Problem with cronjob and ruby script


#1

Hello,

I’m trying to get a ruby script run into a crontab and it keeps failing
saying it can’t find my mechanize gem. When I run the script form the
command line, everything runs fine and I don’t get any failures.

Anyone ever had that problem before?


#2

On Fri, Jun 5, 2009 at 3:48 PM, Matthew L. removed_email_address@domain.invalid wrote:

Hello,

I’m trying to get a ruby script run into a crontab and it keeps failing
saying it can’t find my mechanize gem. When I run the script form the
command line, everything runs fine and I don’t get any failures.

Anyone ever had that problem before?

Make sure you have this ENV variables pointing to the correct dirs:

GEM_HOME=/usr/local/rubygems/gems
GEM_PATH=/usr/local/rubygems/gems
RUBYLIB=/usr/local/rubygems/lib/ruby/site_ruby/1.8

-drd


#3

Matthew L. wrote:

Hello,

Hi.

I’m trying to get a ruby script run into a crontab and it keeps failing
saying it can’t find my mechanize gem. When I run the script form the
command line, everything runs fine and I don’t get any failures.

Anyone ever had that problem before?

Oh yes.

Try getting it to run from the command line with a blank
environment with ‘env -’, e.g.,

% env - run_stuff.sh

Typically a crontab job runs with a much reduced environment.

Alternatively, stick a printenv in your crontab to see
what environment it is working with and compare to your
interactive environment.

You might also find crontab’s sister command, ‘at’, helpful
to get tighter feedback cycles.

Regards,


#4

Matthew L. removed_email_address@domain.invalid writes:

Hello,

I’m trying to get a ruby script run into a crontab and it keeps failing
saying it can’t find my mechanize gem. When I run the script form the
command line, everything runs fine and I don’t get any failures.

Often and often when cron jobs fail it is because the environment
variables
are not set. Cron jobs do not automatically execute .bashrc (or
equivalent)
you generally need to create a script that calls your program after
either
setting the environment by hand or doing eg “. .bashrc”.

Eddie


#5

Hi,

If I start by a human-written block of data, such as ITEMS below, is it
possible to deserialize these into objects of type Item? How might this
be done?

Thanks for any help,
James

ITEMS = %q{

item:

  • name: blah
  • type: blah
  • location: blah
    }

class Item

attr_accessor :name
attr_accessor :type
attr_accessor :location

def initialize
@name = “”
@type = “”
@location = “”
end

end


#6

Hmm I’ve tried running with a blank environment and it fails with the
same error not finding the gems. I have set the ENV variables to the
proper directories and it is still giving me the same error. I’m not
sure what else to try although I appreciate all your recommendations!

Bil K. wrote:

Matthew L. wrote:

Hello,

Hi.

I’m trying to get a ruby script run into a crontab and it keeps failing
saying it can’t find my mechanize gem. When I run the script form the
command line, everything runs fine and I don’t get any failures.

Anyone ever had that problem before?

Oh yes.

Try getting it to run from the command line with a blank
environment with ‘env -’, e.g.,

% env - run_stuff.sh

Typically a crontab job runs with a much reduced environment.

Alternatively, stick a printenv in your crontab to see
what environment it is working with and compare to your
interactive environment.

You might also find crontab’s sister command, ‘at’, helpful
to get tighter feedback cycles.

Regards,


#7

On Fri, Jun 5, 2009 at 8:00 AM, Matthew L.removed_email_address@domain.invalid wrote:

Hmm I’ve tried running with a blank environment and it fails with the
same error not finding the gems. I have set the ENV variables to the
proper directories and it is still giving me the same error.

Set them where? You need to set them in your crontab directly,
not in your personal e.g. .bashrc.


#8

Oh I see can you give me an example please?

Thanks!

Hassan S. wrote:

On Fri, Jun 5, 2009 at 8:00 AM, Matthew L.removed_email_address@domain.invalid wrote:

Hmm I’ve tried running with a blank environment and it fails with the
same error not finding the gems. I have set the ENV variables to the
proper directories and it is still giving me the same error.

Set them where? You need to set them in your crontab directly,
not in your personal e.g. .bashrc.


#9

On Jun 5, 2009, at 10:36 AM, Matthew L. wrote:

Oh I see can you give me an example please?

Thanks!

You may find this helpful: http://blog.spikesource.com/crontab.htm

Cheers–

Charles

Charles J.
Advanced Computing Center for Research and Education
Vanderbilt University


#10

On Fri, Jun 5, 2009 at 8:36 AM, Matthew L.removed_email_address@domain.invalid wrote:

Oh I see can you give me an example please?

Sure, here’s one:

5,20,35,50 * * * * export JAVA_HOME=/usr/local/jdk1.6_013 &&
/usr/bin/jruby - S blah blah

HTH,


#11

On Fri, Jun 5, 2009 at 10:36 AM, Matthew L.removed_email_address@domain.invalid wrote:

Oh I see can you give me an example please?

Thanks!

From (recent) experience here, I’ve had similar issues across
different versions of the same distro (CentOS/RedHat). The paths and
environment variables are drastically different. For me, I was
shelling out to lspci

Something along the lines of this would have been a valid fix.

#Crontab
0 1 * * * PATH=$PATH:/sbin /usr/bin/ruby /usr/local/bin/nitejob.rb


#12

On Fri, Jun 5, 2009 at 11:13 AM, Hassan
Schroederremoved_email_address@domain.invalid wrote:

Hassan S. ------------------------ removed_email_address@domain.invalid
Hassan, just a note, you don’t need the “export” part of the line :slight_smile:

–Kyle


#13

On Fri, Jun 5, 2009 at 11:38 AM, Kyle S.removed_email_address@domain.invalid
wrote:

Of course it doesn’t hurt either…


#14

On Fri, Jun 5, 2009 at 9:38 AM, Kyle S.removed_email_address@domain.invalid
wrote:

5,20,35,50 * * * * export JAVA_HOME=/usr/local/jdk1.6_013 &&
/usr/bin/jruby - S blah blah

Hassan, just a note, you don’t need the “export” part of the line :slight_smile:

Force of habit; in this example, no, but if a subsequent part of the
entry spawns a new shell, I think it’s necessary.

I think. Will have to revisit that sometime, but not today :slight_smile:


#15

Tried everything in here and same problem. What I’ve noticed though this
version of Ubuntu (Feisty Fawn 7.04) which I know is outdated messed up
all the paths for ruby and rubygems.

Hassan S. wrote:

On Fri, Jun 5, 2009 at 9:38 AM, Kyle S.removed_email_address@domain.invalid
wrote:

5,20,35,50 * * * * export JAVA_HOME=/usr/local/jdk1.6_013 �&&
/usr/bin/jruby - S blah blah

Hassan, just a note, you don’t need the “export” part of the line :slight_smile:

Force of habit; in this example, no, but if a subsequent part of the
entry spawns a new shell, I think it’s necessary.

I think. Will have to revisit that sometime, but not today :slight_smile:


#16

James F. wrote:

Hi,

If I start by a human-written block of data, such as ITEMS below, is it possible to deserialize these into objects of type Item? How might this be done?

Easy, just yaml them to find out how the serialized form should look:

class Item

 attr_accessor :name
 attr_accessor :type
 attr_accessor :location

 def initialize
   @name = ""
   @type = ""
   @location = ""
 end

end

require ‘yaml’
y Item.new

If you run this you get:

— !ruby/object:Item
location: “”
name: “”
type: “”

Then you can play with the string and check that YAML.load does the
right thing on this data


#17

Matthew L. wrote:

Hassan, just a note, you don’t need the “export” part of the line :slight_smile:
Force of habit; in this example, no, but if a subsequent part of the
entry spawns a new shell, I think it’s necessary.

I think. Will have to revisit that sometime, but not today :slight_smile:

Hey, does this thread have anything to do with the Bourne-shell usage
bias which
first manifested itself for me in at last year? In other words, if you
use a
shell, any shell, in at you get sh, not bash, the former being
considered
lighter weight and perhaps somehow safer and more standard, but on the
other
hand breaks things like some commands you are used to in some syntax in
Bash.
For instance, you must do the following to export:

x=y
export x

because export x=y does not work in sh. ???


#18

On Fri, Jun 5, 2009 at 11:19 AM, Matthew L.removed_email_address@domain.invalid wrote:

Tried everything in here and same problem. What I’ve noticed though this
version of Ubuntu (Feisty Fawn 7.04) which I know is outdated messed up
all the paths for ruby and rubygems.

Shouldn’t matter if you put in full paths to everything you reference.


#19

I honestly don’t know, I’ve tried everything in here and I still can’t
get it to work.

Hassan S. wrote:

On Fri, Jun 5, 2009 at 11:19 AM, Matthew L.removed_email_address@domain.invalid wrote:

Tried everything in here and same problem. What I’ve noticed though this
version of Ubuntu (Feisty Fawn 7.04) which I know is outdated messed up
all the paths for ruby and rubygems.

Shouldn’t matter if you put in full paths to everything you reference.


#20

On Fri, Jun 5, 2009 at 12:42 PM, Matthew L.removed_email_address@domain.invalid wrote:

I honestly don’t know, I’ve tried everything in here and I still can’t
get it to work.

Maybe if you post the actual crontab entry that you’re having trouble
with, we’d have a chance of finding the specific problem :slight_smile: