax: mem.ProtocolMax,
+			ProtocolCur: mem.ProtocolCur,
+			DelegateMin: mem.DelegateMin,
+			DelegateMax: mem.DelegateMax,
+			DelegateCur: mem.DelegateCur,
+		}
+	}
+	*reply = structs.ServerMembersResponse{
+		ServerName:   s.srv.config.NodeName,
+		ServerRegion: s.srv.config.Region,
+		ServerDC:     s.srv.config.Datacenter,
+		Members:      members,
+	}
+	return nil
+}

nomad/structs/structs.go

@@ -10,6 +10,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"net"
 	"os"
 	"path/filepath"
 	"reflect"
@@ -359,6 +360,30 @@ type PeriodicForceRequest struct {
 	WriteRequest
 }
 
+// ServerMembersResponse has the list of servers in a cluster
+type ServerMembersResponse struct {
+	ServerName   string
+	ServerRegion string
+	ServerDC     string
+	Members      []*ServerMember
+	QueryMeta
+}
+
+// ServerMember holds information about a Nomad server agent in a cluster
+type ServerMember struct {
+	Name        string
+	Addr        net.IP
+	Port        uint16
+	Tags        map[string]string
+	Status      string
+	ProtocolMin uint8
+	ProtocolMax uint8
+	ProtocolCur uint8
+	DelegateMin uint8
+	DelegateMax uint8
+	DelegateCur uint8
+}
+
 // DeriveVaultTokenRequest is used to request wrapped Vault tokens for the
 // following tasks in the given allocation
 type DeriveVaultTokenRequest struct {