agent: Fixing blocking queries on internal endpoints

This commit is contained in:
Armon Dadgar 2015-02-11 13:35:46 -08:00
parent a446fbd098
commit aadec620ff
1 changed files with 54 additions and 64 deletions

View File

@ -1,10 +1,11 @@
package agent
import (
"github.com/hashicorp/consul/consul/structs"
"net/http"
"sort"
"strings"
"github.com/hashicorp/consul/consul/structs"
)
// ServiceSummary is used to summarize a service
@ -19,99 +20,88 @@ type ServiceSummary struct {
// UINodes is used to list the nodes in a given datacenter. We return a
// NodeDump which provides overview information for all the nodes
func (s *HTTPServer) UINodes(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
// Get the datacenter
var dc string
s.parseDC(req, &dc)
// Try to ge ta node dump
var dump structs.NodeDump
if err := s.getNodeDump(resp, dc, "", &dump); err != nil {
return nil, err
// Parse arguments
args := structs.DCSpecificRequest{}
if done := s.parse(resp, req, &args.Datacenter, &args.QueryOptions); done {
return nil, nil
}
return dump, nil
// Make the RPC request
var out structs.IndexedNodeDump
defer setMeta(resp, &out.QueryMeta)
RPC:
if err := s.agent.RPC("Internal.NodeDump", &args, &out); err != nil {
// Retry the request allowing stale data if no leader
if strings.Contains(err.Error(), structs.ErrNoLeader.Error()) && !args.AllowStale {
args.AllowStale = true
goto RPC
}
return nil, err
}
return out.Dump, nil
}
// UINodeInfo is used to get info on a single node in a given datacenter. We return a
// NodeInfo which provides overview information for the node
func (s *HTTPServer) UINodeInfo(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
// Get the datacenter
var dc string
s.parseDC(req, &dc)
// Parse arguments
args := structs.NodeSpecificRequest{}
if done := s.parse(resp, req, &args.Datacenter, &args.QueryOptions); done {
return nil, nil
}
// Verify we have some DC, or use the default
node := strings.TrimPrefix(req.URL.Path, "/v1/internal/ui/node/")
if node == "" {
args.Node = strings.TrimPrefix(req.URL.Path, "/v1/internal/ui/node/")
if args.Node == "" {
resp.WriteHeader(400)
resp.Write([]byte("Missing node name"))
return nil, nil
}
// Try to get a node dump
var dump structs.NodeDump
if err := s.getNodeDump(resp, dc, node, &dump); err != nil {
// Make the RPC request
var out structs.IndexedNodeDump
defer setMeta(resp, &out.QueryMeta)
RPC:
if err := s.agent.RPC("Internal.NodeInfo", &args, &out); err != nil {
// Retry the request allowing stale data if no leader
if strings.Contains(err.Error(), structs.ErrNoLeader.Error()) && !args.AllowStale {
args.AllowStale = true
goto RPC
}
return nil, err
}
// Return only the first entry
if len(dump) > 0 {
return dump[0], nil
if len(out.Dump) > 0 {
return out.Dump[0], nil
}
return nil, nil
}
// getNodeDump is used to get a dump of all node data. We make a best effort by
// reading stale data in the case of an availability outage.
func (s *HTTPServer) getNodeDump(resp http.ResponseWriter, dc, node string, dump *structs.NodeDump) error {
var args interface{}
var method string
var allowStale *bool
if node == "" {
raw := structs.DCSpecificRequest{Datacenter: dc}
method = "Internal.NodeDump"
allowStale = &raw.AllowStale
args = &raw
} else {
raw := &structs.NodeSpecificRequest{Datacenter: dc, Node: node}
method = "Internal.NodeInfo"
allowStale = &raw.AllowStale
args = &raw
}
var out structs.IndexedNodeDump
defer setMeta(resp, &out.QueryMeta)
START:
if err := s.agent.RPC(method, args, &out); err != nil {
// Retry the request allowing stale data if no leader. The UI should continue
// to function even during an outage
if strings.Contains(err.Error(), structs.ErrNoLeader.Error()) && !*allowStale {
*allowStale = true
goto START
}
return err
}
// Set the result
*dump = out.Dump
return nil
}
// UIServices is used to list the services in a given datacenter. We return a
// ServiceSummary which provides overview information for the service
func (s *HTTPServer) UIServices(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
// Get the datacenter
var dc string
s.parseDC(req, &dc)
// Parse arguments
args := structs.DCSpecificRequest{}
if done := s.parse(resp, req, &args.Datacenter, &args.QueryOptions); done {
return nil, nil
}
// Get the full node dump...
var dump structs.NodeDump
if err := s.getNodeDump(resp, dc, "", &dump); err != nil {
// Make the RPC request
var out structs.IndexedNodeDump
defer setMeta(resp, &out.QueryMeta)
RPC:
if err := s.agent.RPC("Internal.NodeDump", &args, &out); err != nil {
// Retry the request allowing stale data if no leader
if strings.Contains(err.Error(), structs.ErrNoLeader.Error()) && !args.AllowStale {
args.AllowStale = true
goto RPC
}
return nil, err
}
// Generate the summary
return summarizeServices(dump), nil
return summarizeServices(out.Dump), nil
}
func summarizeServices(dump structs.NodeDump) []*ServiceSummary {