Allow AWS modules to enforce minimum botocore library version

[willthames]

Proposal: Allow AWS modules to enforce minimum botocore version

Author: Will Thames <@willthames>

Date: 2018/04/28

• Status: New
• Proposal type: process
• Targeted Release: 2.6
• Associated PR: N/A yet
• Estimated time to implement: 1 day

Motivation

We try and maintain backwards compatibility for AWS modules for a reasonable amount of time, but we also wish to reduce the complexity of the codebase. Adding version checks for new features so that we can fail with a nice warning message when people try to use new features with old botocore libraries is a tradeoff between usability and simplicity.

Allowing a minimum version to be mandated by specific modules will allow us to add features that have been possible for a reasonable amount of time without including version checks.

Allowing a minimum version to be mandated allows us to remove old version checks from the codebase.

A minimum version specification may encourage people to update their botocore libraries.

Problems

What problems exist that this proposal will solve?

• Reduces version check complexity

Solution proposal

• Add a botocore_minimum_version parameter to the AnsibleAWSModule constructor. Modules using that parameter will fail if botocore does not meet that version.
• Document botocore minimum versions in modules in the requirements section (currently typically just says boto3, should say botocore > 1.5.2
• Document the minimum supported version of botocore in the AWS Guidelines page, and also document in the CHANGELOG.
• Existing modules wouldn't be allowed to specify a minimum botocore version lower than this supported version, unless they just wouldn't work (e.g. an existing module for a six month old service). Preview modules may also be allowed exceptions (but some preview modules should also graduate to stableinterface by now, so this should not be a blanket exception)
• As of 27th April 2018, proposed minimum botocore version would be 1.5.44 (26th April 2017) but we'd firm that up nearer to Ansible 2.6 release

Documentation (optional)

See above

Anything else?

No

[ryansb]

botocore-versions.txt boto3-versions.txt

Attached are the full histories to-date of the boto3/botocore releases from late 2015 to now for reference.

For a minimum version, do you think the right length of time would be botocore stable version on ([day of stable release] - 1 year)?