Initial commit

docker/Dockerfile

@@ -0,0 +1,11 @@
+FROM python:3.9.2-alpine
+
+WORKDIR /usr/src/app
+
+COPY src .
+
+RUN pip install --no-cache-dir -r requirements.txt
+
+CMD [ "uvicorn", "--host", "0.0.0.0", "rest_queue:app" ]
+
+

rest_queue/src/requirements.txt

@@ -0,0 +1,2 @@
+uvicorn
+fastapi

rest_queue/src/rest_queue.py

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+#
+# simple_rest_queue.py
+#
+# A simple FastAPI web service that maintains multiple named FIFO queues
+# that can be created, pushed, and popped using REST calls
+#
+from collections import deque
+from typing import Dict
+
+import fastapi
+
+# registry for REST-accessible queues
+queues: Dict[str, deque] = {}
+
+
+app = fastapi.FastAPI()
+
+
+@app.post("/queues/{queue_name}", status_code=fastapi.status.HTTP_201_CREATED)
+async def queue_new(queue_name: str):
+    """
+    Create new queue with given queue name.
+
+    Raises an exception if the queue already exists.
+    """
+    if queue_name in queues:
+        raise fastapi.HTTPException(status_code=fastapi.status.HTTP_409_CONFLICT,
+                                    detail=f"Queue {queue_name!r} already exists")
+
+    # create new deque and add to registry under the given name
+    queues[queue_name] = deque()
+
+    return {"message": f"created {queue_name!r}"}
+
+
+@app.get("/queues/{queue_name}", status_code=fastapi.status.HTTP_200_OK)
+async def queue_pop(queue_name: str):
+    """
+    Pop oldest value from queue, or None if queue is empty.
+    """
+    if queue_name not in queues:
+        raise fastapi.HTTPException(status_code=fastapi.status.HTTP_404_NOT_FOUND,
+                                    detail=f"No such queue {queue_name!r}")
+
+    q = queues[queue_name]
+    if q:
+        value = q.popleft()
+    else:
+        value = None
+
+    return {"message": f"get from queue {queue_name!r}",
+            "data": value,
+            "remaining_queue_size": len(q),
+            }
+
+
+@app.put("/queues/{queue_name}", status_code=fastapi.status.HTTP_200_OK)
+async def queue_push(queue_name: str, value: str):
+    """
+    Push new value onto queue.
+    """
+    if queue_name not in queues:
+        raise fastapi.HTTPException(status_code=fastapi.status.HTTP_404_NOT_FOUND,
+                                    detail=f"No such queue {queue_name!r}")
+
+    q = queues[queue_name]
+    q.append(value)
+
+    return {
+        "message": f"put to queue {queue_name!r}",
+        "remaining_queue_size": len(q),
+    }
+
+
+@app.delete("/queues/{queue_name}", status_code=fastapi.status.HTTP_200_OK)
+async def queue_delete(queue_name: str,
+                       safe_delete: bool = True):
+    """
+    Delete queue.
+    """
+    if queue_name not in queues:
+        raise fastapi.HTTPException(status_code=fastapi.status.HTTP_404_NOT_FOUND,
+                                    detail=f"No such queue {queue_name!r}")
+
+    q = queues[queue_name]
+
+    if safe_delete and q:
+        raise fastapi.HTTPException(status_code=fastapi.status.HTTP_409_CONFLICT,
+                                    detail=f"Queue {queue_name!r} not empty (contains {len(q)} items)")
+
+    # remove queue from registry
+    del queues[queue_name]
+
+    return {
+        "message": f"deleted queue {queue_name!r}",
+        "remaining_queue_size": len(q),
+    }
+
+
+@app.get("/queues/{queue_name}/list", status_code=fastapi.status.HTTP_200_OK)
+async def queue_list(queue_name: str):
+    """
+    List out contents of queue.
+    """
+    if queue_name not in queues:
+        raise fastapi.HTTPException(status_code=fastapi.status.HTTP_404_NOT_FOUND,
+                                    detail=f"No such queue {queue_name!r}")
+
+    q = queues[queue_name]
+
+    return {
+        "message": f"items in queue {queue_name!r}",
+        "items": list(q),
+    }
+
+
+@app.get("/queues", status_code=fastapi.status.HTTP_200_OK)
+async def queue_list_all():
+    """
+    List out all queue names.
+    """
+    return {
+        "message": f"list of queue names",
+        "items": list(queues),
+    }