fix: template issues

[moolen]

This fixes #124 and #125.

What was the issue?
It did not work as documented.

1. Secret.Metadata and Secret.Data was not updated after the external-secret has been changed: CreateOrUpdate does a .Get() before .Update() and modifies the object at the pointer.
2. External Secrets templates use []byte instead of string. #125 Template.Data was basically unusable due to having a Data: []byte. users would have to base64 encode the template string 😰. This is now a simple string like it should have been from the get-go.
3. External Secrets w/templated keys are overwritten by remote keys of the same name #124 Data from the secret provider could not be overridden with a template. Now the template takes precedence.

Example:

apiVersion: external-secrets.io/v1alpha1
kind: ExternalSecret
metadata:
  name: example
spec:
  ...
  target:
    name: secret-to-be-created
    template:
      data:
        firstname: "yadayada {{ .firstname | toString }}!"
  data:
  - secretKey: firstname
    remoteRef:
      key: json-string
      property: mykey

Given a json-string={"mykey": "foobar"} we get a Secret with:

data:
  firstname: "yadayada foobar!"

When we update the ExternalSecret's metadata or template then the secret will change aswell.

I will add proper template-tests later (i did the tests manually for now), i feel like we should refactor the controller_tests like the aws/secrets-manager.

[moolen]

When a user deletes the secret it should not be counted as a syncCallsError

[Sadzeih]

After reading the code, I believe this might fix an issue when only specifying a template type, but not providing data which crashes the external secrets controller.

[moolen]

right! That's something i didn't discover, thanks for pointing that out!
(+1 on my todo list for adding proper tests for the template feature 😄 )

[knelasevero]

Good catch! What @Sadzeih reported also happened with someone else that pinged me on slack. Was going to open a issue for it 😅

[knelasevero]

/approve

[moolen]

/merge