Pass variable via curl to Flask endpoint

Question

Using this:

query_string = "This is some string"
subprocess.call('curl -X POST -d "{\\"query\\":\\"${query_string}\\"}" 0.0.0.0:5000/query --header "Content-Type:application/json"', shell=True)

and having this endpoint in my Flask app:

@app.route('/query', methods=['GET', 'POST'])

def new_user():
   user_data = request.get_json()  
   print(user_data)

return jsonify(user_data)

when I run the curl command as defined above, the response I get from Flask server is:

"POST /query HTTP/1.1" 200 - {'query': ''}

How can I pass the actual content of the parameter : query_string to the Flask endpoint?

LinPy · Accepted Answer · 2019-11-07T10:10:42.353

1

you need to pass it like so:

subprocess.call('curl -X POST -d "query=%s" 0.0.0.0:5000/query --header "Content-Type:application/json"'% query_string, shell=True)

edited Nov 07 '19 at 10:10

answered Nov 07 '19 at 09:48

LinPy

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Hi, if i run this suggestion i am getting: "Argument list too long" error. – K. Psychogyiopoulos Nov 07 '19 at 10:01
what is in query_string exactly ? see this https://stackoverflow.com/questions/54090784/curl-argument-list-too-long – LinPy Nov 07 '19 at 10:02
The problem is that i cannot somehow make curl read the query_string as a variable and pass its content to the endpoint. I have also tried : var = 'this is a string to pass' ; subprocess.call('curl http://localhost:5000/\?name\=\"{$var}"', shell=True) – K. Psychogyiopoulos Nov 07 '19 at 10:05
query_string contains a string – K. Psychogyiopoulos Nov 07 '19 at 10:07
This error, comes up because the string i try to pass is too long. But it is working for a short string. Thank you for your help, i will upvote your answer as soon as i get reputation! – K. Psychogyiopoulos Nov 07 '19 at 10:25

Pass variable via curl to Flask endpoint

1 Answers1