hunfabric/modules/net-firewall-policy

Firewall Policies

This module allows creation and management of two different firewall policy types:

• a hierarchical policy in a folder or organization, or
• a global or regional network policy

The module also manages policy rules via code or a factory, and optional policy attachments. The interface deviates slightly from the net-vpc-firewall module since the underlying resources and API objects are different.

The module also makes fewer assumptions about implicit defaults, only using one to set match.layer4_configs to [{ protocol = "all" }] if no explicit set of protocols and ports has been specified.

• Examples
  • Hierarchical Policy
  • Global Network policy
  • Regional Network policy
  • Factory
    • Firewall Rule Factory Schema
  • Dynamic Rule Matching
    • Ingress Rules (
    • Egress Rules (
    • Rule-Level Mappings
• Variables
• Outputs

Examples

Hierarchical Policy

module "firewall-policy" {
  source    = "./fabric/modules/net-firewall-policy"
  name      = "test-1"
  parent_id = "folders/1234567890"
  attachments = {
    test = "folders/4567890123"
  }
  egress_rules = {
    smtp = {
      priority = 900
      match = {
        destination_ranges = ["0.0.0.0/0"]
        layer4_configs     = [{ protocol = "tcp", ports = ["25"] }]
      }
    }
  }
  ingress_rules = {
    icmp = {
      priority = 1000
      match = {
        source_ranges  = ["0.0.0.0/0"]
        layer4_configs = [{ protocol = "icmp" }]
      }
    }
    mgmt = {
      priority       = 1001
      enable_logging = true
      match = {
        source_ranges = ["10.1.1.0/24"]
      }
    }
    ssh = {
      priority       = 1002
      enable_logging = true
      match = {
        source_ranges = ["10.0.0.0/8"]
        # source_tags    = ["tagValues/123456"]
        layer4_configs = [{ protocol = "tcp", ports = ["22"] }]
      }
    }
  }
}
# tftest modules=1 resources=6 inventory=hierarchical.yaml

Global Network policy

module "vpc" {
  source     = "./fabric/modules/net-vpc"
  project_id = "my-project"
  name       = "my-network"
}

module "firewall-policy" {
  source    = "./fabric/modules/net-firewall-policy"
  name      = "test-1"
  parent_id = "my-project"
  region    = "global"
  attachments = {
    my-vpc = module.vpc.self_link
  }
  egress_rules = {
    smtp = {
      priority = 900
      match = {
        destination_ranges = ["0.0.0.0/0"]
        layer4_configs     = [{ protocol = "tcp", ports = ["25"] }]
      }
    }
  }
  ingress_rules = {
    icmp = {
      priority = 1000
      match = {
        source_ranges  = ["0.0.0.0/0"]
        layer4_configs = [{ protocol = "icmp" }]
      }
    }
    mgmt = {
      priority       = 1001
      enable_logging = true
      match = {
        source_ranges = ["10.1.1.0/24"]
      }
    }
    ssh = {
      priority       = 1002
      enable_logging = true
      match = {
        source_ranges = ["10.0.0.0/8"]
        # source_tags    = ["tagValues/123456"]
        layer4_configs = [{ protocol = "tcp", ports = ["22"] }]
      }
    }
  }
}
# tftest modules=2 resources=10 inventory=global-net.yaml

Regional Network policy

module "vpc" {
  source     = "./fabric/modules/net-vpc"
  project_id = "my-project"
  name       = "my-network"
}

module "firewall-policy" {
  source    = "./fabric/modules/net-firewall-policy"
  name      = "test-1"
  parent_id = "my-project"
  region    = "europe-west8"
  attachments = {
    my-vpc = module.vpc.self_link
  }
  egress_rules = {
    smtp = {
      priority = 900
      match = {
        destination_ranges = ["0.0.0.0/0"]
        layer4_configs     = [{ protocol = "tcp", ports = ["25"] }]
      }
    }
  }
  ingress_rules = {
    icmp = {
      priority = 1000
      match = {
        source_ranges  = ["0.0.0.0/0"]
        layer4_configs = [{ protocol = "icmp" }]
      }
    }
  }
}
# tftest modules=2 resources=8 inventory=regional-net.yaml

Factory

Similarly to other modules, a rules factory is also included here to allow route management via descriptive configuration files.

Factory configuration is via three optional attributes in the rules_factory_config variable:

• cidr_file_path specifying the path to a mapping of logical names to CIDR ranges, used for source and destination ranges in rules when available
• egress_rules_file_path specifying the path to the egress rules file
• ingress_rules_file_path specifying the path to the ingress rules file

Factory rules are merged with rules declared in code, with the latter taking precedence where both use the same key. Also, the factory applies implicit defaults: action defaults to deny for egress and allow for ingress, while omitting layer4_configs makes the rule match all protocols.

This is an example of a simple factory:

module "firewall-policy" {
  source    = "./fabric/modules/net-firewall-policy"
  name      = "test-1"
  parent_id = "folders/1234567890"
  attachments = {
    test = "folders/4567890123"
  }
  ingress_rules = {
    ssh = {
      priority = 1002
      match = {
        source_ranges  = ["10.0.0.0/8"]
        layer4_configs = [{ protocol = "tcp", ports = ["22"] }]
      }
    }
  }
  factories_config = {
    cidr_file_path          = "configs/cidrs.yaml"
    egress_rules_file_path  = "configs/egress.yaml"
    ingress_rules_file_path = "configs/ingress.yaml"
  }
}
# tftest modules=1 resources=6 files=cidrs,egress,ingress inventory=factory.yaml

rfc1918:
  - 10.0.0.0/8
  - 172.16.0.0/12
  - 192.168.0.0/24
gke-nodes-range:
  - 10.0.1.0/24
# tftest-file id=cidrs path=configs/cidrs.yaml

smtp:
  priority: 900
  match:
   destination_ranges:
   - rfc1918
   layer4_configs:
   - protocol: tcp
     ports:
     - 25
# tftest-file id=egress path=configs/egress.yaml schema=firewall-policy-rules.schema.json

icmp:
  priority: 1000
  match:
   source_ranges:
   - 10.0.0.0/8
   layer4_configs:
   - protocol: icmp
issue-1995:
  priority: 10020
  description: Allow intra-cluster communication required by k8s networking model
  enable_logging: true
  target_service_accounts:
  - sa-gke-cluster@burner-project.iam.gserviceaccount.com
  match:
    source_ranges:
    - gke-nodes-range
    layer4_configs:
    - protocol: tcp
      ports:
      - 1-65535
    - protocol: udp
      ports:
      - 1-65535
    - protocol: icmp
# tftest-file id=ingress path=configs/ingress.yaml schema=firewall-policy-rules.schema.json

You might need to reference external security profile groups in your firewall rules, using their Terraform ids. For example, //networksecurity.googleapis.com/${google_network_security_security_profile_group.security_profile_group.id}. To do so, list your security profile groups in the security_profile_group_ids map variable. Then reference them by key from your factories.

module "vpc" {
  source     = "./fabric/modules/net-vpc"
  project_id = "my-project"
  name       = "my-network"
}

resource "google_network_security_security_profile" "security_profile" {
  name     = "security-profile"
  type     = "THREAT_PREVENTION"
  parent   = "organizations/0123456789"
  location = "global"
}

resource "google_network_security_security_profile_group" "security_profile_group" {
  name                      = "security-profile-group"
  parent                    = "organizations/0123456789"
  location                  = "global"
  description               = "Sample security profile group."
  threat_prevention_profile = google_network_security_security_profile.security_profile.id
}

module "firewall-policy" {
  source    = "./fabric/modules/net-firewall-policy"
  name      = "fw-policy"
  parent_id = "my-project"
  security_profile_group_ids = {
    http-sg = "//networksecurity.googleapis.com/${google_network_security_security_profile_group.security_profile_group.id}"
  }
  attachments = {
    my-vpc = module.vpc.self_link
  }
  factories_config = {
    ingress_rules_file_path = "configs/ingress-spg.yaml"
  }
}
# tftest modules=2 resources=9 files=ingress-spg inventory=factory-spg.yaml

# tftest-file id=ingress-spg path=configs/ingress-spg.yaml
http:
  priority: 1000
  action: apply_security_profile_group
  security_profile_group: http-sg
  match:
    source_ranges:
    - 10.0.0.0/8
    layer4_configs:
    - protocol: tcp
      ports:
      - 80

Firewall Rule Factory Schema

The following schema outlines all available fields for defining a rule within a factory YAML file. Use this as a reference, and note the inline comments for fields that apply only to specific policy types.

rule-name:
  priority:
  action:
  description:
  disabled:
  enable_logging:
  security_profile_group: # Not for Regional policies
  target_service_accounts: []
  target_tags: [] # Not for Hierarchical policies
  target_resources: [] # For Hierarchical policies only
  tls_inspect: # Not for Regional policies
  match:
    source_ranges: []
    destination_ranges: []
    source_tags: [] # Not for Hierarchical policies
    threat_intelligences: []
    fqdns: []
    address_groups: []
    region_codes: []
    layer4_configs:
      - protocol:
        ports: []

Dynamic Rule Matching

This module simplifies firewall rule creation by using generic, context-aware variables within the match block. Based on the rule's specified direction (INGRESS or EGRESS), the module maps these generic variables to the correct source- (src_*) or destination-specific (dest_*) arguments in the underlying resource.

The tables below provide a complete reference for these dynamic mappings.

Ingress Rules (direction = "INGRESS")

Module Variable (match.*)	Mapped Resource Attribute
address_groups	src_address_groups
fqdns	src_fqdns
region_codes	src_region_codes
source_tags	src_secure_tags
threat_intelligences	src_threat_intelligences

Egress Rules (direction = "EGRESS")

Module Variable (match.*)	Mapped Resource Attribute
address_groups	dest_address_groups
fqdns	dest_fqdns
region_codes	dest_region_codes
threat_intelligences	dest_threat_intelligences

Rule-Level Mappings

The following variable is defined at the top level of the rule (not within the match block) and is mapped directly, regardless of the rule's direction.

Module Variable	Mapped Resource Attribute
target_tags	target_secure_tags

Variables

name	description	type	required	default
name	Policy name.	string	✓
parent_id	Parent node where the policy will be created, folders/nnn or organizations/nnn for hierarchical policy, project id for a network policy.	string	✓
attachments	Ids of the resources to which this policy will be attached, in descriptive name => self link format. Specify folders or organization for hierarchical policy, VPCs for network policy.	map(string)		{}
description	Policy description.	string		null
egress_rules	List of egress rule definitions, action can be 'allow', 'deny', 'goto_next' or 'apply_security_profile_group'. The match.layer4configs map is in protocol => optional [ports] format.	map(object({…}))		{}
factories_config	Paths to folders for the optional factories.	object({…})		{}
ingress_rules	List of ingress rule definitions, action can be 'allow', 'deny', 'goto_next' or 'apply_security_profile_group'.	map(object({…}))		{}
region	Policy region. Leave null for hierarchical policy, set to 'global' for a global network policy.	string		null
security_profile_group_ids	The optional security groups ids to be referenced in factories.	map(string)		{}

Outputs

name	description	sensitive
id	Fully qualified firewall policy id.