A list of breaking changes we're holding back for 6.0

[yob]

We have a few breaking changes we might make in 6.0, whenever that ends up being. I considered making a GitHub milestone for this list, but we don't have a culture of using them and I worried we might overlook it.

• update awscli to v2 aws-cli v2 installed on the agent #688
• remove the IMDSv2Tokens param added in IMDSv2Tokens parameter: optional / required #789 and just make v2 tokens required all the t ime
• remove deprecated SpotPrice param Support multiple instance types by switching to a Mixed Instance ASG #710
• Enable SSM access and disable SSH access Enable SSM access and disable SSH access. #738
• Rename SecurityGroupId to SecurityGroupIds?
• Make instance names default to the stack name
• Rename base branch from master to main - this would cause people using master branch releases to stop receiving builds

See also: Agent: A list of breaking changes we're holding back for 4.0

[nitrocode]

Renaming SecurityGroupId to SecurityGroupIds would be good too

[woodhull]

Update docker to 20.x?

[chloeruka]

Update docker to 20.x?

@woodhull Docker bumps are not usually considered breaking, are there significant implications of moving to v20?

@yob I'd also like to see #738 if we don't merge it sooner.

[yob]

Thanks all - list updated

[jdub]

If you're doing SecurityGroupIds, perhaps ManagedPolicyARNs? Just discovered it. 😆

[nitrocode]

@chloeruka that wouldn't be a breaking change since ssh access would still be available just through ssm instead of port 22.

If it's not a breaking change, could it be added prior to a 6.0 release?

[chloeruka]

It's not so much the availability of equivalent/replacement features, but removal of parameters that would make us consider it more appropriate for a major version. Changing things around might require users adjust parameters or automation surrounding their stacks. We want low friction Cloudformation upgrades since it's currently tied to Agent updates.

[nitrocode]

I'd like to second the docker 20.x upgrade as that would allow us to no longer have to set environment variables DOCKER_EXPERIMENTAL and DOCKER_CLI_EXPERIMENTAL which would deprecate the EnableDockerExperimental parameter on the stack.

[triarius]

v6 is out, so I'm going to close this.