senro線路

Slack

Posts a short line a person can read in a channel, to a Slack incoming webhook.

import "github.com/xavidop/senro/notify"

n := notify.New(notify.Slack(os.Getenv("SLACK_WEBHOOK_URL")))
defer func() { _ = n.Close() }()

err := senro.Run(ctx, p, senro.WithSink(n))

You need an incoming webhook URL from Slack. senro does not read your environment looking for one: the URL is an argument.

What lands in the channel

By default, one message per run, when it finishes:

senro: run 20260807T101503-a1b2c3 succeeded in 1m12s (7 succeeded, 1 cached)
senro: run 20260807T101503-a1b2c3 failed in 41s (5 succeeded, 1 failed, 2 skipped_upstream_failed)

Widen it with On and you get a line per event type you asked for:

notify.Slack(url, notify.On(api.RunStarted, api.StepFinished, api.RunFinished))
senro: pipeline ci started (run 20260807T101503-a1b2c3)
senro: step test succeeded (run 20260807T101503-a1b2c3)
senro: step build failed (run 20260807T101503-a1b2c3): exit status 2
senro: run 20260807T101503-a1b2c3 failed in 41s (1 succeeded, 1 failed)

StepFinished on a fan-out is one message per unit. A two hundred step expansion is two hundred Slack messages. The default is run.finished only for exactly this reason.

Sending to more than one channel

One destination per channel, each with its own webhook URL and its own name:

n := notify.New(
	notify.Slack(buildsURL, notify.Named("slack-builds")),
	notify.Slack(alertsURL,
		notify.Named("slack-oncall"),
		notify.On(api.RunFinished)),
)

Named matters here: both would otherwise be called slack in the run’s notify.delivered events and in the shutdown report, and you could not tell which one failed.

The URL is a credential

A Slack incoming webhook URL is the whole of one: anybody holding it can post to that channel. So notify strips it out of every error it records or prints. It never appears in an event, in the shutdown report, or in a log line.

Keep it out of your source. os.Getenv in the example above is the shape to copy.

Options

Every option works here. The two you are most likely to want:

On(types...)Which events reach the channel. Default: api.RunFinished only.
Named(name)The name in the run’s ledger and the shutdown report. Default: slack.

Rendering it yourself

notify.Slack(url) is exactly notify.To(url, notify.SlackText(), notify.Named("slack"), notify.On(api.RunFinished)). If you want Slack Block Kit, threading, or a different wording, write a renderer and post to the same URL:

notify.To(os.Getenv("SLACK_WEBHOOK_URL"),
	notify.RendererFunc(func(e api.Event) ([]byte, error) {
		var b api.RunFinishedBody
		if err := e.Decode(&b); err != nil {
			return nil, err
		}
		emoji := ":white_check_mark:"
		if b.Status != api.StatusSucceeded {
			emoji = ":x:"
		}
		return json.Marshal(map[string]string{
			"text": fmt.Sprintf("%s `%s` %s in %s", emoji, e.Run, b.Status, b.Duration),
		})
	}),
	notify.Named("slack"),
	notify.On(api.RunFinished),
)

See Write your own for the full seam.

Where to go next