392

I have a crontab running every hour. The user running it has environment variabless in the .bash_profile that work when the user runs the job from the terminal, however, obviously these don't get picked up by crontab when it runs.

I've tried setting them in .profile and .bashrc but they still don't seem to get picked up. Does anyone know where I can put environment vars that crontab can pick up?

1

22 Answers 22

324

You can define environment variables in the crontab itself when running crontab -e from the command line.

LANG=nb_NO.UTF-8 LC_ALL=nb_NO.UTF-8 # m h dom mon dow command * * * * * sleep 5s && echo "yo" 

This feature is only available to certain implementations of cron. Ubuntu and Debian currently use vixie-cron which allows these to be declared in the crontab file (also GNU mcron).

Archlinux and RedHat use cronie which does not allow environment variables to be declared and will throw syntax errors in the cron.log. Workaround can be done per-entry:

# m h dom mon dow command * * * * * export LC_ALL=nb_NO.UTF-8; sleep 5s && echo "yo" 
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7 Comments

Note that you can't use variable substitution as in shell, so a declaration like PATH=/usr/local/bin:$PATH is interpreted literally.
I was able to set the environment variables in the crontab itself under RedHat 4.4.7-3 and cronie-1.4.4-15.el6.x86_64
You don't really need to export variables if the variables are only used within the command, just prepend them before your command. "* * * * * sleep 5s; LC_ALL=nb_NO.UTF-8 echo $LC_ALL"
@Zac You can use variables this way (option 3)
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217

I got one more solution for this problem:

0 5 * * * . $HOME/.profile; /path/to/command/to/run 

In this case it will pick all the environment variable defined in your $HOME/.profile file.

Of course $HOME is also not set, you have to replace it with the full path of your $HOME.

12 Comments

this wasn't working for me until I realized I had left out that period preceding $HOME. What, exactly, does that period do?
The period is equivalent to the "source" command: tldp.org/LDP/abs/html/special-chars.html#DOTREF
@PeterLee does anything mentioned worked for you? I wrote this as the above mentioned solutions were not effective for me. If above mentioned solution does not work, I will have to do some research to find the reason. ;-)
@Vishal Actually, it now works for me. I was trying to source ~/.bashrc, and it turns out that my .bashrc file is sort-of conflicting with the cron job. If I use a very simple .env_setup_rc file with only one line: export MY_ENV_VAR=my_env_val, it actually works. See my post: stackoverflow.com/questions/15557777/…
This is not a good practice at all. $HOME/.profile should be limited to interactive sessions (I mean, a real person logging in and doing things) only - an inadvertent edit of .profile shouldn't break production cron jobs! It is much better to have a common environment setup script that is called from .profile as well as a cron wrapper. See this answer for more info: Effecting cron job management
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150

Setting vars in /etc/environment also worked for me in Ubuntu. As of 12.04, variables in /etc/environment are loaded for cron.

9 Comments

Best answer, just execute env >> /etc/environment and all the current env vars are now available in the CRON jobs.
this works great for me. especially because i'm running into a Docker Container, so I don't care much about "system wide" implications.
@Savageman that's like killing flies with fusion bombs, also the stakes of unexpected behavior are extremely high doing so.
Be CAREFUL: env >> /etc/environment will FAIL if there is a hash sign in one of the environment variables. I had the hardest time troubleshooting my application. It turned out to be a password containing '#' which was getting truncated at that step.
This should be the chosen answer. I don't know why people are complicating things with the other answers or with this stuff about env >> /etc/environment. Just blinking well edit etc/environment if you want these env vars to be universally available: my experiments seem to confirm that export statements for env vars in /etc/environment are available to crontab and also for users. THE PROBLEM: again from my experiments: it appears that these env vars are NOT EXPANDED within crontab itself! ... i.e. they are expanded only in the scripts called!
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107

If you start the scripts you are executing through cron with:

#!/bin/bash -l 

They should pick up your ~/.bash_profile environment variables

11 Comments

In the script itself. Which you then run with cron normally.
@Jim see this example, classic executable file (chmod 777) use #!/bin/bash. The magic here is to add -l
Explanation from the man: -l Make bash act as if it had been invoked as a login shell (see INVOCATION below).
You can also call the script in cron with the -l option: 0 * * * * bash -l hourly.sh, which I personally prefer. (also see unix.stackexchange.com/a/422505/436224)
@PeterKrauss Whatever you are hoping to accomplish, chmod 777 is wrong and dangerous. You will want to revert to sane permissions ASAP (for your use case, probably chmod 755) and if you have had world writable system files on a public-facing system, at the very least investigate whether it could have been breached and used as a pivot point for breaking into your organization’s network.
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98

Have 'cron' run a shell script that sets the environment before running the command.

Always.

# @(#)$Id: crontab,v 4.2 2007/09/17 02:41:00 jleffler Exp $ # Crontab file for Home Directory for Jonathan Leffler (JL) #----------------------------------------------------------------------------- #Min Hour Day Month Weekday Command #----------------------------------------------------------------------------- 0 * * * * /usr/bin/ksh /work1/jleffler/bin/Cron/hourly 1 1 * * * /usr/bin/ksh /work1/jleffler/bin/Cron/daily 23 1 * * 1-5 /usr/bin/ksh /work1/jleffler/bin/Cron/weekday 2 3 * * 0 /usr/bin/ksh /work1/jleffler/bin/Cron/weekly 21 3 1 * * /usr/bin/ksh /work1/jleffler/bin/Cron/monthly 

The scripts in ~/bin/Cron are all links to a single script, 'runcron', which looks like:

: "$Id: runcron.sh,v 2.1 2001/02/27 00:53:22 jleffler Exp $" # # Commands to be performed by Cron (no debugging options) # Set environment -- not done by cron (usually switches HOME) . $HOME/.cronfile base=`basename $0` cmd=${REAL_HOME:-/real/home}/bin/$base if [ ! -x $cmd ] then cmd=${HOME}/bin/$base fi exec $cmd ${@:+"$@"} 

(Written using an older coding standard - nowadays, I'd use a shebang '#!' at the start.)

The '~/.cronfile' is a variation on my profile for use by cron - rigorously non-interactive and no echoing for the sake of being noisy. You could arrange to execute the .profile and so on instead. (The REAL_HOME stuff is an artefact of my environment - you can pretend it is the same as $HOME.)

So, this code reads the appropriate environment and then executes the non-Cron version of the command from my home directory. So, for example, my 'weekday' command looks like:

: "@(#)$Id: weekday.sh,v 1.10 2007/09/17 02:42:03 jleffler Exp $" # # Commands to be done each weekday # Update ICSCOPE n.updics 

The 'daily' command is simpler:

: "@(#)$Id: daily.sh,v 1.5 1997/06/02 22:04:21 johnl Exp $" # # Commands to be done daily # Nothing -- most things are done on weekdays only exit 0 

Comments

31

Expanding on @carestad example, which I find easier, is to run the script with cron and have the environment in the script.

In crontab -e file:

SHELL=/bin/bash */1 * * * * $HOME/cron_job.sh 

In cron_job.sh file:

#!/bin/bash source $HOME/.bash_profile some_other_cmd 

Any command after the source of .bash_profile will have your environment as if you logged in.

2 Comments

What is the purpose of SHELL=/bin/bash line? Wouldn't #!/bin/bash by itself be enough?
crontab is not a script file but a program that has it's own format. To keep things consistent with possible commands, all shells are the same from start to finish. Please see: man7.org/linux/man-pages/man5/crontab.5.html and search for SHELL
22

Whatever you set in crontab will be available in the cronjobs, both directly and using the variables in the scripts.

Use them in the definition of the cronjob

You can configure crontab so that it sets variables that then the can cronjob use:

$ crontab -l myvar="hi man" * * * * * echo "$myvar. date is $(date)" >> /tmp/hello 

Now the file /tmp/hello shows things like:

$ cat /tmp/hello hi man. date is Thu May 12 12:10:01 CEST 2016 hi man. date is Thu May 12 12:11:01 CEST 2016 

Use them in the script run by cronjob

You can configure crontab so that it sets variables that then the scripts can use:

$ crontab -l myvar="hi man" * * * * * /bin/bash /tmp/myscript.sh 

And say script /tmp/myscript.sh is like this:

echo "Now is $(date). myvar=$myvar" >> /tmp/myoutput.res 

It generates a file /tmp/myoutput.res showing:

$ cat /tmp/myoutput.res Now is Thu May 12 12:07:01 CEST 2016. myvar=hi man Now is Thu May 12 12:08:01 CEST 2016. myvar=hi man ... 

Comments

17

For me I had to set the environment variable for a php application. I resolved it by adding the following code to my crontab.

$ sudo crontab -e 

crontab:

ENVIRONMENT_VAR=production * * * * * /home/deploy/my_app/cron/cron.doSomethingWonderful.php 

and inside doSomethingWonderful.php I could get the environment value with:

<?php echo $_SERVER['ENVIRONMENT_VAR']; # => "production" 

I hope this helps!

2 Comments

This didn't work for me. The environment variable was not available in the script that was invoked inside the crontab.
crontab doesn't support user defined variables. Kind of counterintuitive, but...
13

Instead of

0 * * * * sh /my/script.sh 

Use bash -l -c

0 * * * * bash -l -c 'sh /my/script.sh' 

1 Comment

What if I need to run a perl/python/ruby script not bash? I can’t add #!/bin/bash -l to the top of a python script.
11

You can also prepend your command with env to inject Environment variables like so:

0 * * * * env VARIABLE=VALUE /usr/bin/mycommand 

Comments

8

Expanding on @Robert Brisita has just expand , also if you don't want to set up all the variables of the profile in the script, you can select the variables to export on the top of the script

In crontab -e file:

SHELL=/bin/bash */1 * * * * /Path/to/script/script.sh 

In script.sh

#!/bin/bash export JAVA_HOME=/path/to/jdk some-other-command 

Comments

8

I'm using Oh-my-zsh in my macbook so I've tried many things to get the crontab task runs but finally, my solution was prepending the .zshrc before the command to run.

*/30 * * * * . $HOME/.zshrc; node /path/for/my_script.js 

This task runs every 30 minutes and uses .zshrc profile to execute my node command.

Don't forget to use the dot before the $HOME var.

2 Comments

Is your crontab's $SHELL already zsh? Mine is /bin/sh though I use zsh interactively.
Or, conversely, does your .zshrc only contain expressions which are also valid sh syntax? For quick and dirty fixes, sourcing a file which is used for interactive shells in a noninteractive one like your crontab is probably fine if you know what you are doing, but error-prone and hairy to troubleshoot if you don't.
5

I tried most of the provided solutions, but nothing worked at first. It turns out, though, that it wasn't the solutions that failed to work. Apparently, my ~/.bashrc file starts with the following block of code:

case $- in *i*) ;; *) return;; esac 

This basically is a case statement that checks the current set of options in the current shell to determine that the shell is running interactively. If the shell happens to be running interactively, then it moves on to sourcing the ~/.bashrc file. However, in a shell invoked by cron, the $- variable doesn't contain the i value which indicates interactivity. Therefore, the ~/.bashrc file never gets sourced fully. As a result, the environment variables never got set. If this happens to be your issue, feel free to comment out the block of code as follows and try again:

# case $- in # *i*) ;; # *) return;; # esac 

I hope this turns out useful

2 Comments

Should be a comment instead of an answer, but I upvote it anyway
The reason this code is there is to prevent you from abusing a file whose purpose is to configure interactive shell sessions. Several answers here misleadingly suggest this, but it is not best practice. A much better solution is to separate your noninteractive settings into a separate file, and then source only that from your crontab, as well as from your various interactive shell startup files.
3

Unfortunately, crontabs have a very limited environment variables scope, thus you need to export them every time the corntab runs.

An easy approach would be the following example, suppose you've your env vars in a file called env, then:

* * * * * . ./env && /path/to_your/command

this part . ./env will export them and then they're used within the same scope of your command

Comments

2

Another way - inspired by this this answer - to "inject" variables is the following (fcron example):

%daily 00 12 \ set -a; \ . /path/to/file/containing/vars; \ set +a; \ /path/to/script/using/vars 

From help set:

-a Mark variables which are modified or created for export.

Using + rather than - causes these flags to be turned off.

So everything in between set - and set + gets exported to env and is then available for other scripts, etc. Without using set the variables get sourced but live in set only.

Aside from that it's also useful to pass variables when a program requires a non-root account to run but you'd need some variables inside that other user's environment. Below is an example passing in nullmailer vars to format the e-mail header:

su -s /bin/bash -c "set -a; \ . /path/to/nullmailer-vars; \ set +a; \ /usr/sbin/logcheck" logcheck 

Comments

2

All the above solutions work fine.

It will create issues when there are any special characters in your environment variable.

I have found the solution:

eval $(printenv | awk -F= '{print "export " "\""$1"\"""=""\""$2"\"" }' >> /etc/profile)

1 Comment

This worked for me in a Docker/Kubernetes set up. Put this command in a bash script and run this in the entry command, then prepend each crontab entry with: . /etc/profile; (eg. * * * * * . /etc/profile; echo "$environmental_variable1")
2

None of the above worked for me. What did work was:

* * * * * /usr/bin/bash -ic "your_command" 

or wherever your bash is located. Double quotes are important. -i causes bash to be interactive and .bashrc will be processed.

1 Comment

This does not provide an answer to the question. Once you have sufficient reputation you will be able to comment on any post; instead, provide answers that don't require clarification from the asker. - From Review
1

For me I had to specify path in my NodeJS file.

// did not work!!!!! require('dotenv').config() 

instead

// DID WORK!! require('dotenv').config({ path: '/full/custom/path/to/your/.env' }) 

Comments

1

I found this issue while looking at a similar problem that matched the title, but I am stuck with the environment file syntax that systemd or docker use:

FOO=bar BAZ=qux 

This won't work for Vishal's excellent answer because they aren't bash scripts (note the lack of export).
The solution I've used is to read each line into xargs and export them before running the command:

0 5 * * * export $(xargs < $HOME/.env); /path/to/command/to/run 

Comments

0
  • Set Globally env
sudo sh -c "echo MY_GLOBAL_ENV_TO_MY_CURRENT_DIR=$(pwd)" >> /etc/environment" 
  • Add scheduled job to start a script
crontab -e */5 * * * * sh -c "$MY_GLOBAL_ENV_TO_MY_CURRENT_DIR/start.sh" 

=)

Comments

0

I ran into this problem today where I had to get following scenario working:

  1. debian-slim image with required tools
  2. Expose set of ENV variables as part of k8s deployment (deplopyments.yaml)
  3. Make the variables available to my cron job.

How did I do it?

Container Spec (k8s pod):

 spec: containers: - name: my-container image: my-registry-host/my-image:1.1.0_DV9qfuY37AWw imagePullPolicy: IfNotPresent command: ["/bin/bash", "-c", "/apps/my-awesome-app/scripts/startup.sh"] ... env: - name: ENV_VAR1 value: "env-var1-value" - name: ENV_VAR2 value: "env-var2-value" - name: ENV_VAR3 value: "env-var3-value" 

Dockerfile

... RUN crontab -l | { cat; echo "*/15 14-19 23 * * /apps/my-awesome-app/scripts/cronsjob.sh >> cronjob-journal.log"; } | crontab - ... 

/apps/my-awesome-app/scripts/startup.sh listing ENV_VAR1, ENV_VAR2, ENV_VAR3 are exposed to the pod (as shown above):

... #Make all the environment variables available to crontab shell(s) crontab -l | { echo "ENV_VAR1=${ENV_VAR1}";cat; } | crontab - crontab -l | { echo "ENV_VAR2=${ENV_VAR2}";cat; } | crontab - crontab -l | { echo "ENV_VAR3=${ENV_VAR3}";cat; } | crontab - ... # Other startup commands/scripts ... 

Validation/Verification

1) kubectl exec -i -t <podname> -n <namespace> -- bash 2) execute `crontab -l` 3) Verify the following listing ENV_VAR1=env-var1-value ENV_VAR2=env-var2-value ENV_VAR3=env-var3-value */15 14-19 23 * * /apps/my-awesome-app/scripts/cronsjob.sh >> cronjob-journal.log 

Now all 3 of your environment variables are available to /apps/my-awesome-app/scripts/cronsjob.sh when cron scheduler invokes it.

Comments

-1

what worked for me (debian based):

  1. create a file with all the needed env var :

    #!/bin/bash
    env | grep VAR1= > /etc/environment
    env | grep VAR2= >> /etc/environment
    env | grep VAR3= >> /etc/environment

  2. then build the crontab content, by calling the env file before calling the script that needs it, therefore start the cron service

    (crontab -l ; echo '* * * * * . /etc/environment; /usr/local/bin/python /mycode.py >> /var/log/cron-1.log 2>&1') | crontab
    service cron start

nb : for python use case, be sure to call the whole python path, else wrong python could be invocated, generating non-sense syntax error

2 Comments

You can easily use a single grep; viz. env | grep -E ^(VAR1|VAR2|VAR3)=' >>/etc/environment` (for this simple task grep '^VAR[123]=' would suffice, but real-world variables are rarely named so neatly).
Perhaps emphasize that /etc/environment is one of several possible configuration files, and not necessarily portable to other Linuxes, let alone proper Unixes.

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