{section: How to adjust the job's environment for the execute machine}

Known to work with HTCondor version: 7.0

If you simply need to insert an environment variable, you can do that by putting the following in your configuration file on the execute machine:

{code}
STARTER_JOB_ENVIRONMENT = "APP1_PATH=/opt/app1 APP2_PATH=/opt/app2"
{endcode}

If you need to dynamically modify an environment variable, you can do that in a wrapper script around the job.  Here is what you would put in the configuration file:

{code}
USER_JOB_WRAPPER=/path/to/condor_job_wrapper
{endcode}

Then you would create a file named condor_job_wrapper (or whatever name you choose), make it executable, and put in something like the following:

{code}
#!/bin/sh

# insert /s/std/bin into the PATH
export PATH=/s/std/bin:$PATH

exec "$@"
{endcode}


Another way for information from the machine to enter the job environment is to publish the information in the machine {quote: ClassAd} and leave it up to the user to insert it into the job's environment via the $$() mechanism, which substitutes in values from the target {quote: ClassAd}.  Example machine configuration:

{code}
APP1_PATH = "/opt/app1"
APP2_PATH = "/opt/app2"
STARTD_ATTRS = $(STARTD_ATTRS) APP1_PATH APP2_PATH
{endcode}

Then the user can insert this information into the job environment by putting the following in the job submit file:

{code}
environment = "APP1_PATH=$$(APP1_PATH) APP2_PATH=$$(APP2_PATH)"
{endcode}

If it is expected that the job may run on machines where these attributes of the machine {quote: ClassAd} are not defined, a default value should be specified like this.  For example, if it should just be empty when undefined, use this: {code}APP1_PATH=$$(APP1_PATH:){endcode}