open-nomad/command/agent/http.go
2016-01-22 11:00:43 -08:00

297 lines
8 KiB
Go

package agent
import (
"encoding/json"
"fmt"
"io"
"log"
"net"
"net/http"
"net/http/pprof"
"strconv"
"time"
"github.com/hashicorp/nomad/nomad/structs"
)
const (
// ErrInvalidMethod is used if the HTTP method is not supported
ErrInvalidMethod = "Invalid method"
// scadaHTTPAddr is the address associated with the
// HTTPServer. When populating an ACL token for a request,
// this is checked to switch between the ACLToken and
// AtlasACLToken
scadaHTTPAddr = "SCADA"
)
// HTTPServer is used to wrap an Agent and expose it over an HTTP interface
type HTTPServer struct {
agent *Agent
mux *http.ServeMux
listener net.Listener
logger *log.Logger
addr string
}
// NewHTTPServer starts new HTTP server over the agent
func NewHTTPServer(agent *Agent, config *Config, logOutput io.Writer) (*HTTPServer, error) {
// Start the listener
ln, err := config.Listener("tcp", config.Addresses.HTTP, config.Ports.HTTP)
if err != nil {
return nil, fmt.Errorf("failed to start HTTP listener: %v", err)
}
// Create the mux
mux := http.NewServeMux()
// Create the server
srv := &HTTPServer{
agent: agent,
mux: mux,
listener: ln,
logger: log.New(logOutput, "", log.LstdFlags),
addr: ln.Addr().String(),
}
srv.registerHandlers(config.EnableDebug)
// Start the server
go http.Serve(ln, mux)
return srv, nil
}
// newScadaHttp creates a new HTTP server wrapping the SCADA
// listener such that HTTP calls can be sent from the brokers.
func newScadaHttp(agent *Agent, list net.Listener) *HTTPServer {
// Create the mux
mux := http.NewServeMux()
// Create the server
srv := &HTTPServer{
agent: agent,
mux: mux,
listener: list,
logger: agent.logger,
addr: scadaHTTPAddr,
}
srv.registerHandlers(false) // Never allow debug for SCADA
// Start the server
go http.Serve(list, mux)
return srv
}
// Shutdown is used to shutdown the HTTP server
func (s *HTTPServer) Shutdown() {
if s != nil {
s.logger.Printf("[DEBUG] http: Shutting down http server")
s.listener.Close()
}
}
// registerHandlers is used to attach our handlers to the mux
func (s *HTTPServer) registerHandlers(enableDebug bool) {
s.mux.HandleFunc("/v1/jobs", s.wrap(s.JobsRequest))
s.mux.HandleFunc("/v1/job/", s.wrap(s.JobSpecificRequest))
s.mux.HandleFunc("/v1/nodes", s.wrap(s.NodesRequest))
s.mux.HandleFunc("/v1/node/", s.wrap(s.NodeSpecificRequest))
s.mux.HandleFunc("/v1/allocations", s.wrap(s.AllocsRequest))
s.mux.HandleFunc("/v1/allocation/", s.wrap(s.AllocSpecificRequest))
s.mux.HandleFunc("/v1/evaluations", s.wrap(s.EvalsRequest))
s.mux.HandleFunc("/v1/evaluation/", s.wrap(s.EvalSpecificRequest))
s.mux.HandleFunc("/v1/client/fs/ls/", s.wrap(s.DirectoryListRequest))
s.mux.HandleFunc("/v1/client/fs/stat/", s.wrap(s.FileStatRequest))
s.mux.HandleFunc("/v1/client/fs/readat/", s.wrap(s.FileReadAtRequest))
s.mux.HandleFunc("/v1/agent/self", s.wrap(s.AgentSelfRequest))
s.mux.HandleFunc("/v1/agent/join", s.wrap(s.AgentJoinRequest))
s.mux.HandleFunc("/v1/agent/members", s.wrap(s.AgentMembersRequest))
s.mux.HandleFunc("/v1/agent/force-leave", s.wrap(s.AgentForceLeaveRequest))
s.mux.HandleFunc("/v1/agent/servers", s.wrap(s.AgentServersRequest))
s.mux.HandleFunc("/v1/regions", s.wrap(s.RegionListRequest))
s.mux.HandleFunc("/v1/status/leader", s.wrap(s.StatusLeaderRequest))
s.mux.HandleFunc("/v1/status/peers", s.wrap(s.StatusPeersRequest))
if enableDebug {
s.mux.HandleFunc("/debug/pprof/", pprof.Index)
s.mux.HandleFunc("/debug/pprof/cmdline", pprof.Cmdline)
s.mux.HandleFunc("/debug/pprof/profile", pprof.Profile)
s.mux.HandleFunc("/debug/pprof/symbol", pprof.Symbol)
}
}
// HTTPCodedError is used to provide the HTTP error code
type HTTPCodedError interface {
error
Code() int
}
func CodedError(c int, s string) HTTPCodedError {
return &codedError{s, c}
}
type codedError struct {
s string
code int
}
func (e *codedError) Error() string {
return e.s
}
func (e *codedError) Code() int {
return e.code
}
// wrap is used to wrap functions to make them more convenient
func (s *HTTPServer) wrap(handler func(resp http.ResponseWriter, req *http.Request) (interface{}, error)) func(resp http.ResponseWriter, req *http.Request) {
f := func(resp http.ResponseWriter, req *http.Request) {
setHeaders(resp, s.agent.config.HTTPAPIResponseHeaders)
// Invoke the handler
reqURL := req.URL.String()
start := time.Now()
defer func() {
s.logger.Printf("[DEBUG] http: Request %v (%v)", reqURL, time.Now().Sub(start))
}()
obj, err := handler(resp, req)
// Check for an error
HAS_ERR:
if err != nil {
s.logger.Printf("[ERR] http: Request %v, error: %v", reqURL, err)
code := 500
if http, ok := err.(HTTPCodedError); ok {
code = http.Code()
}
resp.WriteHeader(code)
resp.Write([]byte(err.Error()))
return
}
prettyPrint := false
if _, ok := req.URL.Query()["pretty"]; ok {
prettyPrint = true
}
// Write out the JSON object
if obj != nil {
var buf []byte
if prettyPrint {
buf, err = json.MarshalIndent(obj, "", " ")
} else {
buf, err = json.Marshal(obj)
}
if err != nil {
goto HAS_ERR
}
resp.Header().Set("Content-Type", "application/json")
resp.Write(buf)
}
}
return f
}
// decodeBody is used to decode a JSON request body
func decodeBody(req *http.Request, out interface{}) error {
dec := json.NewDecoder(req.Body)
return dec.Decode(&out)
}
// setIndex is used to set the index response header
func setIndex(resp http.ResponseWriter, index uint64) {
resp.Header().Set("X-Nomad-Index", strconv.FormatUint(index, 10))
}
// setKnownLeader is used to set the known leader header
func setKnownLeader(resp http.ResponseWriter, known bool) {
s := "true"
if !known {
s = "false"
}
resp.Header().Set("X-Nomad-KnownLeader", s)
}
// setLastContact is used to set the last contact header
func setLastContact(resp http.ResponseWriter, last time.Duration) {
lastMsec := uint64(last / time.Millisecond)
resp.Header().Set("X-Nomad-LastContact", strconv.FormatUint(lastMsec, 10))
}
// setMeta is used to set the query response meta data
func setMeta(resp http.ResponseWriter, m *structs.QueryMeta) {
setIndex(resp, m.Index)
setLastContact(resp, m.LastContact)
setKnownLeader(resp, m.KnownLeader)
}
// setHeaders is used to set canonical response header fields
func setHeaders(resp http.ResponseWriter, headers map[string]string) {
for field, value := range headers {
resp.Header().Set(http.CanonicalHeaderKey(field), value)
}
}
// parseWait is used to parse the ?wait and ?index query params
// Returns true on error
func parseWait(resp http.ResponseWriter, req *http.Request, b *structs.QueryOptions) bool {
query := req.URL.Query()
if wait := query.Get("wait"); wait != "" {
dur, err := time.ParseDuration(wait)
if err != nil {
resp.WriteHeader(400)
resp.Write([]byte("Invalid wait time"))
return true
}
b.MaxQueryTime = dur
}
if idx := query.Get("index"); idx != "" {
index, err := strconv.ParseUint(idx, 10, 64)
if err != nil {
resp.WriteHeader(400)
resp.Write([]byte("Invalid index"))
return true
}
b.MinQueryIndex = index
}
return false
}
// parseConsistency is used to parse the ?stale query params.
func parseConsistency(req *http.Request, b *structs.QueryOptions) {
query := req.URL.Query()
if _, ok := query["stale"]; ok {
b.AllowStale = true
}
}
// parsePrefix is used to parse the ?prefix query param
func parsePrefix(req *http.Request, b *structs.QueryOptions) {
query := req.URL.Query()
if prefix := query.Get("prefix"); prefix != "" {
b.Prefix = prefix
}
}
// parseRegion is used to parse the ?region query param
func (s *HTTPServer) parseRegion(req *http.Request, r *string) {
if other := req.URL.Query().Get("region"); other != "" {
*r = other
} else if *r == "" {
*r = s.agent.config.Region
}
}
// parse is a convenience method for endpoints that need to parse multiple flags
func (s *HTTPServer) parse(resp http.ResponseWriter, req *http.Request, r *string, b *structs.QueryOptions) bool {
s.parseRegion(req, r)
parseConsistency(req, b)
parsePrefix(req, b)
return parseWait(resp, req, b)
}