Download a file from Google Drive using google-api-ruby-client

I try to download files from a directory on Google Disk.

The code, mostly copied from official quickstart guide, works fine:

# ... code from official quickstart tutorial...

# Initialize the API
service = Google::Apis::DriveV3::DriveService.new
service.client_options.application_name = APPLICATION_NAME
service.authorization = authorize


# now the real deal
response = service.list_files(q: "'0ByJUN4GMe_2jODVJVVpmRE1VTDg' in parents and trashed != true",
                              page_size: 100,
                              fields: 'nextPageToken, files(id, name)')
puts 'Files:'
puts 'No files found' if response.files.empty?
response.files.each do |file|
  puts "#{file.name} (#{file.id})"
  # content = service.get_file(file.id, download_dest: StringIO.new)
end

The output looks fine:

Files:
k.h264 (0B4D93ILRdf51Sk40UzBoYmZKMTQ)
output_file.h264 (0B4D93ILRdf51V1RGUDFIWFQ5cG8)
test.mp4 (0B4D93ILRdf51dWpoZWdBV3l4WjQ)
test2.mp4 (0B4D93ILRdf51ZmN4ZGlwZjBvR2M)
test3.mp4 (0B4D93ILRdf51ZXo0WnVfdVBjTlk)
12.mp4 (0ByJUN4GMe_2jRzEwS1FWTnVkX00)
01.mp4 (0ByJUN4GMe_2jSlRWVEw4a1gxa2s)
01.mp4 (0ByJUN4GMe_2jOFpPMW9YNjJuY2M)

But once I uncomment content = service.get_file(file.id, download_dest: StringIO.new), I get a lot of errors:

Files:
k.h264 (0B4D93ILRdf51Sk40UzBoYmZKMTQ)
/Users/mvasin/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/google-api-client-0.9.15/lib/google/apis/core/http_command.rb:211:in `check_status': Invalid request (Google::Apis::ClientError)
[...lots of other 'from' stuff...]
from /Users/mvasin/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/google-api-client-0.9.15/generated/google/apis/drive_v3/service.rb:772:in `get_file'
from quickstart.rb:56:in `block in <main>'
from quickstart.rb:54:in `each'
from quickstart.rb:54:in `<main>'

But that's the way it should work according to ruby section in "download files" official tutorial.

I also tried content = service.get_file(file.id, download_dest: "/tmp/#{file.name}"), but it failed with the same set of errors.

UPDATE: Here are my findings. If you start with Google Drive API Ruby quick start tutorial, and want make it download something,

1) change scope to not just let your script read meatadata, but read files contents as well:

SCOPE = Google::Apis::DriveV3::AUTH_DRIVE_METADATA_READONLY to at least SCOPE = Google::Apis::DriveV3::AUTH_DRIVE_READONLY

2) Filter out google docs files, because you can't download them this way, you have to convert them. To filer them:

2.1) Add mime_type to fileds set:

response = service.list_files(page_size: 10, fields: 'nextPageToken, files(id, name, mime_type)')

2.2) and in the final loop where you print files' ids and names, put something like

service.get_file(file.id, download_dest: "/your/path/#{file.name}") unless file.mime_type.include? "application/vnd.google-apps"

Solution

From the error that you got, it says that your request is invalid. So make sure that your request there are correct. Here is the documentation on how to download files using Ruby(just click the Ruby on the example to view the ruby code.)

Take NOTE: Downloading the file requires the user to have at least read access. Additionally, your app must be authorized with a scope that allows reading of file content.

For more information, check these threads: