ENH: Add Ert experiment id to case metadata

src/fmu/dataio/_model/fields.py

@@ -202,6 +202,22 @@ class Case(BaseModel):
     """A free-text description of this case."""
 
 
+class Ert(BaseModel):
+    """The ``fmu.ert`` block contains information about the current ert run."""
+
+    experiment: Optional[Experiment] = Field(default=None)
+    """Reference to the ert experiment.
+    See :class:`Experiment`."""
+
+
+class Experiment(BaseModel):
+    """The ``fmu.ert.experiment`` block contains information about
+    the current ert experiment run."""
+
+    id: Optional[UUID] = Field(default=None)
+    """The unique identifier of this ert experiment run."""
+
+
 class Iteration(BaseModel):
     """
     The ``fmu.iteration`` block contains information about the iteration this data
@@ -543,6 +559,10 @@ class FMUBase(BaseModel):
     """The ``fmu.case`` block contains information about the case from which this data
     object was exported. See :class:`Case`."""
 
+    ert: Optional[Ert] = Field(default=None)
+    """The ``fmu.ert`` block contains information about the current ert run
+    object was exported. See :class:`Ert`."""
+
     model: Model
     """The ``fmu.model`` block contains information about the model used.
     See :class:`Model`."""

src/fmu/dataio/_model/internal.py

@@ -111,6 +111,7 @@ class JsonSchemaMetadata(BaseModel, populate_by_name=True):
 class FMUModelCase(BaseModel):
     model: fields.Model
     case: fields.Case
+    ert: Optional[fields.Ert] = Field(default=None)
 
 
 class Context(BaseModel, use_enum_values=True):

src/fmu/dataio/case.py

@@ -14,7 +14,8 @@
 from . import _utils
 from ._logging import null_logger
 from ._model import global_configuration, internal
-from ._model.fields import Access, Case, Masterdata, Model, User
+from ._model.fields import Access, Case, Ert, Experiment, Masterdata, Model, User
+from .providers._fmu import FmuEnv
 
 logger: Final = null_logger(__name__)
 
@@ -131,6 +132,13 @@ def generate_metadata(self) -> dict:
                     user=User(id=self.caseuser),
                     description=None,
                 ),
+                ert=Ert(
+                    experiment=Experiment(
+                        id=uuid.UUID(FmuEnv.EXPERIMENT_ID.value)
+                        if FmuEnv.EXPERIMENT_ID.value
+                        else None
+                    )
+                ),
             ),
             tracklog=fields.Tracklog.initialize(),
             description=_utils.generate_description(self.description),

tests/test_units/test_initialize_case.py

@@ -141,6 +141,23 @@ def test_create_case_metadata_generate_metadata_warn_if_exists(
         icase.generate_metadata()
 
 
+def test_create_case_metadata_generate_metadata_with_experiment_id(
+    monkeypatch, fmurun, globalconfig2
+):
+    monkeypatch.chdir(fmurun)
+    logger.info("Active folder is %s", fmurun)
+    myroot = fmurun.parent.parent.parent / "mycase"
+    logger.info("Case folder is now %s", myroot)
+
+    icase = CreateCaseMetadata(
+        config=globalconfig2, rootfolder=myroot, casename="mycase", caseuser="user"
+    )
+    metadata = icase.generate_metadata()
+    experiment_id_expected = "6a8e1e0f-9315-46bb-9648-8de87151f4c7"
+    assert metadata
+    assert metadata["fmu"]["ert"]["experiment"]["id"] == experiment_id_expected
+
+
 def test_create_case_metadata_with_export(monkeypatch, globalconfig2, fmurun):
     monkeypatch.chdir(fmurun)
     caseroot = fmurun.parent.parent
@@ -195,3 +212,25 @@ def test_create_case_metadata_export_with_norsk_alphabet(
         metadata_string = stream.read()
 
     assert "æøå" in metadata_string
+
+
+def test_create_case_metadata_with_export_with_experiment_id(
+    monkeypatch, globalconfig2, fmurun
+):
+    monkeypatch.chdir(fmurun)
+    caseroot = fmurun.parent.parent
+
+    icase = CreateCaseMetadata(
+        config=globalconfig2,
+        rootfolder=caseroot,
+        casename="MyCaseName",
+        caseuser="MyUser",
+        description="Some description",
+    )
+    fmu_case_yml = Path(icase.export())
+
+    with open(fmu_case_yml) as stream:
+        metadata = yaml.safe_load(stream)
+
+    experiment_id_expected = "6a8e1e0f-9315-46bb-9648-8de87151f4c7"
+    assert metadata["fmu"]["ert"]["experiment"]["id"] == experiment_id_expected