fix(status): handle Serverless Elasticsearch in elastic status

src/status/checks.ts

@@ -16,14 +16,31 @@ import type { ServiceBlock } from '../config/types.ts'
 import { buildAuthHeader } from '../lib/auth.ts'
 import { clientHeaders } from '../lib/meta.ts'
 
-/** Successful Elasticsearch probe. */
-export interface EsCheckOk {
+/** Successful Elasticsearch probe against a stateful cluster. */
+export interface EsCheckStateful {
   ok: true
   url: string
+  flavor: 'stateful'
   status: string
   nodes: number
 }
 
+/**
+ * Successful Elasticsearch probe against a Serverless project.
+ *
+ * Serverless removes cluster-level APIs (`_cluster/health` returns 410 Gone),
+ * so there is no cluster health colour or node count to report. The root
+ * endpoint is used instead, which yields the build version.
+ */
+export interface EsCheckServerless {
+  ok: true
+  url: string
+  flavor: 'serverless'
+  version: string
+}
+
+export type EsCheckOk = EsCheckStateful | EsCheckServerless
+
 /** Successful Kibana probe. */
 export interface KbCheckOk {
   ok: true
@@ -70,7 +87,7 @@ async function pingService (
   pathSegment: string,
   auth: ServiceBlock['auth'],
   fetchFn: typeof fetch,
-): Promise<{ ok: true, body: unknown } | { ok: false, error: string }> {
+): Promise<{ ok: true, body: unknown } | { ok: false, error: string, status?: number }> {
   const headers: Record<string, string> = {
     ...clientHeaders(),
     'Accept': 'application/json',
@@ -85,7 +102,7 @@ async function pingService (
   } catch (err) {
     return { ok: false, error: classifyNetwork(err) }
   }
-  if (!response.ok) return { ok: false, error: classifyHttp(response.status) }
+  if (!response.ok) return { ok: false, error: classifyHttp(response.status), status: response.status }
 
   const text = await response.text()
   if (text.length === 0) return { ok: true, body: {} }
@@ -99,16 +116,21 @@ async function pingService (
 /**
  * Probes an Elasticsearch service by calling `GET /_cluster/health`.
  *
- * Returns a structured success containing cluster `status` (green / yellow / red)
- * and the `number_of_nodes`, or a classified failure when the request, response,
- * or response shape is invalid.
+ * On a stateful cluster this returns the cluster `status` (green / yellow / red)
+ * and the `number_of_nodes`. Serverless projects remove cluster-level APIs and
+ * answer `_cluster/health` with 410 Gone; in that case the probe falls back to
+ * the root endpoint (see {@link checkServerlessRoot}) and reports the build
+ * version instead. Other request, response, or shape failures are classified.
  */
 export async function checkElasticsearch (
   block: ServiceBlock,
   fetchFn: typeof fetch = globalThis.fetch,
 ): Promise<EsCheck> {
   const result = await pingService(block.url, '/_cluster/health', block.auth, fetchFn)
-  if (!result.ok) return { ok: false, url: block.url, error: result.error }
+  if (!result.ok) {
+    if (result.status === 410) return checkServerlessRoot(block, fetchFn)
+    return { ok: false, url: block.url, error: result.error }
+  }
   const body = result.body
   if (body == null || typeof body !== 'object') {
     return { ok: false, url: block.url, error: 'unexpected response' }
@@ -119,7 +141,32 @@ export async function checkElasticsearch (
   if (typeof status !== 'string' || typeof nodes !== 'number') {
     return { ok: false, url: block.url, error: 'unexpected response' }
   }
-  return { ok: true, url: block.url, status, nodes }
+  return { ok: true, url: block.url, flavor: 'stateful', status, nodes }
+}
+
+/**
+ * Probes a Serverless Elasticsearch project via `GET /`, reading `version.number`.
+ * Reached only after `_cluster/health` returns 410, the Serverless signal.
+ */
+async function checkServerlessRoot (
+  block: ServiceBlock,
+  fetchFn: typeof fetch,
+): Promise<EsCheck> {
+  const result = await pingService(block.url, '/', block.auth, fetchFn)
+  if (!result.ok) return { ok: false, url: block.url, error: result.error }
+  const body = result.body
+  if (body == null || typeof body !== 'object') {
+    return { ok: false, url: block.url, error: 'unexpected response' }
+  }
+  const versionObj = (body as Record<string, unknown>)['version']
+  if (versionObj == null || typeof versionObj !== 'object') {
+    return { ok: false, url: block.url, error: 'unexpected response' }
+  }
+  const version = (versionObj as Record<string, unknown>)['number']
+  if (typeof version !== 'string') {
+    return { ok: false, url: block.url, error: 'unexpected response' }
+  }
+  return { ok: true, url: block.url, flavor: 'serverless', version }
 }
 
 /**

src/status/format.ts

@@ -29,6 +29,7 @@ interface Row {
 
 function esSummary (s: EsCheck): string {
   if (!s.ok) return s.error
+  if (s.flavor === 'serverless') return `serverless (${s.version})`
   const noun = s.nodes === 1 ? 'node' : 'nodes'
   return `${s.status} (${s.nodes} ${noun})`
 }

test/status/checks.test.ts

@@ -37,7 +37,7 @@ describe('checkElasticsearch', () => {
       { url: 'http://localhost:9200', auth: { api_key: 'k' } },
       fetchFn,
     )
-    assert.deepEqual(result, { ok: true, url: 'http://localhost:9200', status: 'green', nodes: 3 })
+    assert.deepEqual(result, { ok: true, url: 'http://localhost:9200', flavor: 'stateful', status: 'green', nodes: 3 })
     assert.equal(calls.length, 1)
     assert.equal(calls[0]!.url, 'http://localhost:9200/_cluster/health')
     const headers = calls[0]!.init.headers as Record<string, string>
@@ -146,6 +146,50 @@ describe('checkElasticsearch', () => {
     assert.deepEqual(result, { ok: false, url: 'http://localhost:9200', error: 'unexpected response' })
   })
 
+  it('falls back to the root endpoint on a 410 (serverless) and reports the version', async () => {
+    const { fetch: fetchFn, calls } = recordingFetch((url) => {
+      if (url.endsWith('/_cluster/health')) return new Response('gone', { status: 410 })
+      return new Response(
+        JSON.stringify({ name: 'serverless', version: { number: '9.5.0', build_flavor: 'serverless' } }),
+        { status: 200 },
+      )
+    })
+    const result = await checkElasticsearch(
+      { url: 'https://x.es.cloud', auth: { username: 'admin', password: 'p' } },
+      fetchFn,
+    )
+    assert.deepEqual(result, { ok: true, url: 'https://x.es.cloud', flavor: 'serverless', version: '9.5.0' })
+    assert.equal(calls.length, 2)
+    assert.equal(calls[0]!.url, 'https://x.es.cloud/_cluster/health')
+    assert.equal(calls[1]!.url, 'https://x.es.cloud/')
+  })
+
+  it('reports unexpected response when the serverless root lacks version.number', async () => {
+    const { fetch: fetchFn } = recordingFetch((url) =>
+      url.endsWith('/_cluster/health')
+        ? new Response('gone', { status: 410 })
+        : new Response(JSON.stringify({ name: 'serverless', version: {} }), { status: 200 })
+    )
+    const result = await checkElasticsearch(
+      { url: 'https://x.es.cloud', auth: { api_key: 'k' } },
+      fetchFn,
+    )
+    assert.deepEqual(result, { ok: false, url: 'https://x.es.cloud', error: 'unexpected response' })
+  })
+
+  it('propagates a serverless root failure', async () => {
+    const { fetch: fetchFn } = recordingFetch((url) =>
+      url.endsWith('/_cluster/health')
+        ? new Response('gone', { status: 410 })
+        : new Response('nope', { status: 401 })
+    )
+    const result = await checkElasticsearch(
+      { url: 'https://x.es.cloud', auth: { api_key: 'bad' } },
+      fetchFn,
+    )
+    assert.deepEqual(result, { ok: false, url: 'https://x.es.cloud', error: 'auth failed (401)' })
+  })
+
 })
 
 describe('checkKibana', () => {

test/status/format.test.ts

@@ -12,7 +12,7 @@ describe('formatStatusText', () => {
     const out = formatStatusText({
       context: 'local',
       services: {
-        elasticsearch: { ok: true, url: 'http://localhost:9200', status: 'green', nodes: 3 },
+        elasticsearch: { ok: true, url: 'http://localhost:9200', flavor: 'stateful', status: 'green', nodes: 3 },
         kibana: { ok: true, url: 'http://localhost:5601', status: 'available', version: '8.18.0' },
         cloud: { ok: false, url: 'https://api.elastic-cloud.com', error: 'auth failed (401)' },
       },
@@ -34,7 +34,7 @@ describe('formatStatusText', () => {
     const out = formatStatusText({
       context: 'es-only',
       services: {
-        elasticsearch: { ok: true, url: 'http://localhost:9200', status: 'green', nodes: 1 },
+        elasticsearch: { ok: true, url: 'http://localhost:9200', flavor: 'stateful', status: 'green', nodes: 1 },
       },
     })
     assert.ok(out.startsWith('Context: es-only\n\n'), `got ${out}`)
@@ -46,18 +46,28 @@ describe('formatStatusText', () => {
   it('pluralises the node count correctly', () => {
     const one = formatStatusText({
       context: 'c',
-      services: { elasticsearch: { ok: true, url: 'u', status: 'green', nodes: 1 } },
+      services: { elasticsearch: { ok: true, url: 'u', flavor: 'stateful', status: 'green', nodes: 1 } },
     })
     assert.ok(one.includes('1 node)'), `got ${one}`)
     assert.ok(!one.includes('1 nodes)'))
 
     const many = formatStatusText({
       context: 'c',
-      services: { elasticsearch: { ok: true, url: 'u', status: 'green', nodes: 5 } },
+      services: { elasticsearch: { ok: true, url: 'u', flavor: 'stateful', status: 'green', nodes: 5 } },
     })
     assert.ok(many.includes('5 nodes)'), `got ${many}`)
   })
 
+  it('renders a serverless Elasticsearch as "serverless (<version>)"', () => {
+    const out = formatStatusText({
+      context: 'cloud',
+      services: {
+        elasticsearch: { ok: true, url: 'https://x.es.cloud', flavor: 'serverless', version: '9.5.0' },
+      },
+    })
+    assert.ok(out.includes('✓  serverless (9.5.0)'), `got ${out}`)
+  })
+
   it('renders failed services with their classified error message', () => {
     const out = formatStatusText({
       context: 'local',
@@ -77,7 +87,7 @@ describe('formatStatusText', () => {
     const out = formatStatusText({
       context: 'c',
       services: {
-        elasticsearch: { ok: true, url: 'http://es', status: 'green', nodes: 1 },
+        elasticsearch: { ok: true, url: 'http://es', flavor: 'stateful', status: 'green', nodes: 1 },
         kibana: { ok: true, url: 'http://kibana-very-long-url.example.com', status: 'available', version: '9' },
       },
     })