Support for file store authentication (docker login)

[AayushSaini101]

Description

Added new support fetching credentials from file storage.
Explanation: Created a class File Store that helps to store the credentials in the particular config.

Closes #15

Testing done

Added test cases to verify the methods of the class

### Submitter checklist
- [x] If an issue exists, it is well described and linked in the description
- [x] The description of this pull request is detailed and explain why this pull request is needed
- [ ] The changeset is on a specific branch. Using `feature/` for new feature, or improvements ; Using `fix/` for bug fixes ; Using `docs/` for any documentation changes.
- [ ] If required, the documentation has been updated
- [ ] There is automated tests to cover the code change / addition or an explanation why there is no tests in the description.

[jonesbusy]

Thanks

How to use this to authenticate to OCI registry?

Would be nice to have some example (documentation) and ideally integration test (with test container).

I'm fine to merge partial implementation, but I think it doesn't solve #15 if we cannot use this new authentication method.

[jonesbusy]

https://github.com/oras-project/oras-java/tree/main/src%2Fmain%2Fjava%2Fland%2Foras%2Fauth

I would expect to see a new implementation here. That get the credentials from the file and use it to perform request against the registry

[AayushSaini101]

https://github.com/oras-project/oras-java/tree/main/src%2Fmain%2Fjava%2Fland%2Foras%2Fauth

I would expect to see a new implementation here. That get the credentials from the file and use it to perform request against the registry

Sure, i will add, also i have added some test case to verify the loadConfig https://github.com/oras-project/oras-java/pull/56/files#diff-06cef6e45e7cf319c09fb997438c922de0ce1f1b256a09826acb23267dcaaeefR113:~:text=testConfigLoad_success()%20throws-,Exception,-%7B

[jonesbusy]

Thanks. In my opinion adding Jackson dependency is not necessary. We use JSONUtils to serialize object from/to.

Internally it used GSON (this might change in the future).

What is the reason to add Jackson? Why is a compile scope and not test scope?

Thanks

[AayushSaini101]

Thanks. In my opinion adding Jackson dependency is not necessary. We use JSONUtils to serialize object from/to.

Internally it used GSON (this might change in the future).

What is the reason to add Jackson? Why is a compile scope and not test scope?

Thanks

@jonesbusy Use JSONutils instead of jackson thanks

[jonesbusy]

Do you think we can have a test on https://github.com/oras-project/oras-java/blob/main/src/test/java/land/oras/RegistryTest.java

Right now they don't user any authentication, but I would be great to have a test with an existing auth file and ensuring it's read automatically if present.

Perhaps it should be the default when we don't provide an authentication to the SDK

[AayushSaini101]

https://github.com/oras-project/oras-java/blob/main/src/test/java/land/oras/RegistryTest.java

yes, we can create another issue to create test cases for different authentication present in java-sdk, what do you think ? i guess creating another issue make sense

[AayushSaini101]

@jonesbusy Added implementation of FileStore, the PR will be very large we can partially merge this what do you think ?

[jonesbusy]

There is no rush to merge this PR. I don't see it as a large PR to read and review

It looks better now with AuthProvider but still need some cleanup to remove code duplicate, getter that alter state etc...

Thanks for your contribution

[AayushSaini101]

There is no rush to merge this PR. I don't see it as a large PR to read and review

It looks better now with AuthProvider but still need some cleanup to remove code duplicate, getter that alter state etc...

Thanks for your contribution

sure, i will add more test case in the registry as well thanks : )

[jonesbusy]

Thanks for the effort. LGTM!