Enable specifying a secret for flux git creds

Add entrypoints into charts values.yaml for (in order):

• using an existing secret for git credentials
• create git-credentials from user defined username/password
• create git-credentials from user defined privateKey/publicKey/knownHosts

if none of the above are specified, repositories will assume unauthenticated access

I think these sort of flags can/should be implemented with the following in mind:

1. global value defaulting to empty
2. global value passed into each implementation
3. optional implementation value to overwrite global

what that looks like in practice:

# values.yaml
gitCreds: foo

# package/gitrepository.yaml
{{- if .Values.gitCreds }}
secretRef: {{ .Values.package.gitCreds | default .Values.gitCreds }}
{{- end }}

marked as a Work In Progress

added 32 commits

• bb99640d...38268b90 - 30 commits from branch master
• 1bca14a7 - Merge branch 'master' into feature/enable-git-creds
• e8367b70 - add entrypoints in values.yaml for user defined git credentials, existing secret, or nothing

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changed the description

The only thing I think we should add is a check in the template to make sure just ONE of the three are set:

1. secret
2. login
3. ssh key

i can imagine a scenario where someone accidentally adds too much

added 1 commit

• 9ba468b1 - explicitly call out git credentials precedence

Compare with previous version

resolved all threads

unmarked as a Work In Progress

merged

mentioned in commit 8ca9e0c0