Arvados

I was running the Ansible-based single-node installation with the config file deployed to the cluster containing this section

      ContainerWebServices:
        # This ExternalURL should match Controller's.
        ExternalURL: "https://xtmp2.halley-mirzam.ts.net:8443" 
        ExternalPortMin: 10000
        ExternalPortMax: 10000

(Here "xtmp2.halley-mirzam.ts.net" is my private Tailscale domain for the test cluster. Detailed set-up guide is in the privately shared doc here).

Then, browsing to the target initial_url at https://xtmp2.halley-mirzam.ts.net:10000/, I get the Firefox "Unable to connect" error page (developer tool -> Network shows NS_ERROR_CONNECTION_REFUSED)

During the lifetime of the service container, the stderr output was

2025-08-06T20:57:26.845792686Z 2025/08/06 20:57:26 [notice] 1#1: using the "epoll" event method
2025-08-06T20:57:26.845800751Z 2025/08/06 20:57:26 [notice] 1#1: nginx/1.29.0
2025-08-06T20:57:26.845803456Z 2025/08/06 20:57:26 [notice] 1#1: built by gcc 12.2.0 (Debian 12.2.0-14+deb12u1)
2025-08-06T20:57:26.845805781Z 2025/08/06 20:57:26 [notice] 1#1: OS: Linux 6.14.0-27-generic
2025-08-06T20:57:26.845807965Z 2025/08/06 20:57:26 [notice] 1#1: getrlimit(RLIMIT_NOFILE): 10000:10000
2025-08-06T20:57:26.845935728Z 2025/08/06 20:57:26 [notice] 1#1: start worker processes
2025-08-06T20:57:26.846075816Z 2025/08/06 20:57:26 [notice] 1#1: start worker process 29
2025-08-06T20:57:26.846428338Z 2025/08/06 20:57:26 [notice] 1#1: start worker process 30
2025-08-06T20:57:26.846433405Z 2025/08/06 20:57:26 [notice] 1#1: start worker process 31
2025-08-06T20:57:26.846499021Z 2025/08/06 20:57:26 [notice] 1#1: start worker process 32

If I change the ExternalPortMax value to 10001 (one above the min), the container service becomes accessible at the URL. The stderr output in the log is essentially the same except now I can see HTTP requests to the server.