Headless Usage & Authorization

In the basic procedure described in Usage, you need a web browser for the authorization step. On a headless server without a GUI interface or a web browser, you can get it to work by using a web browser on a separate computer, and pasting the results into the ~/.gdfuse/default/config (or ~/.gdfuse/label/config if you use labels) file of your headless server.

Caveat: I do not know whether this is the "optimal" way to do this. I was in a pinch, and this approach worked. At first, I had a difficult time getting it to work, but Alessandro responded immediately with help, and we got it to work. These are the steps I followed, and of course, please edit this page if you have tips or a better approach.

(I used the "Alternate Authorization Mode" although the Standard Authorization mode using the GAE (Google App Engine) service may work too.)

1. Install normally as per the Installation page

2. On the computer with the web browser, create an OAuth2 application and credentials. These steps are similar to those described in the "Alternate Authorization Mode" section in Authorization. The following steps are what I did, based on my notes:

   1. Sign in to your Google account and create a project: https://console.cloud.google.com/
   2. Enable the Google Drive API
      1. In the left-hand pane (Navigation menu), open "APIs & Services" -> "Library", this will take you to https://console.cloud.google.com/apis/library
      2. Click on "Google Drive API", this will open https://console.cloud.google.com/apis/library/drive.googleapis.com . Click "ENABLE API".
   3. Get your client ID and client secret
      1. Open the Navigation menu (click the hamburger icon at the top left), open "APIs & Services" -> "Credentials", this will open https://console.cloud.google.com/apis/credentials
      2. Then click on the button "Create Credentials", and choose choose "OAuth client ID", this will take you to https://console.cloud.google.com/apis/credentials/oauthclient .
         • For Application type, choose "Other" or "Desktop"
         • For Name, input something personal, for example "My OCAMLDrive".
      3. Click "Create". You will get a Client ID, a Client Secret.

3. Authorization: Back in your headless server, run google-drive-ocamlfuse for the first time. I used labels (in this document, I use the label "me") because I plan on using multiple accounts. However you can also run it without the -label parameter and it will use a default name for the label called "default". You will need the Client ID and secret you got from google above.

   From version 0.5.3, you should use the -headless option:

      $ google-drive-ocamlfuse -headless -label me -id ##yourClientID##.apps.googleusercontent.com -secret ###yoursecret##### 
   

   You will get an output like this:

      Please, open the following URL in a web browser: https://accounts.google.com/o/oauth2/auth?client_id=##yourClientID##.apps.googleusercontent.com&redirect_uri=urn%3Aietf%3Awg%3Aoauth%3A2.0%3Aoob&scope=https%3A%2F%2Fwww.googleapis.com%2Fauth%2Fdrive&response_type=code&access_type=offline&approval_prompt=force
   

   Then, you should open the URL above in a graphical web browser, get the verification code from Google and put it here:

      Please enter the verification code: 
   

4. That's it. You should be ready to mount.

    mkdir /my_mnt_dir
    google-drive-ocamlfuse -label me /my_mnt_dir
   

5. Finally, to unmount, elsewhere in the instructions it says to use fusermount -u mountpoint. That did not work for me for some reason, but umount mountpoint did.

Troubleshooting

When I first tried to mount my drive, I got an error message:

    Cannot retrieve auth tokens.
    Failure("OAuth2 error: invalid_grant (HTTP response code: 400)")

I then ran the same command above, with the addition of the -debug parameter, and still got an error:

	Starting application setup (label=me).
	Opening log file: /root/.gdfuse/me/gdfuse.log
	Cannot retrieve auth tokens.
	Failure("OAuth2 error: invalid_grant (HTTP response code: 400)")

This is where I got stuck but Alessandro helped me right away. The problem was that my verification code had expired. I don't know what the timeout period is, but I just went back to the google page mentioned above, clicked on "Reset client secret…", which gave me a new secret id and secret, re-ran the auth page to get a new verification code, pasted the new values into the config file, and then it worked like a charm.

Simple another way

1. make a dummy script to just output the autohize URL, named xdg-open, firefox, ...

$ echo $'#!/bin/sh\necho $* > /dev/stderr' > xdg-open
$ chmod 755 xdg-open

2. call google-drive-ocamlfuse with the path in the above dummy script

$ env PATH=`pwd`:$PATH google-drive-ocamlfuse
https://accounts.google.com/signin/oauth/consent?....

3. access the output URL with your browser and authorize it
4. then the command will output "Access token retrieved correctly.", it works

reference: http://moguno.hatenablog.jp/entry/2016/03/24/010502 (Japanese)

Even simpler third way

Access the server using X-forwarding i.e.:

ssh -X user@server.ip

This will forward a graphical browser session to your local machine (provided the remote server has a browser).