feat: default variants

[markphelps]

Redo of #3168

Fixes: #3134

TODO (In this PR)

• Add tests
• Implement in UI
• Add for other relational dbs
• Import/Export support (will also influence declarative backends)
• Add to snapshot builder code (declarative)

In other repos

• Add to API docs (feat: add default variant id flipt-openapi#23)
• Add to client-side eval logic (feat: add support for default variant eval flipt-client-sdks#309)
• Update OpenFeature providers

[codecov]

Codecov Report

Attention: Patch coverage is 57.41935% with 66 lines in your changes missing coverage. Please review.

Project coverage is 64.18%. Comparing base (0b13a4e) to head (5c193ff).

Files	Patch %	Lines
internal/storage/sql/mysql/mysql.go	0.00%	23 Missing ⚠️
internal/server/evaluation/data/server.go	0.00%	17 Missing ⚠️
internal/storage/sql/postgres/postgres.go	0.00%	10 Missing ⚠️
internal/ext/importer.go	75.00%	3 Missing and 2 partials ⚠️
internal/storage/sql/common/flag.go	86.84%	2 Missing and 3 partials ⚠️
internal/storage/sql/sqlite/sqlite.go	60.00%	3 Missing and 1 partial ⚠️
internal/server/evaluation/evaluation.go	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3271      +/-   ##
==========================================
- Coverage   64.24%   64.18%   -0.06%     
==========================================
  Files         168      168              
  Lines       13410    13506      +96     
==========================================
+ Hits         8615     8669      +54     
- Misses       4137     4174      +37     
- Partials      658      663       +5     

Flag	Coverage Δ
unittests	64.18% <57.41%> (-0.06%)	⬇️

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[markphelps]

I'm opening this up for feedback before I get too far in the weeds with adding tests

cc @erka

[erka]

I'm opening this up for feedback before I get too far in the weeds with adding tests

cc @erka

@markphelps Overall, it looks fantastic. There is one white spot with evaluation.proto. I don't see that we set a default variant there.

[markphelps]

I'm opening this up for feedback before I get too far in the weeds with adding tests
cc @erka

@markphelps Overall, it looks fantastic. There is one white spot with evaluation.proto. I don't see that we set a default variant there.

Im not quite sure what you mean. Would you mind showing me in the a comment in the PR if possible?

[erka]

Im not quite sure what you mean. Would you mind showing me in the a comment in the PR if possible?

If I set the default variant for a flag and then look at snapshot at http://localhost:8080/internal/v1/evaluation/snapshot/namespace/default I don't see any changes in the response.

[markphelps]

Im not quite sure what you mean. Would you mind showing me in the a comment in the PR if possible?

If I set the default variant for a flag and then look at snapshot at http://localhost:8080/internal/v1/evaluation/snapshot/namespace/default I don't see any changes in the response.

ah yes! good catch. will add. and also need to add support in the client side evaluator engine

[markphelps]

Eval Data API

With Proper Header Set

curl -H "X-Flipt-Accept-Server-Version: 1.47.0" http://localhost:8080/internal/v1/evaluation/snapshot/namespace/default | jq

{
  "namespace": {
    "key": "default"
  },
  "flags": [
    {
      "key": "fgsdaf",
      "name": "fgsdaf",
      "description": "",
      "enabled": false,
      "type": "BOOLEAN_FLAG_TYPE",
      "createdAt": "2024-07-19T14:18:19.835699Z",
      "updatedAt": "2024-07-19T14:18:19.835699Z",
      "rules": [],
      "rollouts": [
        {
          "type": "THRESHOLD_ROLLOUT_TYPE",
          "rank": 1,
          "threshold": {
            "percentage": 50,
            "value": true
          }
        }
      ]
    },
    {
      "key": "dfsdf",
      "name": "dfsdf",
      "description": "",
      "enabled": true,
      "type": "VARIANT_FLAG_TYPE",
      "createdAt": "2024-07-19T14:20:48.359953Z",
      "updatedAt": "2024-07-21T16:59:59.373240Z",
      "rules": [],
      "rollouts": [],
      "defaultVariant": {
        "id": "e468f221-7e48-4dcf-8f1f-3156a990f363",
        "key": "goo",
        "attachment": ""
      }
    }
  ]
}

---

With Lower Version Header Set

curl -H "X-Flipt-Accept-Server-Version: 1.46.0" http://localhost:8080/internal/v1/evaluation/snapshot/namespace/default | jq

{
  "namespace": {
    "key": "default"
  },
  "flags": [
    {
      "key": "fgsdaf",
      "name": "fgsdaf",
      "description": "",
      "enabled": false,
      "type": "BOOLEAN_FLAG_TYPE",
      "createdAt": "2024-07-19T14:18:19.835699Z",
      "updatedAt": "2024-07-19T14:18:19.835699Z",
      "rules": [],
      "rollouts": [
        {
          "type": "THRESHOLD_ROLLOUT_TYPE",
          "rank": 1,
          "threshold": {
            "percentage": 50,
            "value": true
          }
        }
      ]
    },
    {
      "key": "dfsdf",
      "name": "dfsdf",
      "description": "",
      "enabled": true,
      "type": "VARIANT_FLAG_TYPE",
      "createdAt": "2024-07-19T14:20:48.359953Z",
      "updatedAt": "2024-07-21T16:59:59.373240Z",
      "rules": [],
      "rollouts": []
    }
  ]
}

---

With No Header Set

curl http://localhost:8080/internal/v1/evaluation/snapshot/namespace/default | jq

{
  "namespace": {
    "key": "default"
  },
  "flags": [
    {
      "key": "fgsdaf",
      "name": "fgsdaf",
      "description": "",
      "enabled": false,
      "type": "BOOLEAN_FLAG_TYPE",
      "createdAt": "2024-07-19T14:18:19.835699Z",
      "updatedAt": "2024-07-19T14:18:19.835699Z",
      "rules": [],
      "rollouts": [
        {
          "type": "THRESHOLD_ROLLOUT_TYPE",
          "rank": 1,
          "threshold": {
            "percentage": 50,
            "value": true
          }
        }
      ]
    },
    {
      "key": "dfsdf",
      "name": "dfsdf",
      "description": "",
      "enabled": true,
      "type": "VARIANT_FLAG_TYPE",
      "createdAt": "2024-07-19T14:20:48.359953Z",
      "updatedAt": "2024-07-21T16:59:59.373240Z",
      "rules": [],
      "rollouts": []
    }
  ]
}

[markphelps]

@erka @GeorgeMac this should be ready for another pass now

[erka]

it looks great. I have only one comment about compatibility.