Hi there,
while testing the EC2 interface I've ran into the following problem.

After a fresh EC2 (dependency) install the multipart-post doesn't work (on Ubuntu). This seems to be an
installation issue: multipart-post must be separately installed.

Problem¶

The OCCI userguide mentions that on some platform Curl is buggy, therefore one should use the
multiplart upload (built into Ruby). However, after a fresh install multipart upload doesn't work,
gives back the following error:

$ econe-upload -M ttylinux.img   
/opt/one/lib/ruby/cloud/econe/EC2QueryClient.rb:173:in `upload_image`  Unitialized constant EC2QueryClient::UploadIO (NameError)  
    from /opt/one/bin/econe-upload:115

Investigation¶

Though I have no experience in Ruby programming I did some investigation:

econe-upload:115:  
108: ec2_client = EC2QueryClient::Client.new(auth,url)  
…  
114: rc = ec2_client.upload_image(image, curb)  
115:  

EC2QueryClient.rb:173:  
25: require 'CloudClient'  
26: require 'AWS'  
…  
150: if curb and CURL_LOADED  
…  
168: else  
…  
172:     params["file"]=UploadIO.new(file,  
173:        'application/octet-stream', file_name)  
174:  
175:     req = Net::HTTP::Post::Multipart.new('/', params)  

As far as I see upload_image() tries to set the POST parameter named 'file', however the system cannot resolve the
UploadIO symbol. I did some further investigation eg. checked requires within CloudClient:

CloudClient.rb:  
30: begin  
31:    require 'net/http/post/multipart'  
32: rescue LoadError  
33: end  

It seems that the above net/http/post/multipart handles multipart posts. The multipart-post documentation seems to
confirm this: „Provides an UploadIO helper module to prepare IO objects for inclusion in the params hash of the
multipart post object.” (http://github.com/nicksieger/multipart-post)

Solution¶

$ sudo gem install multipart-post

and now multipart upload works:

$ econe-upload -M ttylinux.img  
Success: ImageId 4  

Testing environment¶

• Ubuntu 9.10 server i386 (Linux 2.6.31)
• Ruby v. 1.8

Cheers,
Gyula