mirror of
https://github.com/zrepl/zrepl.git
synced 2024-11-22 08:23:50 +01:00
320 lines
9.2 KiB
Go
320 lines
9.2 KiB
Go
package cmd
|
|
|
|
import (
|
|
"fmt"
|
|
"io"
|
|
"time"
|
|
|
|
"bytes"
|
|
"encoding/json"
|
|
"github.com/zrepl/zrepl/rpc"
|
|
"github.com/zrepl/zrepl/util"
|
|
"github.com/zrepl/zrepl/zfs"
|
|
)
|
|
|
|
type localPullACL struct{}
|
|
|
|
func (a localPullACL) Filter(p *zfs.DatasetPath) (pass bool, err error) {
|
|
return true, nil
|
|
}
|
|
|
|
const LOCAL_TRANSPORT_IDENTITY string = "local"
|
|
|
|
const DEFAULT_INITIAL_REPL_POLICY = InitialReplPolicyMostRecent
|
|
|
|
type InitialReplPolicy string
|
|
|
|
const (
|
|
InitialReplPolicyMostRecent InitialReplPolicy = "most_recent"
|
|
InitialReplPolicyAll InitialReplPolicy = "all"
|
|
)
|
|
|
|
func closeRPCWithTimeout(log Logger, remote rpc.RPCClient, timeout time.Duration, goodbye string) {
|
|
log.Info("closing rpc connection")
|
|
|
|
ch := make(chan error)
|
|
go func() {
|
|
ch <- remote.Close()
|
|
close(ch)
|
|
}()
|
|
|
|
var err error
|
|
select {
|
|
case <-time.After(timeout):
|
|
err = fmt.Errorf("timeout exceeded (%s)", timeout)
|
|
case closeRequestErr := <-ch:
|
|
err = closeRequestErr
|
|
}
|
|
|
|
if err != nil {
|
|
log.WithError(err).Error("error closing connection")
|
|
}
|
|
return
|
|
}
|
|
|
|
type PullContext struct {
|
|
Remote rpc.RPCClient
|
|
Log Logger
|
|
Mapping DatasetMapping
|
|
InitialReplPolicy InitialReplPolicy
|
|
}
|
|
|
|
func doPull(pull PullContext) (err error) {
|
|
|
|
remote := pull.Remote
|
|
log := pull.Log
|
|
|
|
log.Info("request remote filesystem list")
|
|
fsr := FilesystemRequest{}
|
|
var remoteFilesystems []*zfs.DatasetPath
|
|
if err = remote.Call("FilesystemRequest", &fsr, &remoteFilesystems); err != nil {
|
|
return
|
|
}
|
|
|
|
log.Debug("map remote filesystems to local paths and determine order for per-filesystem sync")
|
|
type RemoteLocalMapping struct {
|
|
Remote *zfs.DatasetPath
|
|
Local *zfs.DatasetPath
|
|
}
|
|
replMapping := make(map[string]RemoteLocalMapping, len(remoteFilesystems))
|
|
localTraversal := zfs.NewDatasetPathForest()
|
|
for fs := range remoteFilesystems {
|
|
var err error
|
|
var localFs *zfs.DatasetPath
|
|
localFs, err = pull.Mapping.Map(remoteFilesystems[fs])
|
|
if err != nil {
|
|
err := fmt.Errorf("error mapping %s: %s", remoteFilesystems[fs], err)
|
|
log.WithError(err).WithField(logMapFromField, remoteFilesystems[fs]).Error("cannot map")
|
|
return err
|
|
}
|
|
if localFs == nil {
|
|
continue
|
|
}
|
|
log.WithField(logMapFromField, remoteFilesystems[fs].ToString()).
|
|
WithField(logMapToField, localFs.ToString()).Debug("mapping")
|
|
m := RemoteLocalMapping{remoteFilesystems[fs], localFs}
|
|
replMapping[m.Local.ToString()] = m
|
|
localTraversal.Add(m.Local)
|
|
}
|
|
|
|
log.Debug("build cache for already present local filesystem state")
|
|
localFilesystemState, err := zfs.ZFSListFilesystemState()
|
|
if err != nil {
|
|
log.WithError(err).Error("cannot request local filesystem state")
|
|
return err
|
|
}
|
|
|
|
log.Info("start per-filesystem sync")
|
|
localTraversal.WalkTopDown(func(v zfs.DatasetPathVisit) bool {
|
|
|
|
log := log.WithField(logFSField, v.Path.ToString())
|
|
|
|
if v.FilledIn {
|
|
if _, exists := localFilesystemState[v.Path.ToString()]; exists {
|
|
// No need to verify if this is a placeholder or not. It is sufficient
|
|
// to know we can add child filesystems to it
|
|
return true
|
|
}
|
|
log.Debug("create placeholder filesystem")
|
|
err = zfs.ZFSCreatePlaceholderFilesystem(v.Path)
|
|
if err != nil {
|
|
log.Error("cannot create placeholder filesystem")
|
|
return false
|
|
}
|
|
return true
|
|
}
|
|
|
|
m, ok := replMapping[v.Path.ToString()]
|
|
if !ok {
|
|
panic("internal inconsistency: replMapping should contain mapping for any path that was not filled in by WalkTopDown()")
|
|
}
|
|
|
|
log = log.WithField(logMapToField, m.Remote.ToString()).
|
|
WithField(logMapFromField, m.Local.ToString())
|
|
|
|
log.Debug("examing local filesystem state")
|
|
localState, localExists := localFilesystemState[m.Local.ToString()]
|
|
var versions []zfs.FilesystemVersion
|
|
switch {
|
|
case !localExists:
|
|
log.Info("local filesystem does not exist")
|
|
case localState.Placeholder:
|
|
log.Info("local filesystem is marked as placeholder")
|
|
default:
|
|
log.Debug("local filesystem exists")
|
|
log.Debug("requesting local filesystem versions")
|
|
if versions, err = zfs.ZFSListFilesystemVersions(m.Local, nil); err != nil {
|
|
log.WithError(err).Error("cannot get local filesystem versions")
|
|
return false
|
|
}
|
|
}
|
|
|
|
log.Info("requesting remote filesystem versions")
|
|
r := FilesystemVersionsRequest{
|
|
Filesystem: m.Remote,
|
|
}
|
|
var theirVersions []zfs.FilesystemVersion
|
|
if err = remote.Call("FilesystemVersionsRequest", &r, &theirVersions); err != nil {
|
|
log.WithError(err).Error("cannot get remote filesystem versions")
|
|
log.Warn("stopping replication for all filesystems mapped as children of receiving filesystem")
|
|
return false
|
|
}
|
|
|
|
log.Debug("computing diff between remote and local filesystem versions")
|
|
diff := zfs.MakeFilesystemDiff(versions, theirVersions)
|
|
log.WithField("diff", diff).Debug("diff between local and remote filesystem")
|
|
|
|
if localState.Placeholder && diff.Conflict != zfs.ConflictAllRight {
|
|
panic("internal inconsistency: local placeholder implies ConflictAllRight")
|
|
}
|
|
|
|
switch diff.Conflict {
|
|
case zfs.ConflictAllRight:
|
|
|
|
log.WithField("replication_policy", pull.InitialReplPolicy).Info("performing initial sync, following policy")
|
|
|
|
if pull.InitialReplPolicy != InitialReplPolicyMostRecent {
|
|
panic(fmt.Sprintf("policy '%s' not implemented", pull.InitialReplPolicy))
|
|
}
|
|
|
|
snapsOnly := make([]zfs.FilesystemVersion, 0, len(diff.MRCAPathRight))
|
|
for s := range diff.MRCAPathRight {
|
|
if diff.MRCAPathRight[s].Type == zfs.Snapshot {
|
|
snapsOnly = append(snapsOnly, diff.MRCAPathRight[s])
|
|
}
|
|
}
|
|
|
|
if len(snapsOnly) < 1 {
|
|
log.Warn("cannot perform initial sync: no remote snapshots")
|
|
return false
|
|
}
|
|
|
|
r := InitialTransferRequest{
|
|
Filesystem: m.Remote,
|
|
FilesystemVersion: snapsOnly[len(snapsOnly)-1],
|
|
}
|
|
|
|
log.WithField("version", r.FilesystemVersion).Debug("requesting snapshot stream")
|
|
|
|
var stream io.Reader
|
|
|
|
if err = remote.Call("InitialTransferRequest", &r, &stream); err != nil {
|
|
log.WithError(err).Error("cannot request initial transfer")
|
|
return false
|
|
}
|
|
log.Debug("received initial transfer request response")
|
|
|
|
log.Debug("invoke zfs receive")
|
|
watcher := util.IOProgressWatcher{Reader: stream}
|
|
watcher.KickOff(1*time.Second, func(p util.IOProgress) {
|
|
log.WithField("total_rx", p.TotalRX).Info("progress on receive operation")
|
|
})
|
|
|
|
recvArgs := []string{"-u"}
|
|
if localState.Placeholder {
|
|
log.Info("receive with forced rollback to replace placeholder filesystem")
|
|
recvArgs = append(recvArgs, "-F")
|
|
}
|
|
|
|
if err = zfs.ZFSRecv(m.Local, &watcher, recvArgs...); err != nil {
|
|
log.WithError(err).Error("canot receive stream")
|
|
return false
|
|
}
|
|
log.WithField("total_rx", watcher.Progress().TotalRX).
|
|
Info("finished receiving stream")
|
|
|
|
log.Debug("configuring properties of received filesystem")
|
|
if err = zfs.ZFSSet(m.Local, "readonly", "on"); err != nil {
|
|
log.WithError(err).Error("cannot set readonly property")
|
|
}
|
|
|
|
log.Info("finished initial transfer")
|
|
return true
|
|
|
|
case zfs.ConflictIncremental:
|
|
|
|
if len(diff.IncrementalPath) < 2 {
|
|
log.Info("remote and local are in sync")
|
|
return true
|
|
}
|
|
|
|
log.Info("following incremental path from diff")
|
|
var pathRx uint64
|
|
|
|
for i := 0; i < len(diff.IncrementalPath)-1; i++ {
|
|
|
|
from, to := diff.IncrementalPath[i], diff.IncrementalPath[i+1]
|
|
|
|
log, _ := log.WithField(logIncFromField, from.Name).WithField(logIncToField, to.Name), 0
|
|
|
|
log.Debug("requesting incremental snapshot stream")
|
|
r := IncrementalTransferRequest{
|
|
Filesystem: m.Remote,
|
|
From: from,
|
|
To: to,
|
|
}
|
|
var stream io.Reader
|
|
if err = remote.Call("IncrementalTransferRequest", &r, &stream); err != nil {
|
|
log.WithError(err).Error("cannot request incremental snapshot stream")
|
|
return false
|
|
}
|
|
|
|
log.Debug("invoking zfs receive")
|
|
watcher := util.IOProgressWatcher{Reader: stream}
|
|
watcher.KickOff(1*time.Second, func(p util.IOProgress) {
|
|
log.WithField("total_rx", p.TotalRX).Info("progress on receive operation")
|
|
})
|
|
|
|
if err = zfs.ZFSRecv(m.Local, &watcher); err != nil {
|
|
log.WithError(err).Error("cannot receive stream")
|
|
return false
|
|
}
|
|
|
|
totalRx := watcher.Progress().TotalRX
|
|
pathRx += totalRx
|
|
log.WithField("total_rx", totalRx).Info("finished incremental transfer")
|
|
|
|
}
|
|
|
|
log.WithField("total_rx", pathRx).Info("finished following incremental path")
|
|
return true
|
|
|
|
case zfs.ConflictNoCommonAncestor:
|
|
fallthrough
|
|
case zfs.ConflictDiverged:
|
|
|
|
var jsonDiff bytes.Buffer
|
|
if err := json.NewEncoder(&jsonDiff).Encode(diff); err != nil {
|
|
log.WithError(err).Error("cannot JSON-encode diff")
|
|
return false
|
|
}
|
|
|
|
var problem, resolution string
|
|
|
|
switch diff.Conflict {
|
|
case zfs.ConflictNoCommonAncestor:
|
|
problem = "remote and local filesystem have snapshots, but no common one"
|
|
resolution = "perform manual establish a common snapshot history"
|
|
case zfs.ConflictDiverged:
|
|
problem = "remote and local filesystem share a history but have diverged"
|
|
resolution = "perform manual replication or delete snapshots on the receiving" +
|
|
"side to establish an incremental replication parse"
|
|
}
|
|
|
|
log.WithField("diff", jsonDiff.String()).
|
|
WithField("problem", problem).
|
|
WithField("resolution", resolution).
|
|
Error("manual conflict resolution required")
|
|
|
|
return false
|
|
|
|
}
|
|
|
|
panic("should not be reached")
|
|
|
|
})
|
|
|
|
return
|
|
|
|
}
|