Files
onvif/examples/event/stream/main.go
Sebastian Norling 1ceef725ec fix(examples): secure credential handling and Errors-arm bug
Two findings from the resource/security and API reviews of the
streamtest example.

Credentials
-----------
* loadPassword resolves the camera password in order:
    1. ONVIF_PASSWORD environment variable (recommended).
    2. -password-file <path> (newline trimmed).
    3. Interactive prompt when nothing else is set.
* -password flag still works but now logs a WARNING that the value
  leaks into shell history and process listings. Documented as
  'INSECURE' in the flag help.
* Updated package godoc with a Credentials section.

Errors-arm bug
--------------
* Previous code: case e := <-s.Errors() with no ok check. When the
  Stream closed, this arm would spin on a closed channel printing
  '<nil>' forever (until ctx-done elsewhere unblocked it). Mirror
  the Events arm's ok pattern.
* Switched the error-log branch to inspect the typed errors added
  in the previous commit: ErrRecreateFailed gets a louder 'camera
  may be offline' log line; ErrPullFailed is a quieter
  'will retry' since the loop handles transient pull errors
  automatically.

Also prints '[after-reconnect]' on events carrying that flag so the
operator can see when the stream silently recovered a dropped
subscription — confirms the new observability surface is useful at
the CLI level.
2026-05-21 15:02:23 +02:00

177 lines
5.0 KiB
Go

// Command streamtest opens an event stream against an ONVIF camera and
// prints decoded events as they arrive. Useful for verifying the
// classifier against real-camera topics; not intended as a production
// tool.
//
// # Usage
//
// go run ./examples/event/stream \
// -xaddr 192.168.1.10 \
// -username root \
// -duration 60s
//
// # Credentials
//
// The camera password is read, in order of preference:
//
// 1. The ONVIF_PASSWORD environment variable.
// 2. A file pointed at by -password-file (newline stripped).
// 3. Interactive prompt when stdin is a tty.
//
// -password is also accepted but DISCOURAGED — it leaks the credential
// into shell history and the system process listing. Use only for
// throwaway dev cameras.
package main
import (
"bufio"
"context"
"errors"
"flag"
"fmt"
"log"
"os"
"os/signal"
"strings"
"syscall"
"time"
"github.com/kerberos-io/onvif"
"github.com/kerberos-io/onvif/event/stream"
)
func main() {
xaddr := flag.String("xaddr", "", "camera host or host:port (required)")
username := flag.String("username", "", "ONVIF user (required)")
insecurePassword := flag.String("password", "", "INSECURE — leaks into shell history; prefer ONVIF_PASSWORD env or -password-file")
passwordFile := flag.String("password-file", "", "read password from this file (newline trimmed)")
deviceID := flag.String("device-id", "", "logical name printed with each event (default: xaddr)")
filter := flag.String("filter", "", "raw ONVIF ConcreteSet topic filter (empty = all topics, works on AXIS)")
pullTimeout := flag.Duration("pull-timeout", 5*time.Second, "server-side wait per PullMessages call")
duration := flag.Duration("duration", 0, "stop after this long (0 = run until Ctrl-C)")
flag.Parse()
if *xaddr == "" || *username == "" {
flag.Usage()
os.Exit(2)
}
if *deviceID == "" {
*deviceID = *xaddr
}
password, err := loadPassword(*insecurePassword, *passwordFile)
if err != nil {
log.Fatalf("password: %v", err)
}
dev, err := onvif.NewDevice(onvif.DeviceParams{
Xaddr: *xaddr,
Username: *username,
Password: password,
AuthMode: onvif.UsernameTokenAuth,
})
if err != nil {
log.Fatalf("connect: %v", err)
}
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
if *duration > 0 {
var done context.CancelFunc
ctx, done = context.WithTimeout(ctx, *duration)
defer done()
}
sigs := make(chan os.Signal, 1)
signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)
go func() {
<-sigs
cancel()
}()
s, err := stream.NewStream(ctx, dev, stream.Options{
DeviceID: *deviceID,
RawTopicFilter: *filter,
PullTimeout: *pullTimeout,
})
if err != nil {
log.Fatalf("open stream: %v", err)
}
defer func() {
if err := s.Close(); err != nil {
log.Printf("stream close: %v", err)
}
}()
log.Printf("streaming from %s (device-id=%s, filter=%q)", *xaddr, *deviceID, *filter)
for {
select {
case <-ctx.Done():
log.Printf("done (%v)", ctx.Err())
return
case ev, ok := <-s.Events():
if !ok {
return
}
fmt.Printf("%s kind=%-15s state=%-9s op=%-12s topic=%s",
ev.Timestamp.Format(time.RFC3339), ev.Kind, ev.State, ev.Operation, ev.Topic)
if ev.AfterReconnect {
fmt.Print(" [after-reconnect]")
}
if len(ev.Source) > 0 {
fmt.Printf(" source=%v", ev.Source)
}
if len(ev.Data) > 0 {
fmt.Printf(" data=%v", ev.Data)
}
fmt.Println()
case e, ok := <-s.Errors():
if !ok {
return
}
var pull stream.ErrPullFailed
var recreate stream.ErrRecreateFailed
switch {
case errors.As(e, &recreate):
log.Printf("RECREATE failed: %v (camera may be offline)", recreate.Err)
case errors.As(e, &pull):
log.Printf("pull error (will retry): %v", pull.Err)
default:
log.Printf("stream error: %v", e)
}
}
}
}
// loadPassword resolves the camera password from the environment first
// (ONVIF_PASSWORD), then -password-file, then an interactive prompt as
// a last resort. The insecure -password flag is honoured only if
// nothing else is set, and a warning is logged.
func loadPassword(insecure, file string) (string, error) {
if env := os.Getenv("ONVIF_PASSWORD"); env != "" {
return env, nil
}
if file != "" {
b, err := os.ReadFile(file)
if err != nil {
return "", fmt.Errorf("read %s: %w", file, err)
}
return strings.TrimRight(string(b), "\r\n"), nil
}
if insecure != "" {
log.Print("WARNING: -password leaks into shell history and process listings; prefer ONVIF_PASSWORD env or -password-file")
return insecure, nil
}
// Interactive prompt — works when stdin is a tty. We use a plain
// reader (rather than golang.org/x/term hidden input) to keep
// this example dependency-free; in production, callers should
// integrate term.ReadPassword.
fmt.Fprint(os.Stderr, "ONVIF password (visible): ")
r := bufio.NewReader(os.Stdin)
line, err := r.ReadString('\n')
if err != nil {
return "", errors.New("no password supplied (set ONVIF_PASSWORD, -password-file, or pipe input)")
}
return strings.TrimRight(line, "\r\n"), nil
}