An error occurs with {"ok": false, "error": "invalid_auth"} when posting a text file from AWS Lambda to slack

Question

I would like to implement the function to post the string 'dialogs' as a text file to Slack Channels using AWS Lambda. The runtime is Python 3.8 and the code is below.

import os
import requests

def lambda_handler(event, context):

 SLACK_TOKEN = os.environ['SLACK_TOKEN']
 SLACK_CHANNEL = os.environ['SLACK_CHANNEL']

 data = {
         "token": SLACK_TOKEN,
         "channels": SLACK_CHANNEL,
         "title": "Dialog_Bot",
         "initial_comment": "New post"
         }

     f = open('/tmp/Slack.txt','w+b')
     f.write(dialogs.encode('utf-8'))
     f.seek(0)
     f.read()
     f.close()

 file_name = open('/tmp/Slack.txt', 'rb')
 files = {'file': ('/tmp/Slack.txt', file_name, 'text/plain')}

 response = requests.post(url="https://slack.com/api/files.upload", params=data, files=files)
 print(response.text)

However, when I looked at the value of response.text, the following error was displayed.

{
    "ok": false,
    "error": "invalid_auth"
}

I was wondering if the token value was wrong, but when I ran the curl command in my local environment with the same token value, the process was successful.

%curl --request POST \
     --form channels=XXXXXXXXXXXX（Same value as SLACK_CHANNEL） \
     --form token=xoxb-XXXXXXXXXXXX-XXXXXXXXXXXX-XXXXXXXXXXXXXXXXXXXXXXXX（Same value as SLACK_TOKEN） \
     --form file=@/./test.txt \
     --form title=test \
     --form initial_comment=test \
     https://slack.com/api/files.upload

{"ok":true,"file":{"id":……（Status information follows）

I also tried the chat.postMessage method with an environment variable of the same token and it succeeded.

data = {
        "token": SLACK_TOKEN,
        "channel": SLACK_CHANNEL,
        "title": "Dialog_Bot",
        "text": "New post"
        }
response = requests.post(url="https://slack.com/api/chat.postMessage", data=data)

{"ok":true,"channel":……（Status information follows）

I have the Slack app's IP address range set to default (nothing is set).

If you know the cause and solution, I would appreciate it if you could let me know.

user_14886053 · Answer

As a result, I was able to post using io streaming.

import os
import requests
import io

def lambda_handler (event, context):

SLACK_TOKEN = os.environ ['SLACK_TOKEN']
SLACK_CHANNEL = os.environ ['SLACK_CHANNEL']

Data = {
         "token": SLACK_TOKEN,
         "channels": SLACK_CHANNEL,
         "title": "Dialog_Bot",
         "initial_comment": "There was a post"
         }

    with io.StringIO () as txt_stream:
        txt_stream.write (dialogs)
        files = {'file': ('/tmp/ Slack.txt', txt_stream.getvalue ())}
    requests.post (url = "https://slack.com/api/files.upload", params = data, files = files)
    print (response.text)

As a test, I used slack's chat.postMessage method with the token name and channel name as they are, and I was able to post here as well, although it is in text format. I'm sorry I don't know the details, but it may be that there is a problem with the files.upload method when posting from Lambda as a .txt file (please let me know if you know the details ...).

An error occurs with {"ok": false, "error": "invalid_auth"} when posting a text file from AWS Lambda to slack

1 Answers