cert-manager vs SPIFFE / SPIRE
cert-manager
cert-manager is the leading Kubernetes controller for X.509 certificate management. It automates the issuance and renewal of certificates from Let's Encrypt, HashiCorp Vault, Venafi, AWS Private CA, Google CAS, and internal CA setups. cert-manager is a CNCF Graduated project originally built by Jetstack, and it's the go-to tool for any team running TLS on Kubernetes.
Pros
- De facto standard for TLS on Kubernetes
- Wide CA provider support (public and private)
- Automatic renewal eliminates expired-cert incidents
- Massive community and active development
Cons
- Kubernetes-only; not for non-container workloads
- Configuration has many CRDs to understand (Issuer, ClusterIssuer, Certificate)
- ACME rate limits can surprise teams doing heavy issuance
- Complex certificate chains require custom Issuer logic
Pricing: Free (open source); enterprise support from Venafi/CyberArk
SPIFFE / SPIRE
SPIFFE (Secure Production Identity Framework For Everyone) is a CNCF-graduated open standard for workload identity, and SPIRE is the reference implementation. Instead of giving workloads shared secrets, SPIRE issues short-lived, cryptographically verifiable identities (SVIDs) to each service, using attestation (where is this workload running, what image, what namespace) to prove who it is. SPIFFE is the foundation for zero-trust service-to-service authentication at companies like Bloomberg, Uber, and Square.
Pros
- Eliminates shared secrets between services entirely
- Short-lived identities limit blast radius of any compromise
- Vendor-neutral standard; avoids lock-in to cloud provider IAM
- Strong adoption at hyperscale companies (Bloomberg, Uber, etc.)
Cons
- Steep conceptual learning curve (trust domains, attestation)
- Operational complexity to run SPIRE server and agents
- Requires application integration (use the SPIFFE Workload API)
- Not a drop-in for teams without existing microservice maturity
Pricing: Free (open source)