Publish alerts to a Sandbar topic and keep a Sandbar monitor for every resource with health checks

A Sandbar topic channel publishes alerts as ntfy-style messages (API key
optional). Under Server, Settings, Hammerhead can create, update and remove a
Sandbar monitor per enabled resource with health checks, linked by resource id
so monitors made by hand are left alone. The key is sealed at rest.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

web/index.html

@@ -1140,32 +1140,36 @@ const FORMATS = [['json', 'JSON'], ['slack', 'Slack'], ['discord', 'Discord'], [
 function channelForm(base, existing, trusted) {
   const c = existing || {kind:'email', format:'json', enabled:true};
   const name = h('input', {value:c.name || '', placeholder:'e.g. On-call'});
-  const kind = h('select', {}, [['email', 'Email'], ['sandbar', 'Sandbar'], ['webhook', 'Webhook']].map(([v, t]) => h('option', {value:v, selected:v === c.kind}, t)));
+  const kind = h('select', {}, [['email', 'Email'], ['sandbar', 'Sandbar (pages on-call)'], ['topic', 'Sandbar topic'], ['webhook', 'Webhook']].map(([v, t]) => h('option', {value:v, selected:v === c.kind}, t)));
   const target = h('input', {value:c.kind === 'email' ? c.target || '' : '', placeholder:c.kind === 'webhook' && existing ? 'unchanged' : ''});
   const token = h('input', {type:'password', autocomplete:'off', placeholder:existing && c.kind === 'sandbar' ? 'unchanged' : 'sb_…'});
   const policy = h('input', {value:c.policy || '', placeholder:'Optional'});
+  const topic = h('input', {value:c.topic || '', placeholder:'e.g. alerts'});
+  const topicToken = h('input', {type:'password', autocomplete:'off', placeholder:existing && c.kind === 'topic' ? 'unchanged' : 'Optional'});
   const sandbarBox = h('div', {class:'grid'}, field('API key', token, 'Create one on Sandbar\'s Account page.'), field('Escalation policy ID', policy, 'Who gets paged. Leave blank to send alerts without paging anyone.'));
+  const topicBox = h('div', {class:'grid'}, field('Topic', topic, 'Messages are published here, so anyone subscribed (including the ntfy app) sees them.'), field('API key (optional)', topicToken, 'Leave blank for a server that lets anyone publish. Sandbar itself asks for a key.'));
   const fmt = h('select', {}, FORMATS.map(([v, t]) => h('option', {value:v, selected:v === (c.format || 'json')}, t)));
   const priv = chk('This address is on a private network (like a home server)', c.allowPrivate);
   const en = chk('Enabled', c.enabled !== false);
   const fmtBox = field('Webhook format', fmt, 'Slack and Discord incoming-webhook URLs work as they are. ntfy sends a push notification.');
   const targetBox = field('Where', target);
   const redraw = () => {
-    const w = kind.value === 'webhook', sb = kind.value === 'sandbar';
+    const w = kind.value === 'webhook', sb = kind.value === 'sandbar' || kind.value === 'topic';
     fmtBox.style.display = w ? '' : 'none';
-    sandbarBox.style.display = sb ? '' : 'none';
+    sandbarBox.style.display = kind.value === 'sandbar' ? '' : 'none';
+    topicBox.style.display = kind.value === 'topic' ? '' : 'none';
     priv.style.display = (w || sb) && trusted ? '' : 'none';
     targetBox.firstChild.textContent =sb ? 'Sandbar address' : 'Where';
-    target.placeholder = sb ? (existing && c.kind === 'sandbar' ? 'unchanged' : 'https://sandbar.example.com') :
+    target.placeholder = sb ? (existing && c.kind === kind.value ? 'unchanged' : 'https://sandbar.example.com') :
       w ? (existing && c.kind === 'webhook' ? 'unchanged (it may contain a secret token)' : 'https://hooks.example.com/…') : 'you@example.com, oncall@example.com';
   };
   kind.onchange = redraw; redraw();
   const save = act(async () => {
-    await api(existing ? 'PUT' : 'POST', base + '/channels' + (existing ? '/' + existing.id : ''), {name:name.value, kind:kind.value, target:target.value, format:kind.value === 'webhook' ? fmt.value : '', token:token.value, policy:policy.value, allowPrivate:trusted && priv.box.checked, enabled:en.box.checked});
+    await api(existing ? 'PUT' : 'POST', base + '/channels' + (existing ? '/' + existing.id : ''), {name:name.value, kind:kind.value, target:target.value, format:kind.value === 'webhook' ? fmt.value : '', token:kind.value === 'topic' ? topicToken.value : token.value, policy:policy.value, topic:topic.value, allowPrivate:trusted && priv.box.checked, enabled:en.box.checked});
     close(); toast(existing ? 'Alert channel saved' : 'Alert channel added'); refresh();
   });
   const close = modal(existing ? 'Edit channel' : 'Add an alert channel', h('div', {class:'stack'},
-    h('div', {class:'grid'}, field('Name', name), field('Type', kind)), targetBox, sandbarBox, fmtBox, priv, en,
+    h('div', {class:'grid'}, field('Name', name), field('Type', kind)), targetBox, sandbarBox, topicBox, fmtBox, priv, en,
     h('div', {class:'actions form-actions'}, h('button', {class:'ghost', onclick:() => close()}, 'Cancel'), h('button', {class:'btn', onclick:save}, 'Save'))), {sticky:true});
 }
 
@@ -1173,7 +1177,7 @@ async function alertsView(base, scoped, trusted) {
   const d = await api('GET', base);
   const channels = h('table', {}, h('thead', {}, h('tr', {}, ['Name', 'Type', 'Sends to', ''].map(x => h('th', {}, x)))),
     h('tbody', {}, d.channels.map(c => h('tr', {}, h('td', {}, c.name, c.enabled ? null : h('span', {class:'tag', style:'margin-left:6px'}, 'off')),
-      h('td', {}, c.kind === 'email' ? 'Email' : c.kind === 'sandbar' ? 'Sandbar' : 'Webhook (' + c.format + ')'), h('td', {class:'mono small'}, c.preview),
+      h('td', {}, c.kind === 'email' ? 'Email' : c.kind === 'sandbar' ? 'Sandbar' : c.kind === 'topic' ? 'Sandbar topic' : 'Webhook (' + c.format + ')'), h('td', {class:'mono small'}, c.preview),
       h('td', {}, h('div', {class:'actions'},
         h('button', {class:'ghost', onclick: act(async () => { await api('POST', base + '/channels/' + c.id + '/test'); toast('Test sent'); })}, 'Send test'),
         h('button', {class:'ghost', onclick:() => channelForm(base, c, trusted)}, 'Edit'),
@@ -1354,13 +1358,19 @@ serverViews.idps = async () => {
 };
 
 serverViews.settings = async () => {
-  const { settings: s, smtpPassSet } = await api('GET', '/api/admin/settings');
+  const { settings: s, smtpPassSet, sandbarTokenSet, sandbarSync } = await api('GET', '/api/admin/settings');
   const f = {url:h('input', {value:s.dashboardUrl, placeholder:'https://hammerhead.example.com'}), acme:h('input', {type:'email', value:s.acmeEmail, placeholder:'you@example.com'}),
     host:h('input', {value:s.smtp.host}), port:h('input', {type:'number', value:s.smtp.port || ''}), user:h('input', {value:s.smtp.user}), pass:h('input', {type:'password', placeholder:smtpPassSet ? 'unchanged' : ''}), from:h('input', {value:s.smtp.from, placeholder:'Hammerhead <no-reply@example.com>'}),
     mode:h('select', {}, [['starttls', 'STARTTLS'], ['tls', 'TLS'], ['none', 'None']].map(([m, l]) => h('option', {value:m, selected:(s.smtp.mode || 'starttls') === m}, l)))};
   const staging = chk('Use the Let\'s Encrypt staging server (untrusted test certificates)', s.acmeStaging);
+  const sb = s.sandbar || {};
+  const sbOn = chk('Create a Sandbar monitor for every resource that has health checks', sb.enabled);
+  const sbf = {url:h('input', {value:sb.url || '', placeholder:'https://sandbar.example.com'}), key:h('input', {type:'password', autocomplete:'off', placeholder:sandbarTokenSet ? 'unchanged' : 'sb_…'}), policy:h('input', {value:sb.policyId || '', placeholder:'Optional'})};
+  const sbPublic = chk('Show the monitors on the status page', sb.public), sbPriv = chk('Sandbar and the edge addresses are on a private network', sb.allowPrivate);
+  const sbOut = h('div', {class:'dim'}, sandbarSync && sandbarSync.at && sandbarSync.at.slice(0, 4) !== '0001' ? (sandbarSync.error ? 'The last sync failed: ' + sandbarSync.error : 'Last synced ' + ago(sandbarSync.at) + ', ' + sandbarSync.monitors + ' monitors.') : 'Not synced yet.');
   const save = act(async () => { await api('PUT', '/api/admin/settings', {dashboardUrl:f.url.value, acmeEmail:f.acme.value, acmeStaging:staging.box.checked,
-    smtp:{host:f.host.value, port:+f.port.value, user:f.user.value, pass:f.pass.value, from:f.from.value, mode:f.mode.value}}); S.me = await api('GET', '/api/me'); toast('Settings saved'); });
+    smtp:{host:f.host.value, port:+f.port.value, user:f.user.value, pass:f.pass.value, from:f.from.value, mode:f.mode.value},
+    sandbar:{enabled:sbOn.box.checked, url:sbf.url.value, token:sbf.key.value, policyId:sbf.policy.value, public:sbPublic.box.checked, allowPrivate:sbPriv.box.checked}}); S.me = await api('GET', '/api/me'); toast('Settings saved'); });
   const updOut = h('div', {class:'dim'}, 'Not checked yet.');
   const updNow = h('button', {class:'ghost', style:'display:none', onclick: act(async () => {
     await api('POST', '/api/admin/update/apply');
@@ -1388,6 +1398,9 @@ serverViews.settings = async () => {
     card('Email', h('p', {class:'dim'}, 'Needed for invitation emails and one-time sign-in codes.'),
       h('div', {class:'grid'}, field('SMTP host', f.host), field('Port', f.port), field('Security', f.mode), field('Username', f.user), field('Password', f.pass), field('From', f.from)),
       h('div', {class:'actions', style:'margin-top:10px'}, h('button', {class:'ghost', onclick: act(async () => { await save(); await api('POST', '/api/admin/settings/test-mail'); toast('Test email sent to ' + S.me.email); })}, 'Save and send a test email'))),
+    card('Sandbar monitors', h('p', {class:'dim'}, 'Hammerhead adds a monitor to Sandbar for each enabled resource with health checks (a website is fetched at its address, a port is connected to), so it gets uptime history, a status page and on-call paging. Monitors you add in Sandbar yourself are never touched. Hammerhead keeps them up to date every minute and removes the ones it created when a resource is deleted or its checks are turned off.'),
+      sbOn, h('div', {class:'grid'}, field('Sandbar address', sbf.url), field('Administrator API key', sbf.key, 'Create one on the Account page in Sandbar. Managing monitors needs an administrator.'), field('Escalation policy ID', sbf.policy, 'Who gets paged when a monitor goes down. Leave blank to page nobody.')), sbPublic, sbPriv,
+      h('div', {class:'actions', style:'margin-top:10px'}, h('button', {class:'ghost', onclick: act(async () => { await save(); const r = await api('POST', '/api/admin/settings/sandbar-sync'); sbOut.textContent = 'Synced, ' + r.monitors + ' monitors.'; toast('Sandbar monitors synced'); })}, 'Save and sync now')), sbOut),
     h('div', {class:'actions form-actions', style:'margin-bottom:24px'}, h('button', {class:'btn', onclick:save}, 'Save settings')),
     card('Updates', h('p', {class:'dim'}, 'Hammerhead, Blacktip and Bamboo can update themselves from new releases when auto-update is on (HAMMERHEAD_AUTO_UPDATE=1). This checks the newest release for Hammerhead; it installs nothing.'),
       updOut, h('div', {class:'actions', style:'margin-top:10px'}, h('button', {class:'ghost', onclick:checkUpdate}, 'Check for updates'), updNow), updBox));