Crontab Not Running Ruby Script

Crontab not running ruby script

Edit: I just noticed the user answered his own post, but I'll leave this up in case someone stumbles across here with a similar issue. I've found it's helpful for some.

I've run into this and found that this is the solution for Ruby scripts.

Ruby needs to be executed in a particular environment. RVM handles this by sourcing a ruby environment file for you particular version of ruby that sets all the required environment variables. For example if you have ruby 1.9.3 patch 448, you can look at the environment file that is sourced:

cat /usr/local/rvm/environments/ruby-1.9.3-p484

export PATH="/usr/local/rvm/gems/ruby-1.9.3-p484/bin:/usr/local/rvm/gems/ruby-1.9.3-p484@global/bin:/usr/local/rvm/rubies/ruby-1.9.3-p484/bin:$PATH"
export GEM_HOME='/usr/local/rvm/gems/ruby-1.9.3-p484'
export GEM_PATH='/usr/local/rvm/gems/ruby-1.9.3-p484:/usr/local/rvm/gems/ruby-1.9.3-p484@global'
export IRBRC='/usr/local/rvm/rubies/ruby-1.9.3-p484/.irbrc'
unset MAGLEV_HOME
unset RBXOPT

(Note: My installation of rvm was under /usr/local/.. but yours may be elsewhere. Use which ruby to figure out where your ruby is installed)

Here you can see that it's setting the PATH and some other important environment variables. When you type rvm use ruby-1.9.3-p448, rvm actually sources this file in the background.

Cron executions are non-interactive sessions, which means they have no "live" user logged-in in front of a session. When you do it manually and run an interactive session, all this is taken care of for you, but for a non-interactive session, it doesn't know what the shell is or where to find the environment path. Maybe someone with more knowledge can provide a technical explanation as to why.

Anyways, to get around that, add this to the top of your crontab:

SHELL=/bin/bash
BASH_ENV=/home/gigawatt/.bashrc

* * * * * /home/gigawatt/.rvm/rubies/ruby-2.0.0-p247/bin/ruby /home/gigawatt/drbronnersbot/drbronnersbot.rb

This is telling the non-interactive cron user which shell to use and then telling it to source the .bashrc file. What's in the .bashrc file? Good question, you should add this line -

source /usr/local/rvm/environments/ruby-1.9.3-p484

(Once again, replace with your own ruby path)
Basically you are manually sourcing the environment file that rvm would have sourced for you. It's a way of getting cron to use a particular gem environment or gemset.

It should work with those two changes.

Edit2: On Ubuntu and similar systems, the default .bashrc often contains something like

# If not running interactively, don't do anything
case $- in
    *i*) ;;
      *) return;;
esac

As the comment implies, the file wont run in a non-interactive/cron session. Anything you add under that line won't be executed.

In that case, either put your source command above that line or just use a different file all together, like ~/.cronrc for example.

how to create a cron job to run a ruby script?

If your ruby is in non standard paths then personally I like to wrap my ruby calls in a shell script, thereby ensuring that all the paths etc. my ruby program needs are set correctly, and schedule the script in crontab. Do something like

2 * * * * /home/mark/project/ruby_wrapper_sh >> /home/mark/cronOutput.txt 2>&1

and your /home/mark/project/ruby_wrapper_sh should read something like

#!/bin/bash

. ~mark/.bash_profile 
`ruby /home/mark/project/script.rb`

ruby script cron not working

This has nothing to do with cron, actually. ~ is a feature of the shell, Ruby doesn't know what it is. Only some methods in Ruby deal with ~, e.g. File::expand_path. So, Ruby is literally trying to open a file named newfile.txt in directory named ~ in the current working directory. Try it out yourself: create an empty directory named ~ in your home directory, and sure enough, after 1 minute, you should find a new file named newfile.txt with the content hi.. in there.

There are a couple of ways to fix this, I will leave it up to you which one to use:

File.open(File.expand_path('~/newfile.txt'), 'a') do |f| end
File.open(File.join(Dir.home, 'newfile.txt'), 'a') do |f| end

[Note: if you only want to append to the end of the file, not move around or read, a is enough, you don't need a+.]

See the documentation for File::expand_path (bold emphasis mine):

expand_path(file_name [, dir_string] ) → abs_file_name

Converts a pathname to an absolute pathname. Relative paths are referenced from the current working directory of the process unless dir_string is given, in which case it will be used as the starting point. The given pathname may start with a “~”, which expands to the process owner’s home directory (the environment variable HOME must be set correctly). “~user” expands to the named user’s home directory.

Crontab execute the command but the ruby script is not running

Try:

12 10 * * * /bin/bash  -c 'source /home/user/.rvm/scripts/rvm && cd /home/user/path/ && /home/user/.rvm/bin/ruby-1.9.2-p136 -rubygems script.rb'

Cron won't execute ruby script

In your question, the cron you are running goes like

2 * * * * . $HOME/.bash_profile ~/jek.sh

There are multiple things you need to correct/verify with this entry

1. Check that file permissions for both is 777 or 775 (rwx). If not, then change the file permission using chmod 777 ~/jek.sh
2. Check that each of them define in their shebang line which language script they are (#!/usr/local/env sh)
3. Separate the two scripts by an && or ; so that both of them are run properly. Currently, the second script's name will be treated as a parameter for the first.
4. There is a . after the 2 * * * * part. I am not sure why you added it - it has to be removed.

In case @psny's answer doesn't work for you, try exporting your path variable in your cron entry. After that, the whole thing should work properly. Steps

1) Find the value of $PATH

echo $PATH #Lets call the string :some/path/:another/path

2) Manually set the path in your crontab entry

2 * * * * export PATH=:some/path/:another/path && /bin/bash /home/username/jek.sh

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