Enable append_env in operator_args by default (astronomer#899)

The default behaviour when parsing Cosmos DAGs is to use the system
environment variables, but to execute dbt commands from Airflow
operators is not. This PR solves this, making the behaviour consistent
in DAG parsing and dbt command execution.

Closes: astronomer#595

cosmos/operators/base.py

@@ -43,10 +43,11 @@ class AbstractDbtBaseOperator(BaseOperator, metaclass=ABCMeta):
         environment variables for the new process; these are used instead
         of inheriting the current process environment, which is the default
         behavior. (templated)
-    :param append_env: If False(default) uses the environment variables passed in env params
-        and does not inherit the current process environment. If True, inherits the environment variables
+    :param append_env: . If True (default), inherits the environment variables
         from current passes and then environment variable passed by the user will either update the existing
-        inherited environment variables or the new variables gets appended to it
+        inherited environment variables or the new variables gets appended to it.
+        If False, only uses the environment variables passed in env params
+        and does not inherit the current process environment.
     :param output_encoding: Output encoding of bash command
     :param skip_exit_code: If task exits with this exit code, leave the task
         in ``skipped`` state (default: 99). If set to ``None``, any non-zero
@@ -99,7 +100,7 @@ def __init__(
         db_name: str | None = None,
         schema: str | None = None,
         env: dict[str, Any] | None = None,
-        append_env: bool = False,
+        append_env: bool = True,
         output_encoding: str = "utf-8",
         skip_exit_code: int = 99,
         partial_parse: bool = True,

tests/operators/test_azure_container_instance.py

@@ -53,6 +53,7 @@ def test_dbt_azure_container_instance_operator_get_env(p_context_to_airflow_vars
         name="my-aci",
         resource_group="my-rg",
         project_dir="my/dir",
+        append_env=False,
     )
     dbt_base_operator.env = {
         "start_date": "20220101",
@@ -90,6 +91,7 @@ def test_dbt_azure_container_instance_operator_check_environment_variables(
         resource_group="my-rg",
         project_dir="my/dir",
         environment_variables={"FOO": "BAR"},
+        append_env=False,
     )
     dbt_base_operator.env = {
         "start_date": "20220101",

tests/operators/test_docker.py

@@ -73,10 +73,7 @@ def test_dbt_docker_operator_get_env(p_context_to_airflow_vars: MagicMock, base_
     If an end user passes in a
     """
     dbt_base_operator = base_operator(
-        conn_id="my_airflow_connection",
-        task_id="my-task",
-        image="my_image",
-        project_dir="my/dir",
+        conn_id="my_airflow_connection", task_id="my-task", image="my_image", project_dir="my/dir", append_env=False
     )
     dbt_base_operator.env = {
         "start_date": "20220101",

tests/operators/test_kubernetes.py

@@ -81,10 +81,7 @@ def test_dbt_kubernetes_operator_get_env(p_context_to_airflow_vars: MagicMock, b
     If an end user passes in a
     """
     dbt_kube_operator = base_operator(
-        conn_id="my_airflow_connection",
-        task_id="my-task",
-        image="my_image",
-        project_dir="my/dir",
+        conn_id="my_airflow_connection", task_id="my-task", image="my_image", project_dir="my/dir", append_env=False
     )
     dbt_kube_operator.env = {
         "start_date": "20220101",
@@ -254,7 +251,7 @@ def cleanup(pod: str, remote_pod: str):
 
 
 def test_created_pod():
-    ls_kwargs = {"env_vars": {"FOO": "BAR"}, "namespace": "foo"}
+    ls_kwargs = {"env_vars": {"FOO": "BAR"}, "namespace": "foo", "append_env": False}
     ls_kwargs.update(base_kwargs)
     ls_operator = DbtLSKubernetesOperator(**ls_kwargs)
     ls_operator.hook = MagicMock()

tests/operators/test_local.py

@@ -329,9 +329,7 @@ def test_dbt_base_operator_get_env(p_context_to_airflow_vars: MagicMock) -> None
     If an end user passes in a
     """
     dbt_base_operator = ConcreteDbtLocalBaseOperator(
-        profile_config=profile_config,
-        task_id="my-task",
-        project_dir="my/dir",
+        profile_config=profile_config, task_id="my-task", project_dir="my/dir", append_env=False
     )
     dbt_base_operator.env = {
         "start_date": "20220101",