Application Hub - error 503

[blaziq]

While the Deployment Guide explicitly says that in the current state i.e. without an OIDC provider (Keycloak) the Application Hub will not work, the actual result seems even more incorrect - see the screenshot below:

This happens for any URL:
https://app-hub.eoepca-sciencehub.esa.int/hub/home
https://app-hub.eoepca-sciencehub.esa.int/hub/login
etc.

One would expect that at least the basic pages will open correctly and only a login attempt will fail due to the lack of an OIDC provider. Instead, the component fails at the very basic level.

Logs from application-hub-hub:

[D 2024-11-25 16:32:23.556 JupyterHub pages:584] No template for 503
[I 2024-11-25 16:32:23.557 JupyterHub log:191] 200 GET /hub/error/503?url=%2Fhub%2Fhome (@10.42.89.121) 2.07ms
[D 2024-11-25 16:32:23.616 JupyterHub pages:584] No template for 503
[I 2024-11-25 16:32:23.617 JupyterHub log:191] 200 GET /hub/error/503?url=%2Fhub%2Fstatic%2Fcss%2Fstyle.min.css%3Fv%3D01598a5386176f0279952a3b9632a07e7fce9a12aa53108973c83be9ec3473e7a59354876fab64bfeb01892eb503870183707aa03f207d7a94845ca7980c3819 (@10.42.89.121) 1.91ms
[D 2024-11-25 16:32:23.620 JupyterHub pages:584] No template for 503
[I 2024-11-25 16:32:23.621 JupyterHub log:191] 200 GET /hub/error/503?url=%2Fhub%2Fstatic%2Fcomponents%2Fjquery%2Fdist%2Fjquery.min.js%3Fv%3Da6e981b23351186aa43f32879dd64c6801be6e2af7ef8b0e472cccdeeba52d5d7894de4bcb292a364f1e11e525524077534338140a72687ada4fae62849843a5 (@10.42.89.121) 3.24ms
[D 2024-11-25 16:32:23.621 JupyterHub pages:584] No template for 503
[I 2024-11-25 16:32:23.623 JupyterHub log:191] 200 GET /hub/error/503?url=%2Fhub%2Fstatic%2Fcomponents%2Frequirejs%2Frequire.js%3Fv%3Dbd1aa102bdb0b27fbf712b32cfcd29b016c272acf3d864ee8469376eaddd032cadcf827ff17c05a8c8e20061418fe58cf79947049f5c0dff3b4f73fcc8cad8ec (@10.42.89.121) 5.20ms
[D 2024-11-25 16:32:23.624 JupyterHub pages:584] No template for 503
[I 2024-11-25 16:32:23.625 JupyterHub log:191] 200 GET /hub/error/503?url=%2Fhub%2Fstatic%2Fcomponents%2Fbootstrap%2Fdist%2Fjs%2Fbootstrap.min.js%3Fv%3Da014e9acc78d10a0a7a9fbaa29deac6ef17398542d9574b77b40bf446155d210fa43384757e3837da41b025998ebfab4b9b6f094033f9c226392b800df068bce (@10.42.89.121) 7.02ms
[D 2024-11-25 16:32:23.625 JupyterHub pages:584] No template for 503
[I 2024-11-25 16:32:23.627 JupyterHub log:191] 200 GET /hub/error/503?url=%2Fhub%2Flogo (@10.42.89.121) 8.63ms
[D 2024-11-25 16:32:23.695 JupyterHub pages:584] No template for 503
[I 2024-11-25 16:32:23.696 JupyterHub log:191] 200 GET /hub/error/503?url=%2Fhub%2Fstatic%2Ffavicon.ico%3Fv%3Dfde5757cd3892b979919d3b1faa88a410f28829feb5ba22b6cf069f2c6c98675fceef90f932e49b510e74d65c681d5846b943e7f7cc1b41867422f0481085c1f (@10.42.89.121) 2.02ms
[D 2024-11-25 16:32:24.286 JupyterHub log:191] 200 GET /hub/health (@10.28.9.17) 0.63ms
[D 2024-11-25 16:32:26.287 JupyterHub log:191] 200 GET /hub/health (@10.28.9.17) 0.66ms

(this is what happens when an Application Hub page is loaded in the browser)

Also, describe of application-hub-hub:

Events:
  Type     Reason                  Age                From                     Message
  ----     ------                  ----               ----                     -------
  Warning  FailedScheduling        13m (x2 over 13m)  default-scheduler        0/4 nodes are available: pod has unbound immediate PersistentVolumeClaims. preemption: 0/4 nodes are available: 4 Preemption is not helpful for scheduling..
  Normal   Scheduled               13m                default-scheduler        Successfully assigned application-hub/application-hub-hub-869d9bfc9c-njjks to eoepkak4
  Normal   SuccessfulAttachVolume  13m                attachdetach-controller  AttachVolume.Attach succeeded for volume "pvc-955d3f87-cd2e-4ae9-b39f-b3509c8ecf03"
  Normal   Pulling                 13m                kubelet                  Pulling image "eoepca/application-hub:1.2.0"
  Normal   Pulled                  13m                kubelet                  Successfully pulled image "eoepca/application-hub:1.2.0" in 969ms (969ms including waiting)
  Normal   Created                 13m                kubelet                  Created container hub
  Normal   Started                 13m                kubelet                  Started container hub
  Warning  Unhealthy               13m                kubelet                  Readiness probe failed: Get "http://10.42.89.120:8081/hub/health": dial tcp 10.42.89.120:8081: connect: connection refused

Also, logs from application-hub-proxy:

16:35:01.156 [ConfigProxy] error: 503 GET /hub/home Error: getaddrinfo ENOTFOUND application-hub-hub.default
    at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:69:26) {
  errno: -3008,
  code: 'ENOTFOUND',
  syscall: 'getaddrinfo',
  hostname: 'application-hub-hub.default'
}
16:35:01.204 [ConfigProxy] error: 503 GET /hub/static/components/requirejs/require.js Error: getaddrinfo ENOTFOUND application-hub-hub.default
    at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:69:26) {
  errno: -3008,
  code: 'ENOTFOUND',
  syscall: 'getaddrinfo',
  hostname: 'application-hub-hub.default'
}
16:35:01.205 [ConfigProxy] error: 503 GET /hub/static/css/style.min.css Error: getaddrinfo ENOTFOUND application-hub-hub.default
    at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:69:26) {
  errno: -3008,
  code: 'ENOTFOUND',
  syscall: 'getaddrinfo',
  hostname: 'application-hub-hub.default'
}
16:35:01.236 [ConfigProxy] error: 503 GET /hub/static/components/jquery/dist/jquery.min.js Error: getaddrinfo ENOTFOUND application-hub-hub.default
    at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:69:26) {
  errno: -3008,
  code: 'ENOTFOUND',
  syscall: 'getaddrinfo',
  hostname: 'application-hub-hub.default'
}
16:35:01.238 [ConfigProxy] error: 503 GET /hub/static/components/bootstrap/dist/js/bootstrap.min.js Error: getaddrinfo ENOTFOUND application-hub-hub.default
    at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:69:26) {
  errno: -3008,
  code: 'ENOTFOUND',
  syscall: 'getaddrinfo',
  hostname: 'application-hub-hub.default'
}
16:35:01.240 [ConfigProxy] error: 503 GET /hub/logo Error: getaddrinfo ENOTFOUND application-hub-hub.default
    at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:69:26) {
  errno: -3008,
  code: 'ENOTFOUND',
  syscall: 'getaddrinfo',
  hostname: 'application-hub-hub.default'
}
16:35:01.307 [ConfigProxy] error: 503 GET /hub/static/favicon.ico Error: getaddrinfo ENOTFOUND application-hub-hub.default
    at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:69:26) {
  errno: -3008,
  code: 'ENOTFOUND',
  syscall: 'getaddrinfo',
  hostname: 'application-hub-hub.default'
}

(as above, happens when an Application Hub page is loaded in the browser)

[james-hinton]

I can also recreate all of the above bugs. All that I'm able to say is that when this was first written for the EOEPCA 1.4 release and we had the Keycloak Identity Service, the app hub did not have any of these problems.

I am thinking that the 503 has manifested itself due to the absence of the OIDC, which in App Hub's case will be a required pre-requisite.