open-consul/command/snapshot_save.go

123 lines
2.9 KiB
Go

package command
import (
"fmt"
"io"
"os"
"strings"
"github.com/hashicorp/consul/api"
"github.com/hashicorp/consul/snapshot"
)
// SnapshotSaveCommand is a Command implementation that is used to save the
// state of the Consul servers for disaster recovery.
type SnapshotSaveCommand struct {
BaseCommand
}
func (c *SnapshotSaveCommand) Help() string {
helpText := `
Usage: consul snapshot save [options] FILE
Retrieves an atomic, point-in-time snapshot of the state of the Consul servers
which includes key/value entries, service catalog, prepared queries, sessions,
and ACLs.
If ACLs are enabled, a management token must be supplied in order to perform
snapshot operations.
To create a snapshot from the leader server and save it to "backup.snap":
$ consul snapshot save backup.snap
To create a potentially stale snapshot from any available server (useful if no
leader is available):
$ consul snapshot save -stale backup.snap
For a full list of options and examples, please see the Consul documentation.
` + c.BaseCommand.Help()
return strings.TrimSpace(helpText)
}
func (c *SnapshotSaveCommand) Run(args []string) int {
flagSet := c.BaseCommand.NewFlagSet(c)
if err := c.BaseCommand.Parse(args); err != nil {
return 1
}
var file string
args = flagSet.Args()
switch len(args) {
case 0:
c.UI.Error("Missing FILE argument")
return 1
case 1:
file = args[0]
default:
c.UI.Error(fmt.Sprintf("Too many arguments (expected 1, got %d)", len(args)))
return 1
}
// Create and test the HTTP client
client, err := c.BaseCommand.HTTPClient()
if err != nil {
c.UI.Error(fmt.Sprintf("Error connecting to Consul agent: %s", err))
return 1
}
// Take the snapshot.
snap, qm, err := client.Snapshot().Save(&api.QueryOptions{
AllowStale: c.BaseCommand.HTTPStale(),
})
if err != nil {
c.UI.Error(fmt.Sprintf("Error saving snapshot: %s", err))
return 1
}
defer snap.Close()
// Save the file.
f, err := os.Create(file)
if err != nil {
c.UI.Error(fmt.Sprintf("Error creating snapshot file: %s", err))
return 1
}
if _, err := io.Copy(f, snap); err != nil {
f.Close()
c.UI.Error(fmt.Sprintf("Error writing snapshot file: %s", err))
return 1
}
if err := f.Close(); err != nil {
c.UI.Error(fmt.Sprintf("Error closing snapshot file after writing: %s", err))
return 1
}
// Read it back to verify.
f, err = os.Open(file)
if err != nil {
c.UI.Error(fmt.Sprintf("Error opening snapshot file for verify: %s", err))
return 1
}
if _, err := snapshot.Verify(f); err != nil {
f.Close()
c.UI.Error(fmt.Sprintf("Error verifying snapshot file: %s", err))
return 1
}
if err := f.Close(); err != nil {
c.UI.Error(fmt.Sprintf("Error closing snapshot file after verify: %s", err))
return 1
}
c.UI.Info(fmt.Sprintf("Saved and verified snapshot to index %d", qm.LastIndex))
return 0
}
func (c *SnapshotSaveCommand) Synopsis() string {
return "Saves snapshot of Consul server state"
}