Managing Certificates Using AppViewX Terraform Provider

What is Terraform?

Terraform is an Infrastructure as Code (IaC) tool that allows you to define, provision, and manage infrastructure using human-readable configuration files.

Terraform configurations can be versioned, reused, and shared, enabling teams to manage infrastructure consistently throughout its lifecycle.

Terraform can manage both cloud and on-premises resources, including low-level infrastructure such as compute, storage, and networking, as well as higher-level resources such as DNS records and SaaS services.

How does Terraform work?

Terraform manages resources through APIs exposed by cloud platforms and other services.

Terraform uses providers to communicate with these platforms and services. A provider acts as an interface between Terraform and the target system's API, allowing Terraform to create, read, update, and delete resources.

There are thousands of providers available through the Terraform Registry, including providers maintained by HashiCorp, third-party organizations, and the community.

AppViewX Terraform Provider is a third-party Terraform provider that enables Terraform to interact with AppViewX and manage supported AppViewX resources through Terraform configurations.

Terraform Core Workflow

The core Terraform workflow consists of three stages:

• Write: Define the desired infrastructure in Terraform configuration files. You can define resources across multiple cloud providers and services. For example, you can configure an application to run on virtual machines within a Virtual Private Cloud (VPC), along with security groups and a load balancer.
• Plan: Terraform creates an execution plan that shows the changes it intends to make such as which resources will be created, updated, or destroyed based on the current infrastructure state and your Terraform configuration.
• Apply: After reviewing the plan, Terraform executes the proposed changes in the appropriate order, taking resource dependencies into account.

What does the AppViewX Terraform Provider do?

• Creates certificates using the provided certificate/CSR parameters through AppViewX.
• Downloads certificates in supported formats, along with the certificate chain/trust store certificates when required.
• Downloads private keys from AppViewX in either password-protected format or plain .pem format, based on the configured options.
• Optionally stores certificate and private key content in the Terraform state file when store_certificate_in_state is set to true. When enabled, the certificate and private key content can be consumed by downstream Terraform resources without requiring the certificate and key to be stored as local files.

Where is the AppViewX Terraform Provider hosted?

• The latest version of the AppViewX Terraform Provider is 1.1.2, hosted in the HashiCorp Terraform Registry.
• The open-source GitHub repository is synced with the Terraform Registry.

Supported authentication models

• AppViewX username and password credentials
• AppViewX service account credentials

Supported APIs and details

How to use the AppViewX Terraform Provider

• Install and configure Terraform on the local machine where you intend to use the provider.
• Configure the AppViewX Terraform provider in your Terraform configuration.
• Create a .tf configuration file with the required certificate parameters.
• Initialize the Terraform working directory:

  terraform init

• Validate the Terraform configuration:

  terraform validate

• Review the execution plan:

  terraform plan

• Apply the Terraform configuration:

  terraform apply

  The terraform apply command executes the planned changes and triggers the certificate creation process.

 ....
 ....
}
resource "time_sleep" "wait" {
           depends_on = [appviewx_create_certificate.createcert]
           create_duration = "10s"
}
resource "appviewx_download_certificate" "downloadcert"{
    depends_on = [time_sleep.wait]
    resource_id=appviewx_create_certificate.createcert.resource_id
            .....
}

Store certificate and private key content in Terraform state

The AppViewX Terraform Provider can store certificate and private key content directly in the Terraform state file. This removes the requirement to write these artifacts to a local file path, and enables downstream Terraform resources to reference the certificate and key programmatically.

To enable this behavior, set store_certificate_in_state = true in the appviewx_download_certificate resource.

Example: Download certificate and store in state

resource "appviewx_download_certificate" "downloadcert" {
  common_name                       = "example.certplus.in"
  serial_number                     = "6F:48:A5:01:6B:20:C8:DD:C3:71:C7:32:BA:A7:2A:1D"
  certificate_download_format       = "PEM"
  certificate_chain_required        = true
  key_download_password             = "AppViewX@123"
  download_password_protected_key   = false
  store_certificate_in_state        = true
}

Automate service account client secret rotation

The AppViewX Terraform Provider can automatically rotate the service account client secret when it expires and write the new secret back to a .tfvars file. This removes the need for manual intervention when a client secret expires during Terraform operations.

To enable automatic rotation with file persistence, configure the appviewx_tfvars_file_path parameter in the provider block.

When the provider detects that the client secret has expired, it:

1. Requests a new client secret from AppViewX.
2. Writes the new client secret to the specified .tfvars file, updating the appviewx_client_secret value.
3. Continues the current Terraform operation using the new secret without requiring a re-run.

If appviewx_tfvars_file_path is not configured, the provider still rotates the secret automatically, but displays the new client ID and secret in the console output with instructions for persisting them. The provider then retries the current operation using the new secret.

codeblock_rotation_console_output
=== NEW CLIENT SECRET REGENERATED ===
Client ID:     <client-id-value>
Client Secret: <new-client-secret-value>

Please configure one of the following:
1. Add appviewx_tfvars_file_path to your provider block
2. Update appviewx_client_secret in your .tf file
3. Update APPVIEWX_TERRAFORM_CLIENT_SECRET environment variable

Then re-run: terraform apply

Set up variables for secure credential handling

Declare sensitive variables in a variables.tf file so that the client ID and secret are never hardcoded in your .tf files.

variables.tf

variable "appviewx_client_id" {
  description = "AppViewX client ID"
  type        = string
  sensitive   = true
}

variable "appviewx_client_secret" {
  description = "AppViewX client secret"
  type        = string
  sensitive   = true
}

Provider block referencing variables

provider "appviewx" {
  appviewx_client_id            = var.appviewx_client_id
  appviewx_client_secret        = var.appviewx_client_secret
  appviewx_environment_is_https = true
  appviewx_environment_ip       = "<AppViewX-FQDN-or-IP>"
  appviewx_environment_port     = "31443"
  appviewx_tfvars_file_path     = "/home/user/Terraform-Demo/terraform-dev.auto.tfvars"
}

terraform-dev.auto.tfvars (auto-updated on rotation)

appviewx_client_id     = "<your-client-id>"
appviewx_client_secret = "<your-client-secret>"

Sample provider and resource .tf files

terraform {
  required_providers {
    appviewx = {
      source  = "AppViewX/appviewx"
      version = "1.1.2"
    }
  }
}

Troubleshooting

1. Verify that the provider version is correct.
2. Confirm that the fields in the .tf files use the exact field names and types.
3. Review the console output after running the terraform apply command.
4. Set the logging level by running export TF_LOG=DEBUG or export TF_LOG=TRACE.
5. For authentication errors: Verify the AppViewX user account role and permissions in the AppViewX interface to confirm the user has access to create and download certificates.
6. For internal server errors: Verify the input parameters and review the AppViewX server logs for failures.
7. For expired client secret errors: The provider returns a clear error message when the service account client secret has expired. To resolve this, configure appviewx_tfvars_file_path in the provider block to enable automatic secret rotation, or manually update the client secret by following the instructions in the console output. For more information, see Automate service account client secret rotation.
8. For invalid file path errors: The provider returns a clear error message when a path specified in certificate_download_path or key_download_path does not exist or is inaccessible. Verify that the path exists and that Terraform has write permission to it.

Enhancements implemented

1. The group name is included in the payload when creating the certificate.
2. Option to download the certificate and private key separately.
3. Support for service account credentials alongside username and password.
4. Support for pulling updates directly from the AppViewX Terraform registry.
5. Improved logging to display AppViewX error messages in Terraform output.
6. Support for specifying certificate validity in days, months, and years.
7. Support for storing certificate and private key content in the Terraform state file using the store_certificate_in_state parameter.
8. Support for automated service account client secret rotation. When appviewx_tfvars_file_path is configured, the provider writes the new client secret to the specified .tfvars file after rotation.
9. Improved error messages for expired client secrets and invalid certificate or private key file paths. The provider now returns descriptive error messages instead of terminating unexpectedly.

Points to remember

• Authenticate using either username and password, or client ID and client secret.
• Downloading the private key is optional, but the AppViewX user account must have permission to download private keys.
• Certificate download fields are required when is_sync=true and within the appviewx_download_certificate resource.
• The certificate_download_password field is required only for PFX, P12, and JKS formats.
• The certificate_chain_required field applies only to CRT, CER, CERT, PEM, and DER formats.
• If you are using an earlier version of the provider, update your resource names to appviewx_create_certificate and appviewx_download_certificate. All other fields remain unchanged.
• When store_certificate_in_state is enabled, certificate and private key content are present in the Terraform state file. Secure your state backend appropriately.
• The appviewx_tfvars_file_path parameter must point to a writable file. Terraform must have write permission to this path for automatic client secret rotation to work.
• Exclude the .tfvars file used for secret rotation from version control.