consul/command/snapshotsave/snapshot_save.go

135 lines
3.1 KiB
Go

package snapshotsave
import (
"flag"
"fmt"
"io"
"os"
"github.com/hashicorp/consul/api"
"github.com/hashicorp/consul/command/flags"
"github.com/hashicorp/consul/snapshot"
"github.com/mitchellh/cli"
)
func New(ui cli.Ui) *cmd {
c := &cmd{UI: ui}
c.init()
return c
}
type cmd struct {
UI cli.Ui
flags *flag.FlagSet
http *flags.HTTPFlags
usage string
}
func (c *cmd) init() {
c.flags = flag.NewFlagSet("", flag.ContinueOnError)
c.http = &flags.HTTPFlags{}
flags.Merge(c.flags, c.http.ClientFlags())
flags.Merge(c.flags, c.http.ServerFlags())
c.usage = flags.Usage(usage, c.flags, c.http.ClientFlags(), c.http.ServerFlags())
}
func (c *cmd) Synopsis() string {
return "Saves snapshot of Consul server state"
}
func (c *cmd) Help() string {
return c.usage
}
func (c *cmd) Run(args []string) int {
if err := c.flags.Parse(args); err != nil {
return 1
}
var file string
args = c.flags.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.http.APIClient()
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.http.Stale(),
})
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
}
const usage = `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.`