ℹ️Running Veza Scripts with Python

Veza Python Script Setup and Execution Guide for Linux, Windows, and Mac

This document provides instructions for setting up and running Veza Python scripts on Linux, Windows, and Mac operating systems. Users seeking to automate Veza Python scripts on different platforms can refer to the sections below to learn about:

• Verifying Python Installations

• Installing Required Packages

• Setting Environment Variables

• Executing Scripts

• Scheduling Periodic Script Runs

• Setting Temporary and Persistent Environment Variables

These instructions are especially intended to help run and schedule Open Authorization API connectors provided as Python packages.

Linux

Setup

Verify Python3 Installation

Many current Linux distributions typically have python3 installed by default.

To verify that python3 is installed on your system, run the following command:

which python3
which pip3

If the outputs are filesystem paths (ex: /usr/bin/python3), the applications are installed.

Installing Required Packages

Veza Python scripts may rely on external dependencies; if this is the case, the script package will include a requirements.txt file.

To ensure that the dependencies are installed, run the following command from the directory in which the requirements.txt file is located:

pip3 install -r requirements.txt

Setting Environment Variables

Veza Python scripts often require some variable input at run time (ex: API key, service URL).

Non-secret data can be passed to the script as arguments or set as environment variables, but sensitive data must be set as an environment variable.

See the README.md packaged with a script for a description of required input data.

Temporary Environment Variables

Environment variables can be set temporarily from the Linux shell; these settings will last until the shell process in which they are set is terminated.

To temporarily set an environment variable from the Linux shell, run the following command:

export <variable_name>="<value>"

An example setting VEZA_URL to the FQDN of a Veza instance:

export VEZA_URL="https://example.vezacloud.com"

To verify currently set environment variables and their values, run the env command from the terminal.

To remove a currently set environment variable, run the following command:

unset <variable_name>

Unsetting the previously established VEZA_URL example:

unset VEZA_URL

Persistent Environment Variables

Environment variables can be set persistently in several ways, each with their own scope.

In each case, edit the relevant file and add the following line to set the new variable:

export <variable_name>="<value>"

• To set a persistent environment variable for only the currently logged-on user, edit ~/.bashrc and add the export to the end of the file.

• To set a variable for all login shell sessions, edit /etc/profile and add the export to the end of the file.

• To set a system-wide variable, edit /etc/environment and add the export to the end of the file.

Current shell sessions will not reflect the file update immediately - to make use of the newly set variable, source the file first:

source ~/.bashrc

Execution

To run the Veza Python script, chmod the file to make it executable, then execute it:

chmod +x <script_name>.py
./<script_name>.py

To pass additional parameters not set as environment variables when executing the script:

./<script_name>.py --<parmeter1_name> <parameter1_value> --<flag_parmeter>

An example of setting a parameter with a value along with a flag parameter:

./veza_script.py --veza_url https://example.vezacloud.com --debug

Scheduling

Periodic executions of scripts can be configured to run via cron or via systemd, depending on your environment.

Cron

Scheduling via cron requires a line to be added to the crontab.

Note: cron executes commands without a login shell; environment variables set in ~/.bashrc or /etc/profile will not be loaded.

To edit the crontab, run crontab -e, then add the following:

VEZA_URL="https://example.vezacloud.com"
VEZA_API_KEY="k124c021...fc1d281"
0 * * * * /usr/bin/python3 /path/to/<veza_script.py>

Some distributions do not honor environment variables set in the crontab file; in those cases, they can be set inline:

0 * * * * root env VEZA_URL="https://example.vezacloud.com" VEZA_API_KEY="k124c021...fc1d281" /usr/bin/python3 /path/to/<veza_script.py>

Systemd

Scheduling via systemd requires a timer unit file and a corresponding service unit file.

Begin by creating the timer unit file (vim /etc/system/systemd/<veza_script>.timer):

[Unit]
Description=Execute Veza Python Script Every Hour

[Timer]
OnCalendar=daily

Unit=<veza_script>.service

[Install]
WantedBy=timers.target

Then create the service file (vim /etc/system/systemd/<veza_script>.service):

[Unit]
Description=Veza Python Script Service

[Service]
# Environment variables can be defined here
Environment=VEZA_URL="https://example.vezacloud.com"
Environment=VEZA_API_KEY="k124c021...fc1d281"
Type=simple
ExecStart=/usr/bin/python3 /path/to/<veza_script.py>

[Install]
WantedBy=multi-user.target

Run the following commands to reload service definitions and enable the new service:

systemctl daemon-reload
systemctl enable <veza_script>.service
systemctl start <veza_script>.service

Windows

Setup

Verify Python Installation

Install python by browsing to https://www.python.org/downloads/windows/ and selecting the latest stable 64-bit installer.

Alternatively, on Windows workstations, Python may be installed via the Microsoft Store. See https://learn.microsoft.com/en-us/windows/python/beginners for details.

Note: During installation, ensure the Add python.exe to PATH checkbox is selected.

To ensure that python and pip are properly installed and added to the PATH, open a Command Prompt and run:

where python
where pip

Both commands will return paths on the filesystem if the executables are located.

Installing Required Packages

Veza Python scripts may rely on external dependencies; if this is the case, the script package will include a requirements.txt file.

To ensure that the dependencies are installed, run the following command from the directory in which the requirements.txt file is located:

pip install -r requirements.txt

Setting Environment Variables

Temporary Environment Variables

Command Prompt

To set an environment variable for an existing Command Prompt session, run the following:

set <variable_name>=<value>

An example setting VEZA_URL to the FQDN of a Veza instance:

set VEZA_URL="https://example.vezacloud.com"

To remove the previously set VEZA_URL example:

set VEZA_URL=

PowerShell

To set an environment variable for an existing PowerShell session, run the following:

$env:<variable_name> = '<value'

An example setting VEZA_URL to the FQDN of a Veza instance:

$env:VEZA_URL = 'https://example.vezacloud.com'

To remove the previously set VEZA_URL example:

Remove-Item env:\VEZA_URL

Persistent Environment Variables

To set environment variables on a Windows system, follow these steps:

• On the taskbar, right-click the Windows icon and click System

• In the Settings window, locate and click Advanced system settings

• In the System Properties window that appears, click the Environment Variables button near the bottom.

• In the Environment Variables window that appears, choose the scope for the new variable. User-specific variables are listed at the top of the window with system-wide variables below.

• Click the New button underneath the appropriate scope.

• Complete the New System Variable dialog that appears, providing a Variable name and Variable value, then click OK Note: no quotes are required for complex variable values when set via this method

Current Command Prompt and PowerShell sessions will not update immediately - to make use of the newly set variable, start a new Command Prompt or PowerShell session.

Execution

To run the Veza Python script, open a Command Prompt window and execute the following:

python <script_name>.py

To pass additional parameters not set as environment variables when executing the script:

./<script_name>.py --<parmeter1_name> <parameter1_value> --<flag_parmeter>

An example of setting a parameter with a value along with a flag parameter:

./veza_script.py --veza_url https://example.vezacloud.com --debug

Scheduling

Periodic executions of scripts can be configured via the Task Scheduler interface on Windows.

Note: ensure that any required environment variables have been stored as system-wide variables before scheduling a task that utilizes them. Also stop the Taskeng.exe process to force Task Scheduler to reload environment variables.

• In the search bar, type Task Scheduler, then click on the search result to open the interface.

• In the Actions pane on the right side of the window, click Create Basic Task

• In the Create Basic Task Wizard, provide the following:

  • Name: A name for the scheduled task

  • Description: An optional longer description of what the task does

  • Trigger: Select a time-based trigger (Daily)

  • Daily time settings for task triggering

  • Program/script: Enter or browse to the installation location of the python executable

    • Add arguments: <script_name>.py --<parameter1_name> <parameter1_value>

    • Start in: c:\path\to\script\

Mac

Setup

Verify Python3 Installation

To install python3 on MacOS, ensure that Homebrew is installed and run the following command:

brew install python

To verify that python3 is installed on your system, run the following command:

which python3
which pip3

If the outputs are filesystem paths (ex: /usr/local/bin/python3), the applications are installed.

Installing Required Packages

Veza Python scripts may rely on external dependencies; if this is the case, the script package will include a requirements.txt file.

To ensure that the dependencies are installed, run the following command from the directory in which the requirements.txt file is located:

pip3 install -r requirements.txt

Setting Environment Variables

Veza Python scripts often require some variable input at run time (ex: API key, service URL).

Non-secret data can be passed to the script as arguments or set as environment variables, but sensitive data must be set as an environment variable.

See the README.md packaged with a script for a description of required input data.

Temporary Environment Variables

Environment variables can be set temporarily from the Linux shell; these settings will last until the shell process in which they are set is terminated.

To temporarily set an environment variable from the Linux shell, run the following command:

export <variable_name>="<value>"

An example setting VEZA_URL to the FQDN of a Veza instance:

export VEZA_URL="https://example.vezacloud.com"

To verify currently set environment variables and their values, run the env command from the terminal.

To remove a currently set environment variable, run the following command:

unset <variable_name>

Unsetting the previously established VEZA_URL example:

unset VEZA_URL

Persistent Environment Variables

Environment variables can be set persistently in several ways, each with their own scope.

In each case, edit the relevant file and add the following line to set the new variable:

export <variable_name>="<value>"

• To set a persistent environment variable for only the currently logged-on user, edit ~/.zshrc and add the export to the end of the file.

• To set a variable for all login shell sessions, edit /etc/profile and add the export to the end of the file.

Current shell sessions will not reflect the file update immediately - to make use of the newly set variable, source the file first:

source ~/.zshrc

Execution

To run the Veza Python script, chmod the file to make it executable, then execute it:

chmod +x <script_name>.py
./<script_name>.py

To pass additional parameters not set as environment variables when executing the script:

./<script_name>.py --<parmeter1_name> <parameter1_value> --<flag_parmeter>

An example of setting a parameter with a value along with a flag parameter:

./veza_script.py --veza_url https://example.vezacloud.com --debug

Scheduling

Cron

Scheduling via cron requires a line to be added to the crontab.

Note: cron executes commands without a login shell; environment variables set outside of the crontab will not be loaded.

To edit the crontab, run crontab -e, then add the following:

VEZA_URL="https://example.vezacloud.com"
VEZA_API_KEY="k124c021...fc1d281"
0 * * * * /usr/bin/python3 /path/to/<veza_script.py>