VictoriaMetrics/app/vlogscli/main.go
Aliaksandr Valialkin 8faee6b446
app/vlogscli: print hint on how to see available commands when starting vlogscli
This should improve the first-time experience with vlogscli
2024-10-29 16:44:46 +01:00

423 lines
11 KiB
Go

package main
import (
"context"
"errors"
"flag"
"fmt"
"io"
"io/fs"
"net/http"
"net/url"
"os"
"os/signal"
"strconv"
"strings"
"syscall"
"time"
"github.com/ergochat/readline"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/buildinfo"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/envflag"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/flagutil"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/logstorage"
)
var (
datasourceURL = flag.String("datasource.url", "http://localhost:9428/select/logsql/query", "URL for querying VictoriaLogs; "+
"see https://docs.victoriametrics.com/victorialogs/querying/#querying-logs . See also -tail.url")
tailURL = flag.String("tail.url", "", "URL for live tailing queries to VictoriaLogs; see https://docs.victoriametrics.com/victorialogs/querying/#live-tailing ."+
"The url is automatically detected from -datasource.url by replacing /query with /tail at the end if -tail.url is empty")
historyFile = flag.String("historyFile", "vlogscli-history", "Path to file with command history")
header = flagutil.NewArrayString("header", "Optional header to pass in request -datasource.url in the form 'HeaderName: value'")
accountID = flag.Int("accountID", 0, "Account ID to query; see https://docs.victoriametrics.com/victorialogs/#multitenancy")
projectID = flag.Int("projectID", 0, "Project ID to query; see https://docs.victoriametrics.com/victorialogs/#multitenancy")
)
const (
firstLinePrompt = ";> "
nextLinePrompt = ""
)
func main() {
// Write flags and help message to stdout, since it is easier to grep or pipe.
flag.CommandLine.SetOutput(os.Stdout)
flag.Usage = usage
envflag.Parse()
buildinfo.Init()
logger.InitNoLogFlags()
hes, err := parseHeaders(*header)
if err != nil {
fatalf("cannot parse -header command-line flag: %s", err)
}
headers = hes
incompleteLine := ""
cfg := &readline.Config{
Prompt: firstLinePrompt,
DisableAutoSaveHistory: true,
Listener: func(line []rune, pos int, _ rune) ([]rune, int, bool) {
incompleteLine = string(line)
return line, pos, false
},
}
rl, err := readline.NewFromConfig(cfg)
if err != nil {
fatalf("cannot initialize readline: %s", err)
}
fmt.Fprintf(rl, "sending queries to -datasource.url=%s\n", *datasourceURL)
fmt.Fprintf(rl, `type ? and press enter to see available commands`+"\n")
runReadlineLoop(rl, &incompleteLine)
if err := rl.Close(); err != nil {
fatalf("cannot close readline: %s", err)
}
}
func runReadlineLoop(rl *readline.Instance, incompleteLine *string) {
historyLines, err := loadFromHistory(*historyFile)
if err != nil {
fatalf("cannot load query history: %s", err)
}
for _, line := range historyLines {
if err := rl.SaveToHistory(line); err != nil {
fatalf("cannot initialize query history: %s", err)
}
}
outputMode := outputModeJSONMultiline
s := ""
for {
line, err := rl.ReadLine()
if err != nil {
switch err {
case io.EOF:
if s != "" {
// This is non-interactive query execution.
executeQuery(context.Background(), rl, s, outputMode)
}
return
case readline.ErrInterrupt:
if s == "" && *incompleteLine == "" {
fmt.Fprintf(rl, "interrupted\n")
os.Exit(128 + int(syscall.SIGINT))
}
// Default value for Ctrl+C - clear the prompt and store the incompletely entered line into history
s += *incompleteLine
historyLines = pushToHistory(rl, historyLines, s)
s = ""
rl.SetPrompt(firstLinePrompt)
continue
default:
fatalf("unexpected error in readline: %s", err)
}
}
s += line
if s == "" {
// Skip empty lines
continue
}
if isQuitCommand(s) {
fmt.Fprintf(rl, "bye!\n")
_ = pushToHistory(rl, historyLines, s)
return
}
if isHelpCommand(s) {
printCommandsHelp(rl)
historyLines = pushToHistory(rl, historyLines, s)
s = ""
continue
}
if s == `\s` {
fmt.Fprintf(rl, "singleline json output mode\n")
outputMode = outputModeJSONSingleline
historyLines = pushToHistory(rl, historyLines, s)
s = ""
continue
}
if s == `\m` {
fmt.Fprintf(rl, "multiline json output mode\n")
outputMode = outputModeJSONMultiline
historyLines = pushToHistory(rl, historyLines, s)
s = ""
continue
}
if s == `\c` {
fmt.Fprintf(rl, "compact output mode\n")
outputMode = outputModeCompact
historyLines = pushToHistory(rl, historyLines, s)
s = ""
continue
}
if s == `\logfmt` {
fmt.Fprintf(rl, "logfmt output mode\n")
outputMode = outputModeLogfmt
historyLines = pushToHistory(rl, historyLines, s)
s = ""
continue
}
if line != "" && !strings.HasSuffix(line, ";") {
// Assume the query is incomplete and allow the user finishing the query on the next line
s += "\n"
rl.SetPrompt(nextLinePrompt)
continue
}
// Execute the query
ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt)
executeQuery(ctx, rl, s, outputMode)
cancel()
historyLines = pushToHistory(rl, historyLines, s)
s = ""
rl.SetPrompt(firstLinePrompt)
}
}
func pushToHistory(rl *readline.Instance, historyLines []string, s string) []string {
s = strings.TrimSpace(s)
if len(historyLines) == 0 || historyLines[len(historyLines)-1] != s {
historyLines = append(historyLines, s)
if len(historyLines) > 500 {
historyLines = historyLines[len(historyLines)-500:]
}
if err := saveToHistory(*historyFile, historyLines); err != nil {
fatalf("cannot save query history: %s", err)
}
}
if err := rl.SaveToHistory(s); err != nil {
fatalf("cannot update query history: %s", err)
}
return historyLines
}
func loadFromHistory(filePath string) ([]string, error) {
data, err := os.ReadFile(filePath)
if err != nil {
if errors.Is(err, fs.ErrNotExist) {
return nil, nil
}
return nil, err
}
linesQuoted := strings.Split(string(data), "\n")
lines := make([]string, 0, len(linesQuoted))
i := 0
for _, lineQuoted := range linesQuoted {
i++
if lineQuoted == "" {
continue
}
line, err := strconv.Unquote(lineQuoted)
if err != nil {
return nil, fmt.Errorf("cannot parse line #%d at %s: %w; line: [%s]", i, filePath, err, line)
}
lines = append(lines, line)
}
return lines, nil
}
func saveToHistory(filePath string, lines []string) error {
linesQuoted := make([]string, len(lines))
for i, line := range lines {
lineQuoted := strconv.Quote(line)
linesQuoted[i] = lineQuoted
}
data := strings.Join(linesQuoted, "\n")
return os.WriteFile(filePath, []byte(data), 0600)
}
func isQuitCommand(s string) bool {
switch s {
case `\q`, "q", "quit", "exit":
return true
default:
return false
}
}
func isHelpCommand(s string) bool {
switch s {
case `\h`, "h", "help", "?":
return true
default:
return false
}
}
func printCommandsHelp(w io.Writer) {
fmt.Fprintf(w, "%s", `Available commands:
\q - quit
\h - show this help
\s - singleline json output mode
\m - multiline json output mode
\c - compact output
\logfmt - logfmt output mode
\tail <query> - live tail <query> results
See https://docs.victoriametrics.com/victorialogs/querying/vlogscli/ for more details
`)
}
func executeQuery(ctx context.Context, output io.Writer, qStr string, outputMode outputMode) {
if strings.HasPrefix(qStr, `\tail `) {
tailQuery(ctx, output, qStr, outputMode)
return
}
respBody := getQueryResponse(ctx, output, qStr, outputMode, *datasourceURL)
if respBody == nil {
return
}
defer func() {
_ = respBody.Close()
}()
if err := readWithLess(respBody); err != nil {
fmt.Fprintf(output, "error when reading query response: %s\n", err)
return
}
}
func tailQuery(ctx context.Context, output io.Writer, qStr string, outputMode outputMode) {
qStr = strings.TrimPrefix(qStr, `\tail `)
qURL, err := getTailURL()
if err != nil {
fmt.Fprintf(output, "%s\n", err)
return
}
respBody := getQueryResponse(ctx, output, qStr, outputMode, qURL)
if respBody == nil {
return
}
defer func() {
_ = respBody.Close()
}()
if _, err := io.Copy(output, respBody); err != nil {
if !errors.Is(err, context.Canceled) && !isErrPipe(err) {
fmt.Fprintf(output, "error when live tailing query response: %s\n", err)
}
fmt.Fprintf(output, "\n")
return
}
}
func getTailURL() (string, error) {
if *tailURL != "" {
return *tailURL, nil
}
u, err := url.Parse(*datasourceURL)
if err != nil {
return "", fmt.Errorf("cannot parse -datasource.url=%q: %w", *datasourceURL, err)
}
if !strings.HasSuffix(u.Path, "/query") {
return "", fmt.Errorf("cannot find /query suffix in -datasource.url=%q", *datasourceURL)
}
u.Path = u.Path[:len(u.Path)-len("/query")] + "/tail"
return u.String(), nil
}
func getQueryResponse(ctx context.Context, output io.Writer, qStr string, outputMode outputMode, qURL string) io.ReadCloser {
// Parse the query and convert it to canonical view.
qStr = strings.TrimSuffix(qStr, ";")
q, err := logstorage.ParseQuery(qStr)
if err != nil {
fmt.Fprintf(output, "cannot parse query: %s\n", err)
return nil
}
qStr = q.String()
fmt.Fprintf(output, "executing [%s]...", qStr)
// Prepare HTTP request for qURL
args := make(url.Values)
args.Set("query", qStr)
data := strings.NewReader(args.Encode())
req, err := http.NewRequestWithContext(ctx, "POST", qURL, data)
if err != nil {
panic(fmt.Errorf("BUG: cannot prepare request to server: %w", err))
}
req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
for _, h := range headers {
req.Header.Set(h.Name, h.Value)
}
req.Header.Set("AccountID", strconv.Itoa(*accountID))
req.Header.Set("ProjectID", strconv.Itoa(*projectID))
// Execute HTTP request at qURL
startTime := time.Now()
resp, err := httpClient.Do(req)
queryDuration := time.Since(startTime)
fmt.Fprintf(output, "; duration: %.3fs\n", queryDuration.Seconds())
if err != nil {
if errors.Is(err, context.Canceled) {
fmt.Fprintf(output, "\n")
} else {
fmt.Fprintf(output, "cannot execute query: %s\n", err)
}
return nil
}
// Verify response code
if resp.StatusCode != http.StatusOK {
body, err := io.ReadAll(resp.Body)
if err != nil {
body = []byte(fmt.Sprintf("cannot read response body: %s", err))
}
fmt.Fprintf(output, "unexpected status code: %d; response body:\n%s\n", resp.StatusCode, body)
return nil
}
// Prettify the response body
jp := newJSONPrettifier(resp.Body, outputMode)
return jp
}
var httpClient = &http.Client{}
var headers []headerEntry
type headerEntry struct {
Name string
Value string
}
func parseHeaders(a []string) ([]headerEntry, error) {
hes := make([]headerEntry, len(a))
for i, s := range a {
a := strings.SplitN(s, ":", 2)
if len(a) != 2 {
return nil, fmt.Errorf("cannot parse header=%q; it must contain at least one ':'; for example, 'Cookie: foo'", s)
}
hes[i] = headerEntry{
Name: strings.TrimSpace(a[0]),
Value: strings.TrimSpace(a[1]),
}
}
return hes, nil
}
func fatalf(format string, args ...any) {
fmt.Fprintf(os.Stderr, format+"\n", args...)
os.Exit(1)
}
func usage() {
const s = `
vlogscli is a command-line tool for querying VictoriaLogs.
See the docs at https://docs.victoriametrics.com/victorialogs/querying/vlogscli/
`
flagutil.Usage(s)
}