python – how to pass slack token to python app from dockerfile

I have my python app, in which i am passing my slack tokens via json file.

so my config.json is :

{
  "slack_bot_token":"xoxb-12345789",
  "slack_signing_secret":"AAA23245GJ"
}

So my slackeventsapp.py is :

 from slackeventsapi import SlackEventAdapter
    from slackclient import SlackClient
    import json

    tokens = {}
    with open('config.json') as json_data:
        tokens = json.load(json_data)

    EVENT_ADAPTER = SlackEventAdapter(tokens.get("slack_signing_secret"), "/slack/events")
    SLACK_CLIENT = SlackClient(tokens.get("slack_bot_token"))

    def PostMsg(channel, text):
        SLACK_CLIENT.api_call("chat.postMessage", channel=channel, text=text)

so I need to pass the two values slack_signing_secret and slack_bot_token via dockerfile. Please help how cna we pass this.

Source: StackOverflow