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Entries tagged "ruby".

Tonight I've mostly been using Sinatra

6th January 2012

This evening I've mostly been using Sinatra to build a little file storage service which uses a REST API.

That means I can upload a file:

skx@birthday:~/hg/sinatra$ curl -X PUT -F file=@/etc/fstab http://localhost:4567/
{"id":"dbd1bdc11b5a1a8e80588a135648b4c2edffb49a","path":"/"}

Download that same file:

skx@birthday:~/hg/sinatra$ curl -X GET -F id=dbd1bdc11b5a1a8e80588a135648b4c2edffb49a  \
   http://localhost:4567/
# /etc/fstab: static file system information.
..
/dev/cdrom        /media/cdrom0   udf,iso9660 user,noauto     0       0

Get an index of files:

skx@birthday:~/hg/sinatra$ curl http://localhost:4567/
[{"id":"dbd1bdc11b5a1a8e80588a135648b4c2edffb49a","type":"file"}]

And finally we can delete a file:

skx@birthday:~/hg/sinatra$ curl -X DELETE -F "id=dbd1bdc11b5a1a8e80588a135648b4c2edffb49a" \
  http://localhost:4567/
Removed

We can also upload to different paths so we can replicate a file-system if we wanted to. (I added in "type" to hold either "file" or "directory", though I guess if we were to code up a FUSE client we'd want to store things like ctime, UID, GID, etc. THe list operation will show both files and sub-directories)

The code was trivial once I got the hang of Sinatra, and I'm pretty pleased with it so far. I don't yet need to use it for anything, but I'm thinking of unifying the way that I store images on a couple of sites - and fetching them via JSON and Javascript might be an option this was an experiment in that direction. (Though I'd probably want to hook in rsync so we replicated the eventual upload location for safety.)

In other news I've been all organized and upgraded the kernel on my guest:

steve@steve:~$ uptime
 22:00:28 up  4:18,  1 user,  load average: 0.14, 0.05, 0.05
steve@steve:~$ uname -r
3.2.0-kvm-hosting.org-i386-20120106

So for once I'm up to date with a cutting edge kernel. Happy times.

ObQuote: "How you expect to run with the wolves come night when you spend all day sparring with the puppies? " - The Wire (Omar)

Tags: json, kvm, kvm-hosting, ruby. | 2 comments.

 

It is an army bred for a single purpose

9th February 2009

It is funny the way things work out when you're looking for help.

Recently I was working on a Ruby + FUSE based filesystem and as part of the development I added simple diagnostic output via trivial code such as this:

@debug && puts "called foo(#{param});"

That was adequate for minimal interactive use, but not so good for real live use. In real live use I started outputing messages to a dedicated logfile, but in practise became overwhelmed by thousands of lines of output describing everything ever applied to the filesystem.

I figured the natural solution was to have a ring-buffer. (Everybody knows what a ringbuffer is, right?) It could keep the last 500 messages and newer debug information would just replace older entreis. That'd be just enough to be useful if I had a problem, but not so overwhelming it would get ignored.

In Perl I found a nice ringbuffer library, but for Ruby nothing. Locking a region of shared memory via shmget, shmset and keeping an array of a few hunded strings would be simple, but it seems odd I have to code this myself.

I started searching around and I accidentally stumbled upon the unrelated IPC::DirQueue perl module. Not useful for my ringbuffer logging problem, but beautifully useful.

There is no package for Debian but that was easily created:

dh-make-perl --build --cpan IPC::DirQueue

Already I have a million and one uses for it - not least to solve my problem of maintaining a centralised quarantine for all the spam mail rejected by N MX machines. (Which currently uses a combination of rsync and lockfiles.)

This is the reason why sites like Perl Advent Calendar are useful - they introduce a useful module every day or two, and introduce you to thinks that you can use in the future.

Of course keeping a sustainable site like that up and running is hard which is why sites like debaday struggle to attract contributors, for example.

Anyway random happyness.

ObFilm: Lord of the rings: Two Towers

Tags: fuse, perl, random, ruby. | 3 comments.

 

When the light begins to change

30th January 2007

All being well I now have a blog working using Typo, instead of Wordpress 2 – and no broken links!

We’ll see.

Now to make sure that my server load doesn’t rise through the roof this time.

For future reference importing entries from Wordpress2 -> Typo will almost certainly give you this error:

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const_missing': uninitialized constant TestRequest (NameError)
        from ./db/converters/../../config/../app/models/blog.rb
...
..
.

This can be fixed by changing:

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def really_send_pings(serverurl = blog.server_url, articleurl = nil)
   return unless blog.send_outbound_pings
   ...
   ...
end

To this:

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def really_send_pings(serverurl = blog.server_url, articleurl = nil) 
   return
end
Tags: rails, ruby, typo, wordpress. | No comments