Ahs extra values

[ozydingo]

what

• Add support for passing values into the helmfile deploy
• Accepts a yaml blob of values, writes these to a temporary file used in the helmfile
• (abandoned approach) use helmfile's --state-values-set flag. This requires a foo=x,bar=y string from the github action

why

• We want to pass values overrides in certain conditions determined by the github actions workflow.
• Use case: setting a temporary password for preview deployments
• In more detail:
  • Our preview deployments have URLs like {SUBDOMAIN}-{PREVIEW_NAMESPACE}.{DOMAIN}.
  • This causes our login via AWS Cognito to fail as it has fully-qualified redirect URLs registered, and so will refuse to redirect to a preview namespace. We do not have authn information stored in our app resources.
  • Therefore, we want to create a temporary password on the fly to allow user login in preview.
  • We prefer to do this in the github action rather than helm, since the former creates an easy way to inform the developer what the password is for that specific PR directly in the github action summary output

references

Example run