I'm happy to help! @rabernat, Makhan @virdi from NASA Langley just reminded me the other day that there is a forum for NASA Earthdata users with a direct line to the program managers and scientists that may be the best place to ask data related questions. I think you only need to register with EDL.

https://forum.earthdata.nasa.gov/

Quick update, MERRA2 worked as expected after accepting the EULA again. GPM_L3 redirects to an empty .dods file, I guess that's a bug. I'll ask the OpenDAP team tomorrow if they are aware of this behavior and what would be a workaround/solution.

I just asked on Slack about how to check for these changes (if at the end this issue is indeed related to an updated EULA) and unfortunately there is no way around it other than doing what Jan did(and still got the 302s). About feedback, yes there are channels but they are on a per-DAAC basis (cries). In this case that would be going to https://daac.gsfc.nasa.gov/ and clicking on the feedback button. I'll keep looking at this after the cloud hackathon today.

Yeah, definitely not ideal. I'm going to test it again this evening with a new Earthdata user. I'll send you a binder link to a notebook to test it with both accounts.

Looks like the dataset got updated and when that happens NASA requires users to accept the end user license agreement (again). That's why the request ends up in a redirect. This EULA is also required the first time a user requests the data. Here are the instructions for accepting GESDISC EULA. https://disc.gsfc.nasa.gov/earthdata-login

After the GESDIC data archive app shows up in our authorized apps list the code above works like a charm. I'll ask to see if there is a way to automate this @rabernat @zjans

@betolink Thanks for looking into this. GESDISC was already in my lists of accepted EULAS & authorized Apps. I also deleted them and re-authorized, but no change. I still get the "302 The document has moved" message when trying to access the HDF-datasets under https://gpm1.gesdisc.eosdis.nasa.gov/opendap/hyrax/GPM_L3/... with xr.backends.PydapDataStore and ds.open_dataset()

In the meantime, I changed my scripts to download the entire HDF files from https://gpm1.gesdisc.eosdis.nasa.gov/data/GPM_L3/... and open them locally with xarray (and do spatial subsetting etc) - which works fine but is not quite ideal.

This looks familiar. I'm going to take a look at this when I get home and will report back. @rabernat

@AyrtonB I'm getting the same error now, did you manage to solve it?

@wallissoncarvalho Were you ever able to make that example work? I have been getting this error using the same example as well and haven't been able to find a solution

Dear all, anyone knows if it is possible in xarray.open_dataset (pydap or netcdf engines) to pass Authorization or Cookie header along with opendap request? For example: Authorization: Bearer u32t4o3tb3gg43 or Cookie: foo=u32t4o3tb3gg43

No, actually the problem was with my authorization. I had to accept a EULA before my password was valid. Once I did that, everything worked.

I'm trying this example:

python url = 'https://gpm1.gesdisc.eosdis.nasa.gov:443/opendap/hyrax/GPM_L3/GPM_3IMERGHH.06/2019/087/3B-HHR.MS.MRG.3IMERG.20190328-S000000-E002959.0000.V06B.HDF5' try: session = setup_session(username, password, check_url=url) pydap_ds = open_url(url, session=session) store = xr.backends.PydapDataStore(pydap_ds) ds = xr.open_dataset(store) except Exception as err: print(err)

which returns:

``` 302 Found

Found

The document has moved here.

/usr/local/lib/python3.8/site-packages/xarray/backends/common.py:87: FutureWarning: The variables property has been deprecated and will be removed in xarray v0.11. return len(self.variables) ``` The error message just comes when I try to use xr.open_dataset I've already accepted the EULA. Does anyone know what can be?

So, I tried Ryan's example, and got to the same error, where do you accept the EULA? It doesn't pop up on screen.

El dom., 22 mar. 2020 a las 6:29, ahahmann (notifications@github.com) escribió:

One can also add username and password to the .netrc file and all works very smoothly, without a need for explicit username and password in the script.

However, there was one more issue. With Python 3.7.6, I was getting the following error:

File "MERRA2.py", line 16, in <module> session = setup_session(username, password, check_url=url) File "/groups/FutureWind/xesmf_env/lib/python3.7/site-packages/pydap/cas/urs.py", line 19, in setup_session verify=verify) File "/groups/FutureWind/xesmf_env/lib/python3.7/site-packages/pydap/cas/get_cookies.py", line 75, in setup_session password_field=password_field) File "/groups/FutureWind/xesmf_env/lib/python3.7/site-packages/pydap/cas/get_cookies.py", line 123, in soup_login soup = BeautifulSoup(resp.content, 'lxml') File "/groups/FutureWind/xesmf_env/lib/python3.7/site-packages/bs4/init.py", line 228, in init % ",".join(features)) bs4.FeatureNotFound: Couldn't find a tree builder with the features you requested: lxml. Do you need to install a parser library?

That was solved by pip install lxml

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One can also add username and password to the .netrc file and all works very smoothly, without a need for explicit username and password in the script.

However, there was one more issue. With Python 3.7.6, I was getting the following error:

Traceback (most recent call last): File "MERRA2.py", line 16, in <module> session = setup_session(username, password, check_url=url) File "/groups/FutureWind/xesmf_env/lib/python3.7/site-packages/pydap/cas/urs.py", line 19, in setup_session verify=verify) File "/groups/FutureWind/xesmf_env/lib/python3.7/site-packages/pydap/cas/get_cookies.py", line 75, in setup_session password_field=password_field) File "/groups/FutureWind/xesmf_env/lib/python3.7/site-packages/pydap/cas/get_cookies.py", line 123, in soup_login soup = BeautifulSoup(resp.content, 'lxml') File "/groups/FutureWind/xesmf_env/lib/python3.7/site-packages/bs4/__init__.py", line 228, in __init__ % ",".join(features)) bs4.FeatureNotFound: Couldn't find a tree builder with the features you requested: lxml. Do you need to install a parser library?

That was solved by pip install lxml

Dear all, Thank you very much for all the time you've put into fixing this issue. I'm a fresh PhD student, started working on solar radiation forecast four months ago, and right now I'm trying to use MERRA 2 aerosol data to initialize WRF Solar. The bug fix on this thread has helped me a lot, since I was trying to avoid the straight forward method of downloading the files by date and then merging them in a single python object. This way I can directly create my python object without downloading one by one and then merging! It's awesome! Thank you all very much!

Awesome, thanks so much @laliberte!

I also like the idea of passing PydapDataStore objects that include the session object. Delving deeper into the pydap authentication, I found that there are already several different setup_session functions available to create the session object, corresponding to different authentication procedures (pydap.cas.get_cookies.setup_session, pydap.cas.urs.setup_session, pydap.cas.esgf.setup_session) as well as additional arguments to setup_session beyond username and password. Best to deal with all this separately with pydap rather than trying to embed it within xarray.

I'm still having problems trying to get xarray.open_dataset to work with pydap. Using the latest commit on pydap/master (in which https://github.com/pydap/pydap/pull/48 is merged) I'm now getting a new error: AttributeError: '<class 'pydap.model.BaseType'>' object has no attribute 'encode'. When I have some time, I'll look into it further and try to see what else is needed to restore compatibility.

Thanks, @rabernat! I'd be happy to try implementing this in the project. I'm a newbie when it comes to contributing to big projects like this (so far I've just used Github for my own little projects) so I might have some naive questions as I figure out how things work.

The two options you mentioned for passing username and password info to open_dataset both sound good to me. I don't have any strong preference between them. How do I get other opinions on which approach to use? Should I start a new issue thread?

Also, I realized that there is another hiccup along the way. When I try to specify engine='pydap' in open_dataset, I get the same error message as mentioned in #1174, that the object has no attribute iteritems. When I wrote the first post in this thread, back in October, I was able to use engine='pydap' without any problems. This seems to be related to recent upstream changes in Pydap: https://github.com/pydap/pydap/issues/43 and I presume might require more substantial changes either in Xarray or Pydap so that they can work together again. Any thoughts on how to handle this?

I've finally found something useful online and am able to use Pydap to open these files -- hoping someone can help me find a way to integrate this into an xarray.open_dataset() function call and then I will be a very happy camper!

Turns out much of the info posted by NASA online is out of date and based on a different implementation of Pydap than what is actually being used currently (argh). Here is something that actually works, from http://www.pydap.org/en/latest/client.html#urs-nasa-earthdata: ``` from pydap.client import open_url from pydap.cas.urs import setup_session

url = 'https://goldsmr4.gesdisc.eosdis.nasa.gov/opendap/MERRA2/M2T1NXSLV.5.12.4/2016/06/MERRA2_400.tavg1_2d_slv_Nx.20160601.nc4'

session = setup_session(username, password) dataset = open_url(url, session=session) ``` where I've assigned the username and password variables with the appropriate values in another function.

I've tested this and it is working, but I would prefer to do things within Xarray since all my code is already using it. Just for fun, I tried ds = xarray.open_dataset(url, engine='pydap', session=session), to see if the extra keyword would be magically sent to the pydap engine, but got an error message. Is there a way to incorporate this functionality into xarray.open_dataset? Thank you so much for any assistance!

@j08lue no, not yet. I've been in touch with the folks at NASA who run the server, but their suggestions didn't work for me and I haven't had time to keep troubleshooting. I will need to sort out this issue in the next couple of months to get some data that I need, so if/when I ever resolve it, I'll post the solution here.

Ah, I see. Thanks for the suggestion. Using Pydap I'm able to see all the variables and their metadata, so I thought it was working, but when I try to actually access the data values, I get the same error message as from Xarray. The issue must be something unrelated to Xarray -- I'll keep investigating. Thanks for your help!

Thanks very much for your reply! I still get an error from xarray when I use the engine='pydap' option. Here's a minimum (almost) working example (almost because you need an account with the server so you can substitute your username/password into the url string):

``` import xarray from pydap.client import open_url

url = 'http://<username>:<password>@goldsmr5.sci.gsfc.nasa.gov/opendap/MERRA2/M2I3NPASM.5.12.4/1986/01/MERRA2_100.inst3_3d_asm_Np.19860101.nc4'

ds1 = open_url(url) # Works but data isn't in xarray format ds2 = xarray.open_dataset(url, engine='pydap') # Error message, see attached ```

I've attached the error message here -- error_msg.txt I don't know enough about the inner workings of xarray to trace through it. Please let me know if any of this means anything to you and has a reasonably easy fix or workaround. Thank you!