Secret Management with Terraform

It’s a common worry: How do you keep secrets safe when you build with Terraform? You craft your infrastructure as code, but some parts, like passwords and API keys, should not be in plain text. These bits of info, the secrets, need extra care. You must store them safe, access them in a secure way, and keep them from prying eyes. This article will show you how to handle secrets well with Terraform, so your builds can be safe and strong.

Table of Contents

Why Terraform Secret Management Is Vital

Think of secrets as the keys to your kingdom. If you leave them out in the open, anyone could waltz in. This is why you must not put secrets directly into your Terraform code. You also must not save them in your code files. This makes them easy to find and can cause big problems. If someone gets hold of those secrets, they could change your infrastructure. Or they could steal your data.

Compliance is key. Many rules say you must keep secrets safe. If you don’t, you could face fines. Or you could hurt your name. Also, good secret care makes it easier for your team to work together with trust. You can control who sees what. This helps stop mistakes and lowers risks. This is why you must have solid secret care with Terraform. It’s not just a good idea, it’s a must for any safe and solid build.

The Basic Ways to Handle Secrets in Terraform

Before we get into the advanced stuff, let’s look at some common ways people handle secrets in Terraform. Some of these are not that safe, but it’s good to know about them.

Variable Files

One simple way is to put your secrets in a variable file. You keep your usual code in the main files, and then use a file for values that change. This can work for some things. But it is not good for real secrets. The variable files can still be stored in the wrong place. And they can still be read without a lot of effort. Also, you can forget to leave them out of your code save spot. Which puts them right back where you don’t want them: where anyone can find them.

Environment Variables

Another way to pass secrets to Terraform is by using the environment. You set the values in your work space and then Terraform uses them. This helps to keep secrets out of your code. But, you must set up and keep watch on your environment. And this method can still be prone to leaks. These settings are often easy to see by those who have access to the work space.

The Problem With These Basic Methods

The core issue with these ways is they still need care from you. They’re not bad for simple setup, but they are not meant for real secrets. These methods also need a lot of manual work and can get complex as your setup grows. They lack the care you need for safety and to follow the rules. And these methods do not help you to watch or audit who is accessing your secrets. Which makes it hard to see when things go wrong.

Better Ways to Handle Secrets in Terraform

Now let’s talk about better, more solid ways to care for secrets in Terraform. These ways add the layers of safety you need. And they help you follow the rules, making your setup safe and strong.

Using HashiCorp Vault

HashiCorp Vault is a strong tool for keeping secrets. It helps you save and access secrets safely. It also watches who uses them. With Vault, you do not put secrets right in your code. Instead, your Terraform code asks Vault for them when it needs them.

How Vault works with Terraform:

Set up Vault: First, you set up Vault and save your secrets.
Set up Terraform: Then, you set up Terraform to work with Vault. You tell Terraform how to talk to Vault.
Access secrets: In your code, you ask Vault for secrets, not for a value.
Use the secrets: Terraform gets the secrets from Vault, and uses them as it builds.

Key benefits of Vault:

Strong safety: Vault keeps secrets safe with coding.
Control access: You decide who can see and use each secret.
Keep watch: You can watch who uses secrets.
Easy to use: You can access secrets with one code line.

Vault is a great way to keep your secrets safe with Terraform.

Using Cloud Provider Secret Services

Each cloud provider like AWS, Azure, and Google Cloud offers its own secret service. These services are built right into the cloud. And they work well with other cloud tools.

AWS Secrets Manager:

AWS Secrets Manager lets you save database login info, API keys, and other secrets. You can access these secrets from Terraform code. It saves, turns, and handles secrets with care, and it works well with AWS tools.

Azure Key Vault:

Azure Key Vault is Azure’s secret service. It lets you save and access secrets. It works well with Azure setups. You can control who sees and uses each secret, and keep watch on who uses secrets.

Google Cloud Secret Manager:

Google Cloud Secret Manager is for Google Cloud. It keeps secrets safe. It works with Google’s tools. You can access and keep watch on your secrets, helping you build in a safe way on the Google platform.

How to Use These Services With Terraform:

Save secrets: First, save your secrets in the service.
Set up Terraform: Then, set up Terraform to talk to the secret service.
Access secrets: Ask the secret service for secrets, not for a value.
Use the secrets: Terraform gets the secrets, and uses them to build things.

Key benefits of Cloud Provider Services:

Built into the cloud: These tools are built right into your cloud setup.
Easy to use: They work well with Terraform.
Good safety: They keep secrets safe with coding.
Full control: You can watch who accesses what.

Cloud provider secret services are a good choice if you build mainly in one cloud. They are easy to start with. And they work well with the rest of your cloud setup.

Using Third-Party Secret Services

Besides Vault and cloud tools, other services help keep secrets safe. These services can work with many clouds and tools. They can be a good fit if you use many different tools.

Key features of these services:

Cross-cloud work: These tools often work with many cloud setups.
Good safety: They keep secrets safe with coding.
Work with many tools: They can work with many different tools.

Third-party services give you another choice for secret care. Pick one that fits your needs.

Best Practices for Terraform Secret Management

No matter which tool you pick, there are some key rules to follow for secret care in Terraform. These rules will make your setup even more safe and solid.

Never Hard-Code Secrets

Never put secrets right into your Terraform code or config files. This is the worst thing you can do. When secrets are in your code, anyone with access to those files can see them. This puts your whole setup at risk. Instead, keep secrets safe. And get them from a safe tool.

Use a Least Privilege Model

Only give people and tools the access they need. This lowers the risk of leaks. It also stops anyone who might gain access from doing too much damage. With a least privilege setup, secrets are only used when needed, and by those who should have access.

Rotate Secrets Often

Change your secrets often. This stops old secrets from being used if they’re leaked. Rotating secrets is a big part of keeping secrets safe. Many secret tools have ways to rotate secrets on a schedule. Which means less manual work for you.

Keep Audit Trails

Keep track of who accessed which secrets. And when they did it. Audit trails help you find problems fast. And to check that safety steps are working. Audit trails also help you follow the rules.

Encrypt Secrets in Transit and At Rest

Make sure your secrets are coded, both when moving from one place to another. And when sitting still in a save spot. Coding keeps secrets safe from anyone who may try to look at them without a key.

Use Strong Passwords and Keys

Use hard-to-guess secrets. Strong secrets make it harder for bad actors to get in. Random keys and long passwords are your best bet. Do not use things like “password123” or “admin”.

Separate Development and Production Secrets

Do not use the same secrets for your build and real setup. This helps stop problems in one place from spreading to the other. Use a different set of secrets for each place. This lowers the risk and gives you extra care.

Manage Secrets With a Team

You should not handle secrets alone. You must set up a good way for the team to care for secrets. This lowers the risk of human mistakes. And makes it easy to follow best steps for the whole team. Make it a team goal to handle secrets with care.

Regularly Check Your Secret Setup

Check your secret setup often. Look for holes or ways to make it stronger. A good checkup of your secret care setup will help you find issues fast, and make sure your setup is as safe as it can be.

How to Implement Secure Secret Management

Now, let’s go over how to make these ways for secret care work in your code and builds.

Terraform Configuration

To use secrets in your Terraform builds, you must first set up your provider. And then tell Terraform how to get secrets. You use a “data” source to get secrets from a secret tool.

Here is an example of using the aws_secretsmanager_secret_version to access a secret in AWS Secrets Manager:

data "aws_secretsmanager_secret_version" "example" {
  secret_id = "arn:aws:secretsmanager:us-west-2:123456789012:secret:MySecret"
}

resource "aws_instance" "example" {
  ami           = "ami-0c55b9529a8072c0b"
  instance_type = "t2.micro"
  tags = {
    Name = "MyInstance"
    Secret = data.aws_secretsmanager_secret_version.example.secret_string
  }
}

In this example:

data "aws_secretsmanager_secret_version" "example": This uses a data block to get a secret from AWS Secrets Manager, using the ARN of a secret.
secret_id: This points to the ARN of your secret, this ARN will be different for your setup.
data.aws_secretsmanager_secret_version.example.secret_string: This grabs the string value of the secret from the data source.
resource "aws_instance" "example": This creates an AWS instance using that secret as a tag.

This is just an example. How you code your access will depend on your secret tool and what you plan to do with the secret. No matter your way, never save secrets directly into code.

Setting Up CI/CD Pipelines

If you’re using CI/CD (Continuous Integration/Continuous Deployment) to automate your Terraform builds, then your secret care must be part of this process. You need to make sure your pipeline tools can get secrets safely. This means using methods and tools that work well with your setup. It also means keeping watch to make sure your CI/CD builds are not leaking secrets.

This is the general way to handle secrets in your CI/CD pipeline:

Set up Secret Access: Set up your CI/CD tool to access secrets from your tool of choice.
Inject Secrets: Your pipeline grabs the needed secrets.
Run Terraform: Your pipeline runs your Terraform code using the secrets.
Clean Up: Make sure you clean up any access to secrets when the job is done.

Examples for popular CI/CD tools:

GitHub Actions: You can use GitHub Actions secrets to store API keys and credentials, and access them in your workflows, and you can integrate with external secret tools like Vault.
GitLab CI/CD: You can use GitLab CI/CD variables to store your secrets, and you can integrate with external secret tools.
Jenkins: You can use Jenkins’ credential plugin to store and access your secrets, and you can integrate with external secret tools.

CI/CD pipelines must be set up well to make sure your secrets stay safe. Do not leave any way for them to leak.

Common Mistakes to Avoid

There are common mistakes people make with Terraform secret care. Let’s look at them so you can avoid them:

Saving Secrets in Your Code

As we have said before, this is the worst mistake you can make. It makes your secrets open to anyone who looks at your code. Do not do this.

Not Rotating Secrets

If you keep secrets the same for too long, they are more likely to be leaked. And it makes them less useful if they are ever found. Rotate secrets often to keep them safe.

Over-Granting Access

Giving too many people or tools access to secrets can lead to big issues. Stick to the least privilege way. Only give access to those who need it, and when they need it.

Forgetting Audit Trails

If you don’t keep track of who accesses your secrets, it’s hard to know when something goes wrong. Always log who is using your secrets.

Ignoring Cloud Safety

You must use your cloud’s safety tools. This includes ways for keeping secrets safe. Do not leave your cloud without these setup.

Setting Up Weak Secrets

If you use easy to guess secrets, then it makes it easier for bad people to get in. Use strong, random, and long secrets.

Not Testing Your Secrets Setup

Do not assume your secret care plan works. Test it often. Test it to make sure it’s doing what it should. And that it’s not causing problems in your setup.

The Future of Terraform Secret Management

Terraform secret care is always changing. New tools and methods come along all the time. It is key to stay up to date with best steps. Here are some trends you should keep in mind:

More Cloud Tool Work: Cloud providers are making their secret tools even better. They’re making them work more with Terraform and other tools.
Zero Trust Tools: Zero trust is a big idea. It says you should never trust anyone or anything. This is changing how secret care is done. Zero trust tools require strong checkups every time.
AI in Secret Care: AI (artificial intelligence) could soon help find leaks. AI could also help spot when people use secrets in a way they shouldn’t.
Automation: Automation is key to make the care of secrets easy and safe. Tools that automate secret rotation, access checkups, and other tasks are growing more common.

As Terraform grows, so too will the care of secrets. Look to new ways, tools, and steps to make sure your setups are safe.

The Path to Secure Builds

Good secret care is key for any Terraform setup. You must not leave keys out in the open. You must use safe, solid ways to handle your secrets. Use the best steps, tools, and methods for secret care. It is not a choice but a need to have. And remember, good secret care is not a one time event. It’s a habit that must be part of your work. Do not forget this. With these tips and ideas, you can build safely and with trust.