How to get EC2 instance tags when pulling CloudWatch data?
CloudWatch metrics contain "dimensions" that loosely match InfluxDB's concept of "tags". The list of dimensions available for EC2 metrics is available in the AWS documentation. Instances tags are not available and I'm not sure what you mean by env_variables but since all that is supported is


AutoScalingGroupName
ImageId
InstanceId
InstanceType


the answer is still going to be this is not possible.