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I am trying to template-ize my Apache httpd configuration for deployment to different environments and I would like to use the Python language Cheetah application to do so. However, I am having difficulty with the command line cheetah program and I believe its a combination of my misunderstanding Cheetah along with a lack of documentation.

My goal is to have a single httpd.conf template file and substitute variables from an environment specific definition file.

httpd.tmpl:

Listen $HTTP_PORT
...
#if $ENABLE_HTTPS == true
<Virtual Host *:$HTTPS_PORT>
    ...
</VirtualHost>
#end if

production.env:

HTTP_PORT=34120
HTTPS_PORT=34121
ENABLE_HTTPS=true

What is the command line needed to fill this Cheetah template? I've used:

cheetah f --oext conf --debug httpd

But obviously prod.env is not read as an input file. Adding an #include to the top of my template file:

#include "prod.env"

And none of my names are found:

Cheetah.NameMapper.NotFound: cannot find 'APACHE_PORT'

This is not the ideal situation anyway, because I want the ability to specify the name/value mapping file on the command line for each invocation of cheetah.

Thanks!

EDIT: I am aware that I can write a python script to perform the file reading and then substitute using the Cheetah API. However, I'm looking for a way to use the command line to fill my template.

SOLVED

Thanks to the documentation link provided by @pyfunc I now understand how to accomplish this. The main issue is to supply --env on the cheetah command line which passes the current environment variables to cheetah. These environment variables must be exported first however.

purecharger
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1 Answers1

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Cheetah wraps each chunk of #include text inside a nested Template object.

Use

#include raw "prod.env"

also

#set global $HTTP_PORT="34120"

To include different env files, you will have too templatize that too.

Please look at the following for examples that should help you.

pyfunc
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  • Thanks for posting. How would you address substituting the environment filename ("prod.env") for different environments? I want to avoid hardcoding values in the templates. – purecharger Sep 02 '10 at 21:15
  • I have edited my answer. The above link demonstrates and can help youdo that. – pyfunc Sep 02 '10 at 21:31
  • Thanks for the pointer! So the following produces the expected output: `APACHE_PORT=10240 ENABLE_HTTPS=true cheetah f --env --oext conf httpd` However, setting these environment variables in a separate step does NOT produce the desired output: $ source prod.env $ set | egrep "(APACHE|HTTPS)" APACHE_PORT=10800 ENABLE_HTTPS=true $ cheetah f --env --oext conf httpd ... Cheetah.NameMapper.NotFound: cannot find 'APACHE_PORT' Any ideas? EDIT: arrg! comments don't allow full formatting, sorry! – purecharger Sep 02 '10 at 21:56