lib/controller/federation.go

   1 // Copyright (C) The Arvados Authors. All rights reserved.
   2 //
   3 // SPDX-License-Identifier: AGPL-3.0
   4
   5 package controller
   6
   7 import (
   8         "bufio"
   9         "bytes"
  10         "database/sql"
  11         "encoding/json"
  12         "fmt"
  13         "io/ioutil"
  14         "net/http"
  15         "net/url"
  16         "regexp"
  17         "strings"
  18
  19         "git.curoverse.com/arvados.git/sdk/go/arvados"
  20         "git.curoverse.com/arvados.git/sdk/go/auth"
  21         "git.curoverse.com/arvados.git/sdk/go/httpserver"
  22 )
  23
  24 var wfRe = regexp.MustCompile(`^/arvados/v1/workflows/([0-9a-z]{5})-[^/]+$`)
  25 var collectionRe = regexp.MustCompile(`^/arvados/v1/collections/([0-9a-z]{5})-[^/]+$`)
  26
  27 type GenericFederatedRequestHandler struct {
  28         next    http.Handler
  29         handler *Handler
  30 }
  31
  32 type CollectionFederatedRequestHandler struct {
  33         next    http.Handler
  34         handler *Handler
  35 }
  36
  37 func (h *Handler) remoteClusterRequest(remoteID string, w http.ResponseWriter, req *http.Request, filter ResponseFilter) {
  38         remote, ok := h.Cluster.RemoteClusters[remoteID]
  39         if !ok {
  40                 httpserver.Error(w, "no proxy available for cluster "+remoteID, http.StatusNotFound)
  41                 return
  42         }
  43         scheme := remote.Scheme
  44         if scheme == "" {
  45                 scheme = "https"
  46         }
  47         err := h.saltAuthToken(req, remoteID)
  48         if err != nil {
  49                 httpserver.Error(w, err.Error(), http.StatusBadRequest)
  50                 return
  51         }
  52         urlOut := &url.URL{
  53                 Scheme:   scheme,
  54                 Host:     remote.Host,
  55                 Path:     req.URL.Path,
  56                 RawPath:  req.URL.RawPath,
  57                 RawQuery: req.URL.RawQuery,
  58         }
  59         client := h.secureClient
  60         if remote.Insecure {
  61                 client = h.insecureClient
  62         }
  63         h.proxy.Do(w, req, urlOut, client, filter)
  64 }
  65
  66 func (h *GenericFederatedRequestHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
  67         m := wfRe.FindStringSubmatch(req.URL.Path)
  68         if len(m) < 2 || m[1] == h.handler.Cluster.ClusterID {
  69                 h.next.ServeHTTP(w, req)
  70                 return
  71         }
  72         h.handler.remoteClusterRequest(m[1], w, req, nil)
  73 }
  74
  75 var SignedLocatorPattern = regexp.MustCompile(
  76         `^([0-9a-fA-F]{32}\+[0-9]+)((\+[B-Z][A-Za-z0-9@_-]*)*)(\+A[A-Za-z0-9@_-]*)((\+[B-Z][A-Za-z0-9@_-]*)*)$`)
  77
  78 type rewriteSignaturesClusterId string
  79
  80 func (clusterId rewriteSignaturesClusterId) rewriteSignatures(resp *http.Response) (newResponse *http.Response, err error) {
  81         if resp.StatusCode != 200 {
  82                 return resp, nil
  83         }
  84
  85         originalBody := resp.Body
  86         defer originalBody.Close()
  87
  88         var col arvados.Collection
  89         err = json.NewDecoder(resp.Body).Decode(&col)
  90         if err != nil {
  91                 return nil, err
  92         }
  93
  94         // rewriting signatures will make manifest text 5-10% bigger so calculate
  95         // capacity accordingly
  96         updatedManifest := bytes.NewBuffer(make([]byte, 0, len(col.ManifestText)+(len(col.ManifestText)/10)))
  97
  98         scanner := bufio.NewScanner(strings.NewReader(col.ManifestText))
  99         scanner.Buffer(make([]byte, 1048576), len(col.ManifestText))
 100         for scanner.Scan() {
 101                 line := scanner.Text()
 102                 tokens := strings.Split(line, " ")
 103                 if len(tokens) < 3 {
 104                         return nil, fmt.Errorf("Invalid stream (<3 tokens): %q", line)
 105                 }
 106
 107                 updatedManifest.WriteString(tokens[0])
 108                 for _, token := range tokens[1:] {
 109                         updatedManifest.WriteString(" ")
 110                         m := SignedLocatorPattern.FindStringSubmatch(token)
 111                         if m != nil {
 112                                 // Rewrite the block signature to be a remote signature
 113                                 fmt.Fprintf(updatedManifest, "%s%s+R%s-%s%s", m[1], m[2], clusterId, m[4][2:], m[5])
 114                         } else {
 115                                 updatedManifest.WriteString(token)
 116                         }
 117
 118                 }
 119                 updatedManifest.WriteString("\n")
 120         }
 121
 122         col.ManifestText = updatedManifest.String()
 123
 124         newbody, err := json.Marshal(col)
 125         if err != nil {
 126                 return nil, err
 127         }
 128
 129         buf := bytes.NewBuffer(newbody)
 130         resp.Body = ioutil.NopCloser(buf)
 131         resp.ContentLength = int64(buf.Len())
 132         resp.Header.Set("Content-Length", fmt.Sprintf("%v", buf.Len()))
 133
 134         return resp, nil
 135 }
 136
 137 func (h *CollectionFederatedRequestHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 138         m := collectionRe.FindStringSubmatch(req.URL.Path)
 139         if len(m) < 2 || m[1] == h.handler.Cluster.ClusterID {
 140                 h.next.ServeHTTP(w, req)
 141                 return
 142         }
 143         h.handler.remoteClusterRequest(m[1], w, req,
 144                 rewriteSignaturesClusterId(m[1]).rewriteSignatures)
 145 }
 146
 147 func (h *Handler) setupProxyRemoteCluster(next http.Handler) http.Handler {
 148         mux := http.NewServeMux()
 149         mux.Handle("/arvados/v1/workflows", next)
 150         mux.Handle("/arvados/v1/workflows/", &GenericFederatedRequestHandler{next, h})
 151         mux.Handle("/arvados/v1/collections/", &CollectionFederatedRequestHandler{next, h})
 152         mux.Handle("/", next)
 153
 154         return mux
 155 }
 156
 157 type CurrentUser struct {
 158         Authorization arvados.APIClientAuthorization
 159         UUID          string
 160 }
 161
 162 func (h *Handler) validateAPItoken(req *http.Request, user *CurrentUser) error {
 163         db, err := h.db(req)
 164         if err != nil {
 165                 return err
 166         }
 167         return db.QueryRowContext(req.Context(), `SELECT api_client_authorizations.uuid, users.uuid FROM api_client_authorizations JOIN users on api_client_authorizations.user_id=users.id WHERE api_token=$1 AND (expires_at IS NULL OR expires_at > current_timestamp) LIMIT 1`, user.Authorization.APIToken).Scan(&user.Authorization.UUID, &user.UUID)
 168 }
 169
 170 // Extract the auth token supplied in req, and replace it with a
 171 // salted token for the remote cluster.
 172 func (h *Handler) saltAuthToken(req *http.Request, remote string) error {
 173         creds := auth.NewCredentials()
 174         creds.LoadTokensFromHTTPRequest(req)
 175         if len(creds.Tokens) == 0 && req.Header.Get("Content-Type") == "application/x-www-form-encoded" {
 176                 // Override ParseForm's 10MiB limit by ensuring
 177                 // req.Body is a *http.maxBytesReader.
 178                 req.Body = http.MaxBytesReader(nil, req.Body, 1<<28) // 256MiB. TODO: use MaxRequestSize from discovery doc or config.
 179                 if err := creds.LoadTokensFromHTTPRequestBody(req); err != nil {
 180                         return err
 181                 }
 182                 // Replace req.Body with a buffer that re-encodes the
 183                 // form without api_token, in case we end up
 184                 // forwarding the request.
 185                 if req.PostForm != nil {
 186                         req.PostForm.Del("api_token")
 187                 }
 188                 req.Body = ioutil.NopCloser(bytes.NewBufferString(req.PostForm.Encode()))
 189         }
 190         if len(creds.Tokens) == 0 {
 191                 return nil
 192         }
 193         token, err := auth.SaltToken(creds.Tokens[0], remote)
 194         if err == auth.ErrObsoleteToken {
 195                 // If the token exists in our own database, salt it
 196                 // for the remote. Otherwise, assume it was issued by
 197                 // the remote, and pass it through unmodified.
 198                 currentUser := CurrentUser{Authorization: arvados.APIClientAuthorization{APIToken: creds.Tokens[0]}}
 199                 err = h.validateAPItoken(req, &currentUser)
 200                 if err == sql.ErrNoRows {
 201                         // Not ours; pass through unmodified.
 202                         token = currentUser.Authorization.APIToken
 203                 } else if err != nil {
 204                         return err
 205                 } else {
 206                         // Found; make V2 version and salt it.
 207                         token, err = auth.SaltToken(currentUser.Authorization.TokenV2(), remote)
 208                         if err != nil {
 209                                 return err
 210                         }
 211                 }
 212         } else if err != nil {
 213                 return err
 214         }
 215         req.Header.Set("Authorization", "Bearer "+token)
 216
 217         // Remove api_token=... from the the query string, in case we
 218         // end up forwarding the request.
 219         if values, err := url.ParseQuery(req.URL.RawQuery); err != nil {
 220                 return err
 221         } else if _, ok := values["api_token"]; ok {
 222                 delete(values, "api_token")
 223                 req.URL.RawQuery = values.Encode()
 224         }
 225         return nil
 226 }