services/keepstore/router.go

   1 // Copyright (C) The Arvados Authors. All rights reserved.
   2 //
   3 // SPDX-License-Identifier: AGPL-3.0
   4
   5 package keepstore
   6
   7 import (
   8         "encoding/json"
   9         "errors"
  10         "fmt"
  11         "io"
  12         "net/http"
  13         "os"
  14         "strconv"
  15         "strings"
  16         "sync/atomic"
  17
  18         "git.arvados.org/arvados.git/lib/service"
  19         "git.arvados.org/arvados.git/sdk/go/arvados"
  20         "git.arvados.org/arvados.git/sdk/go/auth"
  21         "git.arvados.org/arvados.git/sdk/go/httpserver"
  22         "git.arvados.org/arvados.git/sdk/go/keepclient"
  23         "github.com/gorilla/mux"
  24 )
  25
  26 type router struct {
  27         http.Handler
  28         keepstore *keepstore
  29         puller    *puller
  30         trasher   *trasher
  31 }
  32
  33 func newRouter(keepstore *keepstore, puller *puller, trasher *trasher) service.Handler {
  34         rtr := &router{
  35                 keepstore: keepstore,
  36                 puller:    puller,
  37                 trasher:   trasher,
  38         }
  39         adminonly := func(h http.HandlerFunc) http.HandlerFunc {
  40                 return auth.RequireLiteralToken(keepstore.cluster.SystemRootToken, h).ServeHTTP
  41         }
  42
  43         r := mux.NewRouter()
  44         locatorPath := `/{locator:[0-9a-f]{32}.*}`
  45         get := r.Methods(http.MethodGet, http.MethodHead).Subrouter()
  46         get.HandleFunc(locatorPath, rtr.handleBlockRead)
  47         get.HandleFunc(`/index`, adminonly(rtr.handleIndex))
  48         get.HandleFunc(`/index/{prefix:[0-9a-f]{0,32}}`, adminonly(rtr.handleIndex))
  49         get.HandleFunc(`/mounts`, adminonly(rtr.handleMounts))
  50         get.HandleFunc(`/mounts/{uuid}/blocks`, adminonly(rtr.handleIndex))
  51         get.HandleFunc(`/mounts/{uuid}/blocks/{prefix:[0-9a-f]{0,32}}`, adminonly(rtr.handleIndex))
  52         put := r.Methods(http.MethodPut).Subrouter()
  53         put.HandleFunc(locatorPath, rtr.handleBlockWrite)
  54         put.HandleFunc(`/pull`, adminonly(rtr.handlePullList))
  55         put.HandleFunc(`/trash`, adminonly(rtr.handleTrashList))
  56         put.HandleFunc(`/untrash`+locatorPath, adminonly(rtr.handleUntrash))
  57         touch := r.Methods("TOUCH").Subrouter()
  58         touch.HandleFunc(locatorPath, adminonly(rtr.handleBlockTouch))
  59         delete := r.Methods(http.MethodDelete).Subrouter()
  60         delete.HandleFunc(locatorPath, adminonly(rtr.handleBlockTrash))
  61         options := r.Methods(http.MethodOptions).Subrouter()
  62         options.NewRoute().PathPrefix(`/`).HandlerFunc(rtr.handleOptions)
  63         r.NotFoundHandler = http.HandlerFunc(rtr.handleBadRequest)
  64         r.MethodNotAllowedHandler = http.HandlerFunc(rtr.handleBadRequest)
  65         rtr.Handler = corsHandler(auth.LoadToken(r))
  66         return rtr
  67 }
  68
  69 func (rtr *router) CheckHealth() error {
  70         return nil
  71 }
  72
  73 func (rtr *router) Done() <-chan struct{} {
  74         return nil
  75 }
  76
  77 func (rtr *router) handleBlockRead(w http.ResponseWriter, req *http.Request) {
  78         // Intervening proxies must not return a cached GET response
  79         // to a prior request if a X-Keep-Signature request header has
  80         // been added or changed.
  81         w.Header().Add("Vary", keepclient.XKeepSignature)
  82         var localLocator func(string)
  83         if strings.SplitN(req.Header.Get(keepclient.XKeepSignature), ",", 2)[0] == "local" {
  84                 localLocator = func(locator string) {
  85                         w.Header().Set(keepclient.XKeepLocator, locator)
  86                 }
  87         }
  88         out := w
  89         if req.Method == http.MethodHead {
  90                 out = discardWrite{ResponseWriter: w}
  91         } else if li, err := getLocatorInfo(mux.Vars(req)["locator"]); err != nil {
  92                 rtr.handleError(w, req, err)
  93                 return
  94         } else if li.size == 0 && li.hash != "d41d8cd98f00b204e9800998ecf8427e" {
  95                 // GET {hash} (with no size hint) is not allowed
  96                 // because we can't report md5 mismatches.
  97                 rtr.handleError(w, req, errMethodNotAllowed)
  98                 return
  99         }
 100         n, err := rtr.keepstore.BlockRead(req.Context(), arvados.BlockReadOptions{
 101                 Locator:      mux.Vars(req)["locator"],
 102                 WriteTo:      out,
 103                 LocalLocator: localLocator,
 104         })
 105         if err != nil && (n == 0 || req.Method == http.MethodHead) {
 106                 rtr.handleError(w, req, err)
 107                 return
 108         }
 109 }
 110
 111 func (rtr *router) handleBlockWrite(w http.ResponseWriter, req *http.Request) {
 112         dataSize, _ := strconv.Atoi(req.Header.Get("Content-Length"))
 113         replicas, _ := strconv.Atoi(req.Header.Get(keepclient.XKeepDesiredReplicas))
 114         resp, err := rtr.keepstore.BlockWrite(req.Context(), arvados.BlockWriteOptions{
 115                 Hash:           mux.Vars(req)["locator"],
 116                 Reader:         req.Body,
 117                 DataSize:       dataSize,
 118                 RequestID:      req.Header.Get("X-Request-Id"),
 119                 StorageClasses: trimSplit(req.Header.Get(keepclient.XKeepStorageClasses), ","),
 120                 Replicas:       replicas,
 121         })
 122         if err != nil {
 123                 rtr.handleError(w, req, err)
 124                 return
 125         }
 126         w.Header().Set(keepclient.XKeepReplicasStored, fmt.Sprintf("%d", resp.Replicas))
 127         scc := ""
 128         for k, n := range resp.StorageClasses {
 129                 if n > 0 {
 130                         if scc != "" {
 131                                 scc += "; "
 132                         }
 133                         scc += fmt.Sprintf("%s=%d", k, n)
 134                 }
 135         }
 136         w.Header().Set(keepclient.XKeepStorageClassesConfirmed, scc)
 137         w.WriteHeader(http.StatusOK)
 138         fmt.Fprintln(w, resp.Locator)
 139 }
 140
 141 func (rtr *router) handleBlockTouch(w http.ResponseWriter, req *http.Request) {
 142         err := rtr.keepstore.BlockTouch(req.Context(), mux.Vars(req)["locator"])
 143         rtr.handleError(w, req, err)
 144 }
 145
 146 func (rtr *router) handleBlockTrash(w http.ResponseWriter, req *http.Request) {
 147         err := rtr.keepstore.BlockTrash(req.Context(), mux.Vars(req)["locator"])
 148         rtr.handleError(w, req, err)
 149 }
 150
 151 func (rtr *router) handleMounts(w http.ResponseWriter, req *http.Request) {
 152         json.NewEncoder(w).Encode(rtr.keepstore.Mounts())
 153 }
 154
 155 func (rtr *router) handleIndex(w http.ResponseWriter, req *http.Request) {
 156         prefix := req.FormValue("prefix")
 157         if prefix == "" {
 158                 prefix = mux.Vars(req)["prefix"]
 159         }
 160         cw := &countingWriter{writer: w}
 161         err := rtr.keepstore.Index(req.Context(), indexOptions{
 162                 MountUUID: mux.Vars(req)["uuid"],
 163                 Prefix:    prefix,
 164                 WriteTo:   cw,
 165         })
 166         if err != nil && cw.n.Load() == 0 {
 167                 // Nothing was written, so it's not too late to report
 168                 // an error via http response header. (Otherwise, all
 169                 // we can do is omit the trailing newline below to
 170                 // indicate something went wrong.)
 171                 rtr.handleError(w, req, err)
 172                 return
 173         }
 174         if err == nil {
 175                 // A trailing blank line signals to the caller that
 176                 // the response is complete.
 177                 w.Write([]byte("\n"))
 178         }
 179 }
 180
 181 func (rtr *router) handlePullList(w http.ResponseWriter, req *http.Request) {
 182         var pl []PullListItem
 183         err := json.NewDecoder(req.Body).Decode(&pl)
 184         if err != nil {
 185                 rtr.handleError(w, req, err)
 186                 return
 187         }
 188         req.Body.Close()
 189         if len(pl) > 0 && len(pl[0].Locator) == 32 {
 190                 rtr.handleError(w, req, httpserver.ErrorWithStatus(errors.New("rejecting pull list containing a locator without a size hint -- this probably means keep-balance needs to be upgraded"), http.StatusBadRequest))
 191                 return
 192         }
 193         rtr.puller.SetPullList(pl)
 194 }
 195
 196 func (rtr *router) handleTrashList(w http.ResponseWriter, req *http.Request) {
 197         var tl []TrashListItem
 198         err := json.NewDecoder(req.Body).Decode(&tl)
 199         if err != nil {
 200                 rtr.handleError(w, req, err)
 201                 return
 202         }
 203         req.Body.Close()
 204         rtr.trasher.SetTrashList(tl)
 205 }
 206
 207 func (rtr *router) handleUntrash(w http.ResponseWriter, req *http.Request) {
 208         err := rtr.keepstore.BlockUntrash(req.Context(), mux.Vars(req)["locator"])
 209         rtr.handleError(w, req, err)
 210 }
 211
 212 func (rtr *router) handleBadRequest(w http.ResponseWriter, req *http.Request) {
 213         http.Error(w, "Bad Request", http.StatusBadRequest)
 214 }
 215
 216 func (rtr *router) handleOptions(w http.ResponseWriter, req *http.Request) {
 217 }
 218
 219 func (rtr *router) handleError(w http.ResponseWriter, req *http.Request, err error) {
 220         if req.Context().Err() != nil {
 221                 w.WriteHeader(499)
 222                 return
 223         }
 224         if err == nil {
 225                 return
 226         } else if os.IsNotExist(err) {
 227                 w.WriteHeader(http.StatusNotFound)
 228         } else if statusErr := interface{ HTTPStatus() int }(nil); errors.As(err, &statusErr) {
 229                 w.WriteHeader(statusErr.HTTPStatus())
 230         } else {
 231                 w.WriteHeader(http.StatusInternalServerError)
 232         }
 233         fmt.Fprintln(w, err.Error())
 234 }
 235
 236 type countingWriter struct {
 237         writer io.Writer
 238         n      atomic.Int64
 239 }
 240
 241 func (cw *countingWriter) Write(p []byte) (int, error) {
 242         n, err := cw.writer.Write(p)
 243         cw.n.Add(int64(n))
 244         return n, err
 245 }
 246
 247 // Split s by sep, trim whitespace from each part, and drop empty
 248 // parts.
 249 func trimSplit(s, sep string) []string {
 250         var r []string
 251         for _, part := range strings.Split(s, sep) {
 252                 part = strings.TrimSpace(part)
 253                 if part != "" {
 254                         r = append(r, part)
 255                 }
 256         }
 257         return r
 258 }
 259
 260 // setSizeOnWrite sets the Content-Length header to the given size on
 261 // first write.
 262 type setSizeOnWrite struct {
 263         http.ResponseWriter
 264         size  int
 265         wrote bool
 266 }
 267
 268 func (ss *setSizeOnWrite) Write(p []byte) (int, error) {
 269         if !ss.wrote {
 270                 ss.Header().Set("Content-Length", fmt.Sprintf("%d", ss.size))
 271                 ss.wrote = true
 272         }
 273         return ss.ResponseWriter.Write(p)
 274 }
 275
 276 type discardWrite struct {
 277         http.ResponseWriter
 278 }
 279
 280 func (discardWrite) Write(p []byte) (int, error) {
 281         return len(p), nil
 282 }
 283
 284 func corsHandler(h http.Handler) http.Handler {
 285         return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 286                 SetCORSHeaders(w)
 287                 h.ServeHTTP(w, r)
 288         })
 289 }
 290
 291 var corsHeaders = map[string]string{
 292         "Access-Control-Allow-Methods":  "GET, HEAD, PUT, OPTIONS",
 293         "Access-Control-Allow-Origin":   "*",
 294         "Access-Control-Allow-Headers":  "Authorization, Content-Length, Content-Type, " + keepclient.XKeepDesiredReplicas + ", " + keepclient.XKeepSignature + ", " + keepclient.XKeepStorageClasses,
 295         "Access-Control-Expose-Headers": keepclient.XKeepLocator + ", " + keepclient.XKeepReplicasStored + ", " + keepclient.XKeepStorageClassesConfirmed,
 296         "Access-Control-Max-Age":        "86486400",
 297 }
 298
 299 func SetCORSHeaders(w http.ResponseWriter) {
 300         for k, v := range corsHeaders {
 301                 w.Header().Set(k, v)
 302         }
 303 }