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         "bytes"
   9         "database/sql"
  10         "encoding/json"
  11         "fmt"
  12         "io"
  13         "io/ioutil"
  14         "mime"
  15         "net/http"
  16         "net/url"
  17         "regexp"
  18         "strings"
  19
  20         "git.arvados.org/arvados.git/sdk/go/arvados"
  21         "git.arvados.org/arvados.git/sdk/go/auth"
  22         "github.com/jmcvetta/randutil"
  23 )
  24
  25 var pathPattern = `^/arvados/v1/%s(/([0-9a-z]{5})-%s-[0-9a-z]{15})?(.*)$`
  26 var wfRe = regexp.MustCompile(fmt.Sprintf(pathPattern, "workflows", "7fd4e"))
  27 var containersRe = regexp.MustCompile(fmt.Sprintf(pathPattern, "containers", "dz642"))
  28 var containerRequestsRe = regexp.MustCompile(fmt.Sprintf(pathPattern, "container_requests", "xvhdp"))
  29 var collectionsRe = regexp.MustCompile(fmt.Sprintf(pathPattern, "collections", "4zz18"))
  30 var collectionsByPDHRe = regexp.MustCompile(`^/arvados/v1/collections/([0-9a-fA-F]{32}\+[0-9]+)+$`)
  31 var linksRe = regexp.MustCompile(fmt.Sprintf(pathPattern, "links", "o0j2j"))
  32
  33 func (h *Handler) remoteClusterRequest(remoteID string, req *http.Request) (*http.Response, error) {
  34         remote, ok := h.Cluster.RemoteClusters[remoteID]
  35         if !ok {
  36                 return nil, HTTPError{fmt.Sprintf("no proxy available for cluster %v", remoteID), http.StatusNotFound}
  37         }
  38         scheme := remote.Scheme
  39         if scheme == "" {
  40                 scheme = "https"
  41         }
  42         saltedReq, err := h.saltAuthToken(req, remoteID)
  43         if err != nil {
  44                 return nil, err
  45         }
  46         urlOut := &url.URL{
  47                 Scheme:   scheme,
  48                 Host:     remote.Host,
  49                 Path:     saltedReq.URL.Path,
  50                 RawPath:  saltedReq.URL.RawPath,
  51                 RawQuery: saltedReq.URL.RawQuery,
  52         }
  53         client := h.secureClient
  54         if remote.Insecure {
  55                 client = h.insecureClient
  56         }
  57         return h.proxy.Do(saltedReq, urlOut, client)
  58 }
  59
  60 // Buffer request body, parse form parameters in request, and then
  61 // replace original body with the buffer so it can be re-read by
  62 // downstream proxy steps.
  63 func loadParamsFromForm(req *http.Request) error {
  64         var postBody *bytes.Buffer
  65         if ct := req.Header.Get("Content-Type"); ct == "" {
  66                 // Assume application/octet-stream, i.e., no form to parse.
  67         } else if ct, _, err := mime.ParseMediaType(ct); err != nil {
  68                 return err
  69         } else if ct == "application/x-www-form-urlencoded" && req.Body != nil {
  70                 var cl int64
  71                 if req.ContentLength > 0 {
  72                         cl = req.ContentLength
  73                 }
  74                 postBody = bytes.NewBuffer(make([]byte, 0, cl))
  75                 originalBody := req.Body
  76                 defer originalBody.Close()
  77                 req.Body = ioutil.NopCloser(io.TeeReader(req.Body, postBody))
  78         }
  79
  80         err := req.ParseForm()
  81         if err != nil {
  82                 return err
  83         }
  84
  85         if req.Body != nil && postBody != nil {
  86                 req.Body = ioutil.NopCloser(postBody)
  87         }
  88         return nil
  89 }
  90
  91 func (h *Handler) setupProxyRemoteCluster(next http.Handler) http.Handler {
  92         mux := http.NewServeMux()
  93
  94         wfHandler := &genericFederatedRequestHandler{next, h, wfRe, nil}
  95         containersHandler := &genericFederatedRequestHandler{next, h, containersRe, nil}
  96         containerRequestsHandler := &genericFederatedRequestHandler{next, h, containerRequestsRe,
  97                 []federatedRequestDelegate{remoteContainerRequestCreate}}
  98         collectionsRequestsHandler := &genericFederatedRequestHandler{next, h, collectionsRe,
  99                 []federatedRequestDelegate{fetchRemoteCollectionByUUID, fetchRemoteCollectionByPDH}}
 100         linksRequestsHandler := &genericFederatedRequestHandler{next, h, linksRe, nil}
 101
 102         mux.Handle("/arvados/v1/workflows", wfHandler)
 103         mux.Handle("/arvados/v1/workflows/", wfHandler)
 104         mux.Handle("/arvados/v1/containers", containersHandler)
 105         mux.Handle("/arvados/v1/containers/", containersHandler)
 106         mux.Handle("/arvados/v1/container_requests", containerRequestsHandler)
 107         mux.Handle("/arvados/v1/container_requests/", containerRequestsHandler)
 108         mux.Handle("/arvados/v1/collections", collectionsRequestsHandler)
 109         mux.Handle("/arvados/v1/collections/", collectionsRequestsHandler)
 110         mux.Handle("/arvados/v1/links", linksRequestsHandler)
 111         mux.Handle("/arvados/v1/links/", linksRequestsHandler)
 112         mux.Handle("/", next)
 113
 114         return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
 115                 parts := strings.Split(req.Header.Get("Authorization"), "/")
 116                 alreadySalted := (len(parts) == 3 && parts[0] == "Bearer v2" && len(parts[2]) == 40)
 117
 118                 if alreadySalted ||
 119                         strings.Index(req.Header.Get("Via"), "arvados-controller") != -1 {
 120                         // The token is already salted, or this is a
 121                         // request from another instance of
 122                         // arvados-controller.  In either case, we
 123                         // don't want to proxy this query, so just
 124                         // continue down the instance handler stack.
 125                         next.ServeHTTP(w, req)
 126                         return
 127                 }
 128
 129                 mux.ServeHTTP(w, req)
 130         })
 131
 132         return mux
 133 }
 134
 135 type CurrentUser struct {
 136         Authorization arvados.APIClientAuthorization
 137         UUID          string
 138 }
 139
 140 // validateAPItoken extracts the token from the provided http request,
 141 // checks it again api_client_authorizations table in the database,
 142 // and fills in the token scope and user UUID.  Does not handle remote
 143 // tokens unless they are already in the database and not expired.
 144 func (h *Handler) validateAPItoken(req *http.Request, token string) (*CurrentUser, error) {
 145         user := CurrentUser{Authorization: arvados.APIClientAuthorization{APIToken: token}}
 146         db, err := h.db(req)
 147         if err != nil {
 148                 return nil, err
 149         }
 150
 151         var uuid string
 152         if strings.HasPrefix(token, "v2/") {
 153                 sp := strings.Split(token, "/")
 154                 uuid = sp[1]
 155                 token = sp[2]
 156         }
 157         user.Authorization.APIToken = token
 158         var scopes string
 159         err = db.QueryRowContext(req.Context(), `SELECT api_client_authorizations.uuid, api_client_authorizations.scopes, 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`, token).Scan(&user.Authorization.UUID, &scopes, &user.UUID)
 160         if err != nil {
 161                 return nil, err
 162         }
 163         if uuid != "" && user.Authorization.UUID != uuid {
 164                 return nil, fmt.Errorf("UUID embedded in v2 token did not match record")
 165         }
 166         err = json.Unmarshal([]byte(scopes), &user.Authorization.Scopes)
 167         if err != nil {
 168                 return nil, err
 169         }
 170         return &user, nil
 171 }
 172
 173 func (h *Handler) createAPItoken(req *http.Request, userUUID string, scopes []string) (*arvados.APIClientAuthorization, error) {
 174         db, err := h.db(req)
 175         if err != nil {
 176                 return nil, err
 177         }
 178         rd, err := randutil.String(15, "abcdefghijklmnopqrstuvwxyz0123456789")
 179         if err != nil {
 180                 return nil, err
 181         }
 182         uuid := fmt.Sprintf("%v-gj3su-%v", h.Cluster.ClusterID, rd)
 183         token, err := randutil.String(50, "abcdefghijklmnopqrstuvwxyz0123456789")
 184         if err != nil {
 185                 return nil, err
 186         }
 187         if len(scopes) == 0 {
 188                 scopes = append(scopes, "all")
 189         }
 190         scopesjson, err := json.Marshal(scopes)
 191         if err != nil {
 192                 return nil, err
 193         }
 194         _, err = db.ExecContext(req.Context(),
 195                 `INSERT INTO api_client_authorizations
 196 (uuid, api_token, expires_at, scopes,
 197 user_id,
 198 api_client_id, created_at, updated_at)
 199 VALUES ($1, $2, CURRENT_TIMESTAMP + INTERVAL '2 weeks', $3,
 200 (SELECT id FROM users WHERE users.uuid=$4 LIMIT 1),
 201 0, CURRENT_TIMESTAMP, CURRENT_TIMESTAMP)`,
 202                 uuid, token, string(scopesjson), userUUID)
 203
 204         if err != nil {
 205                 return nil, err
 206         }
 207
 208         return &arvados.APIClientAuthorization{
 209                 UUID:      uuid,
 210                 APIToken:  token,
 211                 ExpiresAt: "",
 212                 Scopes:    scopes}, nil
 213 }
 214
 215 // Extract the auth token supplied in req, and replace it with a
 216 // salted token for the remote cluster.
 217 func (h *Handler) saltAuthToken(req *http.Request, remote string) (updatedReq *http.Request, err error) {
 218         updatedReq = (&http.Request{
 219                 Method:        req.Method,
 220                 URL:           req.URL,
 221                 Header:        req.Header,
 222                 Body:          req.Body,
 223                 ContentLength: req.ContentLength,
 224                 Host:          req.Host,
 225         }).WithContext(req.Context())
 226
 227         creds := auth.NewCredentials()
 228         creds.LoadTokensFromHTTPRequest(updatedReq)
 229         if len(creds.Tokens) == 0 && updatedReq.Header.Get("Content-Type") == "application/x-www-form-encoded" {
 230                 // Override ParseForm's 10MiB limit by ensuring
 231                 // req.Body is a *http.maxBytesReader.
 232                 updatedReq.Body = http.MaxBytesReader(nil, updatedReq.Body, 1<<28) // 256MiB. TODO: use MaxRequestSize from discovery doc or config.
 233                 if err := creds.LoadTokensFromHTTPRequestBody(updatedReq); err != nil {
 234                         return nil, err
 235                 }
 236                 // Replace req.Body with a buffer that re-encodes the
 237                 // form without api_token, in case we end up
 238                 // forwarding the request.
 239                 if updatedReq.PostForm != nil {
 240                         updatedReq.PostForm.Del("api_token")
 241                 }
 242                 updatedReq.Body = ioutil.NopCloser(bytes.NewBufferString(updatedReq.PostForm.Encode()))
 243         }
 244         if len(creds.Tokens) == 0 {
 245                 return updatedReq, nil
 246         }
 247
 248         token, err := auth.SaltToken(creds.Tokens[0], remote)
 249
 250         if err == auth.ErrObsoleteToken {
 251                 // If the token exists in our own database, salt it
 252                 // for the remote. Otherwise, assume it was issued by
 253                 // the remote, and pass it through unmodified.
 254                 currentUser, err := h.validateAPItoken(req, creds.Tokens[0])
 255                 if err == sql.ErrNoRows {
 256                         // Not ours; pass through unmodified.
 257                         token = creds.Tokens[0]
 258                 } else if err != nil {
 259                         return nil, err
 260                 } else {
 261                         // Found; make V2 version and salt it.
 262                         token, err = auth.SaltToken(currentUser.Authorization.TokenV2(), remote)
 263                         if err != nil {
 264                                 return nil, err
 265                         }
 266                 }
 267         } else if err != nil {
 268                 return nil, err
 269         }
 270         updatedReq.Header = http.Header{}
 271         for k, v := range req.Header {
 272                 if k != "Authorization" {
 273                         updatedReq.Header[k] = v
 274                 }
 275         }
 276         updatedReq.Header.Set("Authorization", "Bearer "+token)
 277
 278         // Remove api_token=... from the query string, in case we
 279         // end up forwarding the request.
 280         if values, err := url.ParseQuery(updatedReq.URL.RawQuery); err != nil {
 281                 return nil, err
 282         } else if _, ok := values["api_token"]; ok {
 283                 delete(values, "api_token")
 284                 updatedReq.URL = &url.URL{
 285                         Scheme:   req.URL.Scheme,
 286                         Host:     req.URL.Host,
 287                         Path:     req.URL.Path,
 288                         RawPath:  req.URL.RawPath,
 289                         RawQuery: values.Encode(),
 290                 }
 291         }
 292         return updatedReq, nil
 293 }