This Terraform module allows users to support Application Segments by integrating Consul Terraform Sync with Zscaler Private Access ZPA Cloud to dynamically manage the Domain Names, TCP and UDP port list based on service definition in Consul Catalog.
Using this Terraform module in conjunction with consul-terraform-sync enables teams to reduce manual ticketing processes and automate Day-2 operations related to application scale up/down in a way that is both declarative and repeatable across the organization and across multiple Application Segments.
This module supports the following:
- Create, update and delete Application Segments based on the services in Consul catalog.
If there is a missing feature or a bug - - open an issue
The consul-terraform-sync runs as a daemon that enables a publisher-subscriber paradigm between Consul and ZPA Cloud to support Network Infrastructure Automation (NIA).
-
consul-terraform-sync subscribes to updates from the Consul catalog and executes one or more automation "tasks" with appropriate value of service variables based on those updates. consul-terraform-sync leverages Terraform as the underlying automation tool and utilizes the Terraform provider ecosystem to drive relevant change to the network infrastructure.
-
Each task consists of a runbook automation written as a compatible Terraform module using resources and data sources for the underlying network infrastructure provider.
Please refer to this link for getting started with consul-terraform-sync
| Ecosystem | Version |
|---|---|
| consul | >= 1.7 |
| consul-terraform-sync | >= 0.1.0 |
| terraform | >= 0.13 |
| Name | Version |
|---|---|
| zpa | >= 2.2.0 |
This module is meant for use with consul-terraform-sync >= 0.1.0 and Terraform >= 0.13.
-
Modules have been used in order to provider a seamless experience during deployment, due to the several dependencies existent in the application segment resource.
-
An application segment requires both a
segment groupandserver groupresource. In turn, a server group depends on anapp connector groupresource. -
This module provides conditional capabilities where, the user can indicate the creation of a new segment group, server group and app connector groups, or utilization of existing resources via the
terraform.tfvarsfile.
| Name | Type |
|---|---|
| zpa_app_connector_group.this | resource |
| zpa_application_segment.application_segment | resource |
| zpa_segment_group.this | resource |
| zpa_server_group.this | resource |
| zpa_app_connector_group.this | data source |
| zpa_segment_group.this | data source |
| zpa_server_group.this | data source |
| Name | Description | Type | Default | Required |
|---|---|---|---|---|
| app_connector_group_description | Description of the App Connector Group. | string |
"AppConnector" |
no |
| app_connector_group_name | Name of the App Connector Group. | string |
"AppConnector" |
no |
| appsegment_prefix | (Optional) Prefix added to the dynamic application segment created by Consul | string |
"" |
no |
| byo_app_connector_group | Bring your own App Connector Group | bool |
false |
no |
| byo_app_connector_group_id | User provided existing App Connector Group ID | string |
null |
no |
| byo_segment_group | Bring your own Segment Group | bool |
false |
no |
| byo_segment_group_id | User provided existing Segment Group ID | string |
null |
no |
| byo_server_group | Bring your own Server Group | bool |
false |
no |
| byo_server_group_id | User provided existing Server Group ID | string |
null |
no |
| bypass_type | Bypass Type for the application segment created by Consul-Terraform-Sync. | string |
"NEVER" |
no |
| cts_prefix | (Optional) Prefix that will be applied to all objects created via Consul-Terraform-Sync | string |
"cts-" |
no |
| health_reporting | Health reporting for the application segment created by Consul-Terraform-Sync. | string |
"ON_ACCESS" |
no |
| icmp_access_type | ICMP Access Type for the application segment created by Consul-Terraform-Sync. | string |
"NONE" |
no |
| segment_group_description | Description of the segment group. | string |
"SegmentGroup" |
no |
| segment_group_enabled | Whether this segment group is enabled or not. | bool |
true |
no |
| segment_group_name | Name of the segment group. | string |
"SegmentGroup" |
no |
| server_group_description | This field is the description of the server group. | string |
"ServerGroup" |
no |
| server_group_dynamic_discovery | This field controls dynamic discovery of the servers. | bool |
true |
no |
| server_group_enabled | This field defines if the server group is enabled or disabled. | bool |
true |
no |
| server_group_name | This field defines the name of the server group. | string |
"ServerGroup" |
no |
| services | Consul services monitored by Consul NIA | map( |
n/a | yes |
| tcp_keep_alive_enabled | Segment Group Keep Alive Status | string |
"1" |
no |
- Application Segments can be associated to one or more access polices in the ZPA Cloud. Once an application segment is associated to a policy, it can only be deleted if there are no policies associated with that application segment. If the user tries to delete an application segment that is associated with any policy, they will encounter an error. This module creates, updates and deletes application segment based on the sevices in Consul catalog. If the service associated to the application segment de-registers from the Consul catalog, the module will throw an error when trying to destroy the application segment. This is the correct and expected behavior as the application segment is being used in a policy.
- This behavior does not affect individual
domain_namesentries in an individual application segment.
In order to use this module, you will need to install consul-terraform-sync, create a "task" with this Terraform module as a source within the task, and run consul-terraform-sync.
The users can subscribe to the services in the consul catalog and define the Terraform module which will be executed when there are any updates to the subscribed services using a "task".
~> Note: It is recommended to have the consul-terraform-sync config guide for reference.
- Download the consul-terraform-sync on a node which is highly available (prefrably, a node running a consul client)
- Add consul-terraform-sync to the PATH on that node
- Check the installation
$ consul-terraform-sync --version 0.1.0 Compatible with Terraform ~>0.13.0 - Create a config file "tasks.hcl" for consul-terraform-sync. Please note that this is just an example.
log_level = <log_level> # eg. "info"
driver "terraform" {
log = true
required_providers {
zpa = {
source = "zscaler/zpa"
}
}
}
consul {
address = "<consul agent address>" # eg. "1.1.1.1:8500"
}
provider "zpa" {
zpa_client_id = "xxxxxxxxx"
zpa_client_secret = "xxxxxxxxx"
zpa_customer_id = "123456789"
}
task {
name = <name of the task (has to be unique)> # eg. "Create_Application_Segment"
description = <description of the task> # eg. "Application Segment based on service definition"
source = "zscaler/application-segment/zpa" # to be updated
providers = ["zpa"]
condition "services" { ["<list of services you want to subscribe to>"] # eg. ["web", "api"]
names = ["nginx","web","api"]
}
variable_files = ["<list of files that have user variables for this module (please input full path)>"] # eg. ["/opt/zpa-config/demo.tfvars"]
}- Start consul-terraform-sync
$ consul-terraform-sync -config-file=tasks.hcl
consul-terraform-sync will create right set of application segments in the ZPA Cloud based on the values in consul catalog.
consul-terraform-sync is now subscribed to the Consul catalog. Any updates to the services identified in the task will result in updating the application segment in the ZPA Cloud
~> Note: If you are interested in how consul-terraform-sync works, please refer to this section.
There are 2 aspects of consul-terraform-sync.
-
Updates from Consul catalog: In the backend, consul-terraform-sync creates a blocking API query session with the Consul agent indentified in the config to get updates from the Consul catalog. consul-terraform-sync. consul-terraform-sync will get an update for the services in the consul catalog when any of the following service attributes are created, updated or deleted. These updates include service creation and deletion as well.
- service id
- service name
- service address
- service port
- service meta
- service tags
- service namespace
- service health status
- node id
- node address
- node datacenter
- node tagged addresses
- node meta
-
Managing the entire Terraform workflow: If a task and is defined, one or more services are associated with the task, provider is declared in the task and a Terraform module is specified using the source field of the task, the following sequence of events will occur:
- consul-terraform-sync will install the required version of Terraform.
- consul-terraform-sync will install the required version of the Terraform provider defined in the config file and declared in the "task".
- A new direstory "nia-tasks" with a sub-directory corresponding to each "task" will be created. This is the reason for having strict guidelines around naming.
- Each sub-directory corresponds to a separate Terraform workspace.
- Within each sub-directory corresponding a task, consul-terraform-sync will template a main.tf, variables.tf, terraform.tfvars and terraform.tfvars.tmpl.
-
main.tf:
- This files contains declaration for the required terraform and provider versions based on the task definition.
- In addition, this file has the module (identified by the 'source' field in the task) declaration with the input variables
- Consul K/V is used as the backend state for fo this Terraform workspace.
example generated main.tf:
# This file is generated by Consul NIA. # # The HCL blocks, arguments, variables, and values are derived from the # operator configuration for Consul NIA. Any manual changes to this file # may not be preserved and could be clobbered by a subsequent update. terraform { required_version = "~>0.13.0" required_providers { zpa = { source = "zscaler/zpa" } } backend "consul" { address = "1.1.1.1:8500" gzip = true path = "consul-nia/terraform" } } provider "zpa" { zpa_client_id = var.zpa.zpa_client_id zpa_client_secret = var.zpa.zpa_client_secret zpa_customer_id = var.zpa.zpa_customer_id } # Dynamic Application Segment based on service definition module "Create_Application_Segment_on_ZPA" { source = "zscaler/application-segment/zpa" services = var.services }
-
variables.tf:
- This is variables.tf file defined in the module
example generated variables.tf
variable "services" { description = "Consul services monitored by Consul NIA" type = map( object({ id = string name = string address = string port = number status = string meta = map(string) tags = list(string) namespace = string node = string node_id = string node_address = string node_datacenter = string node_tagged_addresses = map(string) node_meta = map(string) }) ) } variable "appsegment_prefix" { type = string description = "(Optional) Prefix added to the dynamic application segment created by Consul" default = "" } variable "appsegment_suffix" { type = string description = "(Optional) Suffix added to the dynamic application segment created by Consul" default = "" }
-
terraform.tfvars:
- This is the most important file generated by consul-terraform-sync.
- This variables file is generated with the most updated values from Consul catalog for all the services identified in the task.
- consul-terraform-sync updates this file with the latest values when the corresponding service gets updated in Consul catalog.
example terraform.tfvars
services = { "web.hpc152-nginx.sgio01" = { id = "web" name = "web" kind = "" address = "10.0.31.152" port = 80 meta = {} tags = [] namespace = "" status = "passing" node = "hpc152-nginx" node_id = "517051df-974b-5765-9941-6399f2679106" node_address = "10.0.31.152" node_datacenter = "dc01" node_tagged_addresses = { lan = "10.0.31.152" lan_ipv4 = "10.0.31.152" wan = "10.0.31.152" wan_ipv4 = "10.0.31.152" } node_meta = { consul-network-segment = "" } cts_user_defined_meta = {} }, "web.hpc153-nginx.sgio01" = { id = "web" name = "web" kind = "" address = "10.0.31.153" port = 80 meta = {} tags = [] namespace = "" status = "passing" node = "hpc153-nginx" node_id = "2504f4de-287a-0fe1-dd78-6c313ba0cb58" node_address = "10.0.31.153" node_datacenter = "dc01" node_tagged_addresses = { lan = "10.0.31.153" lan_ipv4 = "10.0.31.153" wan = "10.0.31.153" wan_ipv4 = "10.0.31.153" } node_meta = { consul-network-segment = "" } cts_user_defined_meta = {} }, "web.hpc154-nginx.sgio01" = { id = "web" name = "web" kind = "" address = "10.0.31.154" port = 80 meta = {} tags = [] namespace = "" status = "passing" node = "hpc154-nginx" node_id = "8af55392-5756-2511-77e7-1b6f0627ff5f" node_address = "10.0.31.154" node_datacenter = "dc01" node_tagged_addresses = { lan = "10.0.31.154" lan_ipv4 = "10.0.31.154" wan = "10.0.31.154" wan_ipv4 = "10.0.31.154" } node_meta = { consul-network-segment = "" } cts_user_defined_meta = {} }, }
* **Network Infrastructure Automation (NIA) compatible modules are built to utilize the above service variables** -
- consul-terraform-sync manages the entire Terraform workflow of plan, apply and destroy for all the individual workspaces corrresponding to the defined "tasks" based on the updates to the services to those tasks.
In summary, consul-terraform-sync triggers a Terraform workflow (plan, apply, destroy) based on updates it detects from Consul catalog.
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