consul/command/snapshot/inspect/snapshot_inspect.go

273 lines
6.3 KiB
Go

package inspect
import (
"bytes"
"flag"
"fmt"
"io"
"os"
"sort"
"strconv"
"strings"
"text/tabwriter"
"github.com/hashicorp/consul/agent/consul/fsm"
"github.com/hashicorp/consul/agent/structs"
"github.com/hashicorp/consul/command/flags"
"github.com/hashicorp/consul/snapshot"
"github.com/hashicorp/go-hclog"
"github.com/hashicorp/go-msgpack/codec"
"github.com/hashicorp/raft"
"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
help string
}
func (c *cmd) init() {
c.flags = flag.NewFlagSet("", flag.ContinueOnError)
c.help = flags.Usage(help, c.flags)
}
func (c *cmd) Run(args []string) int {
if err := c.flags.Parse(args); err != nil {
c.UI.Error(err.Error())
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
}
// Open the file.
f, err := os.Open(file)
if err != nil {
c.UI.Error(fmt.Sprintf("Error opening snapshot file: %s", err))
return 1
}
defer f.Close()
readFile, meta, err := snapshot.Read(hclog.New(nil), f)
if err != nil {
c.UI.Error(fmt.Sprintf("Error reading snapshot: %s", err))
}
defer func() {
if err := readFile.Close(); err != nil {
c.UI.Error(fmt.Sprintf("Failed to close temp snapshot: %v", err))
}
if err := os.Remove(readFile.Name()); err != nil {
c.UI.Error(fmt.Sprintf("Failed to clean up temp snapshot: %v", err))
}
}()
stats, totalSize, err := enhance(readFile)
if err != nil {
c.UI.Error(fmt.Sprintf("Error extracting snapshot data: %s", err))
return 1
}
// Outputs the original style of inspect information
legacy, err := c.legacyStats(meta)
if err != nil {
c.UI.Error(fmt.Sprintf("Error outputting snapshot data: %s", err))
}
c.UI.Info(legacy.String())
// Outputs the more detailed snapshot information
enhanced, err := c.readStats(stats, totalSize)
if err != nil {
c.UI.Error(fmt.Sprintf("Error outputting enhanced snapshot data: %s", err))
return 1
}
c.UI.Info(enhanced.String())
return 0
}
// legacyStats outputs the expected stats from the original snapshot
// inspect command
func (c *cmd) legacyStats(meta *raft.SnapshotMeta) (bytes.Buffer, error) {
var b bytes.Buffer
tw := tabwriter.NewWriter(&b, 0, 2, 6, ' ', 0)
fmt.Fprintf(tw, "ID\t%s\n", meta.ID)
fmt.Fprintf(tw, "Size\t%d\n", meta.Size)
fmt.Fprintf(tw, "Index\t%d\n", meta.Index)
fmt.Fprintf(tw, "Term\t%d\n", meta.Term)
fmt.Fprintf(tw, "Version\t%d\n", meta.Version)
if err := tw.Flush(); err != nil {
return b, err
}
return b, nil
}
type typeStats struct {
Name string
Sum int
Count int
}
// countingReader helps keep track of the bytes we have read
// when reading snapshots
type countingReader struct {
wrappedReader io.Reader
read int
}
func (r *countingReader) Read(p []byte) (n int, err error) {
n, err = r.wrappedReader.Read(p)
if err == nil {
r.read += n
}
return n, err
}
// enhance utilizes ReadSnapshot to populate the struct with
// all of the snapshot's itemized data
func enhance(file io.Reader) (map[structs.MessageType]typeStats, int, error) {
stats := make(map[structs.MessageType]typeStats)
cr := &countingReader{wrappedReader: file}
totalSize := 0
handler := func(header *fsm.SnapshotHeader, msg structs.MessageType, dec *codec.Decoder) error {
name := structs.MessageType.String(msg)
s := stats[msg]
if s.Name == "" {
s.Name = name
}
var val interface{}
err := dec.Decode(&val)
if err != nil {
return fmt.Errorf("failed to decode msg type %v, error %v", name, err)
}
size := cr.read - totalSize
s.Sum += size
s.Count++
totalSize = cr.read
stats[msg] = s
return nil
}
if err := fsm.ReadSnapshot(cr, handler); err != nil {
return nil, 0, err
}
return stats, totalSize, nil
}
// readStats takes the information generated from enhance and creates human
// readable output from it
func (c *cmd) readStats(stats map[structs.MessageType]typeStats, totalSize int) (bytes.Buffer, error) {
// Output stats in size-order
ss := make([]typeStats, 0, len(stats))
for _, s := range stats {
ss = append(ss, s)
}
// Sort the stat slice
sort.Slice(ss, func(i, j int) bool { return ss[i].Sum > ss[j].Sum })
var b bytes.Buffer
tw := tabwriter.NewWriter(&b, 8, 8, 6, ' ', 0)
fmt.Fprintln(tw, "\n Type\tCount\tSize\t")
fmt.Fprintf(tw, " %s\t%s\t%s\t", "----", "----", "----")
// For each different type generate new output
for _, s := range ss {
fmt.Fprintf(tw, "\n %s\t%d\t%s\t", s.Name, s.Count, ByteSize(uint64(s.Sum)))
}
fmt.Fprintf(tw, "\n %s\t%s\t%s\t", "----", "----", "----")
fmt.Fprintf(tw, "\n Total\t\t%s\t", ByteSize(uint64(totalSize)))
if err := tw.Flush(); err != nil {
c.UI.Error(fmt.Sprintf("Error rendering snapshot info: %s", err))
return b, err
}
return b, nil
}
// ByteSize returns a human-readable byte string of the form 10MB, 12.5KB, and so forth. The following units are available:
// TB: Terabyte
// GB: Gigabyte
// MB: Megabyte
// KB: Kilobyte
// B: Byte
// The unit that results in the smallest number greater than or equal to 1 is always chosen.
// From https://github.com/cloudfoundry/bytefmt/blob/master/bytes.go
const (
BYTE = 1 << (10 * iota)
KILOBYTE
MEGABYTE
GIGABYTE
TERABYTE
)
func ByteSize(bytes uint64) string {
unit := ""
value := float64(bytes)
switch {
case bytes >= TERABYTE:
unit = "TB"
value = value / TERABYTE
case bytes >= GIGABYTE:
unit = "GB"
value = value / GIGABYTE
case bytes >= MEGABYTE:
unit = "MB"
value = value / MEGABYTE
case bytes >= KILOBYTE:
unit = "KB"
value = value / KILOBYTE
case bytes >= BYTE:
unit = "B"
case bytes == 0:
return "0"
}
result := strconv.FormatFloat(value, 'f', 1, 64)
result = strings.TrimSuffix(result, ".0")
return result + unit
}
func (c *cmd) Synopsis() string {
return synopsis
}
func (c *cmd) Help() string {
return c.help
}
const synopsis = "Displays information about a Consul snapshot file"
const help = `
Usage: consul snapshot inspect [options] FILE
Displays information about a snapshot file on disk.
To inspect the file "backup.snap":
$ consul snapshot inspect backup.snap
For a full list of options and examples, please see the Consul documentation.
`