Elegant Echo

The fifth official release focuses on reduction of complexity and increase of maintainability, further separating stack resources and setup scripts, plus a few security improvements.

Features:

• Use the AWS Secrets Manager to create and store the RDS password
• Use a KDF to derive the Fernet key instead of generating it randomly
• Control RDS access using source security groups instead of CIDR blocks
• Publish no metrics if the there are no workers and the queue is empty

Enhancements:

• Use proper shell scripts to set up instances checked with shellcheck
• Convert load metric to python and check with pylint, flake8, black

Bugfixes:

• Fix pycurl dependency mismatch after its version was pinned by airflow
• Fix connection failure if database password contained special characters
• Fix race condition between instances and codedeploy causing setup to fail

Misc:

• Upgraded to apache-airflow==1.10.9
• Remove non-GPL airflow install flag used in previous airflow versions
• Add tests for guidelines like consistent parameter documentation
• Formally document the load estimation technique