FunctionApp not importing python module

Question

I've spent days trying to deploy a function app using Terraform. It makes use of the requests python module.

I've narrowed the problem down to Azure not importing python modules in the requirements.txt. file.

To test, I created a simple httptrigger function app that simply returns a url parameter. My deployment script zips the directories and deploys the app using terraform. All is well and everything works as expected.

But, if change my python script ( __init__.py ) to import the python modules “urllib3” and/or “requests,” The function fails, even though the simple python script doesn't actually use any methods or classes from the modules. There are no errors when deploying the function. It fails when called from the url.

I verified that the modules are listed in the requirements.txt file.

And just to be sure, if I comment out the import requests and urllib3, everything works.

Any advice or suggestions would be greatly appreciated.

Simple test script ( __init__.py ):

import logging
import azure.functions as func
# function fails with the following line.  Works if commented out.
import urllib3



def main(req: func.HttpRequest) -> func.HttpResponse:
    logging.info('Python HTTP trigger function processed a request.')

    target = req.params.get('target')
    if target:
        return func.HttpResponse("Pretending to use " + target, status_code = 503)
    else:
        return func.HttpResponse("No Taget Specified", status_code = 400)

requirements.txt (Updated 7/15)

azure-functions==1.2.1
future==0.18.2
pefile==2019.4.18
PyInstaller==3.6
pylint==2.5.3
pywin32-ctypes==0.2.0
PyYAML==5.3.1
urllib3==1.25.9
requests==2.24.1

Update 7/16: Terraform file:

variable "prefix" {
    type = "string"
    default = "jis"
}

variable "location" {
    type = "string"
    default = "eastus"
}

variable "environment" {
    type = "string"
    default = "dev"
}

variable "functionapp" {
    type = "string"
    default = "./testit.zip"
}

resource "random_string" "storage_name" {
    length = 24
    upper = false
    lower = true
    number = true
    special = false
}

provider "azurerm" {
  version = "~>2.1.0"
  features {}
}

# Create Storage Account

resource "azurerm_resource_group" "rg" {
    name = "${var.prefix}-${var.environment}"
    location = "${var.location}"
}

resource "azurerm_storage_account" "storage" {
    name = "${random_string.storage_name.result}"
    resource_group_name = "${azurerm_resource_group.rg.name}"
    location = "${var.location}"
    account_tier = "Standard"
    account_replication_type = "LRS"
}

resource "azurerm_storage_container" "deployments" {
    name = "function-releases"
    storage_account_name = "${azurerm_storage_account.storage.name}"
    container_access_type = "private"
}

# upload zip file

resource "azurerm_storage_blob" "appcode" {
    name = "functionapp.zip"
    storage_account_name = "${azurerm_storage_account.storage.name}"
    storage_container_name = "${azurerm_storage_container.deployments.name}"
    type = "Block"
    source = "${var.functionapp}"
}

# Create function app

data "azurerm_storage_account_sas" "sas" {
    connection_string = "${azurerm_storage_account.storage.primary_connection_string}"
    https_only = true
    start = "2020-07-10"
    expiry = "2023-12-31"
    resource_types {
        object = true
        container = false
        service = false
    }
    services {
        blob = true
        queue = false
        table = false
        file = false
    }
    permissions {
        read = true
        write = false
        delete = false
        list = false
        add = false
        create = false
        update = false
        process = false
    }
}

resource "azurerm_app_service_plan" "asp" {
    name = "${var.prefix}-plan"
    resource_group_name = "${azurerm_resource_group.rg.name}"
    location = "${var.location}"
    kind = "Linux"
    reserved = true
    sku {
        tier = "Dynamic"
        size = "Y1"
    }
}

resource "azurerm_function_app" "functions" {
    name = "${var.prefix}-${var.environment}"
    location = "${var.location}"
    resource_group_name = "${azurerm_resource_group.rg.name}"
    app_service_plan_id = "${azurerm_app_service_plan.asp.id}"
    storage_connection_string = "${azurerm_storage_account.storage.primary_connection_string}"
    version = "~2"

    app_settings = {
        https_only = true
        FUNCTIONS_WORKER_RUNTIME = "python"
        WEBSITE_NODE_DEFAULT_VERSION = "~10"
        FUNCTION_APP_EDIT_MODE = "readonly"
        HASH = "${base64encode(filesha256("${var.functionapp}"))}"
        WEBSITE_RUN_FROM_PACKAGE = "https://${azurerm_storage_account.storage.name}.blob.core.windows.net/${azurerm_storage_container.deployments.name}/${azurerm_storage_blob.appcode.name}${data.azurerm_storage_account_sas.sas.sas}"
    }
}

# 

Answer 1

It may be a version compatibility problem.

The versions of urllib3 and requests that you are using are from June 2018, the others (did not check all) appear to be latest versions.

Any reason why you need to use the older versions?

Answer 2

After some struggling, I figured out the problem. Thanks to @HuryShen and @AnkitKumar for pointing me in the right direction.

I did not include the modules urllib3 and requests in the function zip file. They need to be installed to the <funcname>.python_packages/lib/site-packages directory . The easiest way to do that (from the requirements.txt file) is

pip install  --target="azure/.python_packages/lib/site-packages"  -r requirements.txt

Once the modules are downloaded, they can be included in the zip file. After that, the terraform script works fine.