zrepl/daemon/control.go

286 lines
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package daemon
import (
"bytes"
"context"
"encoding/json"
"fmt"
"io"
"net"
"net/http"
"time"
"github.com/pkg/errors"
"github.com/prometheus/client_golang/prometheus"
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"github.com/zrepl/zrepl/daemon/job"
"github.com/zrepl/zrepl/daemon/nethelpers"
new features: {resumable,encrypted,hold-protected} send-recv, last-received-hold - **Resumable Send & Recv Support** No knobs required, automatically used where supported. - **Hold-Protected Send & Recv** Automatic ZFS holds to ensure that we can always resume a replication step. - **Encrypted Send & Recv Support** for OpenZFS native encryption. Configurable at the job level, i.e., for all filesystems a job is responsible for. - **Receive-side hold on last received dataset** The counterpart to the replication cursor bookmark on the send-side. Ensures that incremental replication will always be possible between a sender and receiver. Design Doc ---------- `replication/design.md` doc describes how we use ZFS holds and bookmarks to ensure that a single replication step is always resumable. The replication algorithm described in the design doc introduces the notion of job IDs (please read the details on this design doc). We reuse the job names for job IDs and use `JobID` type to ensure that a job name can be embedded into hold tags, bookmark names, etc. This might BREAK CONFIG on upgrade. Protocol Version Bump --------------------- This commit makes backwards-incompatible changes to the replication/pdu protobufs. Thus, bump the version number used in the protocol handshake. Replication Cursor Format Change -------------------------------- The new replication cursor bookmark format is: `#zrepl_CURSOR_G_${this.GUID}_J_${jobid}` Including the GUID enables transaction-safe moving-forward of the cursor. Including the job id enables that multiple sending jobs can send the same filesystem without interfering. The `zrepl migrate replication-cursor:v1-v2` subcommand can be used to safely destroy old-format cursors once zrepl has created new-format cursors. Changes in This Commit ---------------------- - package zfs - infrastructure for holds - infrastructure for resume token decoding - implement a variant of OpenZFS's `entity_namecheck` and use it for validation in new code - ZFSSendArgs to specify a ZFS send operation - validation code protects against malicious resume tokens by checking that the token encodes the same send parameters that the send-side would use if no resume token were available (i.e. same filesystem, `fromguid`, `toguid`) - RecvOptions support for `recv -s` flag - convert a bunch of ZFS operations to be idempotent - achieved through more differentiated error message scraping / additional pre-/post-checks - package replication/pdu - add field for encryption to send request messages - add fields for resume handling to send & recv request messages - receive requests now contain `FilesystemVersion To` in addition to the filesystem into which the stream should be `recv`d into - can use `zfs recv $root_fs/$client_id/path/to/dataset@${To.Name}`, which enables additional validation after recv (i.e. whether `To.Guid` matched what we received in the stream) - used to set `last-received-hold` - package replication/logic - introduce `PlannerPolicy` struct, currently only used to configure whether encrypted sends should be requested from the sender - integrate encryption and resume token support into `Step` struct - package endpoint - move the concepts that endpoint builds on top of ZFS to a single file `endpoint/endpoint_zfs.go` - step-holds + step-bookmarks - last-received-hold - new replication cursor + old replication cursor compat code - adjust `endpoint/endpoint.go` handlers for - encryption - resumability - new replication cursor - last-received-hold - client subcommand `zrepl holds list`: list all holds and hold-like bookmarks that zrepl thinks belong to it - client subcommand `zrepl migrate replication-cursor:v1-v2`
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"github.com/zrepl/zrepl/endpoint"
"github.com/zrepl/zrepl/logger"
"github.com/zrepl/zrepl/util/envconst"
"github.com/zrepl/zrepl/version"
"github.com/zrepl/zrepl/zfs"
"github.com/zrepl/zrepl/zfs/zfscmd"
)
type controlJob struct {
sockaddr *net.UnixAddr
jobs *jobs
}
func newControlJob(sockpath string, jobs *jobs) (j *controlJob, err error) {
j = &controlJob{jobs: jobs}
j.sockaddr, err = net.ResolveUnixAddr("unix", sockpath)
if err != nil {
err = errors.Wrap(err, "cannot resolve unix address")
return
}
return
}
func (j *controlJob) Name() string { return jobNameControl }
func (j *controlJob) Status() *job.Status { return &job.Status{Type: job.TypeInternal} }
func (j *controlJob) OwnedDatasetSubtreeRoot() (p *zfs.DatasetPath, ok bool) { return nil, false }
new features: {resumable,encrypted,hold-protected} send-recv, last-received-hold - **Resumable Send & Recv Support** No knobs required, automatically used where supported. - **Hold-Protected Send & Recv** Automatic ZFS holds to ensure that we can always resume a replication step. - **Encrypted Send & Recv Support** for OpenZFS native encryption. Configurable at the job level, i.e., for all filesystems a job is responsible for. - **Receive-side hold on last received dataset** The counterpart to the replication cursor bookmark on the send-side. Ensures that incremental replication will always be possible between a sender and receiver. Design Doc ---------- `replication/design.md` doc describes how we use ZFS holds and bookmarks to ensure that a single replication step is always resumable. The replication algorithm described in the design doc introduces the notion of job IDs (please read the details on this design doc). We reuse the job names for job IDs and use `JobID` type to ensure that a job name can be embedded into hold tags, bookmark names, etc. This might BREAK CONFIG on upgrade. Protocol Version Bump --------------------- This commit makes backwards-incompatible changes to the replication/pdu protobufs. Thus, bump the version number used in the protocol handshake. Replication Cursor Format Change -------------------------------- The new replication cursor bookmark format is: `#zrepl_CURSOR_G_${this.GUID}_J_${jobid}` Including the GUID enables transaction-safe moving-forward of the cursor. Including the job id enables that multiple sending jobs can send the same filesystem without interfering. The `zrepl migrate replication-cursor:v1-v2` subcommand can be used to safely destroy old-format cursors once zrepl has created new-format cursors. Changes in This Commit ---------------------- - package zfs - infrastructure for holds - infrastructure for resume token decoding - implement a variant of OpenZFS's `entity_namecheck` and use it for validation in new code - ZFSSendArgs to specify a ZFS send operation - validation code protects against malicious resume tokens by checking that the token encodes the same send parameters that the send-side would use if no resume token were available (i.e. same filesystem, `fromguid`, `toguid`) - RecvOptions support for `recv -s` flag - convert a bunch of ZFS operations to be idempotent - achieved through more differentiated error message scraping / additional pre-/post-checks - package replication/pdu - add field for encryption to send request messages - add fields for resume handling to send & recv request messages - receive requests now contain `FilesystemVersion To` in addition to the filesystem into which the stream should be `recv`d into - can use `zfs recv $root_fs/$client_id/path/to/dataset@${To.Name}`, which enables additional validation after recv (i.e. whether `To.Guid` matched what we received in the stream) - used to set `last-received-hold` - package replication/logic - introduce `PlannerPolicy` struct, currently only used to configure whether encrypted sends should be requested from the sender - integrate encryption and resume token support into `Step` struct - package endpoint - move the concepts that endpoint builds on top of ZFS to a single file `endpoint/endpoint_zfs.go` - step-holds + step-bookmarks - last-received-hold - new replication cursor + old replication cursor compat code - adjust `endpoint/endpoint.go` handlers for - encryption - resumability - new replication cursor - last-received-hold - client subcommand `zrepl holds list`: list all holds and hold-like bookmarks that zrepl thinks belong to it - client subcommand `zrepl migrate replication-cursor:v1-v2`
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func (j *controlJob) SenderConfig() *endpoint.SenderConfig { return nil }
var promControl struct {
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requestBegin *prometheus.CounterVec
requestFinished *prometheus.HistogramVec
}
func (j *controlJob) RegisterMetrics(registerer prometheus.Registerer) {
promControl.requestBegin = prometheus.NewCounterVec(prometheus.CounterOpts{
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Namespace: "zrepl",
Subsystem: "control",
Name: "request_begin",
Help: "number of request we started to handle",
}, []string{"endpoint"})
promControl.requestFinished = prometheus.NewHistogramVec(prometheus.HistogramOpts{
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Namespace: "zrepl",
Subsystem: "control",
Name: "request_finished",
Help: "time it took a request to finish",
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Buckets: []float64{1e-6, 10e-6, 100e-6, 500e-6, 1e-3, 10e-3, 100e-3, 200e-3, 400e-3, 800e-3, 1, 10, 20},
}, []string{"endpoint"})
registerer.MustRegister(promControl.requestBegin)
registerer.MustRegister(promControl.requestFinished)
}
const (
ControlJobEndpointPProf string = "/debug/pprof"
ControlJobEndpointVersion string = "/version"
ControlJobEndpointStatus string = "/status"
ControlJobEndpointSignal string = "/signal"
)
func (j *controlJob) Run(ctx context.Context) {
log := job.GetLogger(ctx)
defer log.Info("control job finished")
l, err := nethelpers.ListenUnixPrivate(j.sockaddr)
if err != nil {
log.WithError(err).Error("error listening")
return
}
pprofServer := NewPProfServer(ctx)
if listen := envconst.String("ZREPL_DAEMON_AUTOSTART_PPROF_SERVER", ""); listen != "" {
pprofServer.Control(PprofServerControlMsg{
Run: true,
HttpListenAddress: listen,
})
}
mux := http.NewServeMux()
mux.Handle(ControlJobEndpointPProf,
requestLogger{log: log, handler: jsonRequestResponder{log, func(decoder jsonDecoder) (interface{}, error) {
var msg PprofServerControlMsg
err := decoder(&msg)
if err != nil {
return nil, errors.Errorf("decode failed")
}
pprofServer.Control(msg)
return struct{}{}, nil
}}})
mux.Handle(ControlJobEndpointVersion,
requestLogger{log: log, handler: jsonResponder{log, func() (interface{}, error) {
return version.NewZreplVersionInformation(), nil
}}})
mux.Handle(ControlJobEndpointStatus,
// don't log requests to status endpoint, too spammy
jsonResponder{log, func() (interface{}, error) {
jobs := j.jobs.status()
globalZFS := zfscmd.GetReport()
s := Status{Jobs: jobs, Global: GlobalStatus{ZFSCmds: globalZFS}}
return s, nil
}})
mux.Handle(ControlJobEndpointSignal,
requestLogger{log: log, handler: jsonRequestResponder{log, func(decoder jsonDecoder) (interface{}, error) {
type reqT struct {
Name string
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Op string
}
var req reqT
if decoder(&req) != nil {
return nil, errors.Errorf("decode failed")
}
var err error
switch req.Op {
case "wakeup":
err = j.jobs.wakeup(req.Name)
case "reset":
err = j.jobs.reset(req.Name)
default:
err = fmt.Errorf("operation %q is invalid", req.Op)
}
return struct{}{}, err
}}})
server := http.Server{
Handler: mux,
// control socket is local, 1s timeout should be more than sufficient, even on a loaded system
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WriteTimeout: 1 * time.Second,
ReadTimeout: 1 * time.Second,
}
outer:
for {
served := make(chan error)
go func() {
served <- server.Serve(l)
close(served)
}()
select {
case <-ctx.Done():
log.WithError(ctx.Err()).Info("context done")
err := server.Shutdown(context.Background())
if err != nil {
log.WithError(err).Error("cannot shutdown server")
}
break outer
case err = <-served:
if err != nil {
log.WithError(err).Error("error serving")
break outer
}
}
}
}
type jsonResponder struct {
log Logger
producer func() (interface{}, error)
}
func (j jsonResponder) ServeHTTP(w http.ResponseWriter, r *http.Request) {
logIoErr := func(err error) {
if err != nil {
j.log.WithError(err).Error("control handler io error")
}
}
res, err := j.producer()
if err != nil {
j.log.WithError(err).Error("control handler error")
w.WriteHeader(http.StatusInternalServerError)
_, err = io.WriteString(w, err.Error())
logIoErr(err)
return
}
var buf bytes.Buffer
err = json.NewEncoder(&buf).Encode(res)
if err != nil {
j.log.WithError(err).Error("control handler json marshal error")
w.WriteHeader(http.StatusInternalServerError)
_, err = io.WriteString(w, err.Error())
} else {
_, err = io.Copy(w, &buf)
}
logIoErr(err)
}
type jsonDecoder = func(interface{}) error
type jsonRequestResponder struct {
log Logger
producer func(decoder jsonDecoder) (interface{}, error)
}
func (j jsonRequestResponder) ServeHTTP(w http.ResponseWriter, r *http.Request) {
logIoErr := func(err error) {
if err != nil {
j.log.WithError(err).Error("control handler io error")
}
}
var decodeError error
decoder := func(i interface{}) error {
err := json.NewDecoder(r.Body).Decode(&i)
decodeError = err
return err
}
res, producerErr := j.producer(decoder)
//If we had a decode error ignore output of producer and return error
if decodeError != nil {
w.WriteHeader(http.StatusBadRequest)
_, err := io.WriteString(w, decodeError.Error())
logIoErr(err)
return
}
if producerErr != nil {
j.log.WithError(producerErr).Error("control handler error")
w.WriteHeader(http.StatusInternalServerError)
_, err := io.WriteString(w, producerErr.Error())
logIoErr(err)
return
}
var buf bytes.Buffer
encodeErr := json.NewEncoder(&buf).Encode(res)
if encodeErr != nil {
j.log.WithError(producerErr).Error("control handler json marshal error")
w.WriteHeader(http.StatusInternalServerError)
_, err := io.WriteString(w, encodeErr.Error())
logIoErr(err)
} else {
_, err := io.Copy(w, &buf)
logIoErr(err)
}
}
type requestLogger struct {
log logger.Logger
handler http.Handler
handlerFunc http.HandlerFunc
}
func (l requestLogger) ServeHTTP(w http.ResponseWriter, r *http.Request) {
log := l.log.WithField("method", r.Method).WithField("url", r.URL)
log.Debug("start")
promControl.requestBegin.WithLabelValues(r.URL.Path).Inc()
defer prometheus.NewTimer(promControl.requestFinished.WithLabelValues(r.URL.Path)).ObserveDuration()
if l.handlerFunc != nil {
l.handlerFunc(w, r)
} else if l.handler != nil {
l.handler.ServeHTTP(w, r)
} else {
log.Error("no handler or handlerFunc configured")
}
log.Debug("finish")
}