Enable PDC for Grafana-infinity-datasource

[leandro-deveikis]

Enabling Private Datasource Connect for Infinity

Background

This PR enables support for the secure socks proxy, which is a new feature in Grafana 10. The feature allows datasource connections to be proxied through a socks5 proxy with TLS. This enables Grafana users to connect to datasources that live in different networks than where Grafana is running when they cannot open up ports to the public internet.

Implementation notes:

• Added frontend configuration to enable PDC (when running locally) at the Network section of the configuration. This will only be shown when running locally, in HG this is disabled and the PDC App adds another configuration (selector for multiple networks).
• Added proxy configurations in the backend, which are needed to configure the http.Transport object which will be the one connecting to the PDC Server.

Dependency updates:

• Not needed, plugin-sdk was already updated to the required version.

Won't implement for now:

• This should be commented in the documentation, but for now I don't see any reason to implement AWS Sigv4 or Azure blob auth as are mostly used as SaaS. Add a comment if this is wrong.

Tests:

• Test running Grafana locally with mocks:
  • No Authentication:
    • JSON - Using several urls from GitHub and other testing sites (https://jsonplaceholder.typicode.com/)
    • CSV, TSV, XML, HTML - Tested using public endpoints and local project
    • GraphQL - tested using public api
      • https://spacex-production.up.railway.app/
    • UQL
    • GROQ
    • Google Sheets
  • Basic Authentication - JSON, CSV, XML
    • created a basic project to ensure that this is working correctly. Printed the headers in the logs and everything looks fine
    • used local implementation https://github.com/abbot/go-http-auth
  • Bearer Authentication - JSON, CSV, XML
    • Same as basic auth
  • Api Key value Pair - JSON, CSV, XML
    • Same as basic auth
  • Digest Auth - JSON
    • tested using httpbin.org
  • Forward OAuth - Couldnt test but the implementation is the same as Oauth2
  • Oauth2
    - Tested using Azure oauth for logs
• Test in HG - I don't think this will be possible before releasing, after releasing we will be doing another round of tests before announcing the feature
  • Need to test how the PDC network selector will be shown, not pretty for sure.

[yesoreyeram]

LGTM. Good one @leandro-deveikis . @zoltanbedi helped me to test this locally and now I added couple of setup things to test this in future.