Make Awaiting Workflow Run A User Responsibility

Moves the responsibility of re-requesting a workflow run from the API to
the user. This makes the requests much shorter-lived, and allows the
client to control how they want to handle sleeping and retrying.

This also has the benefit of removing the only real piece of async code,
so now the view is completely sync once again.

Signed-off-by: Hassan Abouelela <[email protected]>

Author: HassanAbouelela

pydis_site/apps/api/github_utils.py

@@ -1,17 +1,17 @@
 """Utilities for working with the GitHub API."""
 
-import asyncio
 import datetime
 import math
 
 import httpx
 import jwt
-from asgiref.sync import async_to_sync
 
 from pydis_site import settings
 
-MAX_POLLS = 20
-"""The maximum number of attempts at fetching a workflow run."""
+MAX_RUN_TIME = datetime.timedelta(minutes=3)
+"""The maximum time allowed before an action is declared timed out."""
+ISO_FORMAT_STRING = "%Y-%m-%dT%H:%M:%SZ"
+"""The datetime string format GitHub uses."""
 
 
 class ArtifactProcessingError(Exception):
@@ -44,6 +44,12 @@ class RunTimeoutError(ArtifactProcessingError):
     status = 408
 
 
+class RunPendingError(ArtifactProcessingError):
+    """The requested workflow run is still pending, try again later."""
+
+    status = 202
+
+
 def generate_token() -> str:
     """
     Generate a JWT token to access the GitHub API.
@@ -66,7 +72,7 @@ def generate_token() -> str:
     )
 
 
-async def authorize(owner: str, repo: str) -> httpx.AsyncClient:
+def authorize(owner: str, repo: str) -> httpx.Client:
     """
     Get an access token for the requested repository.
 
@@ -75,15 +81,15 @@ async def authorize(owner: str, repo: str) -> httpx.AsyncClient:
         - POST <app_access_token> to get a token to access the given app
         - GET installation/repositories and check if the requested one is part of those
     """
-    client = httpx.AsyncClient(
+    client = httpx.Client(
         base_url=settings.GITHUB_API,
         headers={"Authorization": f"bearer {generate_token()}"},
         timeout=settings.TIMEOUT_PERIOD,
     )
 
     try:
         # Get a list of app installations we have access to
-        apps = await client.get("app/installations")
+        apps = client.get("app/installations")
         apps.raise_for_status()
 
         for app in apps.json():
@@ -92,11 +98,11 @@ async def authorize(owner: str, repo: str) -> httpx.AsyncClient:
                 continue
 
             # Get the repositories of the specified owner
-            app_token = await client.post(app["access_tokens_url"])
+            app_token = client.post(app["access_tokens_url"])
             app_token.raise_for_status()
             client.headers["Authorization"] = f"bearer {app_token.json()['token']}"
 
-            repos = await client.get("installation/repositories")
+            repos = client.get("installation/repositories")
             repos.raise_for_status()
 
             # Search for the request repository
@@ -111,44 +117,39 @@ async def authorize(owner: str, repo: str) -> httpx.AsyncClient:
 
     except BaseException as e:
         # Close the client if we encountered an unexpected exception
-        await client.aclose()
+        client.close()
         raise e
 
 
-async def wait_for_run(client: httpx.AsyncClient, run: dict) -> str:
-    """Wait for the provided `run` to finish, and return the URL to its artifacts."""
-    polls = 0
-    while polls <= MAX_POLLS:
-        if run["status"] != "completed":
-            # The action is still processing, wait a bit longer
-            polls += 1
-            await asyncio.sleep(10)
-
-        elif run["conclusion"] != "success":
-            # The action failed, or did not run
-            raise ActionFailedError(f"The requested workflow ended with: {run['conclusion']}")
+def check_run_status(run: dict) -> str:
+    """Check if the provided run has been completed, otherwise raise an exception."""
+    created_at = datetime.datetime.strptime(run["created_at"], ISO_FORMAT_STRING)
+    run_time = datetime.datetime.now() - created_at
 
+    if run["status"] != "completed":
+        if run_time <= MAX_RUN_TIME:
+            raise RunPendingError(
+                f"The requested run is still pending. It was created "
+                f"{run_time.seconds // 60}:{run_time.seconds % 60 :>02} minutes ago."
+            )
         else:
-            # The desired action was found, and it ended successfully
-            return run["artifacts_url"]
+            raise RunTimeoutError("The requested workflow was not ready in time.")
 
-        run = await client.get(run["url"])
-        run.raise_for_status()
-        run = run.json()
+    if run["conclusion"] != "success":
+        # The action failed, or did not run
+        raise ActionFailedError(f"The requested workflow ended with: {run['conclusion']}")
 
-    raise RunTimeoutError("The requested workflow was not ready in time.")
+    # The requested action is ready
+    return run["artifacts_url"]
 
 
-@async_to_sync
-async def get_artifact(
-    owner: str, repo: str, sha: str, action_name: str, artifact_name: str
-) -> str:
+def get_artifact(owner: str, repo: str, sha: str, action_name: str, artifact_name: str) -> str:
     """Get a download URL for a build artifact."""
-    client = await authorize(owner, repo)
+    client = authorize(owner, repo)
 
     try:
         # Get the workflow runs for this repository
-        runs = await client.get(f"/repos/{owner}/{repo}/actions/runs", params={"per_page": 100})
+        runs = client.get(f"/repos/{owner}/{repo}/actions/runs", params={"per_page": 100})
         runs.raise_for_status()
         runs = runs.json()
 
@@ -161,16 +162,16 @@ async def get_artifact(
                 "Could not find a run matching the provided settings in the previous hundred runs."
             )
 
-        # Wait for the workflow to finish
-        url = await wait_for_run(client, run)
+        # Check the workflow status
+        url = check_run_status(run)
 
         # Filter the artifacts, and return the download URL
-        artifacts = await client.get(url)
+        artifacts = client.get(url)
         artifacts.raise_for_status()
 
         for artifact in artifacts.json()["artifacts"]:
             if artifact["name"] == artifact_name:
-                data = await client.get(artifact["archive_download_url"])
+                data = client.get(artifact["archive_download_url"])
                 if data.status_code == 302:
                     return str(data.next_request.url)
 
@@ -180,4 +181,4 @@ async def get_artifact(
         raise NotFoundError("Could not find an artifact matching the provided name.")
 
     finally:
-        await client.aclose()
+        client.close()