zrepl/cmd/prune.go
Christian Schwarz a0f72b585b remove JobStatus, Task abstraction and 'control status' subcommand
Control status will be replaced by job-specific output at some point.

Task was not useful anymore with state machine, may reintroduce
something similar at a later point, but consider alternatives:

- opentracing.io
- embedding everything in ctx
	- activity stack would work easily
	- log entries via proxy logger.Logger object
- progress reporting should be in status reports of individial jobs
2018-08-26 19:08:30 +02:00

125 lines
3.2 KiB
Go

package cmd
import (
"context"
"fmt"
"github.com/zrepl/zrepl/zfs"
"time"
)
type Pruner struct {
Now time.Time
DryRun bool
DatasetFilter zfs.DatasetFilter
SnapshotPrefix string
PrunePolicy PrunePolicy
}
type PruneResult struct {
Filesystem *zfs.DatasetPath
All []zfs.FilesystemVersion
Keep []zfs.FilesystemVersion
Remove []zfs.FilesystemVersion
}
func (p *Pruner) filterFilesystems(ctx context.Context) (filesystems []*zfs.DatasetPath, stop bool) {
filesystems, err := zfs.ZFSListMapping(p.DatasetFilter)
if err != nil {
getLogger(ctx).WithError(err).Error("error applying filesystem filter")
return nil, true
}
if len(filesystems) <= 0 {
getLogger(ctx).Info("no filesystems matching filter")
return nil, true
}
return filesystems, false
}
func (p *Pruner) filterVersions(ctx context.Context, fs *zfs.DatasetPath) (fsversions []zfs.FilesystemVersion, stop bool) {
log := getLogger(ctx).WithField("fs", fs.ToString())
filter := NewPrefixFilter(p.SnapshotPrefix)
fsversions, err := zfs.ZFSListFilesystemVersions(fs, filter)
if err != nil {
log.WithError(err).Error("error listing filesytem versions")
return nil, true
}
if len(fsversions) == 0 {
log.WithField("prefix", p.SnapshotPrefix).Info("no filesystem versions matching prefix")
return nil, true
}
return fsversions, false
}
func (p *Pruner) pruneFilesystem(ctx context.Context, fs *zfs.DatasetPath) (r PruneResult, valid bool) {
log := getLogger(ctx).WithField("fs", fs.ToString())
fsversions, stop := p.filterVersions(ctx, fs)
if stop {
return
}
keep, remove, err := p.PrunePolicy.Prune(fs, fsversions)
if err != nil {
log.WithError(err).Error("error evaluating prune policy")
return
}
log.WithField("fsversions", fsversions).
WithField("keep", keep).
WithField("remove", remove).
Debug("prune policy debug dump")
r = PruneResult{fs, fsversions, keep, remove}
makeFields := func(v zfs.FilesystemVersion) (fields map[string]interface{}) {
fields = make(map[string]interface{})
fields["version"] = v.ToAbsPath(fs)
timeSince := v.Creation.Sub(p.Now)
fields["age_ns"] = timeSince
const day time.Duration = 24 * time.Hour
days := timeSince / day
remainder := timeSince % day
fields["age_str"] = fmt.Sprintf("%dd%s", days, remainder)
return
}
for _, v := range remove {
fields := makeFields(v)
log.WithFields(fields).Info("destroying version")
// echo what we'll do and exec zfs destroy if not dry run
// TODO special handling for EBUSY (zfs hold)
// TODO error handling for clones? just echo to cli, skip over, and exit with non-zero status code (we're idempotent)
if !p.DryRun {
err := zfs.ZFSDestroyFilesystemVersion(fs, v)
if err != nil {
log.WithFields(fields).WithError(err).Error("error destroying version")
}
}
}
return r, true
}
func (p *Pruner) Run(ctx context.Context) (r []PruneResult, err error) {
if p.DryRun {
getLogger(ctx).Info("doing dry run")
}
filesystems, stop := p.filterFilesystems(ctx)
if stop {
return
}
r = make([]PruneResult, 0, len(filesystems))
for _, fs := range filesystems {
res, ok := p.pruneFilesystem(ctx, fs)
if ok {
r = append(r, res)
}
}
return
}