Allow the characters _:./+- to be used in tag keys during deploy

[RobReus]

Why is this change necessary?
Using the aws cloudformation deploy --tags command, you are allowed to use these characters in the tag keys. Documentation also lists these characters as supported and allowed. With sam deploy --tags, it did not work properly due to a regex limiting supported characters to A-Za-z0-9.

How does it address the issue?
By adding a regex specifically for tag keys. By using this new regex, sam deploy --tags 'owner:name=son of anton' no longer converts the tag key to name instead of owner:name.
Before:

{"name": "son of anton"}

After:

{"owner:name": "son of anton"}

What side effects does this change have?
None. More characters allowed in keys and fully backwards compatible.

Checklist:

• Write Design Document (Do I need to write a design document?)
• Write unit tests
• Write/update functional tests
• Write/update integration tests
• make pr passes
• Write documentation

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[sriram-mv]

Thanks for the PR! This looks good 👍

[vladb-metapack]

Hi,

I was trying to tag my entire stack with some tags which include colons in them
and using sam deploy to deploy them (sam version 0.40 and awscli version 1.16.230)
and had the same issue as this. Everything before the : including the : itself was removed in the tags.

I have upgraded the aws versions and downgraded sam to 0.15 which enabled me to use this, but alas for safety reasons we went ahead with just using aws cloudformation deploy.

[RobReus]

Hi,

I was trying to tag my entire stack with some tags which include colons in them
and using sam deploy to deploy them (sam version 0.40 and awscli version 1.16.230)
and had the same issue as this. Everything before the : including the : itself was removed in the tags.

I have upgraded the aws versions and downgraded sam to 0.15 which enabled me to use this, but alas for safety reasons we went ahead with just using aws cloudformation deploy.

This was the exact reason for me to create this PR. As per AWS best practices, we too use colons to separate between parts of the tag keys. I got tired of having to use sam package and then aws cloudformation deploy.

@sriram-mv I just realized I did not make the regex a bit nicer. I left some other allowed characters out (like @) and did not add the constraints of the key value (must start and end with A-Za-z0-9). Would you want me to fix this before merging this PR?

[sriram-mv]

@RobReus Yes please, I think its a good idea to add some more constraints on this.

[sriram-mv]

Closing because I was not able to push to the fork.

#1798 is the new PR.