publish removes strain conditions from untouched strains

[tripodsan]

Description
assume a strain breaking-december with a package and a condition already published.
the strain.vcl will look like:

if (req.http.x-preflight-x-pages-version == "breaking-december") {
  set req.http.X-Sticky = "true";
  set req.http.X-Strain = "breaking-december";
} else {
  set req.http.X-Strain = "default";
}

In another branch with a config that only contains a strain breaking-january with a package and a condition.
after publish, the dictionay of the first strain breaking-december is untouched, since the strain is not listed in the config, but the strain.vcl now only contains the 2nd strain:

if (req.http.x-preflight-x-pages-version == "breaking-january") {
  set req.http.X-Sticky = "true";
  set req.http.X-Strain = "breaking-january";
} else {
  set req.http.X-Strain = "default";
}

[trieloff]

I'd close this as WONTFIX, but with an explanation:

Helix Publish should be stateless and only represent the helix-config.yaml at the time of publishing. (This is why we are so reluctant to deploy dirty working copies).

The challenge is therefore how to get a helix-config.yaml that has all the strains you need:

Context:
adobe/helix-cli#895
adobe/helix-cli#898

[tripodsan]

but there is a discrepancy between how the dictionaries are updated and the strains.vcl.
helix publish only updates the dicts of the strains in the config that have a package property.

The challenge is therefore how to get a helix-config.yaml that has all the strains you need:

the only way this could work more or less automatic is to have includes, like:

version: 1

definitions:
  defaults:
    # default repository. set to git remote repository before deployment
    - &defaultRepo https://github.com/tripodsan/helix-pages.git#master

preflight: https://adobeioruntime.net/api/v1/web/helix/helix-services/[email protected]

strains:
  - name: default
    code: *defaultRepo
    content: https://github.com/tripodsan/helix-pages.git#master
    static: https://github.com/tripodsan/helix-pages.git/htdocs#master
    package: tripod/3e0670464bc07f36395ed2eb812fe20e4629f54d

!include https://github.com/adobe/helix-pages#breaking-december/helix-config-strain.yaml
!include https://github.com/adobe/helix-pages#breaking-january/helix-config-strain.yaml

(we would need to build the !include handler).

so how this would work:

1. starting with a main that only has the default strain.
2. create a breaking-december branch. add a strain to a helix-config-strain.yaml
3. add the include directive to the helix-config.yaml
4. commit the altered helix-config.yaml and strain fragment to the breaking-december branch
5. merge the commit back to main, but keep the branch
6. start adding the breaking-december specific changes to the branch; update the version-lock in the helix-config-strain.yaml
7. hlx deploy in the breaking-december branch needs to understand the include and update it accordingly.
8. hlx publish in the breaking-december branch works, since it has the latest helix-config.yaml from main and all it's includes
9. hlx publish in the main branch works, since it has all the includes.

[trieloff]

As discussed, let's try --only $CI_BRANCH