Add configurable HTTP Server header for deception

Add SERVER_HEADER environment variable to customize the HTTP Server
  response header, defaulting to Apache/2.2.22 (Ubuntu). This allows the
  honeypot to masquerade as different web servers to attract attackers.

  - Add server_header field to Config dataclass
  - Override version_string() in Handler to return configured header
  - Update documentation and all deployment configs

helm/templates/configmap.yaml

@@ -14,4 +14,5 @@ data:
   MAX_COUNTER: {{ .Values.config.maxCounter | quote }}
   CANARY_TOKEN_TRIES: {{ .Values.config.canaryTokenTries | quote }}
   PROBABILITY_ERROR_CODES: {{ .Values.config.probabilityErrorCodes | quote }}
+  SERVER_HEADER: {{ .Values.config.serverHeader | quote }}
   CANARY_TOKEN_URL: {{ .Values.config.canaryTokenUrl | quote }}

helm/values.yaml

@@ -73,6 +73,7 @@ config:
   maxCounter: 10
   canaryTokenTries: 10
   probabilityErrorCodes: 0
+  serverHeader: "Apache/2.2.22 (Ubuntu)"
 #  canaryTokenUrl: set-your-canary-token-url-here
 
 networkPolicy: