fix(preview-service): listen externally on metrics port

.github/workflows/preview-service-acceptance.yml

@@ -74,7 +74,7 @@ jobs:
           PREVIEW_SERVICE_IMAGE: speckle/preview-service:local
           OUTPUT_FILE_PATH: /tmp/preview-service-output.png
           NODE_ENV: test
-          PG_CONNECTION_STRING: postgres://preview_service_test:preview_service_test@localhost:5432/preview_service_test
+          PG_CONNECTION_STRING: postgres://preview_service_test:preview_service_test@postgres:5432/preview_service_test
 
       - uses: actions/upload-artifact@v4
         name: Upload the output from the preview-service

docker-compose-speckle.yml

@@ -86,7 +86,8 @@ services:
     mem_limit: '3000m'
     memswap_limit: '3000m'
     environment:
-      HOST: '127.0.0.1'
+      HOST: '127.0.0.1' # Only accept connections from localhost, as preview service does not need to be exposed outside the container.
+      METRICS_HOST: '127.0.0.1' # Amend if you want to expose Prometheus metrics outside of the container
       LOG_LEVEL: 'info'
       PG_CONNECTION_STRING: 'postgres://speckle:speckle@postgres/speckle'
 

packages/preview-service/src/server/server.ts

@@ -1,7 +1,7 @@
 import { serverLogger } from '@/observability/logging.js'
 import { appFactory as metricsAppFactory } from '@/observability/metricsApp.js'
 import { appFactory } from '@/server/app.js'
-import { getAppPort, getHost, getMetricsPort } from '@/utils/env.js'
+import { getAppPort, getHost, getMetricsHost, getMetricsPort } from '@/utils/env.js'
 import http from 'http'
 import type { Knex } from 'knex'
 import { isNaN, isString, toNumber } from 'lodash-es'
@@ -39,12 +39,14 @@ export const startServer = (params: { db: Knex; serveOnRandomPort?: boolean }) =
     onListening(server)
   })
   server.listen(inputPort, host)
+
+  const metricsHost = getMetricsHost()
   metricsServer.on('error', onErrorFactory(inputPort))
   metricsServer.on('listening', () => {
     serverLogger.info('📊 Started Preview Service metrics server')
     onListening(metricsServer)
   })
-  metricsServer.listen(inputMetricsPort, host)
+  metricsServer.listen(inputMetricsPort, metricsHost)
 
   return { app, server, metricsServer }
 }

packages/preview-service/src/utils/env.ts

@@ -6,6 +6,7 @@ export const getChromiumExecutablePath = () => {
 export const getHealthCheckFilePath = () =>
   process.env.HEALTHCHECK_FILE_PATH || '/tmp/last_successful_query'
 export const getHost = () => process.env.HOST || '127.0.0.1'
+export const getMetricsHost = () => process.env.METRICS_HOST || '127.0.0.1'
 export const getLogLevel = () => process.env.LOG_LEVEL || 'info'
 export const getMetricsPort = () => process.env.PROMETHEUS_METRICS_PORT || '9094'
 export const getNodeEnv = () => process.env.NODE_ENV || 'production'

utils/helm/speckle-server/templates/preview_service/deployment.yml

@@ -62,6 +62,10 @@ spec:
         {{- end }}
 
         env:
+          - name: HOST
+            value: '127.0.0.1' # Only accept connections from localhost, as preview service does not need to be exposed outside the container.
+          - name: METRICS_HOST
+            value: '0.0.0.0' # Expose metrics outside of the container so it can be scraped by Prometheus
           - name: PORT
             value: {{ .Values.preview_service.port | quote }}