consul/command/snapshot_save.go
Frank Schroeder a49711b8bf config: refactor commands to print help for flags (#3536)
This patch refactors the commands that use the mitchellh/cli library to
populate the command line flag set in both the Run() and the Help()
method. Earlier versions of the mitchellh/cli library relied on the
Run() method to populuate the flagset for generating the usage screen.
This has changed in later versions and was previously solved with a
small monkey patch to the library to restore the old behavior.

However, this makes upgrading the library difficult since the patch has
to be restored every time.

This patch addresses this by moving the command line flags into an
initFlags() method where appropriate and also moving all variables for
the flags from the Run() method into the command itself.

Fixes #3536
2017-10-18 00:08:45 +02:00

120 lines
2.8 KiB
Go

package command
import (
"fmt"
"io"
"os"
"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 {
c.InitFlagSet()
return c.HelpCommand(`
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.
`)
}
func (c *SnapshotSaveCommand) Run(args []string) int {
c.InitFlagSet()
if err := c.FlagSet.Parse(args); err != nil {
return 1
}
var file string
args = c.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.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.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"
}