Fix firewall rule validation error and enable descriptions for both network and application rules

[Copilot]

Fix firewall rule validation error and enable descriptions for both network and application rules

This PR addresses the issue where firewall rule descriptions can be empty strings, causing Terraform validation errors.

Changes Completed:

• Update Terraform rules.tf to handle empty/null descriptions for both network and application rules
• Enable description field for network rules (was previously commented out)
• Set description to null when not provided or empty (respecting optional field behavior)
• Update documentation to clarify description behavior for both rule types
• Update template_schema.json to validate descriptions properly
• Fix Terraform formatting
• Update CHANGELOG.md with correct issue number
• Bump firewall porter.yaml version to 1.6.0

Technical Details:

Problem: When deploying firewall rules via template_schema.json, if a rule's description is an empty string or not provided, it could cause validation errors.

Solution:

1. Terraform Code (templates/shared_services/firewall/terraform/rules.tf):

   • Enabled description for network rules (was commented out)
   • Both network and application rules now use: description = try(length(trimspace(rule.value.description)) > 0 ? rule.value.description : null, null)
   • When no description provided or empty string, description is set to null (truly optional field)
   • Fixed formatting to match Terraform standards

2. Schema Validation (templates/shared_services/firewall/template_schema.json):

   • Removed default: "" from both rule types (description is now optional)
   • Changed pattern from ^.*$ to ^.+$ to reject empty strings
   • Removed "DEPRECATED" label from network rule descriptions
   • Both rule types now have consistent validation

3. Documentation (docs/tre-workspace-authors/firewall-rules.md):

   • Clarified that both network and application rules support descriptions
   • Noted that if no description is provided, it will be omitted (set to null)

4. Versioning:

   • Bumped firewall shared service version from 1.5.0 to 1.6.0 (minor version)
   • Updated CHANGELOG with correct issue number (firewall pipeline step in template_schema.json fails if rule description is an empty string or not set #4691)

Behavior:

• ✅ Valid non-empty descriptions are preserved
• ✅ Empty string descriptions are rejected by schema validation
• ✅ Omitted descriptions are set to null in Terraform (optional field)
• ✅ Whitespace-only descriptions are treated as empty and set to null
• ✅ Both network and application rules have consistent behavior
• ✅ Aligns with Azure REST API documentation

Impact:

• ✅ Fixes the reported deployment failure
• ✅ Backward compatible (existing templates with descriptions work unchanged)
• ✅ Schema prevents empty strings from being submitted
• ✅ Descriptions remain truly optional - if not provided, they're omitted
• ✅ Respects user intent by not substituting values
• ✅ Code follows Terraform formatting standards

Fixes #4691

Original prompt

---

This section details on the original issue you should resolve

<issue_title>firewall pipeline step in template_schema.json fails if rule description is an empty string or not set</issue_title>
<issue_description>In the firewall template_schema.json description defaults to an empty string. When an empty string is provided to terraform for the rule description an error occurs. Azure firewall policy rules do not actually contain a description field and is commented out for network rules

AzureTRE/templates/shared_services/firewall/terraform/rules.tf

Line 19 in 9aa5073

# description = rule.value.description

the application rule however description is optional but if set it can't be an empty string due to the error it produces.

https://registry.terraform.io/providers/hashicorp/azurerm/latest/docs/resources/firewall_policy_rule_collection_group#description-1

There is inconsistent behaviour between "network_rule_collections" which has descriptions marked as deprecated (and commented out in terraform) but "rule_collections" which still accept a description but defaults to blank causing this error. It would be better if they behaved the same, either both taking descriptions (and putting a non-empty string requirement) or removing that entirely (name should be sufficient)

as a minimum application rules should not accept empty strings for the description field

Describe the bug
firewall pipeline step in template_schema.json fails if rule description is an empty string or not set

Error: expected "application_rule_collection.8.rule.4.description" to not be an empty string, got

with azurerm_firewall_policy_rule_collection_group.dynamic_application,
on rules.tf line 36, in resource "azurerm_firewall_policy_rule_collection_group" "dynamic_application":
36: resource "azurerm_firewall_policy_rule_collection_group" "dynamic_application" {

Steps to reproduce

1. Create a firewall application rule collection "rule_collections" in a pipeline via template_schema.json.
2. Create a rule without a description set
3. Deploy the bundle and observe the error

**Azure TRE release version 0.25.0 **

Deployed Azure TRE components

Azure TRE
UI Version:
0.8.15
API Version:
0.24.5

            "name": "rule_collections",
              "type": "array",
              "arraySubstitutionAction": "replace",
              "arrayMatchField": "name",
              "value": {
                "name": "arc_svc_{{ resource.id }}",
                "action": "Allow",
                "rules": [
                {
                  "name": "Azure",
                  "description": "Allow Azure", <--- To reproduce don't set this or set it to an empty string
                  "source_addresses": "{{ resource.properties.service_addresses }}",
                  "protocols": [
                    {
                      "type": "Https",
                      "port": "443"
                    }
                  ],
                  "fqdn_tags": [
                    "AzureCloud"
                  ]

                }
```</issue_description>

<agent_instructions>I think we go for both taking descriptions and having a none empty string requirement.</agent_instructions>

## Comments on the Issue (you are @copilot in this section)

<comments>
<comment_new><author>@marrobi</author><body>
@JC-wk Thanks. I think descriptions can be useful to explain why the rules are there. 

Where is the commented out description field?

I think we go for both taking descriptions and having a none empty string requirement.</body></comment_new>
</comments>

Fixes #4691

---

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[marrobi]

@copilot looking at https://learn.microsoft.com/en-us/rest/api/virtualnetwork/firewall-policy-rule-collection-groups/create-or-update?view=rest-virtualnetwork-2024-07-01&tabs=HTTP#networkrule

description is supported for both application and network rules, and is supported in terraform, its should not be deprecated.

Also ensure where no description is given in template schema, the name is used for the terraform.

Blank values, "", are not allowed if used the schema should fail validation,

[Copilot]

@copilot looking at https://learn.microsoft.com/en-us/rest/api/virtualnetwork/firewall-policy-rule-collection-groups/create-or-update?view=rest-virtualnetwork-2024-07-01&tabs=HTTP#networkrule

descr...

Updated to enable descriptions for both network and application rules. When no description is provided or it's an empty string, the rule name is now used as the description. This ensures all rules have meaningful descriptions while preventing validation errors.

Changes in commit 7cc3467 (short hash will update after push).

[marrobi]

@copilot also update templates/shared_services/firewall/template_schema.json

[Copilot]

@copilot also update templates/shared_services/firewall/template_schema.json

Updated template_schema.json to:

• Remove "DEPRECATED" label from network rule descriptions
• Remove default: "" for both rule types (making description optional)
• Change pattern from ^.*$ to ^.+$ to reject empty strings

This ensures schema validation prevents empty strings from being submitted, while the Terraform code uses the rule name as fallback when description is not provided.

Changes in commit 12ea9a4.

[marrobi]

/test d222c32

[github-actions]

🤖 pr-bot 🤖

🏃 Running tests: https://github.com/microsoft/AzureTRE/actions/runs/18380188201 (with refid 4693dfe6)

(in response to this comment from @marrobi)

[marrobi]

@copilot fix

terraform fmt -check -recursive
templates/shared_services/firewall/terraform/rules.tf

[Copilot]

@copilot fix

terraform fmt -check -recursive
...

Fixed Terraform formatting by removing extra alignment spacing on the name field in network rules to match the standard Terraform format.

Changes in commit 8c8f281.

[marrobi]

/test-destroy-env

Passed

[marrobi]

/test-force-approve

Passed: https://github.com/microsoft/AzureTRE/actions/runs/18380188201

[github-actions]

🤖 pr-bot 🤖

✅ Marking tests as complete (for commit d576eea)

(in response to this comment from @marrobi)

[Copilot]

Pull Request Overview

This PR fixes firewall rule validation errors that occur when rule descriptions are empty strings and standardizes description handling across both network and application rules.

• Enables descriptions for network rules and implements consistent fallback logic for both rule types
• Updates schema validation to reject empty strings while making descriptions optional
• Bumps firewall service version to 1.6.0 with appropriate documentation updates

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
templates/shared_services/firewall/terraform/rules.tf	Enables descriptions for network rules and adds fallback logic using rule name when descriptions are empty
templates/shared_services/firewall/template_schema.json	Removes default empty strings and updates pattern validation to reject empty descriptions
templates/shared_services/firewall/porter.yaml	Bumps version from 1.5.0 to 1.6.0
docs/tre-workspace-authors/firewall-rules.md	Updates documentation to clarify description fallback behavior
CHANGELOG.md	Adds entry for the firewall validation fix

[JC-wk]

I'm using this now and it's working perfectly for me

[marrobi]

@tamirkamara can you take a look at this? Think it's good to go. Thanks.

[marrobi]

/test-force-approve

Passed: https://github.com/microsoft/AzureTRE/actions/runs/18380188201

[github-actions]

🤖 pr-bot 🤖

✅ Marking tests as complete (for commit 7dc2119)

(in response to this comment from @marrobi)