runservice: maintenance/export/import

Implement runservice maintenance mode and export/import.

When runservice is set in maintenance mode it'll start only the maintenance and
export/import handlers.

Setting maintenance mode will set a key in etcd so all the runservice instances
will detect it and enter in maintenance mode. This is done asyncronously so it
could take some time (future improvements will add some api to show all the
runservice states)

Export is always available and will export the datamanager contents. Currently
only datamanager contents are exported (no logs and workspace archives).

Import is available only during maintenance, given a datamanager export will
import it and reset etcd to this import state.

internal/services/runservice/action/action.go

@@ -37,23 +37,29 @@ import (
 )
 
 type ActionHandler struct {
-	log    *zap.SugaredLogger
-	e      *etcd.Store
-	readDB *readdb.ReadDB
-	ost    *objectstorage.ObjStorage
-	dm     *datamanager.DataManager
+	log             *zap.SugaredLogger
+	e               *etcd.Store
+	readDB          *readdb.ReadDB
+	ost             *objectstorage.ObjStorage
+	dm              *datamanager.DataManager
+	maintenanceMode bool
 }
 
 func NewActionHandler(logger *zap.Logger, e *etcd.Store, readDB *readdb.ReadDB, ost *objectstorage.ObjStorage, dm *datamanager.DataManager) *ActionHandler {
 	return &ActionHandler{
-		log:    logger.Sugar(),
-		e:      e,
-		readDB: readDB,
-		ost:    ost,
-		dm:     dm,
+		log:             logger.Sugar(),
+		e:               e,
+		readDB:          readDB,
+		ost:             ost,
+		dm:              dm,
+		maintenanceMode: false,
 	}
 }
 
+func (h *ActionHandler) SetMaintenanceMode(maintenanceMode bool) {
+	h.maintenanceMode = maintenanceMode
+}
+
 type RunChangePhaseRequest struct {
 	RunID                   string
 	Phase                   types.RunPhase

internal/services/runservice/action/maintenance.go

@@ -0,0 +1,73 @@
+// Copyright 2019 Sorint.lab
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package action
+
+import (
+	"context"
+	"io"
+
+	"agola.io/agola/internal/etcd"
+	"agola.io/agola/internal/services/runservice/common"
+	"agola.io/agola/internal/util"
+
+	errors "golang.org/x/xerrors"
+)
+
+func (h *ActionHandler) MaintenanceMode(ctx context.Context, enable bool) error {
+	resp, err := h.e.Get(ctx, common.EtcdMaintenanceKey, 0)
+	if err != nil && err != etcd.ErrKeyNotFound {
+		return err
+	}
+
+	if enable && len(resp.Kvs) > 0 {
+		return util.NewErrBadRequest(errors.Errorf("maintenance mode already enabled"))
+	}
+	if !enable && len(resp.Kvs) == 0 {
+		return util.NewErrBadRequest(errors.Errorf("maintenance mode already disabled"))
+	}
+
+	if enable {
+		txResp, err := h.e.AtomicPut(ctx, common.EtcdMaintenanceKey, []byte{}, 0, nil)
+		if err != nil {
+			return err
+		}
+		if !txResp.Succeeded {
+			return errors.Errorf("failed to create maintenance mode key due to concurrent update")
+		}
+	}
+
+	if !enable {
+		txResp, err := h.e.AtomicDelete(ctx, common.EtcdMaintenanceKey, resp.Kvs[0].ModRevision)
+		if err != nil {
+			return err
+		}
+		if !txResp.Succeeded {
+			return errors.Errorf("failed to delete maintenance mode key due to concurrent update")
+		}
+	}
+
+	return nil
+}
+
+func (h *ActionHandler) Export(ctx context.Context, w io.Writer) error {
+	return h.dm.Export(ctx, w)
+}
+
+func (h *ActionHandler) Import(ctx context.Context, r io.Reader) error {
+	if !h.maintenanceMode {
+		return util.NewErrBadRequest(errors.Errorf("not in maintenance mode"))
+	}
+	return h.dm.Import(ctx, r)
+}

internal/services/runservice/api/maintenance.go

@@ -0,0 +1,107 @@
+// Copyright 2019 Sorint.lab
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package api
+
+import (
+	"net/http"
+
+	"agola.io/agola/internal/etcd"
+	"agola.io/agola/internal/services/runservice/action"
+
+	"go.uber.org/zap"
+)
+
+type MaintenanceModeHandler struct {
+	log *zap.SugaredLogger
+	ah  *action.ActionHandler
+	e   *etcd.Store
+}
+
+func NewMaintenanceModeHandler(logger *zap.Logger, ah *action.ActionHandler, e *etcd.Store) *MaintenanceModeHandler {
+	return &MaintenanceModeHandler{log: logger.Sugar(), ah: ah, e: e}
+}
+
+func (h *MaintenanceModeHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	ctx := r.Context()
+
+	enable := false
+	switch r.Method {
+	case "PUT":
+		enable = true
+	case "DELETE":
+		enable = false
+	}
+
+	err := h.ah.MaintenanceMode(ctx, enable)
+	if err != nil {
+		h.log.Errorf("err: %+v", err)
+		httpError(w, err)
+		return
+	}
+
+	if err := httpResponse(w, http.StatusOK, nil); err != nil {
+		h.log.Errorf("err: %+v", err)
+	}
+
+}
+
+type ExportHandler struct {
+	log *zap.SugaredLogger
+	ah  *action.ActionHandler
+}
+
+func NewExportHandler(logger *zap.Logger, ah *action.ActionHandler) *ExportHandler {
+	return &ExportHandler{log: logger.Sugar(), ah: ah}
+}
+
+func (h *ExportHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	ctx := r.Context()
+
+	err := h.ah.Export(ctx, w)
+	if err != nil {
+		h.log.Errorf("err: %+v", err)
+		// since we already answered with a 200 we cannot return another error code
+		// So abort the connection and the client will detect the missing ending chunk
+		// and consider this an error
+		//
+		// this is the way to force close a request without logging the panic
+		panic(http.ErrAbortHandler)
+	}
+}
+
+type ImportHandler struct {
+	log *zap.SugaredLogger
+	ah  *action.ActionHandler
+}
+
+func NewImportHandler(logger *zap.Logger, ah *action.ActionHandler) *ImportHandler {
+	return &ImportHandler{log: logger.Sugar(), ah: ah}
+}
+
+func (h *ImportHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	ctx := r.Context()
+
+	err := h.ah.Import(ctx, r.Body)
+	if err != nil {
+		h.log.Errorf("err: %+v", err)
+		httpError(w, err)
+		return
+	}
+
+	if err := httpResponse(w, http.StatusOK, nil); err != nil {
+		h.log.Errorf("err: %+v", err)
+	}
+
+}

internal/services/runservice/common/common.go

@@ -53,6 +53,8 @@ var (
 	EtcdCompactChangeGroupsLockKey = path.Join(EtcdSchedulerBaseDir, "compactchangegroupslock")
 	EtcdCacheCleanerLockKey        = path.Join(EtcdSchedulerBaseDir, "locks", "cachecleaner")
 	EtcdTaskUpdaterLockKey         = path.Join(EtcdSchedulerBaseDir, "locks", "taskupdater")
+
+	EtcdMaintenanceKey = "maintenance"
 )
 
 func EtcdRunKey(runID string) string       { return path.Join(EtcdRunsDir, runID) }

internal/services/runservice/runservice.go

@@ -19,6 +19,7 @@ import (
 	"crypto/tls"
 	"net/http"
 	"path/filepath"
+	"sync"
 	"time"
 
 	scommon "agola.io/agola/internal/common"
@@ -35,6 +36,7 @@ import (
 
 	"github.com/gorilla/mux"
 	etcdclientv3 "go.etcd.io/etcd/clientv3"
+	"go.etcd.io/etcd/mvcc/mvccpb"
 	"go.uber.org/zap/zapcore"
 )
 
@@ -65,13 +67,78 @@ func (s *Runservice) etcdPinger(ctx context.Context) error {
 	return nil
 }
 
+func (s *Runservice) maintenanceModeWatcherLoop(ctx context.Context, runCtxCancel context.CancelFunc, maintenanceModeEnabled bool) {
+	for {
+		log.Debugf("maintenanceModeWatcherLoop")
+
+		// at first watch restart from previous processed revision
+		if err := s.maintenanceModeWatcher(ctx, runCtxCancel, maintenanceModeEnabled); err != nil {
+			log.Errorf("err: %+v", err)
+		}
+
+		sleepCh := time.NewTimer(1 * time.Second).C
+		select {
+		case <-ctx.Done():
+			return
+		case <-sleepCh:
+		}
+	}
+}
+
+func (s *Runservice) maintenanceModeWatcher(ctx context.Context, runCtxCancel context.CancelFunc, maintenanceModeEnabled bool) error {
+	log.Infof("watcher: maintenance mode enabled: %t", maintenanceModeEnabled)
+	resp, err := s.e.Get(ctx, common.EtcdMaintenanceKey, 0)
+	if err != nil && err != etcd.ErrKeyNotFound {
+		return err
+	}
+
+	if len(resp.Kvs) > 0 {
+		log.Infof("maintenance mode key is present")
+		if !maintenanceModeEnabled {
+			runCtxCancel()
+		}
+	}
+
+	revision := resp.Header.Revision
+
+	wctx := etcdclientv3.WithRequireLeader(ctx)
+
+	// restart from previous processed revision
+	wch := s.e.Watch(wctx, common.EtcdMaintenanceKey, revision)
+
+	for wresp := range wch {
+		if wresp.Canceled {
+			return wresp.Err()
+		}
+
+		for _, ev := range wresp.Events {
+			switch ev.Type {
+			case mvccpb.PUT:
+				log.Infof("maintenance mode key set")
+				if !maintenanceModeEnabled {
+					runCtxCancel()
+				}
+
+			case mvccpb.DELETE:
+				log.Infof("maintenance mode key removed")
+				if maintenanceModeEnabled {
+					runCtxCancel()
+				}
+			}
+		}
+	}
+
+	return nil
+}
+
 type Runservice struct {
-	c      *config.Runservice
-	e      *etcd.Store
-	ost    *objectstorage.ObjStorage
-	dm     *datamanager.DataManager
-	readDB *readdb.ReadDB
-	ah     *action.ActionHandler
+	c               *config.Runservice
+	e               *etcd.Store
+	ost             *objectstorage.ObjStorage
+	dm              *datamanager.DataManager
+	readDB          *readdb.ReadDB
+	ah              *action.ActionHandler
+	maintenanceMode bool
 }
 
 func NewRunservice(ctx context.Context, c *config.Runservice) (*Runservice, error) {
@@ -137,31 +204,13 @@ func (s *Runservice) InitEtcd(ctx context.Context) error {
 	return nil
 }
 
-func (s *Runservice) Run(ctx context.Context) error {
-	errCh := make(chan error)
-	dmReadyCh := make(chan struct{})
-
-	go func() { errCh <- s.dm.Run(ctx, dmReadyCh) }()
-
-	// wait for dm to be ready
-	<-dmReadyCh
-
-	for {
-		err := s.InitEtcd(ctx)
-		if err == nil {
-			break
-		}
-		log.Errorf("failed to initialize etcd: %+v", err)
-		time.Sleep(1 * time.Second)
-	}
-
-	go func() { errCh <- s.readDB.Run(ctx) }()
-
-	ch := make(chan *types.ExecutorTask)
+func (s *Runservice) setupDefaultRouter(etCh chan *types.ExecutorTask) http.Handler {
+	maintenanceModeHandler := api.NewMaintenanceModeHandler(logger, s.ah, s.e)
+	exportHandler := api.NewExportHandler(logger, s.ah)
 
 	// executor dedicated api, only calls from executor should happen on these handlers
 	executorStatusHandler := api.NewExecutorStatusHandler(logger, s.e, s.ah)
-	executorTaskStatusHandler := api.NewExecutorTaskStatusHandler(s.e, ch)
+	executorTaskStatusHandler := api.NewExecutorTaskStatusHandler(s.e, etCh)
 	executorTaskHandler := api.NewExecutorTaskHandler(s.e)
 	executorTasksHandler := api.NewExecutorTasksHandler(s.e)
 	archivesHandler := api.NewArchivesHandler(logger, s.ost)
@@ -209,23 +258,55 @@ func (s *Runservice) Run(ctx context.Context) error {
 
 	apirouter.Handle("/changegroups", changeGroupsUpdateTokensHandler).Methods("GET")
 
+	apirouter.Handle("/maintenance", maintenanceModeHandler).Methods("PUT", "DELETE")
+
+	apirouter.Handle("/export", exportHandler).Methods("GET")
+
 	mainrouter := mux.NewRouter()
 	mainrouter.PathPrefix("/").Handler(router)
 
 	// Return a bad request when it doesn't match any route
 	mainrouter.NotFoundHandler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { w.WriteHeader(http.StatusBadRequest) })
 
-	go s.executorTasksCleanerLoop(ctx)
-	go s.runsSchedulerLoop(ctx)
-	go s.runTasksUpdaterLoop(ctx)
-	go s.fetcherLoop(ctx)
-	go s.finishedRunsArchiverLoop(ctx)
-	go s.compactChangeGroupsLoop(ctx)
-	go s.cacheCleanerLoop(ctx, s.c.RunCacheExpireInterval)
-	go s.executorTaskUpdateHandler(ctx, ch)
+	return mainrouter
+}
 
-	go s.etcdPingerLoop(ctx)
+func (s *Runservice) setupMaintenanceRouter() http.Handler {
+	maintenanceModeHandler := api.NewMaintenanceModeHandler(logger, s.ah, s.e)
+	exportHandler := api.NewExportHandler(logger, s.ah)
+	importHandler := api.NewImportHandler(logger, s.ah)
 
+	router := mux.NewRouter()
+	apirouter := router.PathPrefix("/api/v1alpha").Subrouter().UseEncodedPath()
+
+	apirouter.Handle("/maintenance", maintenanceModeHandler).Methods("PUT", "DELETE")
+
+	apirouter.Handle("/export", exportHandler).Methods("GET")
+	apirouter.Handle("/import", importHandler).Methods("POST")
+
+	mainrouter := mux.NewRouter()
+	mainrouter.PathPrefix("/").Handler(router)
+
+	return mainrouter
+}
+
+func (s *Runservice) Run(ctx context.Context) error {
+	for {
+		if err := s.run(ctx); err != nil {
+			log.Errorf("run error: %+v", err)
+		}
+
+		sleepCh := time.NewTimer(1 * time.Second).C
+		select {
+		case <-ctx.Done():
+			log.Infof("runservice exiting")
+			return nil
+		case <-sleepCh:
+		}
+	}
+}
+
+func (s *Runservice) run(ctx context.Context) error {
 	var tlsConfig *tls.Config
 	if s.c.Web.TLS {
 		var err error
@@ -236,32 +317,98 @@ func (s *Runservice) Run(ctx context.Context) error {
 		}
 	}
 
+	resp, err := s.e.Get(ctx, common.EtcdMaintenanceKey, 0)
+	if err != nil && err != etcd.ErrKeyNotFound {
+		return err
+	}
+
+	maintenanceMode := false
+	if len(resp.Kvs) > 0 {
+		log.Infof("maintenance mode key is present")
+		maintenanceMode = true
+	}
+
+	s.maintenanceMode = maintenanceMode
+	s.dm.SetMaintenanceMode(maintenanceMode)
+	s.ah.SetMaintenanceMode(maintenanceMode)
+
+	ctx, cancel := context.WithCancel(ctx)
+	errCh := make(chan error, 100)
+	var wg sync.WaitGroup
+	dmReadyCh := make(chan struct{})
+
+	var mainrouter http.Handler
+	if s.maintenanceMode {
+		mainrouter = s.setupMaintenanceRouter()
+		util.GoWait(&wg, func() { s.maintenanceModeWatcherLoop(ctx, cancel, s.maintenanceMode) })
+
+	} else {
+		ch := make(chan *types.ExecutorTask)
+		mainrouter = s.setupDefaultRouter(ch)
+
+		util.GoWait(&wg, func() { s.maintenanceModeWatcherLoop(ctx, cancel, s.maintenanceMode) })
+
+		// TODO(sgotti) wait for all goroutines exiting
+		util.GoWait(&wg, func() { errCh <- s.dm.Run(ctx, dmReadyCh) })
+
+		// wait for dm to be ready
+		<-dmReadyCh
+
+		for {
+			err := s.InitEtcd(ctx)
+			if err == nil {
+				break
+			}
+			log.Errorf("failed to initialize etcd: %+v", err)
+
+			sleepCh := time.NewTimer(1 * time.Second).C
+			select {
+			case <-ctx.Done():
+				return nil
+			case <-sleepCh:
+			}
+		}
+
+		util.GoWait(&wg, func() { errCh <- s.readDB.Run(ctx) })
+
+		util.GoWait(&wg, func() { s.executorTasksCleanerLoop(ctx) })
+		util.GoWait(&wg, func() { s.runsSchedulerLoop(ctx) })
+		util.GoWait(&wg, func() { s.runTasksUpdaterLoop(ctx) })
+		util.GoWait(&wg, func() { s.fetcherLoop(ctx) })
+		util.GoWait(&wg, func() { s.finishedRunsArchiverLoop(ctx) })
+		util.GoWait(&wg, func() { s.compactChangeGroupsLoop(ctx) })
+		util.GoWait(&wg, func() { s.cacheCleanerLoop(ctx, s.c.RunCacheExpireInterval) })
+		util.GoWait(&wg, func() { s.executorTaskUpdateHandler(ctx, ch) })
+		util.GoWait(&wg, func() { s.etcdPingerLoop(ctx) })
+	}
+
 	httpServer := http.Server{
 		Addr:      s.c.Web.ListenAddress,
 		Handler:   mainrouter,
 		TLSConfig: tlsConfig,
 	}
 
-	lerrCh := make(chan error)
-	go func() {
+	lerrCh := make(chan error, 1)
+	util.GoWait(&wg, func() {
 		lerrCh <- httpServer.ListenAndServe()
-	}()
+	})
 
 	select {
 	case <-ctx.Done():
-		log.Infof("runservice scheduler exiting")
-		httpServer.Close()
-	case err := <-lerrCh:
+		log.Infof("runservice run exiting")
+	case err = <-lerrCh:
 		if err != nil {
 			log.Errorf("http server listen error: %v", err)
-			return err
 		}
 	case err := <-errCh:
 		if err != nil {
 			log.Errorf("error: %+v", err)
-			return err
 		}
 	}
 
-	return nil
+	cancel()
+	httpServer.Close()
+	wg.Wait()
+
+	return err
 }