502 Bad Gateway error when logging in to Event Endpoint Management UI


Logging in to the Event Endpoint Management UI through the exposed ingress fails with a 502 Bad Gateway error message.

Some of the following SSL handshake connection errors are displayed in the ingress controller logs:

2023/11/09 06:42:05 [error] 3243#3243: *28844669 SSL_do_handshake() failed (SSL: error:0A00042E:SSL routines::tlsv1 alert protocol version:SSL alert number 70) while SSL handshaking to upstream, client:, server: qs-eem-ui.mycluster.containers.appdomain.cloud, request: "GET / HTTP/2.0", upstream: "", host: "qs-eem-ui.mycluster.containers.appdomain.cloud"
{"time_date": "2023-11-09T06:42:05+00:00", "client": "", "host": "qs-eem-ui.mycluster.containers.appdomain.cloud", "scheme": "https", "request_method": "GET", "request_uri": "/", "request_id": "a1b2c3", "status": 502, "upstream_addr": ",,", "upstream_status": 502, 502, 502, "request_time": 0.026, "upstream_response_time": 0.010, 0.008, 0.008, "upstream_connect_time": -, -, -, "upstream_header_time": -, -, -}
javax.net.ssl.SSLHandshakeException: Received fatal alert: protocol_version


The default deployment of Event Endpoint Management only allows TLS v1.3 connections but the incoming connection is TLS v1.2, which might be due to configuration of the ingress controller or the client.

Resolving the problem

To resolve the problem, configure the Event Endpoint Management Manager deployment to support earlier versions of the TLS protocol by setting an environment variable for TLS_VERSIONS on the containers.manager section of the Event Endpoint Management custom resource. For example:

# Event Endpoint Management CRD 
              - name: manager
                  - name: TLS_VERSIONS
                    value: 'TLSv1.2,TLSv1.3'

Note: You can establish client connections by using earlier versions of TLS. However, this can result in a higher security risk.