refactor: create getMinikubeAdditionalEnvs method for minikube exec

[axel7083]

Split up of #223.

Related issues

Part of #154

process.env type issue

This PR remove the process.env from the envs passed to the exec api because its type is incompatible with the API, and is unessessary.

When running tsc we see the following error

src/create-cluster.ts:58:53 - error TS2322: Type '{ [x: string]: string | undefined; TZ?: string; }' is not assignable to type '{ [key: string]: string; }'.
  'string' index signatures are incompatible.
    Type 'string | undefined' is not assignable to type 'string'.
      Type 'undefined' is not assignable to type 'string'.

58     await processApi.exec(minikubeCli, startArgs, { env, logger, token });

Incompatible type

process.env is incompatible with our RunOptions#env.

process.env is typed as ProcessEnv, which is the following

interface ProcessEnv extends Dict<string> {
                /**
                 * Can be used to change the default timezone at runtime
                 */
                TZ?: string;
            }

This is not compatible with our RunOptions#env defined as

export interface RunOptions {
    env?: { [key: string]: string };
...

Unnecessary

If only the type was incompatible I would have forced the typecheck by casting it, or using some Object.assign magic, but this is not necessary as podman desktop core is already doing it for us.

Podman desktop automatically adds it see main/src/plugin/util/exec.ts#L50

[benoitf]

my point was that it's not only a type checking issue.

It's still changing how the variables are given as we remove content (even it is might be added by a 3rd party later)

fixing only typechecking is done by changing env to { [key: string]: string } type.

Here it's more related to avoiding to pass original env values as they're added by Podman Desktop core.
(and then it can fix a typechecking issue)

[benoitf]

should it be

• if it exists we add it to env object else we don't
  rather than
  -adding an empty string value

[axel7083]

Yes, I agree, fixed 👍

[benoitf]

not related to this PR but it's strange sometimes we have both MINIKUBE_HOME and sometimes only the PATH

also should we call a custom utility method that will insert minikubePath and MinikubeHome instead of doing that at several places

[axel7083]

I think this is the core issue actually, thanks for pointing that out, the code should be centralized, and we should have a single function that create the envs required