Fix: Make gateway names case-insesitive

docs/concepts/models/external_models.md

@@ -56,6 +56,8 @@ If SQLMesh does not have access to an external table's metadata, the table will
 
 In some use-cases such as [isolated systems with multiple gateways](../../guides/isolated_systems.md#multiple-gateways), there are external models that only exist on a certain gateway.
 
+**Gateway names are case-insensitive in external model configurations.** You can specify the gateway name using any case (e.g., `gateway: dev`, `gateway: DEV`, `gateway: Dev`) and SQLMesh will handle the matching correctly.
+
 Consider the following model that queries an external table with a dynamic database based on the current gateway:
 
 ```
@@ -100,7 +102,7 @@ This example demonstrates the structure of a `external_models.yaml` file:
     column_d: float
 - name: external_db.gateway_specific_external_table
   description: Another external table that only exists when the gateway is set to "test"
-  gateway: test
+  gateway: test  # Case-insensitive - could also be "TEST", "Test", etc.
   columns:
     column_e: int
     column_f: varchar

docs/guides/configuration.md

@@ -322,7 +322,7 @@ SQLMesh creates schemas, physical tables, and views in the data warehouse/engine
 
 The default SQLMesh behavior described in the FAQ is appropriate for most deployments, but you can override *where* SQLMesh creates physical tables and views with the `physical_schema_mapping`, `environment_suffix_target`, and `environment_catalog_mapping` configuration options.
 
-You can also override *what* the physical tables are called by using the `physical_table_naming_convention` option. 
+You can also override *what* the physical tables are called by using the `physical_table_naming_convention` option.
 
 These options are in the [environments](../reference/configuration.md#environments) section of the configuration reference page.
 
@@ -767,7 +767,9 @@ Even though the second change should have been a metadata change (thus not requi
 
 The `gateways` configuration defines how SQLMesh should connect to the data warehouse, state backend, and scheduler. These options are in the [gateway](../reference/configuration.md#gateway) section of the configuration reference page.
 
-Each gateway key represents a unique gateway name and configures its connections. For example, this configures the `my_gateway` gateway:
+Each gateway key represents a unique gateway name and configures its connections. **Gateway names are case-insensitive** - SQLMesh automatically normalizes gateway names to lowercase during configuration validation. This means you can use any case in your configuration files (e.g., `MyGateway`, `mygateway`, `MYGATEWAY`) and they will all work correctly.
+
+For example, this configures the `my_gateway` gateway:
 
 === "YAML"
 

docs/reference/configuration.md

@@ -141,7 +141,7 @@ SQLMesh UI settings.
 
 The `gateways` dictionary defines how SQLMesh should connect to the data warehouse, state backend, test backend, and scheduler.
 
-It takes one or more named `gateway` configuration keys, each of which can define its own connections. A named gateway does not need to specify all four components and will use defaults if any are omitted - more information is provided about [gateway defaults](#gatewayconnection-defaults) below.
+It takes one or more named `gateway` configuration keys, each of which can define its own connections. **Gateway names are case-insensitive** - SQLMesh normalizes all gateway names to lowercase during configuration validation, allowing you to use any case when referencing gateways. A named gateway does not need to specify all four components and will use defaults if any are omitted - more information is provided about [gateway defaults](#gatewayconnection-defaults) below.
 
 For example, a project might configure the `gate1` and `gate2` gateways:
 
@@ -247,7 +247,7 @@ If a configuration contains multiple gateways, SQLMesh will use the first one in
 
 | Option            | Description                                                                                                                  |  Type  | Required |
 | ----------------- | ---------------------------------------------------------------------------------------------------------------------------- | :----: | :------: |
-| `default_gateway` | The name of a gateway to use if one is not provided explicitly (Default: the gateway defined first in the `gateways` option) | string |    N     |
+| `default_gateway` | The name of a gateway to use if one is not provided explicitly (Default: the gateway defined first in the `gateways` option). Gateway names are case-insensitive. | string |    N     |
 
 ### Default connections/scheduler
 

sqlmesh/core/config/root.py

@@ -62,6 +62,9 @@ def gateways_ensure_dict(value: t.Dict[str, t.Any]) -> t.Dict[str, t.Any]:
             GatewayConfig.parse_obj(value)
         return {"": value}
     except Exception:
+        # Normalize all gateway keys to lowercase for case-insensitive matching
+        if isinstance(value, dict):
+            return {k.lower(): v for k, v in value.items()}
         return value
 
 
@@ -298,19 +301,23 @@ def get_gateway(self, name: t.Optional[str] = None) -> GatewayConfig:
         if isinstance(self.gateways, dict):
             if name is None:
                 if self.default_gateway:
-                    if self.default_gateway not in self.gateways:
+                    # Normalize default_gateway name to lowercase for lookup
+                    default_key = self.default_gateway.lower()
+                    if default_key not in self.gateways:
                         raise ConfigError(f"Missing gateway with name '{self.default_gateway}'")
-                    return self.gateways[self.default_gateway]
+                    return self.gateways[default_key]
 
                 if "" in self.gateways:
                     return self.gateways[""]
 
                 return first(self.gateways.values())
 
-            if name not in self.gateways:
+            # Normalize lookup name to lowercase since gateway keys are already lowercase
+            lookup_key = name.lower()
+            if lookup_key not in self.gateways:
                 raise ConfigError(f"Missing gateway with name '{name}'.")
 
-            return self.gateways[name]
+            return self.gateways[lookup_key]
         if name is not None:
             raise ConfigError("Gateway name is not supported when only one gateway is configured.")
         return self.gateways

sqlmesh/core/context.py

@@ -400,9 +400,9 @@ def __init__(
         self.environment_ttl = self.config.environment_ttl
         self.pinned_environments = Environment.sanitize_names(self.config.pinned_environments)
         self.auto_categorize_changes = self.config.plan.auto_categorize_changes
-        self.selected_gateway = gateway or self.config.default_gateway_name
+        self.selected_gateway = (gateway or self.config.default_gateway_name).lower()
 
-        gw_model_defaults = self.config.gateways[self.selected_gateway].model_defaults
+        gw_model_defaults = self.config.get_gateway(self.selected_gateway).model_defaults
         if gw_model_defaults:
             # Merge global model defaults with the selected gateway's, if it's overriden
             global_defaults = self.config.model_defaults.model_dump(exclude_unset=True)

sqlmesh/core/loader.py

@@ -374,6 +374,7 @@ def _load(path: Path) -> t.List[Model]:
 
             # however, if there is a gateway defined, gateway-specific models take precedence
             if gateway:
+                gateway = gateway.lower()
                 for model in external_models:
                     if model.gateway == gateway:
                         if model.fqn in models and models[model.fqn].gateway == gateway:

tests/core/test_context.py

@@ -1221,6 +1221,12 @@ def _get_external_model_names(gateway=None):
     # gateway explicitly set to prod; prod model should now show
     assert "prod_raw.model1" in _get_external_model_names(gateway="prod")
 
+    # test uppercase gateway name should match lowercase external model definition
+    assert "prod_raw.model1" in _get_external_model_names(gateway="PROD")
+
+    # test mixed case gateway name should also work
+    assert "prod_raw.model1" in _get_external_model_names(gateway="Prod")
+
 
 def test_disabled_model(copy_to_temp_path):
     path = copy_to_temp_path("examples/sushi")
@@ -2867,3 +2873,132 @@ def test_model_defaults_statements_with_on_virtual_update(tmp_path: Path):
     # Default statements should come first
     assert model.on_virtual_update[0].sql() == "SELECT 'Model-defailt virtual update' AS message"
     assert model.on_virtual_update[1].sql() == "SELECT 'Model-specific update' AS message"
+
+
+def test_uppercase_gateway_external_models(tmp_path):
+    # Create a temporary SQLMesh project with uppercase gateway name
+    config_py = tmp_path / "config.py"
+    config_py.write_text("""
+from sqlmesh.core.config import Config, DuckDBConnectionConfig, GatewayConfig, ModelDefaultsConfig
+
+config = Config(
+    gateways={
+        "UPPERCASE_GATEWAY": GatewayConfig(
+            connection=DuckDBConnectionConfig(),
+        ),
+    },
+    default_gateway="UPPERCASE_GATEWAY",
+    model_defaults=ModelDefaultsConfig(dialect="duckdb"),
+)
+""")
+
+    # Create external models file with lowercase gateway name (this should still match uppercase)
+    external_models_yaml = tmp_path / "external_models.yaml"
+    external_models_yaml.write_text("""
+- name: test_db.uppercase_gateway_table
+  description: Test external model with lowercase gateway name that should match uppercase gateway
+  gateway: uppercase_gateway  # lowercase in external model, but config has UPPERCASE_GATEWAY
+  columns:
+    id: int
+    name: text
+
+- name: test_db.no_gateway_table
+  description: Test external model without gateway (should be available for all gateways)
+  columns:
+    id: int
+    name: text
+""")
+
+    # Create a model that references the external model
+    models_dir = tmp_path / "models"
+    models_dir.mkdir()
+    model_sql = models_dir / "test_model.sql"
+    model_sql.write_text("""
+MODEL (
+    name test.my_model,
+    kind FULL,
+);
+
+SELECT * FROM test_db.uppercase_gateway_table;
+""")
+
+    # Test with uppercase gateway name - this should find both models
+    context_uppercase = Context(paths=[tmp_path], gateway="UPPERCASE_GATEWAY")
+
+    # Verify external model with lowercase gateway name in YAML is found when using uppercase gateway
+    gateway_specific_models = [
+        model
+        for model in context_uppercase.models.values()
+        if model.name == "test_db.uppercase_gateway_table"
+    ]
+    assert len(gateway_specific_models) == 1, (
+        f"External model with lowercase gateway name should be found with uppercase gateway. Found {len(gateway_specific_models)} models"
+    )
+
+    # Verify external model without gateway is also found
+    no_gateway_models = [
+        model
+        for model in context_uppercase.models.values()
+        if model.name == "test_db.no_gateway_table"
+    ]
+    assert len(no_gateway_models) == 1, (
+        f"External model without gateway should be found. Found {len(no_gateway_models)} models"
+    )
+
+    # Check that the column types are properly loaded (not UNKNOWN)
+    external_model = gateway_specific_models[0]
+    column_types = {name: str(dtype) for name, dtype in external_model.columns_to_types.items()}
+    assert column_types == {"id": "INT", "name": "TEXT"}, (
+        f"External model column types should not be UNKNOWN, got: {column_types}"
+    )
+
+    # Test that when using a different case for the gateway parameter, we get the same results
+    context_mixed_case = Context(
+        paths=[tmp_path], gateway="uppercase_gateway"
+    )  # lowercase parameter
+
+    gateway_specific_models_mixed = [
+        model
+        for model in context_mixed_case.models.values()
+        if model.name == "test_db.uppercase_gateway_table"
+    ]
+    # This should work but might fail if case sensitivity is not handled correctly
+    assert len(gateway_specific_models_mixed) == 1, (
+        f"External model should be found regardless of gateway parameter case. Found {len(gateway_specific_models_mixed)} models"
+    )
+
+    # Test a case that should demonstrate the potential issue:
+    # Create another external model file with uppercase gateway name in the YAML
+    external_models_yaml_uppercase = tmp_path / "external_models_uppercase.yaml"
+    external_models_yaml_uppercase.write_text("""
+- name: test_db.uppercase_in_yaml
+  description: Test external model with uppercase gateway name in YAML
+  gateway: UPPERCASE_GATEWAY  # uppercase in external model yaml
+  columns:
+    id: int
+    status: text
+""")
+
+    # Add the new external models file to the project
+    models_dir = tmp_path / "external_models"
+    models_dir.mkdir(exist_ok=True)
+    (models_dir / "uppercase_gateway_models.yaml").write_text("""
+- name: test_db.uppercase_in_yaml
+  description: Test external model with uppercase gateway name in YAML
+  gateway: UPPERCASE_GATEWAY  # uppercase in external model yaml
+  columns:
+    id: int
+    status: text
+""")
+
+    # Reload context to pick up the new external models
+    context_reloaded = Context(paths=[tmp_path], gateway="UPPERCASE_GATEWAY")
+
+    uppercase_in_yaml_models = [
+        model
+        for model in context_reloaded.models.values()
+        if model.name == "test_db.uppercase_in_yaml"
+    ]
+    assert len(uppercase_in_yaml_models) == 1, (
+        f"External model with uppercase gateway in YAML should be found. Found {len(uppercase_in_yaml_models)} models"
+    )