Journey towards to securely deploy websites on Kubernetes (Part:1)

In this blog we will discuss how we can securely issue a certificate , manages them , and renews them by using multiple offerings of open source tools such as Cert Manager , Let's Encrypt & ACME protocol . So without further delay let's get started from scratch .

1. What is Cert Manager ?
2. What is Let's Encrypt ?
3. How Cert Manager co-relates with Let's Encrypt ?
4. What is ACME ?
5. Real world Example that how its issues certificates and manages the lifecycle of certificates to host an application securely ?

• What is Cert Manager?

Cert Manager is a Kubernetes add-on that automates the management and issuance of TLS (Transport Layer Security) certificates in Kubernetes clusters. It helps to automatically obtain, renew, and manage certificates for your Kubernetes resources (like Ingress, services, etc.), ensuring that your applications are always using valid and secure certificates.

• What is Let's Encrypt?

Let's Encrypt is a free, automated, and open Certificate Authority (CA) that provides SSL/TLS certificates for websites. These certificates help secure the communication between a user's browser and a web server by enabling HTTPS. Let's Encrypt is widely used because it offers a simple, automated way to obtain and renew certificates at no cost.

• Relationship Between Cert Manager & Let's Encrypt

Cert Manager integrates with Let's Encrypt (among other CAs) to automatically issue and manage SSL/TLS certificates for your Kubernetes applications. Cert Manager can request certificates from Let's Encrypt, install them on your Kubernetes resources, and handle automatic renewals when the certificates are about to expire.

• What is ACME?

ACME (Automated Certificate Management Environment) . It's one of the protocol that Let's Encrypt and other CA's use to automate the process of issuing and renewing SSL/TLS Certificates . ACME defines the way a client interacts with the CA to prove control over a domain and request certificates .

• Real world Example :-

Imagine you're running a website, and you need an SSL/TLS certificate to secure it with HTTPS. Normally, getting a certificate involves several steps, like proving that you own the website, generating a certificate request, and then manually installing the certificate.

ACME in Action

The ACME protocol automates all of these steps. Here's how it works in a simplified example:

1. Cert Manager (the client): You set up Cert Manager in your Kubernetes cluster. It uses ACME to handle certificates automatically for your website.
2. Let's Encrypt (the CA): Let's Encrypt is the Certificate Authority that issues the SSL/TLS certificates. It uses ACME to interact with Cert Manager.
3. Domain Ownership Proof: When you need a certificate for your website (e.g., "myappwebsite.com ), Cert Manager uses ACME to communicate with Let's Encrypt. Let's Encrypt needs to verify that you actually own "myappwebsite.com ". It might ask Cert Manager to create a specific file on your website or add a special DNS record. This is called an ACME challenge.
4. Certificate Issuance: Once Let's Encrypt sees that you passed the challenge (proving you own the domain), it issues the certificate.
5. Automatic Renewal: Cert Manager keeps track of when the certificate is about to expire. Before it does, Cert Manager uses ACME to request a new certificate, so your website stays secure without you having to do anything.

To wrap up this introduction of Cert Manager , Let's encrypt & ACME protocol , Cert Manager manages , issues and renews certificates require to establish HTTPS communication on those websites using Let's encrypt who actually issues the certificates . Now in this entire process ACME is a protocol who follows some prov0 or challenges name as ACME challenge to verify whether the domain own actually by that application and request certificate .