Injecting ServiceMonitor CR's having invalid syntax on the proxyUrl attribute will not be valdidated and rejected but will break reloading and restarting of Prometheus due to possible invalid syntax.

4.12.x 4.13.x 4.14.x

always

    1. Inject custom ServiceMonitor CR with an invalid proxyUrl (example: 'http://xxx-${STAGE}.svc.cluster.local:80')
 

apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:  
  name: servicemonitor  
  namespace: xxxx
spec:  
  endpoints:    
    - path: /actuator/prometheus-text      
      port: http-web      
      proxyUrl: 'http://xxx-${STAGE}.svc.cluster.local:80'            
      relabelings:        
       - action: labeldrop          
         regex: pod        
       - action: drop          
         regex: destination          
         sourceLabels:
           - reporter        
       - action: drop          
         regex: ^envoy_.*          
         sourceLabels:
           - __name__  
  selector:
    matchLabels:
      monitored: prometheus 

ts=2024-03-13T13:42:47.471Z caller=main.go:928 level=error msg="Error reloading config" err="couldn't load configuration (--config.file=\"/etc/prometheus/config_out/prometheus.env.yaml\"): parsing YAML file /etc/prometheus/config_out/prometheus.env.yaml: parse \http://XXXX-${STAGE}.svc.cluster.local:80\: invalid character \"{\" in host name"

successful reload