Slack

Slack is a second chat notification channel alongside Mattermost, added so an agency-wide alert can land in Slack instead of (or as well as) Mattermost. There are actually two separate Slack integrations in this codebase that are easy to conflate — this page covers both.

Two notifiers, same interface, different audience

Both implement App\Services\Chat\ChatNotifier and are fanned out to by ChatNotifierDispatcher — see Integrations → Mattermost for how the fan-out works.

SlackNotifier — the ops channel

Why we use it

Some team members or channels prefer Slack over Mattermost, or the agency wants monitoring alerts in both places during a migration between chat tools. SlackNotifier mirrors MattermostNotifier’s full event set exactly — same ChatNotifier::EVENTS registry — so nothing is Mattermost-only by omission.

Setup

1. In Slack: create an Incoming Webhook (api.slack.com/apps → your app → Incoming Webhooks) for the target channel.

2. Set in .env:

   CLOCKWORK_SLACK_ENABLED=true
   CLOCKWORK_SLACK_WEBHOOK_URL=https://hooks.slack.com/services/...
   CLOCKWORK_SLACK_CHANNEL=monitoring
   CLOCKWORK_SLACK_USERNAME=Clockwork Control
   CLOCKWORK_SLACK_ICON_EMOJI=:lock:

3. Configure per-event toggles at Settings → Slack (/settings/slack). All events default to ON — same defaults as Mattermost’s per-event settings, tracked independently (notifications.slack.events vs notifications.mattermost.events in app_settings).

There’s no dedicated clockwork:slack-test command yet — verify by toggling on a low-noise event (e.g. ssl_state_changed) and triggering it, or by temporarily setting CLOCKWORK_SLACK_CHANNEL to a test channel and watching a real transition fire.

SlackNotifier is a real, independently installable module (modules/Slack/, package clockwork/slack) — same pattern as every hosting/cloud-provider module. An agency that only wants Mattermost can leave clockwork/slack out of composer.json entirely; there’s no dead settings page or half-configured integration left behind, since the module owns its own routes, settings controller, and nav link too.

Auth

The webhook URL is the credential, same trust model as Mattermost’s — don’t commit it, rotate if leaked.

What we POST

Slack’s incoming-webhook payload shape (text + attachments), same semantic helpers as MattermostNotifier (send, siteWentDown, siteWentUp, serverWentRed, serverRecovered, aiRemedyTriaged, aiRemedyExecuted, ipBlocked, sslStateChanged, contactFormTestFailed, contactFormTestRecovered, companionUnreachable/companionReachable, pluginUpdateFailed, malwareFindingDetected, serverUpdateFailed, backupRelayStale/backupRelayRecovered, queueWorkerRestartFailed, schedulerStale/schedulerRecovered) since both implement the same ChatNotifier contract — see Mattermost for what each one covers.

Files

• modules/Slack/composer.json — real, independently installable Composer package (clockwork/slack).
• modules/Slack/src/SlackNotifier.php — a thin subclass of Modules\Core\Support\WebhookChatNotifier (shared with Modules\Mattermost\MattermostNotifier — both channels are ~85% identical code, extracted into one base once both were modularized; this class supplies only the clockwork.slack.* config namespace and log-message label).
• modules/Slack/src/SlackSettingsController.php
• modules/Slack/src/SlackCheck.php — the /settings/diagnostics connectivity check, contributed via ModuleRegistry::diagnosticChecks().
• modules/Slack/src/SlackServiceProvider.php — tags the notifier into clockwork.notifiers, loads the module’s own routes, contributes its nav link and diagnostic check.
• modules/Slack/routes/web.php
• resources/views/settings/slack.blade.php — stays in core app (module views aren’t required to move, per the same pattern modules/BillCom established).
• Config: config/clockwork.php → slack key.

ClientSlackNotifier — per-site client alerts

A second, unrelated Slack integration: Modules\ClientSlack\ClientSlackNotifier (modules/ClientSlack/) posts plain-English alerts to a per-site Slack webhook that the client configures themselves — in their own WordPress admin (Companion → Notifications page), not anywhere in this app. The webhook URL is read straight out of $site->companion_snapshot['client_notifications']['slack_webhook_url'], so there’s no separate Clockwork Control-side column or settings screen for it — it rides in on the same snapshot Companion already pushes.

Why it’s scoped down

Clients don’t need to know an IP got blocked or a plugin auto-update failed — those are operational details. ClientSlackNotifier only actually sends for the handful of events a client would recognize as “my website” problems:

• siteWentDown / siteWentUp — “Your website example.com is currently unreachable” / “…is back online,” with a link to your configured support URL (CLOCKWORK_OPERATOR_SUPPORT_URL) on the down message. No status codes, no server names.
• contactFormTestFailed / contactFormTestRecovered — same tone, for the contact-form smoke test.

Every other ChatNotifier method (ipBlocked, sslStateChanged, pluginUpdateFailed, companionUnreachable, malwareFindingDetected, generic send) is implemented as a hard return false — not gated by a setting, just a no-op by design. This is the one channel in the fan-out where “doesn’t send most events” is intentional, not a missing feature.

Why a site-level webhook instead of a Clockwork Control setting

The webhook lives in Companion’s own wp_options, surfaced to Clockwork Control through the snapshot Companion already pushes — same “push pattern” used for backups/traffic/security-summary data (see Architecture → Companion plugin). This means the client sets it up entirely within their own wp-admin, with no Clockwork Control-side UI, credential, or migration needed. If a site has no webhook configured (the common case), webhookUrl() returns '' and every send is skipped silently.

Files

• modules/ClientSlack/src/ClientSlackNotifier.php

Gotchas

• Don’t confuse the two. SlackNotifier (ops, agency-wide) and ClientSlackNotifier (client, per-site) are separate classes with separate webhooks and separate audiences — there’s no shared config between them beyond both implementing ChatNotifier.
• Turning off Mattermost doesn’t turn off Slack, or vice versa. Each channel gates independently on its own config — and, since both are real modules, an agency that only wants one can simply not install the other’s Composer package at all.
• No retries beyond the standard HTTP client behavior, same as Mattermost. A flaky Slack endpoint means a missed post, not a missed check — the underlying event still got recorded.

Related

• Mattermost — the original chat channel and the ChatNotifierDispatcher fan-out both notifiers sit behind.
• Architecture → Companion plugin — the push pattern ClientSlackNotifier’s webhook URL rides in on.