Only enable requester pays when necessary #400

Only enable (Google) requester pays data access when the
given DRS URIs require it and the platform TNU is running
on supports it.

terra_notebook_utils/drs.py

@@ -9,8 +9,8 @@
 
 from terra_notebook_utils import WORKSPACE_BUCKET, WORKSPACE_NAME, DRS_RESOLVER_URL, WORKSPACE_NAMESPACE, \
     WORKSPACE_GOOGLE_PROJECT
-from terra_notebook_utils import workspace, gs, tar_gz, TERRA_DEPLOYMENT_ENV, _GS_SCHEMA
-from terra_notebook_utils.utils import is_notebook
+from terra_notebook_utils import workspace, gs, tar_gz, TERRA_DEPLOYMENT_ENV, _GS_SCHEMA, ExecutionPlatform
+from terra_notebook_utils.utils import is_notebook, get_execution_context
 from terra_notebook_utils.http_utils import http
 from terra_notebook_utils.blobstore.gs import GSBlob
 from terra_notebook_utils.blobstore.local import LocalBlob
@@ -26,16 +26,46 @@
 class DRSResolutionError(Exception):
     pass
 
+class RequesterPaysNotSupported(Exception):
+    pass
+
 def _parse_gs_url(gs_url: str) -> Tuple[str, str]:
     if gs_url.startswith(_GS_SCHEMA):
         bucket_name, object_key = gs_url[len(_GS_SCHEMA):].split("/", 1)
         return bucket_name, object_key
     else:
         raise RuntimeError(f'Invalid gs url schema.  {gs_url} does not start with {_GS_SCHEMA}')
 
+
+def is_requester_pays(drs_urls: Iterable[str]) -> bool:
+    """
+    Identify if any of the given DRS URIs require Google requester pays access
+
+    :raises: RequesterPaysNotSupported
+    """
+    for drs_url in drs_urls:
+        # Currently (1/2023), Gen3-hosted AnVIL data in GCS is the only
+        # DRS data requiring requester pays access.
+        # Even this will end in when the AnVIL data is hosted in TDR.
+        # Note: If the Gen3 AnVIL DRS URI format is retained by TDR, this function must be updated.
+        ANVIL_DRS_URI_PREFIX = "drs://dg.ANV0"
+        if drs_url.strip().startswith(ANVIL_DRS_URI_PREFIX):
+            if get_execution_context().execution_platform == ExecutionPlatform.AZURE:
+                raise RequesterPaysNotSupported(
+                    f"Requester pays data access is not supported on the Azure platform. Cannot access: {drs_url}"
+                )
+            else:
+                return True
+    return False
+
+
 @lru_cache()
 def enable_requester_pays(workspace_name: Optional[str]=WORKSPACE_NAME,
                           workspace_namespace: Optional[str]=WORKSPACE_NAMESPACE):
+
+    assert get_execution_context().execution_platform != ExecutionPlatform.AZURE, \
+        "Requester pays data access is not supported on the Terra Azure platform."
+
     if not workspace_name:
         raise RuntimeError('Workspace name is not set.  Please set the environment variable '
                            'WORKSPACE_NAME with the name of a valid Terra Workspace.')
@@ -92,11 +122,14 @@ def access(drs_url: str,
            workspace_namespace: Optional[str]=WORKSPACE_NAMESPACE,
            billing_project: Optional[str]=WORKSPACE_GOOGLE_PROJECT) -> str:
     """Return a signed url for a drs:// URI, if available."""
-    # We enable requester pays by specifying the workspace/namespace combo, not
-    # with the billing project. Rawls then enables requester pays for the attached
-    # project, but this won't work if a user specifies a project unattached to
-    # the Terra workspace.
-    enable_requester_pays(workspace_name, workspace_namespace)
+
+    if is_requester_pays([drs_url]):
+        # We enable requester pays by specifying the workspace/namespace combo, not
+        # with the billing project. Rawls then enables requester pays for the attached
+        # project, but this won't work if a user specifies a project unattached to
+        # the Terra workspace.
+        enable_requester_pays(workspace_name, workspace_namespace)
+
     info = get_drs_info(drs_url, access_url=True)
 
     if info.access_url:
@@ -232,7 +265,9 @@ def head(drs_url: str,
          workspace_namespace: Optional[str]=WORKSPACE_NAMESPACE,
          billing_project: Optional[str]=WORKSPACE_GOOGLE_PROJECT):
     """Head a DRS object by byte."""
-    enable_requester_pays(workspace_name, workspace_namespace)
+
+    if is_requester_pays(drs_url):
+        enable_requester_pays(workspace_name, workspace_namespace)
     try:
         blob = get_drs_blob(drs_url, billing_project)
         with blob.open(chunk_size=num_bytes) as fh:
@@ -295,7 +330,8 @@ def copy(drs_uri: str,
     """Copy a DRS object to either the local filesystem, or to a Google Storage location if `dst` starts with
     "gs://".
     """
-    enable_requester_pays(workspace_name, workspace_namespace)
+    if is_requester_pays([drs_uri]):
+        enable_requester_pays(workspace_name, workspace_namespace)
     with DRSCopyClient(raise_on_error=True, indicator_type=indicator_type) as cc:
         cc.workspace = workspace_name
         cc.workspace_namespace = workspace_namespace
@@ -340,7 +376,8 @@ def copy_batch_urls(drs_urls: Iterable[str],
                     indicator_type: Indicator = Indicator.notebook_bar if is_notebook() else Indicator.log,
                     workspace_name: Optional[str] = WORKSPACE_NAME,
                     workspace_namespace: Optional[str] = WORKSPACE_NAMESPACE):
-    enable_requester_pays(workspace_name, workspace_namespace)
+    if is_requester_pays(drs_urls):
+        enable_requester_pays(workspace_name, workspace_namespace)
     with DRSCopyClient(indicator_type=indicator_type) as cc:
         cc.workspace = workspace_name
         cc.workspace_namespace = workspace_namespace
@@ -365,7 +402,11 @@ def copy_batch_manifest(manifest: List[Dict[str, str]],
                         workspace_namespace: Optional[str]=WORKSPACE_NAMESPACE):
     from jsonschema import validate
     validate(instance=manifest, schema=manifest_schema)
-    enable_requester_pays(workspace_name, workspace_namespace)
+
+    drs_uri_list = [item['drs_uri'] for item in manifest]
+    if is_requester_pays(drs_uri_list):
+        enable_requester_pays(workspace_name, workspace_namespace)
+
     with DRSCopyClient(indicator_type=indicator_type) as cc:
         cc.workspace = workspace_name
         cc.workspace_namespace = workspace_namespace
@@ -381,7 +422,9 @@ def extract_tar_gz(drs_url: str,
     Default extraction is to the bucket for 'workspace'.
     """
     dst = dst or f"gs://{workspace.get_workspace_bucket(workspace_name)}"
-    enable_requester_pays(workspace_name, workspace_namespace)
+
+    if is_requester_pays(drs_url):
+        enable_requester_pays(workspace_name, workspace_namespace)
     blob = get_drs_blob(drs_url, billing_project)
     with blob.open() as fh:
         tar_gz.extract(fh, dst)