Keda Operator - MetricsAPI Scaler: text format parsing error in line 31: unexpected end of input stream

[jark-AB]

Report

Upgraded from 2.15.1 > 2.16.1 and ran into the following issue across all our scaledObjects that are utilizing the MetricsAPI Scaler

│   Normal   ScaledObjectReady       2m47s                keda-operator  ScaledObject is ready for scaling                                                                                                                                                                   │
│   Warning  KEDAMetricSourceFailed  69s (x5 over 3m45s)  keda-operator  error requesting metrics endpoint: text format parsing error in line 31: unexpected end of input stream

• Events from the SO

│ Events:                                                                                                                                                                                                                                                                    │
│   Type     Reason              Age                   From           Message                                                                                                                                                                                                │
│   ----     ------              ----                  ----           -------                                                                                                                                                                                                │
│   Normal   KEDAScalersStarted  12m                   keda-operator  Scaler metrics-api is built.                                                                                                                                                                           │
│   Normal   ScaledObjectReady   8m54s                 keda-operator  ScaledObject is ready for scaling                                                                                                                                                                      │
│   Warning  KEDAScalerFailed    7m18s                 keda-operator  error requesting metrics endpoint: text format parsing error in line 31: unexpected end of input stream                                                                                                │
│   Warning  KEDAScalerFailed    6m13s                 keda-operator  error requesting metrics endpoint: Get "http://api.sandbox-amazon-gref.svc.cluster.local:9001/api/v1/metrics": context deadline exceeded (Client.Timeout exceeded while awaiting headers)              │
│   Normal   KEDAScalersStarted  6m13s                 keda-operator  Scaler metrics-api is built.                                                                                                                                                                           │
│   Warning  KEDAScalerFailed    3m (x2 over 3m5s)     keda-operator  error requesting metrics endpoint: text format parsing error in line 31: unexpected end of input stream                                                                                                │
│   Normal   KEDAScalersStarted  104s (x2 over 2m45s)  keda-operator  Scaler metrics-api is built.                                                                                                                                                                           │
│   Normal   KEDAScalersStarted  16s                   keda-operator  Scaler metrics-api is built.

Expected Behavior

1. Upgrade Keda > 2.16.1
2. MetricsAPI scaler-api is built
3. ScaledObject is ready for scaling

Actual Behavior

1. Upgrade Keda > 2.16.1
2. Scaler metrics-api is built.
3. ScaledObject is ready for scaling
4. Warning KEDAScalerFailed 7m18s keda-operator error requesting metrics endpoint: text format parsing error in line 31: unexpected end of input stream │

Steps to Reproduce the Problem

1. Upgrade Keda > 2.16.1
2. Create MetricsAPI ScaledObject that uses Prometheus Trigger
3. Observe the errors

Logs from KEDA operator

│   Normal   ScaledObjectReady       2m47s                keda-operator  ScaledObject is ready for scaling                                                                                                                                                                   │
│   Warning  KEDAMetricSourceFailed  69s (x5 over 3m45s)  keda-operator  error requesting metrics endpoint: text format parsing error in line 31: unexpected end of input stream

KEDA Version

2.16.1

Kubernetes Version

< 1.29

Platform

Amazon Web Services

Scaler Details

MetricsAPI Scaler

Anything else?

No response

[jark-AB]

Appears to be related to this PR which was the only change to MetricsAPIScaler
#6078