Why do dashboards download fail with a "timed out" error in standalone Insights 2021.10 airgapped.
Issue Description
No dashboard can be downloaded with a "timed out" error in standalone Insights 2021.10 airgapped.
Error observed in Event Viewer log:
Category: Util.Telemetry.ITelemetryClient
EventId: 0
RequestId: 800037ac-0002-fc00-b63f-84710c7967bb
RequestPath: /insights/api/downloadDashboard/5
SpanId: 1359eb5caa694640
TraceId: ff698b17e1302a42a5e2a21c1b05ef3d
ParentId: 0000000000000000
ActionId: 4d7ef6f0-24f5-4e5e-b6f4-469c6bfcd34a
ActionName: InsightsPortal.Controllers.DownloadDashboardController.GetAsync (InsightsPortal)
- Looker PDF Render timed out. The final status is rendering, running time: 67041
- System.Net.Http.HttpRequestException: No connection could be made because the target machine actively refused it.
Troubleshooting/Analysis
Looker can load a dashboard but is unable to advance during the preparing document process. During the rending process, it is trying to get help from external sources.
- Chromium is an external source for pdf creation.
- Some dashboard visualizations are stored in https://rawcdn.githack.com as javascript files. In newer versions, API calls are made differently.
- Telemetry endpoint: ping.looker.com.
- Insights version (21.10) is not capable of restricting the external help check by the docker (it is a bug from Looker). DISABLE_EXTERNAL_RENDER_ACCESS=true fails in this version - Insights 21.10.1 (Looker 21.6.45).
Whitelisted the URLs also fails to fix the issue:
Resolution
1. Log in to the Windows machine with Wnsights installed, and open a Powershell prompt.
2. Run the following commands:
docker exec -it looker-container bash
echo "127.0.0.1 looker-custom-viz-a.lookercdn.com
127.0.0.1 rawcdn.githack.com
127.0.0.1 ping.looker.com
127.0.0.1 www.google-analytics.com
127.0.0.1 stats.g.doubleclick.net
127.0.0.1 www.google.com" >> /etc/hosts