EarthDataDownloader object to retain user login credentials

[PennyHow]

Description of the desired feature: Functionality added so that login credentials are retained by the EarthDataDownloader object after first inputted, and therefore the user does not have to keep re-defining them for each download.

In the tutorials, there is repeated EarthData login requests. For example, in the 3D_stack tutorial:

measures_shelves = fetch.measures_boundaries(version="IceShelf")

Also, there is nothing in your documentation on how to define credentials as environment variables (the icepack link in the API reference for EarthDataDownloader is broken).

[JessicaS11]

If you're not familiar with it, I strongly recommend earthaccess. It's a great way to manage Earthdata logins. The library I maintain, icepyx has it set up as an authentication MixIn class so the credentials are accessible from any module that needs them but only asks users for them once.

[mdtanker]

Thanks for the suggestions! I had a look, but I'm not sure if this will work here. polartoolkit uses pooch to download the datasets. For the NASA data, pooch requires the earthdata username and password to be entered into the download call. Looking through earthaccess, I couldn't see a way to return the username and password values to pass to pooch. Maybe I missed it, is there a way to do this?

For now, I've kept it as is, but added better documentation for how to set temporarily or permanent environment variables so users don't need to continuously supply the login credentials.

[PennyHow]

For now, I've kept it as is, but added better documentation for how to set temporarily or permanent environment variables so users don't need to continuously supply the login credentials.

I think as long as it is well documented then this is enough to resolve the issue

[mdtanker]

Ok that sounds good to me, I'll close this as I've added better documentation in #212 in this how-to guide.

[JessicaS11]

Looking through earthaccess, I couldn't see a way to return the username and password values to pass to pooch. Maybe I missed it, is there a way to do this?

It's not part of the user api (and probably not documented), but with an earthaccess Auth object (created with myauth = earthaccess.login()) you should be able to get them with myauth.auth_environ() (or possibly myauth.auth.auth_environ()).

As @PennyHow noted - not required for JOSS, but wanted to follow up and answer your question!

[mdtanker]

Ahh great! Thanks for finding that, this is working to access the credentials: earthaccess.auth_environ().

I'll add this into PolarToolkit to replace the custom class I had.