wisski-cloud-distillery/cmd/snapshot.go
2022-09-08 14:39:05 +02:00

110 lines
3.1 KiB
Go

package cmd
import (
"fmt"
"os"
"path/filepath"
wisski_distillery "github.com/FAU-CDI/wisski-distillery"
"github.com/FAU-CDI/wisski-distillery/env"
"github.com/FAU-CDI/wisski-distillery/internal/logging"
"github.com/FAU-CDI/wisski-distillery/internal/targz"
"github.com/tkw1536/goprogram/exit"
)
// Snapshot creates a snapshot of an instance
var Snapshot wisski_distillery.Command = snapshot{}
type snapshot struct {
Keepalive bool `short:"k" long:"keepalive" description:"Keep instance running while taking a backup. Might lead to inconsistent state"`
Positionals struct {
Slug string `positional-arg-name:"SLUG" required:"1-1" description:"slug of instance to take a snapshot of"`
Dest string `positional-arg-name:"DEST" description:"Destination path to write snapshot archive to. Defaults to the snapshots/archives/ directory"`
} `positional-args:"true"`
}
func (snapshot) Description() wisski_distillery.Description {
return wisski_distillery.Description{
Requirements: env.Requirements{
NeedsConfig: true,
},
Command: "snapshot",
Description: "Generates a snapshot archive for the provided archive",
}
}
var errSnapshotFailed = exit.Error{
Message: "Failed to make a snapshot",
ExitCode: exit.ExitGeneric,
}
func (bi snapshot) Run(context wisski_distillery.Context) error {
dis := context.Environment
instance, err := dis.Instance(bi.Positionals.Slug)
if err != nil {
return err
}
// TODO: Allow skipping backups of individual parts and make them concurrent!
// start the snapshot and shutdown the instance (if requested)
logging.LogMessage(context.IOStream, "Creating snapshot of instance %s", bi.Positionals.Slug)
// create a new temporary directory
logging.LogMessage(context.IOStream, "Creating new snapshot staging directory")
sPath, err := dis.NewSnapshotStagingDir(instance.Slug)
if err != nil {
return errSnapshotFailed.Wrap(err)
}
defer func() {
logging.LogMessage(context.IOStream, "Removing snapshot staging directory")
os.RemoveAll(sPath)
}()
// take a snapshot into the staging area!
sreport := instance.Snapshot(context.IOStream, bi.Keepalive, sPath)
// write out the report!
logging.LogOperation(func() error {
logging.LogOperation(func() error {
reportPath := filepath.Join(sPath, "report.txt")
context.Println(reportPath)
// create the report file!
report, err := os.Create(reportPath)
if err != nil {
return err
}
defer report.Close()
// print the report into it!
_, err = fmt.Fprintf(report, "%#v\n", sreport)
return err
}, context.IOStream, "Writing snapshot report")
return nil
}, context.IOStream, "Creating snapshot")
// copy everything into the final archive
finalPath := bi.Positionals.Dest
if finalPath == "" {
finalPath = dis.NewSnapshotArchivePath(instance.Slug)
}
if err := logging.LogOperation(func() error {
context.IOStream.Println(finalPath)
targz.Package(finalPath, sPath, func(src string) {
context.Println(src)
})
return err
}, context.IOStream, "Writing final backup"); err != nil {
return errSnapshotFailed.Wrap(err)
}
context.Printf("Wrote %s\n", finalPath)
return nil
}