Validate namespace parameter as DNS subdomain name

[deric]

Namespace naming should conform to DNS subdomain name as defined in RFC 1035 and RFC 1123:

• contain at most 63 characters
• contain only lowercase alphanumeric characters or '-'
• start with an alphanumeric character
• end with an alphanumeric character

When enforcing such policy code injection should not be possible (no need to escape namespace name).

[puppet-community-rangefinder]

kubernetes::wait_for_default_sa is a type

that may have no external impact to Forge modules.

This module is declared in 0 of 580 indexed public Puppetfiles.

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These results were generated with Rangefinder, a tool that helps predict the downstream impact of breaking changes to elements used in Puppet modules. You can run this on the command line to get a full report.

Exact matches are those that we can positively identify via namespace and the declaring modules' metadata. Non-namespaced items, such as Puppet 3.x functions, will always be reported as near matches only.

[chelnak]

Morning! This looks great. Two things though.

1. Looks like we have a conflict
2. I notice you link to a SO post and mention an RFC.. I wonder if we could also include a link to some official documentation or maybe even the code that enforces the naming policy on the K8s side (appreciate the latter is probably not possible)

[deric]

@chelnak Thanks, I've added links to the documentation, the here's k8s source code for label validation. The code has been moved to a separate repo, but I wouldn't expect major changes in this area.

The go regexp looks like this:

([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9]

[chelnak]

fantastic @deric - specs are green... we know that the integration tests are dead so lets get this merged.