deploycron

A small tool for deploying crontab into your system.

It's useful if you want to deploy some crontab scripts into your system when you deploy your software that contains some extra crontab scripts.

Install

pip install deploycron

Usage

There are two functions in the package now,

def deploycron(filename="", content="", override=False):

Install crontabs into the system if it's not installed.
This will not remove the other crontabs installed in the system if not specified
as override. It just merge the new one with the existing one.
If you provide filename, then will install the crontabs in that file
otherwise install crontabs specified in content

filename - file contains crontab, one crontab for a line
content - string that contains crontab, one crontab for a line
override - override the origin crontab

Example:

from deploycron import deploycron

# specify a filename
deploycron(filename="/tmp/youcrontab.tab")

# or just specify crontab content
deploycron(content="* * * * * echo hello > /tmp/hello")

# if you want to overwrite the existing crontab, set `override` to True
deploycron(content="* * * * * echo hello > /tmp/hello", override=True)

and

def undeploycron_between(start_line, stop_line, occur_start, occur_stop):

Uninstall crontab parts between two lines (included). If the start_line or the stop_line is not found into the installed crontab, it won't be modified. Returns True if the operation succeded and False if the operation failed.

start_line - start crontab line (the actual line, not the line number) to delimit the crontab block to remove
stop_line - stop crontab line (the actual line, not the line number) to delimit the crontab block to remove
occur_start - number of the occurrence of start_line at which the uninstall will start (1 => first occurrence)
occur_start - number of the occurrence of stop_line at which the uninstall will stop

Example 1:

from deploycron import deploycron

# Crontab sample
deploycron(content="* * * * * echo Good > /tmp/buffer")
deploycron(content="* * * * * echo day > /tmp/buffer")
deploycron(content="* * * * * echo to > /tmp/buffer")
deploycron(content="* * * * * echo you > /tmp/buffer")
deploycron(content="* * * * * echo mate > /tmp/buffer")

# We want to remove from line 2 to line 4 included
undeploycron_between("* * * * * echo day > /tmp/buffer",
                     "* * * * * echo mate > /tmp/buffer")

With this script, we first get a crontab like this one :

* * * * * echo Good > /tmp/buffer
* * * * * echo day > /tmp/buffer
* * * * * echo to > /tmp/buffer
* * * * * echo you > /tmp/buffer
* * * * * echo mate > /tmp/buffer

And then, after the undeploycron_between(), we get :

* * * * * echo Good > /tmp/buffer
* * * * * echo mate > /tmp/buffer

Example 2:

from deploycron import deploycron

# Crontab sample
deploycron(content="* * * * * echo Good > /tmp/buffer")
deploycron(content="* * * * * echo day > /tmp/buffer")
deploycron(content="* * * * * echo to > /tmp/buffer")
deploycron(content="* * * * * echo you > /tmp/buffer")
deploycron(content="* * * * * echo mate > /tmp/buffer")
deploycron(content="* * * * * echo Good > /tmp/buffer")
deploycron(content="* * * * * echo to > /tmp/buffer")
deploycron(content="* * * * * echo see > /tmp/buffer")
deploycron(content="* * * * * echo you > /tmp/buffer")

# We want to remove from line 6 to line 9 included
undeploycron_between("* * * * * echo Good > /tmp/buffer",
                     "* * * * * echo you > /tmp/buffer",
                     2,
                     2)

This script allows us to go from this crontab :

* * * * * echo Good > /tmp/buffer
* * * * * echo day > /tmp/buffer
* * * * * echo to > /tmp/buffer
* * * * * echo you > /tmp/buffer
* * * * * echo mate > /tmp/buffer
* * * * * echo Good > /tmp/buffer
* * * * * echo to > /tmp/buffer
* * * * * echo see > /tmp/buffer
* * * * * echo you > /tmp/buffer

To this one :

* * * * * echo Good > /tmp/buffer
* * * * * echo day > /tmp/buffer
* * * * * echo to > /tmp/buffer
* * * * * echo you > /tmp/buffer
* * * * * echo mate > /tmp/buffer

The undeploy doesn't trigger at the first occurrence of the lines here. Instead, it triggers at the second occurrence of both start_line and stop_line as precised in the parameters.

CLI scripts

The package also provides two helpers CLI scripts mapped to corresponding functions:

usage: deploycron_file [-h] filepath

positional arguments:
  filepath    Complete file path of the cron to deploy

optional arguments:
  -h, --help  show this help message and exit

and

usage: undeploycron_between [-h] start_line stop_line

positional arguments:
  start_line  start line to delimit the crontab block to remove
  stop_line   stop line to delimit the crontab block to remove

optional arguments:
  -h, --help  show this help message and exit

Note

Only support in unix-like system, eg. Linux/Mac

Authors

• Monklof ([email protected])

• thefab

• Hawker65

License

MIT