dda-python-terraform/README.md
2020-10-21 00:15:14 +02:00

142 lines
4.9 KiB
Markdown
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

## Introduction
python-terraform is a python module provide a wrapper of `terraform` command line tool.
`terraform` is a tool made by Hashicorp, please refer to https://terraform.io/
[![Code style: black](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/psf/black)
[![pre-commit](https://img.shields.io/badge/pre--commit-enabled-brightgreen?logo=pre-commit&logoColor=white)](https://github.com/pre-commit/pre-commit)
### Status
[![Build Status](https://travis-ci.org/aubustou/python-terraform.svg?branch=develop)](https://travis-ci.org/aubustou/python-terraform)
## Installation
pip install python-terraform
## Usage
#### For any terraform command
from python_terraform import *
t = Terraform()
return_code, stdout, stderr = t.<cmd_name>(*arguments, **options)
**Note**: method name same as reserved keyword like `import` won't be accepted by python interpreter,
to be able to call the method, you could call cmd_name by adding `_cmd` after command name, for example,
`import` here could be called by
from python_terraform import *
t = Terraform()
return_code, stdout, stderr = t.import_cmd(*arguments, **options)
or just call cmd method directly
from python_terraform import *
t = Terraform()
return_code, stdout, stderr = t.cmd(<cmd_name>, *arguments, **options)
#### For any argument
simply pass the string to arguments of the method, for example,
terraform apply target_dir
--> <instance>.apply('target_dir')
terraform import aws_instance.foo i-abcd1234
--> <instance>.import('aws_instance.foo', 'i-abcd1234')
#### For any options
* dash to underscore
remove first dash, and then use underscore to replace dash symbol as option name
ex. -no-color --> no_color
* for a simple flag option
use ```IsFlagged/None``` as value for raising/not raising flag, for example,
terraform taint -allow-missing
--> <instance>.taint(allow_missing=IsFlagged)
terraform taint
--> <instance>.taint(allow_missing=None) or <instance>.taint()
terraform apply -no-color
--> <instance>.apply(no_color=IsFlagged)
* for a boolean value option
assign True or False, for example,
terraform apply -refresh=true --> <instance>.apply(refresh=True)
* if a flag could be used multiple times, assign a list to it's value
terraform apply -target=aws_instance.foo[1] -target=aws_instance.foo[2]
--->
<instance>.apply(target=['aws_instance.foo[1]', 'aws_instance.foo[2]'])
* for the "var" flag, assign dictionary to it
terraform apply -var='a=b' -var='c=d'
--> tf.apply(var={'a':'b', 'c':'d'})
* if an option with None as value, it won't be used
#### Terraform Output
By default, stdout and stderr are captured and returned. This causes the application to appear to hang. To print terraform output in real time, provide the `capture_output` option with any value other than `None`. This will cause the output of terraform to be printed to the terminal in real time. The value of `stdout` and `stderr` below will be `None`.
from python_terraform import Terraform
t = Terraform()
return_code, stdout, stderr = t.<cmd_name>(capture_output=False)
## Examples
### Have a test.tf file under folder "/home/test"
#### 1. apply with variables a=b, c=d, refresh=false, no color in the output
In shell:
cd /home/test
terraform apply -var='a=b' -var='c=d' -refresh=false -no-color
In python-terraform:
from python_terraform import *
tf = Terraform(working_dir='/home/test')
tf.apply(no_color=IsFlagged, refresh=False, var={'a':'b', 'c':'d'})
or
from python_terraform import *
tf = Terraform()
tf.apply('/home/test', no_color=IsFlagged, refresh=False, var={'a':'b', 'c':'d'})
or
from python_terraform import *
tf = Terraform(working_dir='/home/test', variables={'a':'b', 'c':'d'})
tf.apply(no_color=IsFlagged, refresh=False)
#### 2. fmt command, diff=true
In shell:
cd /home/test
terraform fmt -diff=true
In python-terraform:
from python_terraform import *
tf = terraform(working_dir='/home/test')
tf.fmt(diff=True)
## default values
for apply/plan/destroy command, assign with following default value to make
caller easier in python
1. ```input=False```, in this case process won't hang because you missing a variable
1. ```no_color=IsFlagged```, in this case, stdout of result is easier for parsing
## Implementation
IMHO, how terraform design boolean options is confusing.
Take `input=True` and `-no-color` option of `apply` command for example,
they're all boolean value but with different option type.
This make api caller don't have a general rule to follow but to do
a exhaustive method implementation which I don't prefer to.
Therefore I end-up with using `IsFlagged` or `IsNotFlagged` as value of option
like `-no-color` and `True/False` value reserved for option like `refresh=true`