Merge pull request #5 from hellofresh/patch/entry-script

Entry script adjustments

Dockerfile

@@ -12,11 +12,13 @@ RUN apt-get update -y \
         python3-boto3 \
         python3-yaml \
  && rm -rf /var/cache/apt/* \
- && useradd -ms /bin/bash rds_exporter
+ && useradd -ms /bin/bash rds_exporter \
+ && mkdir /rds_exporter \
+ && chown rds_exporter:rds_exporter /rds_exporter
 
 USER rds_exporter
 
-COPY --from=builder /go/src/github.com/hellofresh/rds_exporter/rds_exporter /
+COPY --from=builder /go/src/github.com/hellofresh/rds_exporter/rds_exporter /rds_exporter/rds_exporter
 COPY entry.py /
 
 EXPOSE 9042

entry.py

@@ -7,12 +7,12 @@
 import subprocess
 
 
-REGION = 'eu-west-1'
+AWS_REGION = os.getenv('AWS_REGION', 'eu-west-1')
 ENVIRONMENT = os.getenv('ENVIRONMENT', 'staging')
 
+client = boto3.client('rds', region_name=AWS_REGION)
 
-def get_db_instances(region, page_size=20):
-    client = boto3.client('rds', region_name=region)
+def get_db_instances(page_size=20):
     marker = ""
     pool = []
     while True:
@@ -27,20 +27,35 @@ def get_db_instances(region, page_size=20):
         pool = result.get("DBInstances")
 
 
+def get_rds_tags(instance_arn):
+    response = client.list_tags_for_resource(
+        ResourceName=instance_arn
+    )
+    return { tag['Key']: tag['Value'] for tag in response['TagList'] }
+
+
+def is_applicable(instance):
+    instance_name = instance['DBInstanceIdentifier']
+    instance_arn = instance['DBInstanceArn']
+    instance_tags = get_rds_tags(instance_arn)
+    instance_enhanced_monitoring_arn = instance.get('EnhancedMonitoringResourceArn', None)
+    instance_environment_tag = instance_tags.get('Environment', '')
+    return instance_enhanced_monitoring_arn and (instance_name.lower().endswith(ENVIRONMENT.lower()) or instance_environment_tag.lower() == ENVIRONMENT.lower())
+
+
 if __name__ == "__main__":
     em_enabled_instances = {'instances': []}
 
-    for instance in get_db_instances(REGION):
-        instance_name = instance['DBInstanceIdentifier']
-        if (instance.get('EnhancedMonitoringResourceArn', None) and
-                instance_name.endswith(ENVIRONMENT)):
-            instance = {'instance': instance_name, 'region': REGION}
+    for instance in get_db_instances():
+        if is_applicable(instance):
+            instance_name = instance['DBInstanceIdentifier']
+            instance = {'instance': instance_name, 'region': AWS_REGION}
             em_enabled_instances['instances'].append(instance)
 
-    with open('/config.yml', 'w') as yaml_file:
+    with open('/rds_exporter/config.yml', 'w') as yaml_file:
         yaml.dump(em_enabled_instances, yaml_file, default_flow_style=False)
 
-    rds_exporter = '/rds_exporter \
-                --config.file=/config.yml'
+    rds_exporter = '/rds_exporter/rds_exporter \
+                --config.file=/rds_exporter/config.yml'
 
     subprocess.run(rds_exporter, shell=True)