Files
kopia/internal/server/server.go

652 lines
21 KiB
Go

// Package server implements Kopia API server handlers.
package server
import (
"context"
"encoding/json"
"io"
"net/http"
"net/url"
"sync"
"time"
"github.com/golang-jwt/jwt/v4"
"github.com/google/uuid"
"github.com/gorilla/mux"
"github.com/pkg/errors"
"github.com/kopia/kopia/internal/auth"
"github.com/kopia/kopia/internal/clock"
"github.com/kopia/kopia/internal/passwordpersist"
"github.com/kopia/kopia/internal/serverapi"
"github.com/kopia/kopia/internal/uitask"
"github.com/kopia/kopia/repo"
"github.com/kopia/kopia/repo/logging"
"github.com/kopia/kopia/repo/maintenance"
"github.com/kopia/kopia/snapshot"
"github.com/kopia/kopia/snapshot/policy"
"github.com/kopia/kopia/snapshot/snapshotmaintenance"
)
var log = logging.Module("kopia/server")
const (
maintenanceAttemptFrequency = 10 * time.Minute
kopiaAuthCookie = "Kopia-Auth"
kopiaAuthCookieTTL = 1 * time.Minute
kopiaAuthCookieAudience = "kopia"
kopiaAuthCookieIssuer = "kopia-server"
)
type apiRequestFunc func(ctx context.Context, r *http.Request, body []byte) (interface{}, *apiError)
// Server exposes simple HTTP API for programmatically accessing Kopia features.
type Server struct {
OnShutdown func(ctx context.Context) error
options Options
rep repo.Repository
cancelRep context.CancelFunc
authenticator auth.Authenticator
authorizer auth.Authorizer
// all API requests run with shared lock on this mutex
// administrative actions run with an exclusive lock and block API calls.
mu sync.RWMutex
sourceManagers map[snapshot.SourceInfo]*sourceManager
mounts sync.Map // object.ID -> mount.Controller
uploadSemaphore chan struct{}
taskmgr *uitask.Manager
authCookieSigningKey []byte
grpcServerState
}
// APIHandlers handles API requests.
func (s *Server) APIHandlers(legacyAPI bool) http.Handler {
m := mux.NewRouter()
// sources
m.HandleFunc("/api/v1/sources", s.handleAPI(requireUIUser, s.handleSourcesList)).Methods(http.MethodGet)
m.HandleFunc("/api/v1/sources", s.handleAPI(requireUIUser, s.handleSourcesCreate)).Methods(http.MethodPost)
m.HandleFunc("/api/v1/sources/upload", s.handleAPI(requireUIUser, s.handleUpload)).Methods(http.MethodPost)
m.HandleFunc("/api/v1/sources/cancel", s.handleAPI(requireUIUser, s.handleCancel)).Methods(http.MethodPost)
// snapshots
m.HandleFunc("/api/v1/snapshots", s.handleAPI(requireUIUser, s.handleSnapshotList)).Methods(http.MethodGet)
m.HandleFunc("/api/v1/policy", s.handleAPI(requireUIUser, s.handlePolicyGet)).Methods(http.MethodGet)
m.HandleFunc("/api/v1/policy", s.handleAPI(requireUIUser, s.handlePolicyPut)).Methods(http.MethodPut)
m.HandleFunc("/api/v1/policy", s.handleAPI(requireUIUser, s.handlePolicyDelete)).Methods(http.MethodDelete)
m.HandleFunc("/api/v1/policies", s.handleAPI(requireUIUser, s.handlePolicyList)).Methods(http.MethodGet)
m.HandleFunc("/api/v1/refresh", s.handleAPI(anyAuthenticatedUser, s.handleRefresh)).Methods(http.MethodPost)
m.HandleFunc("/api/v1/shutdown", s.handleAPIPossiblyNotConnected(requireUIUser, s.handleShutdown)).Methods(http.MethodPost)
m.HandleFunc("/api/v1/objects/{objectID}", s.requireAuth(s.handleObjectGet)).Methods(http.MethodGet)
m.HandleFunc("/api/v1/restore", s.handleAPI(requireUIUser, s.handleRestore)).Methods(http.MethodPost)
m.HandleFunc("/api/v1/estimate", s.handleAPI(requireUIUser, s.handleEstimate)).Methods(http.MethodPost)
// methods that can be called by any authenticated user (UI or remote user).
m.HandleFunc("/api/v1/flush", s.handleAPI(anyAuthenticatedUser, s.handleFlush)).Methods(http.MethodPost)
m.HandleFunc("/api/v1/repo/status", s.handleAPIPossiblyNotConnected(anyAuthenticatedUser, s.handleRepoStatus)).Methods(http.MethodGet)
m.HandleFunc("/api/v1/repo/sync", s.handleAPI(anyAuthenticatedUser, s.handleRepoSync)).Methods(http.MethodPost)
m.HandleFunc("/api/v1/repo/connect", s.handleAPIPossiblyNotConnected(requireUIUser, s.handleRepoConnect)).Methods(http.MethodPost)
m.HandleFunc("/api/v1/repo/exists", s.handleAPIPossiblyNotConnected(requireUIUser, s.handleRepoExists)).Methods(http.MethodPost)
m.HandleFunc("/api/v1/repo/create", s.handleAPIPossiblyNotConnected(requireUIUser, s.handleRepoCreate)).Methods(http.MethodPost)
m.HandleFunc("/api/v1/repo/description", s.handleAPI(requireUIUser, s.handleRepoSetDescription)).Methods(http.MethodPost)
m.HandleFunc("/api/v1/repo/disconnect", s.handleAPI(requireUIUser, s.handleRepoDisconnect)).Methods(http.MethodPost)
m.HandleFunc("/api/v1/repo/algorithms", s.handleAPIPossiblyNotConnected(requireUIUser, s.handleRepoSupportedAlgorithms)).Methods(http.MethodGet)
if legacyAPI {
m.HandleFunc("/api/v1/repo/parameters", s.handleAPI(anyAuthenticatedUser, s.handleRepoParameters)).Methods(http.MethodGet)
m.HandleFunc("/api/v1/contents/{contentID}", s.handleAPI(requireContentAccess(auth.AccessLevelRead), s.handleContentInfo)).Methods(http.MethodGet).Queries("info", "1")
m.HandleFunc("/api/v1/contents/{contentID}", s.handleAPI(requireContentAccess(auth.AccessLevelRead), s.handleContentGet)).Methods(http.MethodGet)
m.HandleFunc("/api/v1/contents/{contentID}", s.handleAPI(requireContentAccess(auth.AccessLevelAppend), s.handleContentPut)).Methods(http.MethodPut)
m.HandleFunc("/api/v1/manifests/{manifestID}", s.handleAPI(handlerWillCheckAuthorization, s.handleManifestGet)).Methods(http.MethodGet)
m.HandleFunc("/api/v1/manifests/{manifestID}", s.handleAPI(handlerWillCheckAuthorization, s.handleManifestDelete)).Methods(http.MethodDelete)
m.HandleFunc("/api/v1/manifests", s.handleAPI(handlerWillCheckAuthorization, s.handleManifestCreate)).Methods(http.MethodPost)
m.HandleFunc("/api/v1/manifests", s.handleAPI(handlerWillCheckAuthorization, s.handleManifestList)).Methods(http.MethodGet)
}
m.HandleFunc("/api/v1/mounts", s.handleAPI(requireUIUser, s.handleMountCreate)).Methods(http.MethodPost)
m.HandleFunc("/api/v1/mounts/{rootObjectID}", s.handleAPI(requireUIUser, s.handleMountDelete)).Methods(http.MethodDelete)
m.HandleFunc("/api/v1/mounts/{rootObjectID}", s.handleAPI(requireUIUser, s.handleMountGet)).Methods(http.MethodGet)
m.HandleFunc("/api/v1/mounts", s.handleAPI(requireUIUser, s.handleMountList)).Methods(http.MethodGet)
m.HandleFunc("/api/v1/current-user", s.handleAPIPossiblyNotConnected(requireUIUser, s.handleCurrentUser)).Methods(http.MethodGet)
m.HandleFunc("/api/v1/tasks-summary", s.handleAPI(requireUIUser, s.handleTaskSummary)).Methods(http.MethodGet)
m.HandleFunc("/api/v1/tasks", s.handleAPI(requireUIUser, s.handleTaskList)).Methods(http.MethodGet)
m.HandleFunc("/api/v1/tasks/{taskID}", s.handleAPI(requireUIUser, s.handleTaskInfo)).Methods(http.MethodGet)
m.HandleFunc("/api/v1/tasks/{taskID}/logs", s.handleAPI(requireUIUser, s.handleTaskLogs)).Methods(http.MethodGet)
m.HandleFunc("/api/v1/tasks/{taskID}/cancel", s.handleAPI(requireUIUser, s.handleTaskCancel)).Methods(http.MethodPost)
return m
}
func (s *Server) isAuthenticated(w http.ResponseWriter, r *http.Request) bool {
if s.authenticator == nil {
return true
}
username, password, ok := r.BasicAuth()
if !ok {
w.Header().Set("WWW-Authenticate", `Basic realm="Kopia"`)
http.Error(w, "Missing credentials.\n", http.StatusUnauthorized)
return false
}
if c, err := r.Cookie(kopiaAuthCookie); err == nil && c != nil {
if s.isAuthCookieValid(username, c.Value) {
// found a short-term JWT cookie that matches given username, trust it.
// this avoids potentially expensive password hashing inside the authenticator.
return true
}
}
if !s.authenticator.IsValid(r.Context(), s.rep, username, password) {
w.Header().Set("WWW-Authenticate", `Basic realm="Kopia"`)
http.Error(w, "Access denied.\n", http.StatusUnauthorized)
return false
}
now := clock.Now()
ac, err := s.generateShortTermAuthCookie(username, now)
if err != nil {
log(r.Context()).Errorf("unable to generate short-term auth cookie: %v", err)
} else {
http.SetCookie(w, &http.Cookie{
Name: kopiaAuthCookie,
Value: ac,
Expires: now.Add(kopiaAuthCookieTTL),
})
}
return true
}
func (s *Server) isAuthCookieValid(username, cookieValue string) bool {
tok, err := jwt.ParseWithClaims(cookieValue, &jwt.RegisteredClaims{}, func(t *jwt.Token) (interface{}, error) {
return s.authCookieSigningKey, nil
})
if err != nil {
return false
}
sc, ok := tok.Claims.(*jwt.RegisteredClaims)
if !ok {
return false
}
return sc.Subject == username
}
func (s *Server) generateShortTermAuthCookie(username string, now time.Time) (string, error) {
// nolint:wrapcheck
return jwt.NewWithClaims(jwt.SigningMethodHS256, &jwt.RegisteredClaims{
Subject: username,
NotBefore: jwt.NewNumericDate(now.Add(-time.Minute)),
ExpiresAt: jwt.NewNumericDate(now.Add(kopiaAuthCookieTTL)),
IssuedAt: jwt.NewNumericDate(now),
Audience: jwt.ClaimStrings{kopiaAuthCookieAudience},
ID: uuid.New().String(),
Issuer: kopiaAuthCookieIssuer,
}).SignedString(s.authCookieSigningKey)
}
func (s *Server) requireAuth(f http.HandlerFunc) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
if !s.isAuthenticated(w, r) {
return
}
f(w, r)
}
}
func (s *Server) httpAuthorizationInfo(r *http.Request) auth.AuthorizationInfo {
// authentication already done
userAtHost, _, _ := r.BasicAuth()
authz := s.authorizer.Authorize(r.Context(), s.rep, userAtHost)
if authz == nil {
authz = auth.NoAccess()
}
return authz
}
type isAuthorizedFunc func(s *Server, r *http.Request) bool
func (s *Server) handleAPI(isAuthorized isAuthorizedFunc, f apiRequestFunc) http.HandlerFunc {
return s.handleAPIPossiblyNotConnected(isAuthorized, func(ctx context.Context, r *http.Request, body []byte) (interface{}, *apiError) {
if s.rep == nil {
return nil, requestError(serverapi.ErrorNotConnected, "not connected")
}
return f(ctx, r, body)
})
}
// RequireUIUserAuth wraps the provided http.Handler to only allow UI user and return 403 otherwise.
func (s *Server) RequireUIUserAuth(hf http.Handler) http.Handler {
return s.requireAuth(func(rw http.ResponseWriter, r *http.Request) {
if !requireUIUser(s, r) {
http.Error(rw, `UI Access denied. See https://github.com/kopia/kopia/issues/880#issuecomment-798421751 for more information.`, http.StatusForbidden)
return
}
hf.ServeHTTP(rw, r)
})
}
func (s *Server) handleAPIPossiblyNotConnected(isAuthorized isAuthorizedFunc, f apiRequestFunc) http.HandlerFunc {
return s.requireAuth(func(w http.ResponseWriter, r *http.Request) {
// we must pre-read request body before acquiring the lock as it sometimes leads to deadlock
// in HTTP/2 server.
// See https://github.com/golang/go/issues/40816
body, berr := io.ReadAll(r.Body)
if berr != nil {
http.Error(w, "error reading request body", http.StatusInternalServerError)
return
}
s.mu.RLock()
defer s.mu.RUnlock()
ctx := r.Context()
log(ctx).Debugf("request %v (%v bytes)", r.URL, len(body))
w.Header().Set("Content-Type", "application/json")
e := json.NewEncoder(w)
e.SetIndent("", " ")
var v interface{}
var err *apiError
if isAuthorized(s, r) {
v, err = f(ctx, r, body)
} else {
err = accessDeniedError()
}
if err == nil {
if b, ok := v.([]byte); ok {
if _, err := w.Write(b); err != nil {
log(ctx).Errorf("error writing response: %v", err)
}
} else if err := e.Encode(v); err != nil {
log(ctx).Errorf("error encoding response: %v", err)
}
return
}
w.Header().Set("Content-Type", "text/plain; charset=utf-8")
w.Header().Set("X-Content-Type-Options", "nosniff")
w.WriteHeader(err.httpErrorCode)
log(ctx).Debugf("error code %v message %v", err.apiErrorCode, err.message)
_ = e.Encode(&serverapi.ErrorResponse{
Code: err.apiErrorCode,
Error: err.message,
})
})
}
// Refresh refreshes the state of the server in response to external signal (e.g. SIGHUP).
func (s *Server) Refresh(ctx context.Context) error {
s.mu.RLock()
defer s.mu.RUnlock()
return s.internalRefreshRLocked(ctx)
}
func (s *Server) internalRefreshRLocked(ctx context.Context) error {
if s.rep == nil {
return nil
}
if err := s.rep.Refresh(ctx); err != nil {
return errors.Wrap(err, "unable to refresh repository")
}
if s.authenticator != nil {
if err := s.authenticator.Refresh(ctx); err != nil {
log(ctx).Errorf("unable to refresh authenticator: %v", err)
}
}
if s.authorizer != nil {
if err := s.authorizer.Refresh(ctx); err != nil {
log(ctx).Errorf("unable to refresh authorizer: %v", err)
}
}
// release shared lock so that SyncSources can acquire exclusive lock
s.mu.RUnlock()
err := s.SyncSources(ctx)
s.mu.RLock()
if err != nil {
return errors.Wrap(err, "unable to sync sources")
}
return nil
}
func (s *Server) handleRefresh(ctx context.Context, r *http.Request, body []byte) (interface{}, *apiError) {
// refresh is an alias for /repo/sync
return s.handleRepoSync(ctx, r, body)
}
func (s *Server) handleFlush(ctx context.Context, r *http.Request, body []byte) (interface{}, *apiError) {
rw, ok := s.rep.(repo.RepositoryWriter)
if !ok {
return nil, repositoryNotWritableError()
}
if err := rw.Flush(ctx); err != nil {
return nil, internalServerError(err)
}
return &serverapi.Empty{}, nil
}
func (s *Server) handleShutdown(ctx context.Context, r *http.Request, body []byte) (interface{}, *apiError) {
log(ctx).Infof("shutting down due to API request")
if f := s.OnShutdown; f != nil {
go func() {
if err := f(ctx); err != nil {
log(ctx).Errorf("shutdown failed: %v", err)
}
}()
}
return &serverapi.Empty{}, nil
}
func (s *Server) forAllSourceManagersMatchingURLFilter(ctx context.Context, c func(s *sourceManager, ctx context.Context) serverapi.SourceActionResponse, values url.Values) (interface{}, *apiError) {
resp := &serverapi.MultipleSourceActionResponse{
Sources: map[string]serverapi.SourceActionResponse{},
}
for src, mgr := range s.sourceManagers {
if !sourceMatchesURLFilter(src, values) {
continue
}
resp.Sources[src.String()] = c(mgr, ctx)
}
return resp, nil
}
func (s *Server) handleUpload(ctx context.Context, r *http.Request, body []byte) (interface{}, *apiError) {
return s.forAllSourceManagersMatchingURLFilter(ctx, (*sourceManager).upload, r.URL.Query())
}
func (s *Server) handleCancel(ctx context.Context, r *http.Request, body []byte) (interface{}, *apiError) {
return s.forAllSourceManagersMatchingURLFilter(ctx, (*sourceManager).cancel, r.URL.Query())
}
func (s *Server) beginUpload(ctx context.Context, src snapshot.SourceInfo) {
log(ctx).Debugf("waiting on semaphore to upload %v", src)
s.uploadSemaphore <- struct{}{}
log(ctx).Debugf("entered semaphore to upload %v", src)
}
func (s *Server) endUpload(ctx context.Context, src snapshot.SourceInfo) {
log(ctx).Debugf("finished uploading %v", src)
<-s.uploadSemaphore
}
// SetRepository sets the repository (nil is allowed and indicates server that is not
// connected to the repository).
func (s *Server) SetRepository(ctx context.Context, rep repo.Repository) error {
s.mu.Lock()
defer s.mu.Unlock()
if s.rep == rep {
// nothing to do
return nil
}
if s.rep != nil {
s.unmountAll(ctx)
// close previous source managers
log(ctx).Infof("stopping all source managers")
s.stopAllSourceManagersLocked(ctx)
log(ctx).Infof("stopped all source managers")
if err := s.rep.Close(ctx); err != nil {
return errors.Wrap(err, "unable to close previous repository")
}
cr := s.cancelRep
s.cancelRep = nil
if cr != nil {
cr()
}
}
s.rep = rep
if s.rep == nil {
return nil
}
if err := s.syncSourcesLocked(ctx); err != nil {
s.stopAllSourceManagersLocked(ctx)
s.rep = nil
return err
}
ctx, s.cancelRep = context.WithCancel(ctx)
go s.refreshPeriodically(ctx, rep)
go s.periodicMaintenance(ctx, rep)
return nil
}
func (s *Server) refreshPeriodically(ctx context.Context, r repo.Repository) {
for {
select {
case <-ctx.Done():
return
case <-time.After(s.options.RefreshInterval):
if err := r.Refresh(ctx); err != nil {
log(ctx).Errorf("error refreshing repository: %v", err)
}
if err := s.SyncSources(ctx); err != nil {
log(ctx).Errorf("unable to sync sources: %v", err)
}
}
}
}
func (s *Server) periodicMaintenance(ctx context.Context, rep repo.Repository) {
for {
select {
case <-ctx.Done():
return
case <-time.After(maintenanceAttemptFrequency):
if owned, err := maintenance.IsOwnedByThisUser(ctx, rep); err == nil && !owned {
// maintenance not owned by this user, don't run, but keep trying because
// maintenance ownership MAY change to this user in the future.
continue
}
if err := s.taskmgr.Run(ctx, "Maintenance", "Periodic maintenance", func(ctx context.Context, _ uitask.Controller) error {
return periodicMaintenanceOnce(ctx, rep)
}); err != nil {
log(ctx).Errorf("unable to run maintenance: %v", err)
}
}
}
}
func periodicMaintenanceOnce(ctx context.Context, rep repo.Repository) error {
dr, ok := rep.(repo.DirectRepository)
if !ok {
return errors.Errorf("not a direct repository")
}
// nolint:wrapcheck
return repo.DirectWriteSession(ctx, dr, repo.WriteSessionOptions{
Purpose: "periodicMaintenanceOnce",
}, func(ctx context.Context, w repo.DirectRepositoryWriter) error {
// nolint:wrapcheck
return snapshotmaintenance.Run(ctx, w, maintenance.ModeAuto, false, maintenance.SafetyFull)
})
}
// SyncSources synchronizes the repository and source managers.
func (s *Server) SyncSources(ctx context.Context) error {
s.mu.Lock()
defer s.mu.Unlock()
return s.syncSourcesLocked(ctx)
}
// StopAllSourceManagers causes all source managers to stop.
func (s *Server) StopAllSourceManagers(ctx context.Context) {
s.mu.Lock()
defer s.mu.Unlock()
s.stopAllSourceManagersLocked(ctx)
}
func (s *Server) stopAllSourceManagersLocked(ctx context.Context) {
for _, sm := range s.sourceManagers {
sm.stop(ctx)
}
for _, sm := range s.sourceManagers {
sm.waitUntilStopped(ctx)
}
s.sourceManagers = map[snapshot.SourceInfo]*sourceManager{}
}
func (s *Server) syncSourcesLocked(ctx context.Context) error {
sources := map[snapshot.SourceInfo]bool{}
if s.rep != nil {
snapshotSources, err := snapshot.ListSources(ctx, s.rep)
if err != nil {
return errors.Wrap(err, "unable to list sources")
}
policies, err := policy.ListPolicies(ctx, s.rep)
if err != nil {
return errors.Wrap(err, "unable to list sources")
}
for _, ss := range snapshotSources {
sources[ss] = true
}
for _, pol := range policies {
if pol.Target().Path != "" && pol.Target().Host != "" && pol.Target().UserName != "" {
sources[pol.Target()] = true
}
}
}
// copy existing sources to a map, from which we will remove sources that are found
// in the repository
oldSourceManagers := map[snapshot.SourceInfo]*sourceManager{}
for k, v := range s.sourceManagers {
oldSourceManagers[k] = v
}
for src := range sources {
if _, ok := oldSourceManagers[src]; ok {
// pre-existing source, already has a manager
delete(oldSourceManagers, src)
} else {
sm := newSourceManager(src, s)
s.sourceManagers[src] = sm
go sm.run(ctx)
}
}
// whatever is left in oldSourceManagers are managers for sources that don't exist anymore.
// stop source manager for sources no longer in the repo.
for _, sm := range oldSourceManagers {
sm.stop(ctx)
}
for src, sm := range oldSourceManagers {
sm.waitUntilStopped(ctx)
delete(s.sourceManagers, src)
}
return nil
}
// Options encompasses all API server options.
type Options struct {
ConfigFile string
ConnectOptions *repo.ConnectOptions
RefreshInterval time.Duration
MaxConcurrency int
Authenticator auth.Authenticator
Authorizer auth.Authorizer
PasswordPersist passwordpersist.Strategy
AuthCookieSigningKey string
UIUser string // name of the user allowed to access the UI
}
// New creates a Server.
// The server will manage sources for a given username@hostname.
func New(ctx context.Context, options Options) (*Server, error) {
if options.Authorizer == nil {
return nil, errors.Errorf("missing authorizer")
}
if options.PasswordPersist == nil {
return nil, errors.Errorf("missing password persistence")
}
if options.AuthCookieSigningKey == "" {
// generate random signing key
options.AuthCookieSigningKey = uuid.New().String()
log(ctx).Debugf("generated random auth cookie signing key: %v", options.AuthCookieSigningKey)
}
s := &Server{
options: options,
sourceManagers: map[snapshot.SourceInfo]*sourceManager{},
uploadSemaphore: make(chan struct{}, 1),
grpcServerState: makeGRPCServerState(options.MaxConcurrency),
authenticator: options.Authenticator,
authorizer: options.Authorizer,
taskmgr: uitask.NewManager(),
authCookieSigningKey: []byte(options.AuthCookieSigningKey),
}
return s, nil
}