AzureFW-GitOps

This project intends to provide a GitOps experience for Azure Firewall in order to make Azure Firewall IaC easier and improve the overall user experience of authoring/configuring Azure Firewall Policies and rules. In short AzureFW GitOps creates a new way of configuring Azure Firewall Policies and allows for a two-way sync of rules and configuration allowing Azure FW GitOps & ClickOps Azure FW policy authoring. You can choose yourself if you want to have the repository as single source of truth or if both Repo & Azure Portal authoring is allowed.

Module installation

Install-Module -Name AzureFwGitOps

https://www.powershellgallery.com/packages/AzureFwGitOps/

How it works

This project utilizes AzOps as the IaC backend and aims to mirror the structure that AzOps creates and uses. There is a demo project in Azure DevOps which puts all these things into action and provides a real-world example on how everything can be put together.

• Pipelines (External Azure DevOps)
• Repository (External Azure DevOps)

At the heart of this project is a powershell module which translates between Azure ARM templates and Azure FW GitOps as well as a pipeline to track and implement changes.

• AzureFwGitOps.psm1

To properly use this module it is recommended to integrate it into your ci/cd pipelines. There are some examples in this repository, but feel free to change and integrate and submit a PR to this repo with more examples

• Azure DevOps Pipelines
• Github Actions (not yet built)

Azure ARM templates -> Azure FW GitOps

ConvertFrom-ArmFw -ArmFolder $ArmFolder -PolicyFolder $PolicyFolder -Merge

The above command reads ARM templates for Microsoft.Network/firewallPolicies and Microsoft.Network/firewallPolicies/ruleCollectionGroups resources and generates a easy to read policySettings.json and csv files that are easy to edit for ApplicationRules, NatRules and NetworkRules.

$ArmFolder is the AzOps resource group folder where Firewall resides.

$PolicyFolder is the folder where you intend to place the GitOps content.

The switch parameter -Merge specifies that updates from ARM is merged with any rules written in rule files. This is only recommended if hybrid authoring mode is preferred. For immutable mode is preferred -Merge should be avoided.

Azure FW GitOps -> Azure ARM templates

ConvertTo-ArmFw -ArmFolder $ArmFolder -PolicyFolder $PolicyFolder

The above command reads settings from PolicyFolder and writes to AzOps resource group specified by $ArmFolder. The function is not capbable of creating files on its own nor does it associate policies with firewalls or other policies. See Todo for more information

Setup More information

AzOps file structure

📂<resourceGroupFolder>
 ┣ 📜microsoft.network_firewallpolicies-<policyName>.json
 ┣ 📜microsoft.network_firewallpolicies_rulecollectiongroups-<policyName>_<ruleCollGroupName>.json
 ┣ ...
 ┗ ...

Firewall GitOps file structure

📦policies
 ┣ 📂<policyName>
 ┃ ┗ 📂<ruleCollGroupName>
 ┃ ┃ ┣ 📂<ruleCollName>
 ┃ ┃ ┃ ┗ 📜ApplicationRule.csv
 ┃ ┃ ┗ 📂<ruleCollName>
 ┃ ┃ ┃ ┗ 📜NetworkRule.csv
 ┃ ┃ ┗ 📂<ruleCollName>
 ┃ ┃ ┃ ┗ 📜NatRule.csv
 ┣ 📂<policyName>
 ┃ ┗...
 ┗ 📜policySettings.json

Rule files and configuration

Headers follow FirewallPolicyRule objects, more info in the docs. At the time of writing AzOps performs a pull using apiVersion "2020-11-01". If the apiVersion adds a type it will automatically get included, albeit unsorted.

Examples

policySettings.json

ApplicationRule.csv

NetworkRule.csv

NatRule.csv

policySettings

policySettings.json provides the more static configuration where Policy configuration can be stored, example of configuration defined here is child-policies, RuleCollectionGroup priority settings etc. It is recommended to generate this file using the ConvertFrom-ArmFw function once the initial structure is created in Azure Portal. Be careful with priority when editing this, as deployment will fail if there are conflicting priorities. Please refer to Microosft docs for more information on rule-processing

[
  {
    "name": "<policyName>",
    "childPolicies": [
      "<resourceId>" // Optional
    ],
    "ruleCollectionGroups": {
      "id": "<resourceId>",
      "name": "<policyName>/<ruleCollGroupName>",
      "priority": 100,
      "ruleCollections": [
        {
          "name": "<ruleCollName>",
          "priority": 200,
          "action": {
            "type": "Deny"
          }
        },
        {
          "name": "<ruleCollName>",
          "priority": 100,
          "action": {
            "type": "Allow"
          }
        }
      ]
    }
  },
]

Assumptions

• All firewall policies configured exist in the same resource group.
• To enable two way sync the AzOps Pull pipeline must be run before a push, otherwise it will overwrite changes made in the portal that has not been pulled in.
• The csv delimiter is default ','. space (' ') and semicolon (';') is reserved and should not be used.

TODO

• Create fwPolicies by defining them here
• videos going step-by-step on how to implement and use
• add validate pipeline
• time based fw rules / JIT rules