Convert cmd/secrets-provider to unit testable entrypoint package

[john-odonnell]

Desired Outcome

• Make main package unit testable.
• Create program entrypoint where we can setup dependency injection.

Implemented Changes

• conjur package:
  • Privatized SecretRetriever struct
  • Function NewSecretRetriever now returns type RetrieveSecretsFunc instead of struct SecretRetriever
  • New RetrieverFactory function type, which is implemented by NewSecretRetriever()

    // RetrieverFactory defines a function type for creating a SecretRetriever
    // implementation given an authenticator config.
    type RetrieverFactory func(authnConfig config.Configuration) (RetrieveSecretsFunc, error)

• secrets package:
  • New ProviderFactory function type, which is implemented by NewProviderForType()

    // ProviderFactory defines a function type for creating a ProviderFunc given a
    // RetrieveSecretsFunc and ProviderConfig.
    type ProviderFactory func(traceContent context.Context, secretsRetrieverFunc conjur.RetrieveSecretsFunc, providerConfig ProviderConfig) (ProviderFunc, []error)

  • Refactored RepeatableSecretProvider, which returns a function that wraps a given ProviderFunc in logic to run Secrets Provider in one of its operating modes. Now, this function is called RunSecretsProvider, and the logic is executed instead of returned.
  • New StatusUpdaterFactory function type

    // StatusUpdaterFactory defines a function type for creating a StatusUpdater
    // implementation.
    type StatusUpdaterFactory func() StatusUpdater

  • New function NewStatusUpdater(), which implements StatusUpdaterFactory with default values.
• Moved content of cmd/secrets-provider/* to new entrypoint package.
  • New function startSecretsProviderWithDeps():

    func StartSecretsProviderWithArguments(
        annotationsFilePath string,
        secretsBasePath string,
        templatesBasePath string,
        retrieverFactory conjur.RetrieverFactory,
        providerFactory secrets.ProviderFactory,
        statusUpdater secrets.StatusUpdaterFactory,
    ) (exitCode int)

  • New function StartSecretsProvider(), which calls startSecretsProviderWithDeps() with default values

Connected Issue/Story

CNJR-84

Definition of Done

At least 1 todo must be completed in the sections below for the PR to be
merged.

Changelog

• The CHANGELOG has been updated, or
• This PR does not include user-facing changes and doesn't require a
  CHANGELOG update

Test coverage

• This PR includes new unit and integration tests to go with the code
  changes, or
• The changes in this PR do not require tests

Documentation

• Docs (e.g. READMEs) were updated in this PR
• A follow-up issue to update official docs has been filed here: [insert issue ID]
• This PR does not require updating any documentation

Behavior

• This PR changes product behavior and has been reviewed by a PO, or
• These changes are part of a larger initiative that will be reviewed later, or
• No behavior was changed with this PR

Security

• Security architect has reviewed the changes in this PR,
• These changes are part of a larger initiative with a separate security review, or
• There are no security aspects to these changes

[szh]

@john-odonnell are we going to make changes to make CC happy or just mark these as wontfix?

[john-odonnell]

@szh Refactored repeatableSecretsProvider(), but will mark the rest as wontfix.

[szh]

LGTM

[codeclimate]

Function startSecretsProviderWithDeps has 51 lines of code (exceeds 50 allowed). Consider refactoring.

[codeclimate]

Code Climate has analyzed commit 2d70273 and detected 4 issues on this pull request.

Here's the issue category breakdown:

Category	Count
Complexity	4

The test coverage on the diff in this pull request is 82.9% (50% is the threshold).

This pull request will bring the total coverage in the repository to 88.2% (-1.0% change).

View more on Code Climate.

[doodlesbykumbi]

LGTM! Truly a journey of a thousand miles, thanks for nudging the refactor effort in a good direction

[doodlesbykumbi]

Thoughts on making this more open by just passing along all arguments to this test_unit ... script to go test ...