Improve elasticbeanstalk debugging

Don't print a line for every file, which may blow out if a node_modules
or similar is included.

Add logging around zip file size.

Add logging around S3 upload / EB version registration

lib/dpl/providers/elasticbeanstalk.rb

@@ -89,20 +89,29 @@ def zip_exists?
 
  def create_zip
  ::Zip::File.open(zip_file, ::Zip::File::CREATE) do |zip|
+ n_files = 0
  files.each do |path|
- debug :zip_add, path
+ n_files += 1
  zip.add(path.sub(cwd, ''), path)
  end
+ debug "Zip contains #{n_files} files"
+ size = File.size(zip_file)
+ warn "Zip file is empty." if size == 0
+ # https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/applications-versions.html
+ warn "Zip file may be too large." if size > 524288000
+ debug "Zip file size: #{size.to_f / 2**10}kb"
  end
  end
 
  def upload
+ debug "upload zipfile:#{zip_file} bucket path: #{bucket_path}"
  @object = bucket.object(bucket_path)
  object.put(body: File.open(zip_file))
  sleep 5 # s3 eventual consistency
  end
 
  def create_version
+ debug "create_version app:#{app}, label:#{label}, bucket:#{bucket.name}, key:#{object.key}"
  @version = eb.create_application_version(
  application_name: app,
  version_label: label,