Stats Endpoint

client/client.go

@@ -6,6 +6,7 @@ import (
 	"io/ioutil"
 	"log"
 	"net"
+	"net/rpc"
 	"os"
 	"path/filepath"
 	"strconv"
@@ -157,6 +158,10 @@ type Client struct {
 	// clientACLResolver holds the ACL resolution state
 	clientACLResolver
 
+	// rpcServer is used to serve RPCs by the local agent.
+	rpcServer *rpc.Server
+	endpoints rpcEndpoints
+
 	// baseLabels are used when emitting tagged metrics. All client metrics will
 	// have these tags, and optionally more.
 	baseLabels []metrics.Label
@@ -202,6 +207,9 @@ func NewClient(cfg *config.Config, consulCatalog consul.CatalogAPI, consulServic
 		return nil, fmt.Errorf("failed to initialize client: %v", err)
 	}
 
+	// Setup the clients RPC server
+	c.setupClientRpc()
+
 	// Initialize the ACL state
 	if err := c.clientACLResolver.init(); err != nil {
 		return nil, fmt.Errorf("failed to initialize ACL state: %v", err)
@@ -474,35 +482,6 @@ func (c *Client) Shutdown() error {
 	return c.saveState()
 }
 
-// RPC is used to forward an RPC call to a nomad server, or fail if no servers.
-func (c *Client) RPC(method string, args interface{}, reply interface{}) error {
-	// Invoke the RPCHandler if it exists
-	if c.config.RPCHandler != nil {
-		return c.config.RPCHandler.RPC(method, args, reply)
-	}
-
-	servers := c.servers.all()
-	if len(servers) == 0 {
-		return noServersErr
-	}
-
-	var mErr multierror.Error
-	for _, s := range servers {
-		// Make the RPC request
-		if err := c.connPool.RPC(c.Region(), s.addr, c.RPCMajorVersion(), method, args, reply); err != nil {
-			errmsg := fmt.Errorf("RPC failed to server %s: %v", s.addr, err)
-			mErr.Errors = append(mErr.Errors, errmsg)
-			c.logger.Printf("[DEBUG] client: %v", errmsg)
-			c.servers.failed(s)
-			continue
-		}
-		c.servers.good(s)
-		return nil
-	}
-
-	return mErr.ErrorOrNil()
-}
-
 // Stats is used to return statistics for debugging and insight
 // for various sub-systems
 func (c *Client) Stats() map[string]map[string]string {
@@ -2164,19 +2143,3 @@ func (c *Client) allAllocs() map[string]*structs.Allocation {
 	}
 	return allocs
 }
-
-// resolveServer given a sever's address as a string, return it's resolved
-// net.Addr or an error.
-func resolveServer(s string) (net.Addr, error) {
-	const defaultClientPort = "4647" // default client RPC port
-	host, port, err := net.SplitHostPort(s)
-	if err != nil {
-		if strings.Contains(err.Error(), "missing port") {
-			host = s
-			port = defaultClientPort
-		} else {
-			return nil, err
-		}
-	}
-	return net.ResolveTCPAddr("tcp", net.JoinHostPort(host, port))
-}

client/client_stats_endpoint.go

@@ -0,0 +1,30 @@
+package client
+
+import (
+	"time"
+
+	metrics "github.com/armon/go-metrics"
+	"github.com/hashicorp/nomad/client/structs"
+	nstructs "github.com/hashicorp/nomad/nomad/structs"
+)
+
+// ClientStats endpoint is used for retrieving stats about a client
+type ClientStats struct {
+	c *Client
+}
+
+// Stats is used to retrieve the Clients stats.
+func (s *ClientStats) Stats(args *structs.ClientStatsRequest, reply *structs.ClientStatsResponse) error {
+	defer metrics.MeasureSince([]string{"nomad", "client", "client_stats", "stats"}, time.Now())
+
+	// Check node read permissions
+	if aclObj, err := s.c.ResolveToken(args.AuthToken); err != nil {
+		return err
+	} else if aclObj != nil && !aclObj.AllowNodeRead() {
+		return nstructs.ErrPermissionDenied
+	}
+
+	clientStats := s.c.StatsReporter()
+	reply.HostStats = clientStats.LatestHostStats()
+	return nil
+}

client/client_stats_endpoint_test.go

@@ -0,0 +1,85 @@
+package client
+
+import (
+	"testing"
+
+	"github.com/hashicorp/nomad/acl"
+	"github.com/hashicorp/nomad/client/config"
+	"github.com/hashicorp/nomad/client/structs"
+	"github.com/hashicorp/nomad/nomad/mock"
+	nstructs "github.com/hashicorp/nomad/nomad/structs"
+	"github.com/stretchr/testify/require"
+)
+
+func TestClientStats_Stats(t *testing.T) {
+	t.Parallel()
+	require := require.New(t)
+	client := testClient(t, nil)
+
+	req := &structs.ClientStatsRequest{}
+	var resp structs.ClientStatsResponse
+	require.Nil(client.ClientRPC("ClientStats.Stats", &req, &resp))
+	require.NotNil(resp.HostStats)
+	require.NotNil(resp.HostStats.AllocDirStats)
+	require.NotZero(resp.HostStats.Uptime)
+}
+
+func TestClientStats_Stats_ACL(t *testing.T) {
+	t.Parallel()
+	require := require.New(t)
+	server, addr, root := testACLServer(t, nil)
+	defer server.Shutdown()
+
+	client := testClient(t, func(c *config.Config) {
+		c.Servers = []string{addr}
+		c.ACLEnabled = true
+	})
+	defer client.Shutdown()
+
+	// Try request without a token and expect failure
+	{
+		req := &structs.ClientStatsRequest{}
+		var resp structs.ClientStatsResponse
+		err := client.ClientRPC("ClientStats.Stats", &req, &resp)
+		require.NotNil(err)
+		require.EqualError(err, nstructs.ErrPermissionDenied.Error())
+	}
+
+	// Try request with an invalid token and expect failure
+	{
+		token := mock.CreatePolicyAndToken(t, server.State(), 1005, "invalid", mock.NodePolicy(acl.PolicyDeny))
+		req := &structs.ClientStatsRequest{}
+		req.AuthToken = token.SecretID
+
+		var resp structs.ClientStatsResponse
+		err := client.ClientRPC("ClientStats.Stats", &req, &resp)
+
+		require.NotNil(err)
+		require.EqualError(err, nstructs.ErrPermissionDenied.Error())
+	}
+
+	// Try request with a valid token
+	{
+		token := mock.CreatePolicyAndToken(t, server.State(), 1007, "valid", mock.NodePolicy(acl.PolicyRead))
+		req := &structs.ClientStatsRequest{}
+		req.AuthToken = token.SecretID
+
+		var resp structs.ClientStatsResponse
+		err := client.ClientRPC("ClientStats.Stats", &req, &resp)
+
+		require.Nil(err)
+		require.NotNil(resp.HostStats)
+	}
+
+	// Try request with a management token
+	{
+		req := &structs.ClientStatsRequest{}
+		req.AuthToken = root.SecretID
+
+		var resp structs.ClientStatsResponse
+		err := client.ClientRPC("ClientStats.Stats", &req, &resp)
+
+		require.Nil(err)
+		require.NotNil(resp.HostStats)
+	}
+}

client/client_test.go

@@ -18,6 +18,7 @@ import (
 	"github.com/hashicorp/nomad/client/fingerprint"
 	"github.com/hashicorp/nomad/command/agent/consul"
 	"github.com/hashicorp/nomad/helper"
+	"github.com/hashicorp/nomad/helper/testlog"
 	"github.com/hashicorp/nomad/helper/uuid"
 	"github.com/hashicorp/nomad/nomad"
 	"github.com/hashicorp/nomad/nomad/mock"
@@ -122,7 +123,7 @@ func testClient(t *testing.T, cb func(c *config.Config)) *Client {
 		cb(conf)
 	}
 
-	logger := log.New(conf.LogOutput, "", log.LstdFlags)
+	logger := testlog.Logger(t)
 	catalog := consul.NewMockCatalog(logger)
 	mockService := newMockConsulServiceClient()
 	mockService.logger = logger

client/rpc.go

@@ -0,0 +1,92 @@
+package client
+
+import (
+	"fmt"
+	"net"
+	"net/rpc"
+	"strings"
+
+	multierror "github.com/hashicorp/go-multierror"
+	"github.com/hashicorp/nomad/helper/codec"
+)
+
+// rpcEndpoints holds the RPC endpoints
+type rpcEndpoints struct {
+	ClientStats *ClientStats
+}
+
+// ClientRPC is used to make a local, client only RPC call
+func (c *Client) ClientRPC(method string, args interface{}, reply interface{}) error {
+	codec := &codec.InmemCodec{
+		Method: method,
+		Args:   args,
+		Reply:  reply,
+	}
+	if err := c.rpcServer.ServeRequest(codec); err != nil {
+		return err
+	}
+	return codec.Err
+}
+
+// RPC is used to forward an RPC call to a nomad server, or fail if no servers.
+func (c *Client) RPC(method string, args interface{}, reply interface{}) error {
+	// Invoke the RPCHandler if it exists
+	if c.config.RPCHandler != nil {
+		return c.config.RPCHandler.RPC(method, args, reply)
+	}
+
+	servers := c.servers.all()
+	if len(servers) == 0 {
+		return noServersErr
+	}
+
+	var mErr multierror.Error
+	for _, s := range servers {
+		// Make the RPC request
+		if err := c.connPool.RPC(c.Region(), s.addr, c.RPCMajorVersion(), method, args, reply); err != nil {
+			errmsg := fmt.Errorf("RPC failed to server %s: %v", s.addr, err)
+			mErr.Errors = append(mErr.Errors, errmsg)
+			c.logger.Printf("[DEBUG] client: %v", errmsg)
+			c.servers.failed(s)
+			continue
+		}
+		c.servers.good(s)
+		return nil
+	}
+
+	return mErr.ErrorOrNil()
+}
+
+// setupClientRpc is used to setup the Client's RPC endpoints
+func (c *Client) setupClientRpc() {
+	// Initialize the RPC handlers
+	c.endpoints.ClientStats = &ClientStats{c}
+
+	// Create the RPC Server
+	c.rpcServer = rpc.NewServer()
+
+	// Register the endpoints with the RPC server
+	c.setupClientRpcServer(c.rpcServer)
+}
+
+// setupClientRpcServer is used to populate a client RPC server with endpoints.
+func (c *Client) setupClientRpcServer(server *rpc.Server) {
+	// Register the endpoints
+	server.Register(c.endpoints.ClientStats)
+}
+
+// resolveServer given a sever's address as a string, return it's resolved
+// net.Addr or an error.
+func resolveServer(s string) (net.Addr, error) {
+	const defaultClientPort = "4647" // default client RPC port
+	host, port, err := net.SplitHostPort(s)
+	if err != nil {
+		if strings.Contains(err.Error(), "missing port") {
+			host = s
+			port = defaultClientPort
+		} else {
+			return nil, err
+		}
+	}
+	return net.ResolveTCPAddr("tcp", net.JoinHostPort(host, port))
+}

client/stats/host.go

@@ -93,7 +93,12 @@ func NewHostStatsCollector(logger *log.Logger, allocDir string) *HostStatsCollec
 func (h *HostStatsCollector) Collect() error {
 	h.hostStatsLock.Lock()
 	defer h.hostStatsLock.Unlock()
+	return h.collectLocked()
+}
 
+// collectLocked collects stats related to resource usage of the host but should
+// be called with the lock held.
+func (h *HostStatsCollector) collectLocked() error {
 	hs := &HostStats{Timestamp: time.Now().UTC().UnixNano()}
 
 	// Determine up-time
@@ -185,6 +190,13 @@ func (h *HostStatsCollector) collectDiskStats() ([]*DiskStats, error) {
 func (h *HostStatsCollector) Stats() *HostStats {
 	h.hostStatsLock.RLock()
 	defer h.hostStatsLock.RUnlock()
+
+	if h.hostStats == nil {
+		if err := h.collectLocked(); err != nil {
+			h.logger.Printf("[WARN] client: error fetching host resource usage stats: %v", err)
+		}
+	}
+
 	return h.hostStats
 }
 

client/structs/structs.go

@@ -6,9 +6,22 @@ import (
 	"strconv"
 
 	"github.com/hashicorp/nomad/client/config"
+	"github.com/hashicorp/nomad/client/stats"
 	"github.com/hashicorp/nomad/nomad/structs"
 )
 
+// ClientStatsRequest is used to request stats about a Node.
+type ClientStatsRequest struct {
+	NodeID string
+	structs.QueryOptions
+}
+
+// ClientStatsResponse is used to return statistics about a node.
+type ClientStatsResponse struct {
+	HostStats *stats.HostStats
+	structs.QueryMeta
+}
+
 // MemoryStats holds memory usage related stats
 type MemoryStats struct {
 	RSS            uint64

command/agent/stats_endpoint.go

@@ -3,7 +3,7 @@ package agent
 import (
 	"net/http"
 
-	"github.com/hashicorp/nomad/nomad/structs"
+	cstructs "github.com/hashicorp/nomad/client/structs"
 )
 
 func (s *HTTPServer) ClientStatsRequest(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
@@ -11,16 +11,15 @@ func (s *HTTPServer) ClientStatsRequest(resp http.ResponseWriter, req *http.Requ
 		return nil, clientNotRunning
 	}
 
-	var secret string
-	s.parseToken(req, &secret)
+	// Parse the ACL token
+	var args cstructs.ClientStatsRequest
+	s.parseToken(req, &args.AuthToken)
 
-	// Check node read permissions
-	if aclObj, err := s.agent.Client().ResolveToken(secret); err != nil {
+	// Make the RPC
+	var reply cstructs.ClientStatsResponse
+	if err := s.agent.Client().ClientRPC("ClientStats.Stats", &args, &reply); err != nil {
 		return nil, err
-	} else if aclObj != nil && !aclObj.AllowNodeRead() {
-		return nil, structs.ErrPermissionDenied
 	}
 
-	clientStats := s.agent.client.StatsReporter()
-	return clientStats.LatestHostStats(), nil
+	return reply.HostStats, nil
 }