upstream connect error or disconnect/reset before headers. retried and the latest reset reason: protocol error

Question

Trying to curl to my deployed container app. As far as I see the container started successfully and the listener port is running evidently by running netstat -an within the container. But a curl to the health check endpoint fails.

Host: automatoraca-app.wittymeadow-****.azurecontainerapps.io

user-agent: curl/7.78.0

accept: /

• STATE: DO => DID handle 0x80007eec8; line 2068 (connection #0)
• multi changed, check CONNECT_PEND queue!
• STATE: DID => PERFORMING handle 0x80007eec8; line 2187 (connection #0)
• HTTP/2 found, allow multiplexing

< HTTP/2 502

< content-length: 110

< content-type: text/plain

< date: Fri, 31 Mar 2023 17:43:41 GMT

<

• nread == 0, stream closed, bailing
• STATE: PERFORMING => DONE handle 0x80007eec8; line 2386 (connection #0)
• multi_done
• Connection #0 to host automatoraca-app.wittymeadow-4cc63852.southcentralus.azurecontainerapps.io left intact
• Expire cleared (transfer 0x80007eec8)

upstream connect error or disconnect/reset before headers. retried and the latest reset reason: protocol error

Answer 1

I had the same issue - using Outlook on a desktop Mac.

I solved it using the following steps. I would suggest going straight to step 3 to see if that works outright

1. Turned off Private Relay.
2. Turned off Firewall.
3. Changed default browser from Safari to chrome. Safari kept downloading a file called oauth2redirect which seemed to put the process on hold.

Answer 2

I switched the Azure Container App transport mode from "http2" to "auto" to fix the issue.