terraformmetrics 1.0.6

A module to extract metrics from Terrafor, scripts

The static source code measurement tool for Terraform

TerrafomMetrics is a Python-based static source code measurement tool to characterize Infrastructure-as-Code. It helps quantify the characteristics of infrastructure code to support DevOps engineers when maintaining and evolving it. It currently supports 25 source code metrics, though other metrics can be derived by combining the implemented ones.

How to install

Installation is made simple by the PyPI repository. Download the tool and install it with:

pip install terraformmetrics

or, alternatively from the source code project directory:

pip install -r requirements.txt
pip install .

How to use

Command-line

Run terraform-metrics --help for instructions about the usage:

usage: terraform-metrics [-h] [--omit-zero-metrics] [-d DEST] [-o] [-v] src

Extract metrics from Terraform scripts.

positional arguments:
  src                   source file (tf file) or
                        directory

optional arguments:
  -h, --help            show this help message and exit
  --omit-zero-metrics   omit metrics with value equal 0
  -d DEST, --dest DEST  destination path to save results
  -o, --output          shows output
  -v, --version         show program's version number and exit

This is an example where metrics are calculated on the main.tf file assuming that it is run from the folder where the file is located. The result will be saved in the report.json file

terraform-metrics --omit-zero-metrics main.tf --dest report.json

Python

TerraformMetrics currently supports up to 25 source code metrics, implemented in Python. To extract the value for a given metric follow this pattern:

from terraformmetrics.<general|terraformspec>.metric import Metric

script = 'a valid yaml script'
value = Metric(script).count()

where metric and Metric have to be replaced with the name of the desired metric module to compute the value of a specific metric.
The difference between the general and the terraformspec modules lies in the fact that the terraformspec module contains metrics specific to terraform, while the general module contains metrics that can be generalized to other languages (for example, the lines of code).

For example, to count the number of lines of code:

from terraformmetrics.terraformspec.num_resources import NumResources

script = """ 
     resource "opc_storage_container" "accs-apps" {
       name = "my-accs-apps"
     }

     resource "opc_storage_object" "example-java-app" {
       name         = "employees-web-app.zip"
       container    = "${opc_storage_container.accs-apps.name}"
       file         = "./employees-web-app.zip"
       etag         = "${md5(file("./employees-web-app.zip"))}"
       content_type = "application/zip;charset=UTF-8"
     }
     """

value = NumResources(script).count()
print('Number of resources: ', value)

To extract the value for the 25 metrics at once, import the terraformmetrics.metrics_extractor package and call the method extract_all() (in this case the return value will be a json object):

from terraformmetrics.metrics_extractor import extract_all

script = """ 
     resource "opc_storage_container" "accs-apps" {
       name = "my-accs-apps"
     }

     resource "opc_storage_object" "example-java-app" {
       name         = "employees-web-app.zip"
       container    = "${opc_storage_container.accs-apps.name}"
       file         = "./employees-web-app.zip"
       etag         = "${md5(file("./employees-web-app.zip"))}"
       content_type = "application/zip;charset=UTF-8"
     }
     """

metrics = extract_all(script)
print('Lines of executable code:', metrics['lines_code'])