There OAuth to be a better way (Power BI)

There OAuth to be a better way (Power BI)

Edit: The base URL has changed from https://api.powerbi.com/beta/myorg to https://api.powerbi.com/v1.0/myorg

OAuth is clearly becoming the de-facto standard for authenticating API calls around the web. In the business intelligence arena, while we can discuss its pros and cons, we undoubtedly must get acquainted with it because sooner or later we’ll be tasked with importing data from one of the many “OAuth protected” web services.

In this third release of the OAuth series I’ll show how to get an Access Token from Microsoft Power BI. The same procedure can be used for many other Azure services (by changing the appropriate scope in the resource parameter).

Our typical scenario would be an unattended server process downloading data; I’m using a headless Linux box with cURL and jq.

You can see here and here my previous posts about how to use cURL to authenticate with flickr or BigQuery and make API calls with an Access Token.

The way Azure works is a little different. You get an Access Token valid for 1 hour and a Refresh Token. You can reuse the Access Token for as many calls as you want during the hour, and then you’ll need to ask for a new Access Token presenting the Refresh Token.

Prerequisites:

  • An Azure subscription with a real work domain (no personal account)

loginazure

  • An Azure Active Directory so you can add users to @yourdomain

azuread

  • A Power BI subscription with a user belonging to your Azure Active Directory

azure users

Once you have the requisites in place, follow this article to create an app and get a Client ID.

clientid

With the username, password and the Client ID you can use this script to get an Access Token:

[code language=”bash” gutter=”true” light=”false”]
#!/bin/bash

OAUTH_CLIENT_ID="yourClientId"
OAUTH_USERNAME="youruser@yourdomain.com"
OAUTH_PASSWORD="yourpassword"

POST_RESULT="$(curl -s -X POST -d "resource=https://analysis.windows.net/powerbi/api&client_id="$OAUTH_CLIENT_ID"&grant_type=password&username="$OAUTH_USERNAME"&password="$OAUTH_PASSWORD"&scope=openid" "https://login.windows.net/common/oauth2/token" | jq -r .)"

REFRESH_TOKEN="$(echo ${POST_RESULT} | /usr/local/bin/jq -r .refresh_token)"
ACCESS_TOKEN="$(echo ${POST_RESULT} | /usr/local/bin/jq -r .access_token)"
AUTH_HEADER="Authorization: Bearer ${ACCESS_TOKEN}"
echo "${AUTH_HEADER}"

echo "${AUTH_HEADER}" > ./auth_header.txt
echo "${REFRESH_TOKEN}" > ./refresh_token.txt

[/code]

This script will save two files: one is the Authorization Header and the other is the Refresh Token. You will use the Authorization Header passing it to every API call that you make (during 1 hour), for example to get a list of the available datasets in your Power BI storage use:

[code language=”bash” gutter=”true” light=”false”]
#!/bin/bash

AUTH_HEADER=$(<./auth_header.txt)
curl -k -s "https://api.powerbi.com/beta/myorg/datasets" -H "$AUTH_HEADER" | /usr/local/bin/jq -r .

[/code]

After an hour or so, you will ask for a new Access Token and store the new Authorization Header (can also be crontabbed every nn minutes):

[code language=”bash” gutter=”true” light=”false”]
#!/bin/bash

REFRESH_TOKEN=$(<./refresh_token.txt)
OAUTH_CLIENT_ID="yourClientId"
OAUTH_USERNAME="youruser@yourdomain.com"
OAUTH_PASSWORD="yourpassword"

POST_RESULT="$(curl -k -s -X POST -d "resource=https://analysis.windows.net/powerbi/api&client_id="$OAUTH_CLIENT_ID"&grant_type=refresh_token&username="$OAUTH_USERNAME"&password="$OAUTH_PASSWORD"&scope=openid&refresh_token=${REFRESH_TOKEN}" "https://login.windows.net/common/oauth2/token" | jq -r .)"

REFRESH_TOKEN="$(echo ${POST_RESULT} | /usr/local/bin/jq -r .refresh_token)"
ACCESS_TOKEN="$(echo ${POST_RESULT} | /usr/local/bin/jq -r .access_token)"

AUTH_HEADER="Authorization: Bearer ${ACCESS_TOKEN}"

echo "${AUTH_HEADER}"
echo "${AUTH_HEADER}" > ./auth_header.txt
echo "${REFRESH_TOKEN}" > ./refresh_token.txt

[/code]

So, no browser, no GUI, no problem!

    • Junior
    • June 27, 2016
    Reply

    I’ve applied the Power BI Rest API within SharePoint. Is there a way to pass the SharePoint signed in profile information to generate the authentication token? Specifically, I don’t know how to get at the password information. Or should I go about this a different way?

    • Reply

      Very good question and difficult to answer. I don’t know SP that much but I remember in the SDK there are several calls to get the current user (client side or server side). Not sure if you can do that sincerely: looks to me a serious security threat.

  1. Pingback: Use a Power BI Tile in your web page | Davide Moraschi – Business Intelligence Project Manager, Big Data Architect

  2. Reply

    Reblogged this on Dinesh Ram Kali..

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4 thoughts on “There OAuth to be a better way (Power BI)

  1. I’ve applied the Power BI Rest API within SharePoint. Is there a way to pass the SharePoint signed in profile information to generate the authentication token? Specifically, I don’t know how to get at the password information. Or should I go about this a different way?

    1. Very good question and difficult to answer. I don’t know SP that much but I remember in the SDK there are several calls to get the current user (client side or server side). Not sure if you can do that sincerely: looks to me a serious security threat.

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