Add validation for tracing

* add  validation of tracing in validating process

Signed-off-by: Qian Deng <dengq@vmware.com>

make/photon/prepare/models.py

@@ -161,8 +161,10 @@ class JaegerExporter:
         self.agent_port = config.get('agent_port')
 
     def validate(self):
-        if not self.endpoint and self.agent_host is None:
-            raise Exception('Jaeger Colector Endpoint or Agent host not set')
+        if not self.endpoint and not self.agent_host:
+            raise Exception('Jaeger Colector Endpoint or Agent host not set, must set one')
+        if self.endpoint and self.agent_host:
+            raise Exception('Jaeger Colector Endpoint and Agent host both set, only can set one')
 
 class OtelExporter:
     def __init__(self, config: dict):
@@ -192,9 +194,13 @@ class Trace:
         self.attributes = config.get('attributes') or {}
 
     def validate(self):
-        if not self.jaeger.enabled and not self.enabled:
+        if not self.enabled:
+            return
+        if not self.jaeger.enabled and not self.otel.enabled:
             raise Exception('Trace enabled but no trace exporter set')
-        if self.jaeger.enabled:
-            JaegerExporter(self.jaeger).validate()
-        if self.otel.enabled:
-            OtelExporter(self.otel).validate()
+        elif self.jaeger.enabled and self.otel.enabled:
+            raise Exception('Only can have one trace exporter at a time')
+        elif self.jaeger.enabled:
+            self.jaeger.validate()
+        elif self.otel.enabled:
+            self.otel.validate()

make/photon/prepare/utils/configs.py

@@ -76,6 +76,8 @@ def validate(conf: dict, **kwargs):
     # TODO:
     # If user enable trust cert dir, need check if the files in this dir is readable.
 
+    if conf.get('trace'):
+        conf['trace'].validate()
 
 def parse_versions():
     if not versions_file_path.is_file():