A dream: gem require with auto-installer

Ruby
1

Hello,

When I develop some administration scripts and distribute them to
my colleague, we often encounter issues: I must write a readme or
an email for explain what to do for use them:
mkdir, gem install …

Why ‘require X’ instruction do not make a ‘gem install X’ when
the gem is not installed ?

With (red) Shoes, we got "Shoes.setup { gem ‘json_pure’ } ", this is
really useful for non-native gem !

Sincerely,

Regis d’Aubarede
http://regisaubarede.posterous.com/

2
On 06/10/2011 12:37, Regis d'Aubarede wrote: 
Hello,

When I develop some administration scripts and distribute them to

my colleague, we often encounter issues: I must write a readme or

an email for explain what to do for use them:

mkdir, gem install …


Why ‘require X’ instruction do not make a  ‘gem install X’ when

the gem is not installed ?


With (red) Shoes, we got  "Shoes.setup { gem ‘json_pure’ } ", this is

really useful for non-native gem !


Sincerely,


Regis d’Aubarede

http://regisaubarede.posterous.com/
Hello,

IMHO a such tool would be really dangerous, and not so useful:
the best option is to allow users to install everything in 1 command.

You should try Bundler : even if you don't want to use it in your
application, you can provide a Gemfile (and, even better, a
Gemfile.lock) then user will be able to use it with "bundle install."

An other way is to create a rake task which does to job.

Regards,

--
Étienne Vallette d'Osia
3

On Thu, Oct 6, 2011 at 12:37 PM, Regis d’Aubarede
[email protected] wrote:

Why ‘require X’ instruction do not make a ‘gem install X’ when
the gem is not installed ?

Because not every require statement requires a gem.

–
Phillip G.

gplus.to/phgaw | twitter.com/phgaw

A method of solution is perfect if we can forsee from the start,
and even prove, that following that method we shall attain our aim.
– Leibniz

4

On Thu, Oct 6, 2011 at 3:19 PM, Regis d’Aubarede
[email protected] wrote:

or I can do that at the beginning of my script :

def my_require(gem,pack=nil) require gem
rescue Exception => e
puts “loading #{pack||gem} from internet …”
system(“gem install #{pack||gem} --no-ri --no-rdoc”) ;
require gem
end

Breaks if the user account doesn’t have write permissions to the gem
installation directory.

Also: Who the hell do you think you are that you think you are allowed
to futz around with my OS during your script’s runtime? What you are
doing screams malware behaviour (connecting to the internet and
downloading code; nobody can guarantee that you haven’t done a
system(“gem sources -a http://malicious.url”) somewhere in there).

If you are unable or unwilling to bundle your dependencies into one
package, that’s very much your problem: You can build a custom
RubyInstaller for Windows and include your dependencies, and for *NIX
you can create a tarball for distribution that includes your
dependencies. Heck, the latter works for Windows, too, if you don’t
include native extensions.

–
Phillip G.

gplus.to/phgaw | twitter.com/phgaw

A method of solution is perfect if we can forsee from the start,
and even prove, that following that method we shall attain our aim.
– Leibniz

5

If you sent that kind of script to me, I’d print it out and slap you
with the paper.

For Windows, use Ocra for packaging; for Linux, everyone using it
should already be clever enough to do something as simple as a gem
install themselves.

Also, why a readme file? Just add a note to the top of the file in
question.

– Matma R.

6

You should try Bundler …
An other way is to create a rake task which does to job…

yes, so a readme file is necessary

or I can do that at the beginning of my script :

    def my_require(gem,pack=nil)  require gem
    rescue Exception => e
        puts "loading #{pack||gem} from internet ..."
        system("gem install  #{pack||gem} --no-ri --no-rdoc")  ;
        require gem
    end

and then :

    my_require 'json','json_pure'
    my_require 'green_shoes' ,   'gtk2,green_shoes'
    my_require 'toto' , 'zzz'
7

On Thu, Oct 6, 2011 at 7:12 PM, Hilco Wijbenga
[email protected] wrote:

If you’re worried about malware then I don’t see how running someone’s
custom installer is any safer than running some script. Arguably, with
the script you at least have a chance to look at what it’s doing.

It’s much easier to audit a whole installer (and block it!), than read
a dozen scripts, chasing through whatever rabbit holes the code goes
through.

–
Phillip G.

gplus.to/phgaw | twitter.com/phgaw

A method of solution is perfect if we can forsee from the start,
and even prove, that following that method we shall attain our aim.
– Leibniz

8

With (red) Shoes, we got "Shoes.setup { gem ‘json_pure’ } ", this is
really useful for non-native gem !

And as the Shoes maintainer, the reason that this is in here is
specifically to help new people. This feature is really useful, but it
does semi-violate what most programmers would expect out of a system.
Since Shoes is a custom Ruby distribution, we can play by slightly
different rules. :slight_smile:

9

Perhaps this one will be less blamed :

def my_require(gem,pack=nil)
require gem
rescue LoadError => e
print "’#{gem}’ package is missing. Can I load #{pack||‘it’}
from internet without slap or go to hell ? (y/n) : "
exit! if STDIN.gets.chomp !~ /^y|o$/i
system(“gem install #{pack||gem} --no-ri --no-rdoc”) ;
Gem.clear_paths() && require(gem) && puts(“loading ‘#{gem}’ ok!”)
end

my_require ‘xxx’
my_require ‘json’,‘json_pure’
my_require ‘green_shoes’ , ‘gtk2,green_shoes’
my_require ‘foo’ , ‘zzz’

Thank you very much for your help,
realy…

10

On 6 October 2011 06:34, Phillip G. [email protected]
wrote:

package, that’s very much your problem: You can build a custom
RubyInstaller for Windows and include your dependencies, and for *NIX
you can create a tarball for distribution that includes your
dependencies. Heck, the latter works for Windows, too, if you don’t
include native extensions.

If you’re worried about malware then I don’t see how running someone’s
custom installer is any safer than running some script. Arguably, with
the script you at least have a chance to look at what it’s doing.