Creating an upload service using FastAPI - cern automation

Setup VM prereqs

Ubuntu 2204 VM starting point

sudo apt update
sudo apt install python3-pip
sudo apt install python3-venv

python3 -m venv fastapi-venv
source fastapi-venv/bin/activate

pip install fastapi uvicorn python-multipart pyyaml

Create the uploader app.py

ubuntu@fastapi-test-cern:~$ cat app.py
import time
import uvicorn
from fastapi import FastAPI,File,UploadFile

app = FastAPI()

@app.get("/")
def read_root():
    return {"Hello": "Whats up?"}

@app.post("/upload")
def upload_file(file: UploadFile = File(...)):
    try:
        contents = file.file.read()
        with open(file.filename, 'wb') as f:
            f.write(contents)
    except Exception:
        return {"message": "There was an error uploading the file"}
    finally:
        file.file.close()

    return {"content": f"Uploaded {file.filename}"}

if __name__ == '__main__':
    uvicorn.run(app,host="0.0.0.0",port=6443)

Run the app.py

ubuntu@fastapi-test-cern:~$ source fastapi-venv/bin/activate
(fastapi-venv) ubuntu@fastapi-test-cern:~$ uvicorn app:app --reload

for this app we are using 0.0.0.0:6443 lets sort that now

ubuntu@fastapi-test-cern:~$ screen
ubuntu@fastapi-test-cern:~$ source fastapi-venv/bin/activate
(fastapi-venv) ubuntu@fastapi-test-cern:~$ uvicorn app:app --reload --host 0.0.0.0 --port 6443

Curl command to upload a file

curl -X 'POST' \
  'http://185.93.31.137:6443/upload' \
  -H 'accept: application/json' \
  -H 'Content-Type: multipart/form-data' \
  -F 'file=@2_nodes-64-procs.pdf;type=application/pdf'