consul/agent/http.go

1101 lines
32 KiB
Go

package agent
import (
"encoding/json"
"fmt"
"io"
"net"
"net/http"
"net/http/pprof"
"net/url"
"reflect"
"regexp"
"strconv"
"strings"
"sync/atomic"
"time"
"github.com/NYTimes/gziphandler"
"github.com/armon/go-metrics"
"github.com/armon/go-metrics/prometheus"
"github.com/hashicorp/go-cleanhttp"
"github.com/mitchellh/mapstructure"
"github.com/pkg/errors"
"github.com/hashicorp/consul/acl"
"github.com/hashicorp/consul/agent/cache"
"github.com/hashicorp/consul/agent/config"
"github.com/hashicorp/consul/agent/consul"
"github.com/hashicorp/consul/agent/structs"
"github.com/hashicorp/consul/agent/uiserver"
"github.com/hashicorp/consul/api"
"github.com/hashicorp/consul/lib"
"github.com/hashicorp/consul/logging"
)
var HTTPSummaries = []prometheus.SummaryDefinition{
{
Name: []string{"api", "http"},
Help: "Samples how long it takes to service the given HTTP request for the given verb and path.",
},
}
// MethodNotAllowedError should be returned by a handler when the HTTP method is not allowed.
type MethodNotAllowedError struct {
Method string
Allow []string
}
func (e MethodNotAllowedError) Error() string {
return fmt.Sprintf("method %s not allowed", e.Method)
}
// BadRequestError should be returned by a handler when parameters or the payload are not valid
type BadRequestError struct {
Reason string
}
func (e BadRequestError) Error() string {
return fmt.Sprintf("Bad request: %s", e.Reason)
}
// NotFoundError should be returned by a handler when a resource specified does not exist
type NotFoundError struct {
Reason string
}
func (e NotFoundError) Error() string {
return e.Reason
}
// CodeWithPayloadError allow returning non HTTP 200
// Error codes while not returning PlainText payload
type CodeWithPayloadError struct {
Reason string
StatusCode int
ContentType string
}
func (e CodeWithPayloadError) Error() string {
return e.Reason
}
type ForbiddenError struct {
}
func (e ForbiddenError) Error() string {
return "Access is restricted"
}
// HTTPHandlers provides an HTTP api for an agent.
type HTTPHandlers struct {
agent *Agent
denylist *Denylist
configReloaders []ConfigReloader
h http.Handler
metricsProxyCfg atomic.Value
}
// endpoint is a Consul-specific HTTP handler that takes the usual arguments in
// but returns a response object and error, both of which are handled in a
// common manner by Consul's HTTP server.
type endpoint func(resp http.ResponseWriter, req *http.Request) (interface{}, error)
// unboundEndpoint is an endpoint method on a server.
type unboundEndpoint func(s *HTTPHandlers, resp http.ResponseWriter, req *http.Request) (interface{}, error)
// endpoints is a map from URL pattern to unbound endpoint.
var endpoints map[string]unboundEndpoint
// allowedMethods is a map from endpoint prefix to supported HTTP methods.
// An empty slice means an endpoint handles OPTIONS requests and MethodNotFound errors itself.
var allowedMethods map[string][]string = make(map[string][]string)
// registerEndpoint registers a new endpoint, which should be done at package
// init() time.
func registerEndpoint(pattern string, methods []string, fn unboundEndpoint) {
if endpoints == nil {
endpoints = make(map[string]unboundEndpoint)
}
if endpoints[pattern] != nil || allowedMethods[pattern] != nil {
panic(fmt.Errorf("Pattern %q is already registered", pattern))
}
endpoints[pattern] = fn
allowedMethods[pattern] = methods
}
// wrappedMux hangs on to the underlying mux for unit tests.
type wrappedMux struct {
mux *http.ServeMux
handler http.Handler
}
// ServeHTTP implements the http.Handler interface.
func (w *wrappedMux) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
w.handler.ServeHTTP(resp, req)
}
// ReloadConfig updates any internal state when the config is changed at
// runtime.
func (s *HTTPHandlers) ReloadConfig(newCfg *config.RuntimeConfig) error {
for _, r := range s.configReloaders {
if err := r(newCfg); err != nil {
return err
}
}
return nil
}
// handler is used to initialize the Handler. In agent code we only ever call
// this once during agent initialization so it was always intended as a single
// pass init method. However many test rely on it as a cheaper way to get a
// handler to call ServeHTTP against and end up calling it multiple times on a
// single agent instance. Until this method had to manage state that might be
// affected by a reload or otherwise vary over time that was not problematic
// although it was wasteful to redo all this setup work multiple times in one
// test.
//
// Now uiserver and possibly other components need to handle reloadable state
// having test randomly clobber the state with the original config again for
// each call gets confusing fast. So handler will memoize it's response - it's
// allowed to call it multiple times on the same agent, but it will only do the
// work the first time and return the same handler on subsequent calls.
//
// The `enableDebug` argument used in the first call will be effective and a
// later change will not do anything. The same goes for the initial config. For
// example if config is reloaded with UI enabled but it was not originally, the
// http.Handler returned will still have it disabled.
//
// The first call must not be concurrent with any other call. Subsequent calls
// may be concurrent with HTTP requests since no state is modified.
func (s *HTTPHandlers) handler(enableDebug bool) http.Handler {
// Memoize multiple calls.
if s.h != nil {
return s.h
}
mux := http.NewServeMux()
// handleFuncMetrics takes the given pattern and handler and wraps to produce
// metrics based on the pattern and request.
handleFuncMetrics := func(pattern string, handler http.HandlerFunc) {
// Get the parts of the pattern. We omit any initial empty for the
// leading slash, and put an underscore as a "thing" placeholder if we
// see a trailing slash, which means the part after is parsed. This lets
// us distinguish from things like /v1/query and /v1/query/<query id>.
var parts []string
for i, part := range strings.Split(pattern, "/") {
if part == "" {
if i == 0 {
continue
}
part = "_"
}
parts = append(parts, part)
}
// Tranform the pattern to a valid label by replacing the '/' by '_'.
// Omit the leading slash.
// Distinguish thing like /v1/query from /v1/query/<query_id> by having
// an extra underscore.
path_label := strings.Replace(pattern[1:], "/", "_", -1)
// Register the wrapper.
wrapper := func(resp http.ResponseWriter, req *http.Request) {
start := time.Now()
handler(resp, req)
labels := []metrics.Label{{Name: "method", Value: req.Method}, {Name: "path", Value: path_label}}
metrics.MeasureSinceWithLabels([]string{"api", "http"}, start, labels)
// DEPRECATED Emit pre-1.9 metric as `consul.http...` to maintain backwards compatibility. Enabled by
// default. Users may set `telemetry { disable_compat_1.9 = true }`
if !s.agent.config.Telemetry.DisableCompatOneNine {
key := append([]string{"http", req.Method}, parts...)
metrics.MeasureSince(key, start)
}
}
var gzipHandler http.Handler
minSize := gziphandler.DefaultMinSize
if pattern == "/v1/agent/monitor" {
minSize = 0
}
gzipWrapper, err := gziphandler.GzipHandlerWithOpts(gziphandler.MinSize(minSize))
if err == nil {
gzipHandler = gzipWrapper(http.HandlerFunc(wrapper))
} else {
gzipHandler = gziphandler.GzipHandler(http.HandlerFunc(wrapper))
}
mux.Handle(pattern, gzipHandler)
}
// handlePProf takes the given pattern and pprof handler
// and wraps it to add authorization and metrics
handlePProf := func(pattern string, handler http.HandlerFunc) {
wrapper := func(resp http.ResponseWriter, req *http.Request) {
var token string
s.parseToken(req, &token)
// If enableDebug is not set, and ACLs are disabled, write
// an unauthorized response
if !enableDebug && s.checkACLDisabled(resp, req) {
return
}
rule, err := s.agent.delegate.ResolveTokenAndDefaultMeta(token, nil, nil)
if err != nil {
resp.WriteHeader(http.StatusForbidden)
return
}
// If the token provided does not have the necessary permissions,
// write a forbidden response
if rule != nil && rule.OperatorRead(nil) != acl.Allow {
resp.WriteHeader(http.StatusForbidden)
return
}
// Call the pprof handler
handler(resp, req)
}
handleFuncMetrics(pattern, http.HandlerFunc(wrapper))
}
mux.HandleFunc("/", s.Index)
for pattern, fn := range endpoints {
thisFn := fn
methods := allowedMethods[pattern]
bound := func(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
return thisFn(s, resp, req)
}
handleFuncMetrics(pattern, s.wrap(bound, methods))
}
// Register wrapped pprof handlers
handlePProf("/debug/pprof/", pprof.Index)
handlePProf("/debug/pprof/cmdline", pprof.Cmdline)
handlePProf("/debug/pprof/profile", pprof.Profile)
handlePProf("/debug/pprof/symbol", pprof.Symbol)
handlePProf("/debug/pprof/trace", pprof.Trace)
if s.IsUIEnabled() {
// Note that we _don't_ support reloading ui_config.{enabled, content_dir,
// content_path} since this only runs at initial startup.
uiHandler := uiserver.NewHandler(
s.agent.config,
s.agent.logger.Named(logging.HTTP),
s.uiTemplateDataTransform,
)
s.configReloaders = append(s.configReloaders, uiHandler.ReloadConfig)
// Wrap it to add the headers specified by the http_config.response_headers
// user config
uiHandlerWithHeaders := serveHandlerWithHeaders(
uiHandler,
s.agent.config.HTTPResponseHeaders,
)
mux.Handle("/robots.txt", uiHandlerWithHeaders)
mux.Handle(
s.agent.config.UIConfig.ContentPath,
http.StripPrefix(
s.agent.config.UIConfig.ContentPath,
uiHandlerWithHeaders,
),
)
}
// Initialize (reloadable) metrics proxy config
s.metricsProxyCfg.Store(s.agent.config.UIConfig.MetricsProxy)
s.configReloaders = append(s.configReloaders, func(cfg *config.RuntimeConfig) error {
s.metricsProxyCfg.Store(cfg.UIConfig.MetricsProxy)
return nil
})
// Wrap the whole mux with a handler that bans URLs with non-printable
// characters, unless disabled explicitly to deal with old keys that fail this
// check.
h := cleanhttp.PrintablePathCheckHandler(mux, nil)
if s.agent.config.DisableHTTPUnprintableCharFilter {
h = mux
}
h = s.enterpriseHandler(h)
s.h = &wrappedMux{
mux: mux,
handler: h,
}
return s.h
}
// nodeName returns the node name of the agent
func (s *HTTPHandlers) nodeName() string {
return s.agent.config.NodeName
}
// aclEndpointRE is used to find old ACL endpoints that take tokens in the URL
// so that we can redact them. The ACL endpoints that take the token in the URL
// are all of the form /v1/acl/<verb>/<token>, and can optionally include query
// parameters which are indicated by a question mark. We capture the part before
// the token, the token, and any query parameters after, and then reassemble as
// $1<hidden>$3 (the token in $2 isn't used), which will give:
//
// /v1/acl/clone/foo -> /v1/acl/clone/<hidden>
// /v1/acl/clone/foo?token=bar -> /v1/acl/clone/<hidden>?token=<hidden>
//
// The query parameter in the example above is obfuscated like any other, after
// this regular expression is applied, so the regular expression substitution
// results in:
//
// /v1/acl/clone/foo?token=bar -> /v1/acl/clone/<hidden>?token=bar
// ^---- $1 ----^^- $2 -^^-- $3 --^
//
// And then the loop that looks for parameters called "token" does the last
// step to get to the final redacted form.
var (
aclEndpointRE = regexp.MustCompile("^(/v1/acl/(create|update|destroy|info|clone|list)/)([^?]+)([?]?.*)$")
)
// wrap is used to wrap functions to make them more convenient
func (s *HTTPHandlers) wrap(handler endpoint, methods []string) http.HandlerFunc {
httpLogger := s.agent.logger.Named(logging.HTTP)
return func(resp http.ResponseWriter, req *http.Request) {
setHeaders(resp, s.agent.config.HTTPResponseHeaders)
setTranslateAddr(resp, s.agent.config.TranslateWANAddrs)
setACLDefaultPolicy(resp, s.agent.config.ACLDefaultPolicy)
// Obfuscate any tokens from appearing in the logs
formVals, err := url.ParseQuery(req.URL.RawQuery)
if err != nil {
httpLogger.Error("Failed to decode query",
"from", req.RemoteAddr,
"error", err,
)
resp.WriteHeader(http.StatusInternalServerError)
return
}
logURL := req.URL.String()
if tokens, ok := formVals["token"]; ok {
for _, token := range tokens {
if token == "" {
logURL += "<hidden>"
continue
}
logURL = strings.Replace(logURL, token, "<hidden>", -1)
}
}
logURL = aclEndpointRE.ReplaceAllString(logURL, "$1<hidden>$4")
if s.denylist.Block(req.URL.Path) {
errMsg := "Endpoint is blocked by agent configuration"
httpLogger.Error("Request error",
"method", req.Method,
"url", logURL,
"from", req.RemoteAddr,
"error", errMsg,
)
resp.WriteHeader(http.StatusForbidden)
fmt.Fprint(resp, errMsg)
return
}
isForbidden := func(err error) bool {
if acl.IsErrPermissionDenied(err) || acl.IsErrNotFound(err) {
return true
}
_, ok := err.(ForbiddenError)
return ok
}
isMethodNotAllowed := func(err error) bool {
_, ok := err.(MethodNotAllowedError)
return ok
}
isBadRequest := func(err error) bool {
_, ok := err.(BadRequestError)
return ok
}
isNotFound := func(err error) bool {
_, ok := err.(NotFoundError)
return ok
}
isTooManyRequests := func(err error) bool {
// Sadness net/rpc can't do nice typed errors so this is all we got
return err.Error() == consul.ErrRateLimited.Error()
}
addAllowHeader := func(methods []string) {
resp.Header().Add("Allow", strings.Join(methods, ","))
}
handleErr := func(err error) {
if req.Context().Err() != nil {
httpLogger.Info("Request cancelled",
"method", req.Method,
"url", logURL,
"from", req.RemoteAddr,
"error", err)
} else {
httpLogger.Error("Request error",
"method", req.Method,
"url", logURL,
"from", req.RemoteAddr,
"error", err)
}
switch {
case isForbidden(err):
resp.WriteHeader(http.StatusForbidden)
fmt.Fprint(resp, err.Error())
case structs.IsErrRPCRateExceeded(err):
resp.WriteHeader(http.StatusTooManyRequests)
case isMethodNotAllowed(err):
// RFC2616 states that for 405 Method Not Allowed the response
// MUST include an Allow header containing the list of valid
// methods for the requested resource.
// https://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html
addAllowHeader(err.(MethodNotAllowedError).Allow)
resp.WriteHeader(http.StatusMethodNotAllowed) // 405
fmt.Fprint(resp, err.Error())
case isBadRequest(err):
resp.WriteHeader(http.StatusBadRequest)
fmt.Fprint(resp, err.Error())
case isNotFound(err):
resp.WriteHeader(http.StatusNotFound)
fmt.Fprint(resp, err.Error())
case isTooManyRequests(err):
resp.WriteHeader(http.StatusTooManyRequests)
fmt.Fprint(resp, err.Error())
default:
resp.WriteHeader(http.StatusInternalServerError)
fmt.Fprint(resp, err.Error())
}
}
start := time.Now()
defer func() {
httpLogger.Debug("Request finished",
"method", req.Method,
"url", logURL,
"from", req.RemoteAddr,
"latency", time.Since(start).String(),
)
}()
var obj interface{}
// if this endpoint has declared methods, respond appropriately to OPTIONS requests. Otherwise let the endpoint handle that.
if req.Method == "OPTIONS" && len(methods) > 0 {
addAllowHeader(append([]string{"OPTIONS"}, methods...))
return
}
// if this endpoint has declared methods, check the request method. Otherwise let the endpoint handle that.
methodFound := len(methods) == 0
for _, method := range methods {
if method == req.Method {
methodFound = true
break
}
}
if !methodFound {
err = MethodNotAllowedError{req.Method, append([]string{"OPTIONS"}, methods...)}
} else {
err = s.checkWriteAccess(req)
if err == nil {
// Invoke the handler
obj, err = handler(resp, req)
}
}
contentType := "application/json"
httpCode := http.StatusOK
if err != nil {
if errPayload, ok := err.(CodeWithPayloadError); ok {
httpCode = errPayload.StatusCode
if errPayload.ContentType != "" {
contentType = errPayload.ContentType
}
if errPayload.Reason != "" {
resp.Header().Add("X-Consul-Reason", errPayload.Reason)
}
} else {
handleErr(err)
return
}
}
if obj == nil {
return
}
var buf []byte
if contentType == "application/json" {
buf, err = s.marshalJSON(req, obj)
if err != nil {
handleErr(err)
return
}
} else {
if strings.HasPrefix(contentType, "text/") {
if val, ok := obj.(string); ok {
buf = []byte(val)
}
}
}
resp.Header().Set("Content-Type", contentType)
resp.WriteHeader(httpCode)
resp.Write(buf)
}
}
// marshalJSON marshals the object into JSON, respecting the user's pretty-ness
// configuration.
func (s *HTTPHandlers) marshalJSON(req *http.Request, obj interface{}) ([]byte, error) {
if _, ok := req.URL.Query()["pretty"]; ok || s.agent.config.DevMode {
buf, err := json.MarshalIndent(obj, "", " ")
if err != nil {
return nil, err
}
buf = append(buf, "\n"...)
return buf, nil
}
buf, err := json.Marshal(obj)
if err != nil {
return nil, err
}
return buf, nil
}
// Returns true if the UI is enabled.
func (s *HTTPHandlers) IsUIEnabled() bool {
// Note that we _don't_ support reloading ui_config.{enabled,content_dir}
// since this only runs at initial startup.
return s.agent.config.UIConfig.Dir != "" || s.agent.config.UIConfig.Enabled
}
// Renders a simple index page
func (s *HTTPHandlers) Index(resp http.ResponseWriter, req *http.Request) {
// Send special headers too since this endpoint isn't wrapped with something
// that sends them.
setHeaders(resp, s.agent.config.HTTPResponseHeaders)
// Check if this is a non-index path
if req.URL.Path != "/" {
resp.WriteHeader(http.StatusNotFound)
return
}
// Give them something helpful if there's no UI so they at least know
// what this server is.
if !s.IsUIEnabled() {
fmt.Fprint(resp, "Consul Agent")
return
}
// Redirect to the UI endpoint
http.Redirect(
resp,
req,
s.agent.config.UIConfig.ContentPath,
http.StatusMovedPermanently,
) // 301
}
func decodeBody(body io.Reader, out interface{}) error {
return lib.DecodeJSON(body, out)
}
// decodeBodyDeprecated is deprecated, please ues decodeBody above.
// decodeBodyDeprecated is used to decode a JSON request body
func decodeBodyDeprecated(req *http.Request, out interface{}, cb func(interface{}) error) error {
// This generally only happens in tests since real HTTP requests set
// a non-nil body with no content. We guard against it anyways to prevent
// a panic. The EOF response is the same behavior as an empty reader.
if req.Body == nil {
return io.EOF
}
var raw interface{}
dec := json.NewDecoder(req.Body)
if err := dec.Decode(&raw); err != nil {
return err
}
// Invoke the callback prior to decode
if cb != nil {
if err := cb(raw); err != nil {
return err
}
}
decodeConf := &mapstructure.DecoderConfig{
DecodeHook: mapstructure.ComposeDecodeHookFunc(
mapstructure.StringToTimeDurationHookFunc(),
mapstructure.StringToTimeHookFunc(time.RFC3339),
stringToReadableDurationFunc(),
),
Result: &out,
}
decoder, err := mapstructure.NewDecoder(decodeConf)
if err != nil {
return err
}
return decoder.Decode(raw)
}
// stringToReadableDurationFunc is a mapstructure hook for decoding a string
// into an api.ReadableDuration for backwards compatibility.
func stringToReadableDurationFunc() mapstructure.DecodeHookFunc {
return func(
f reflect.Type,
t reflect.Type,
data interface{}) (interface{}, error) {
var v api.ReadableDuration
if t != reflect.TypeOf(v) {
return data, nil
}
switch {
case f.Kind() == reflect.String:
if dur, err := time.ParseDuration(data.(string)); err != nil {
return nil, err
} else {
v = api.ReadableDuration(dur)
}
return v, nil
default:
return data, nil
}
}
}
// setTranslateAddr is used to set the address translation header. This is only
// present if the feature is active.
func setTranslateAddr(resp http.ResponseWriter, active bool) {
if active {
resp.Header().Set("X-Consul-Translate-Addresses", "true")
}
}
// setIndex is used to set the index response header
func setIndex(resp http.ResponseWriter, index uint64) {
// If we ever return X-Consul-Index of 0 blocking clients will go into a busy
// loop and hammer us since ?index=0 will never block. It's always safe to
// return index=1 since the very first Raft write is always an internal one
// writing the raft config for the cluster so no user-facing blocking query
// will ever legitimately have an X-Consul-Index of 1.
if index == 0 {
index = 1
}
resp.Header().Set("X-Consul-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-Consul-KnownLeader", s)
}
func setConsistency(resp http.ResponseWriter, consistency string) {
if consistency != "" {
resp.Header().Set("X-Consul-Effective-Consistency", consistency)
}
}
func setACLDefaultPolicy(resp http.ResponseWriter, aclDefaultPolicy string) {
if aclDefaultPolicy != "" {
resp.Header().Set("X-Consul-Default-ACL-Policy", aclDefaultPolicy)
}
}
// setLastContact is used to set the last contact header
func setLastContact(resp http.ResponseWriter, last time.Duration) {
if last < 0 {
last = 0
}
lastMsec := uint64(last / time.Millisecond)
resp.Header().Set("X-Consul-LastContact", strconv.FormatUint(lastMsec, 10))
}
// setMeta is used to set the query response meta data
func setMeta(resp http.ResponseWriter, m structs.QueryMetaCompat) {
setIndex(resp, m.GetIndex())
setLastContact(resp, m.GetLastContact())
setKnownLeader(resp, m.GetKnownLeader())
setConsistency(resp, m.GetConsistencyLevel())
setQueryBackend(resp, m.GetBackend())
}
func setQueryBackend(resp http.ResponseWriter, backend structs.QueryBackend) {
if b := backend.String(); b != "" {
resp.Header().Set("X-Consul-Query-Backend", b)
}
}
// setCacheMeta sets http response headers to indicate cache status.
func setCacheMeta(resp http.ResponseWriter, m *cache.ResultMeta) {
if m == nil {
return
}
str := "MISS"
if m.Hit {
str = "HIT"
}
resp.Header().Set("X-Cache", str)
if m.Hit {
resp.Header().Set("Age", fmt.Sprintf("%.0f", m.Age.Seconds()))
}
}
// 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)
}
}
// serveHandlerWithHeaders is used to serve a http.Handler with the specified headers
func serveHandlerWithHeaders(h http.Handler, headers map[string]string) http.HandlerFunc {
return func(resp http.ResponseWriter, req *http.Request) {
setHeaders(resp, headers)
h.ServeHTTP(resp, req)
}
}
// 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.QueryOptionsCompat) bool {
query := req.URL.Query()
if wait := query.Get("wait"); wait != "" {
dur, err := time.ParseDuration(wait)
if err != nil {
resp.WriteHeader(http.StatusBadRequest)
fmt.Fprint(resp, "Invalid wait time")
return true
}
b.SetMaxQueryTime(dur)
}
if idx := query.Get("index"); idx != "" {
index, err := strconv.ParseUint(idx, 10, 64)
if err != nil {
resp.WriteHeader(http.StatusBadRequest)
fmt.Fprint(resp, "Invalid index")
return true
}
b.SetMinQueryIndex(index)
}
return false
}
// parseCacheControl parses the CacheControl HTTP header value. So far we only
// support maxage directive.
func parseCacheControl(resp http.ResponseWriter, req *http.Request, b structs.QueryOptionsCompat) bool {
raw := strings.ToLower(req.Header.Get("Cache-Control"))
if raw == "" {
return false
}
// Didn't want to import a full parser for this. While quoted strings are
// allowed in some directives, max-age does not allow them per
// https://tools.ietf.org/html/rfc7234#section-5.2.2.8 so we assume all
// well-behaved clients use the exact token form of max-age=<delta-seconds>
// where delta-seconds is a non-negative decimal integer.
directives := strings.Split(raw, ",")
parseDurationOrFail := func(raw string) (time.Duration, bool) {
i, err := strconv.Atoi(raw)
if err != nil {
resp.WriteHeader(http.StatusBadRequest)
fmt.Fprint(resp, "Invalid Cache-Control header.")
return 0, true
}
return time.Duration(i) * time.Second, false
}
for _, d := range directives {
d = strings.ToLower(strings.TrimSpace(d))
if d == "must-revalidate" {
b.SetMustRevalidate(true)
}
if strings.HasPrefix(d, "max-age=") {
d, failed := parseDurationOrFail(d[8:])
if failed {
return true
}
b.SetMaxAge(d)
if d == 0 {
// max-age=0 specifically means that we need to consider the cache stale
// immediately however MaxAge = 0 is indistinguishable from the default
// where MaxAge is unset.
b.SetMustRevalidate(true)
}
}
if strings.HasPrefix(d, "stale-if-error=") {
d, failed := parseDurationOrFail(d[15:])
if failed {
return true
}
b.SetStaleIfError(d)
}
}
return false
}
// parseConsistency is used to parse the ?stale and ?consistent query params.
// Returns true on error
func (s *HTTPHandlers) parseConsistency(resp http.ResponseWriter, req *http.Request, b structs.QueryOptionsCompat) bool {
query := req.URL.Query()
defaults := true
if _, ok := query["stale"]; ok {
b.SetAllowStale(true)
defaults = false
}
if _, ok := query["consistent"]; ok {
b.SetRequireConsistent(true)
defaults = false
}
if _, ok := query["leader"]; ok {
defaults = false
}
if _, ok := query["cached"]; ok && s.agent.config.HTTPUseCache {
b.SetUseCache(true)
defaults = false
}
if maxStale := query.Get("max_stale"); maxStale != "" {
dur, err := time.ParseDuration(maxStale)
if err != nil {
resp.WriteHeader(http.StatusBadRequest)
fmt.Fprintf(resp, "Invalid max_stale value %q", maxStale)
return true
}
b.SetMaxStaleDuration(dur)
if dur.Nanoseconds() > 0 {
b.SetAllowStale(true)
defaults = false
}
}
// No specific Consistency has been specified by caller
if defaults {
path := req.URL.Path
if strings.HasPrefix(path, "/v1/catalog") || strings.HasPrefix(path, "/v1/health") {
if s.agent.config.DiscoveryMaxStale.Nanoseconds() > 0 {
b.SetMaxStaleDuration(s.agent.config.DiscoveryMaxStale)
b.SetAllowStale(true)
}
}
}
if b.GetAllowStale() && b.GetRequireConsistent() {
resp.WriteHeader(http.StatusBadRequest)
fmt.Fprint(resp, "Cannot specify ?stale with ?consistent, conflicting semantics.")
return true
}
if b.GetUseCache() && b.GetRequireConsistent() {
resp.WriteHeader(http.StatusBadRequest)
fmt.Fprint(resp, "Cannot specify ?cached with ?consistent, conflicting semantics.")
return true
}
return false
}
// parseDC is used to parse the ?dc query param
func (s *HTTPHandlers) parseDC(req *http.Request, dc *string) {
if other := req.URL.Query().Get("dc"); other != "" {
*dc = other
} else if *dc == "" {
*dc = s.agent.config.Datacenter
}
}
// parseTokenInternal is used to parse the ?token query param or the X-Consul-Token header or
// Authorization Bearer token (RFC6750).
func (s *HTTPHandlers) parseTokenInternal(req *http.Request, token *string) {
if other := req.URL.Query().Get("token"); other != "" {
*token = other
return
}
if ok := s.parseTokenFromHeaders(req, token); ok {
return
}
*token = ""
return
}
func (s *HTTPHandlers) parseTokenFromHeaders(req *http.Request, token *string) bool {
if other := req.Header.Get("X-Consul-Token"); other != "" {
*token = other
return true
}
if other := req.Header.Get("Authorization"); other != "" {
// HTTP Authorization headers are in the format: <Scheme>[SPACE]<Value>
// Ref. https://tools.ietf.org/html/rfc7236#section-3
parts := strings.Split(other, " ")
// Authorization Header is invalid if containing 1 or 0 parts, e.g.:
// "" || "<Scheme><Value>" || "<Scheme>" || "<Value>"
if len(parts) > 1 {
scheme := parts[0]
// Everything after "<Scheme>" is "<Value>", trimmed
value := strings.TrimSpace(strings.Join(parts[1:], " "))
// <Scheme> must be "Bearer"
if strings.ToLower(scheme) == "bearer" {
// Since Bearer tokens shouldn't contain spaces (rfc6750#section-2.1)
// "value" is tokenized, only the first item is used
*token = strings.TrimSpace(strings.Split(value, " ")[0])
return true
}
}
}
return false
}
func (s *HTTPHandlers) clearTokenFromHeaders(req *http.Request) {
req.Header.Del("X-Consul-Token")
req.Header.Del("Authorization")
}
// parseTokenWithDefault passes through to parseTokenInternal and optionally resolves proxy tokens to real ACL tokens.
// If the token is invalid or not specified it will populate the token with the agents UserToken (acl_token in the
// consul configuration)
func (s *HTTPHandlers) parseTokenWithDefault(req *http.Request, token *string) {
s.parseTokenInternal(req, token) // parseTokenInternal modifies *token
if token != nil && *token == "" {
*token = s.agent.tokens.UserToken()
return
}
return
}
// parseToken is used to parse the ?token query param or the X-Consul-Token header or
// Authorization Bearer token header (RFC6750). This function is used widely in Consul's endpoints
func (s *HTTPHandlers) parseToken(req *http.Request, token *string) {
s.parseTokenWithDefault(req, token)
}
func sourceAddrFromRequest(req *http.Request) string {
xff := req.Header.Get("X-Forwarded-For")
forwardHosts := strings.Split(xff, ",")
if len(forwardHosts) > 0 {
forwardIp := net.ParseIP(strings.TrimSpace(forwardHosts[0]))
if forwardIp != nil {
return forwardIp.String()
}
}
host, _, err := net.SplitHostPort(req.RemoteAddr)
if err != nil {
return ""
}
ip := net.ParseIP(host)
if ip != nil {
return ip.String()
} else {
return ""
}
}
// parseSource is used to parse the ?near=<node> query parameter, used for
// sorting by RTT based on a source node. We set the source's DC to the target
// DC in the request, if given, or else the agent's DC.
func (s *HTTPHandlers) parseSource(req *http.Request, source *structs.QuerySource) {
s.parseDC(req, &source.Datacenter)
source.Ip = sourceAddrFromRequest(req)
if node := req.URL.Query().Get("near"); node != "" {
if node == "_agent" {
source.Node = s.agent.config.NodeName
} else {
source.Node = node
}
}
}
// parseMetaFilter is used to parse the ?node-meta=key:value query parameter, used for
// filtering results to nodes with the given metadata key/value
func (s *HTTPHandlers) parseMetaFilter(req *http.Request) map[string]string {
if filterList, ok := req.URL.Query()["node-meta"]; ok {
filters := make(map[string]string)
for _, filter := range filterList {
key, value := parseMetaPair(filter)
filters[key] = value
}
return filters
}
return nil
}
func parseMetaPair(raw string) (string, string) {
pair := strings.SplitN(raw, ":", 2)
if len(pair) == 2 {
return pair[0], pair[1]
}
return pair[0], ""
}
// parse is a convenience method for endpoints that need to use both parseWait
// and parseDC.
func (s *HTTPHandlers) parse(resp http.ResponseWriter, req *http.Request, dc *string, b structs.QueryOptionsCompat) bool {
s.parseDC(req, dc)
var token string
s.parseTokenWithDefault(req, &token)
b.SetToken(token)
var filter string
s.parseFilter(req, &filter)
b.SetFilter(filter)
if s.parseConsistency(resp, req, b) {
return true
}
if parseCacheControl(resp, req, b) {
return true
}
return parseWait(resp, req, b)
}
func (s *HTTPHandlers) checkWriteAccess(req *http.Request) error {
if req.Method == http.MethodGet || req.Method == http.MethodHead || req.Method == http.MethodOptions {
return nil
}
allowed := s.agent.config.AllowWriteHTTPFrom
if len(allowed) == 0 {
return nil
}
ipStr, _, err := net.SplitHostPort(req.RemoteAddr)
if err != nil {
return errors.Wrap(err, "unable to parse remote addr")
}
ip := net.ParseIP(ipStr)
for _, n := range allowed {
if n.Contains(ip) {
return nil
}
}
return ForbiddenError{}
}
func (s *HTTPHandlers) parseFilter(req *http.Request, filter *string) {
if other := req.URL.Query().Get("filter"); other != "" {
*filter = other
}
}