Roadmap: HashiCorp Vault PKI Infrastructure

1. Overview

This roadmap defines the implementation of a dual-PKI architecture using HashiCorp Vault:

  1. Internal PKI (Vault): Machine certificates, EAP-TLS, service-to-service TLS

  2. External PKI (Let’s Encrypt): Public-facing services, ISE Guest Portal, captive portals

This architecture serves both home enterprise and work enterprise environments. The patterns developed here are directly applicable to production deployments.

2. Architecture Vision

Dual-PKI Architecture

3. Current State

Component Status Notes

vault-01 (10.50.1.60)

OPERATIONAL

Primary PKI + SSH CA (8h certs), AppRole, KV v2

vault-02 (10.50.1.61)

PLANNED

Raft follower, HA cluster member

vault-03 (10.50.1.62)

PLANNED

Raft follower, HA cluster member

DOMUS-ROOT-CA

OPERATIONAL

Offline root, 20-year validity

DOMUS-ISSUING-CA

OPERATIONAL

Intermediate, 5-year validity

Let’s Encrypt integration

PARTIAL

Manual certbot, needs automation

dsec PKI integration

PLANNED

Store dsec encryption keys in Vault

4. Phase 1: Vault HA Cluster (3-node)

4.1. Objectives

  • Deploy vault-02 and vault-03 as Raft followers

  • Configure 3-node Raft cluster for quorum

  • Automatic leader election on failure

  • Unseal automation (optional - security tradeoff)

4.2. Tasks

# Task Priority Status

1.1

Deploy vault-02 VM on kvm-02 (Supermicro B)

HIGH

BLOCKED (kvm-02 pending)

1.2

Deploy vault-03 VM on kvm-02

HIGH

BLOCKED

1.3

Join vault-02 to Raft cluster

HIGH

PENDING

1.4

Join vault-03 to Raft cluster

HIGH

PENDING

1.5

Test failover scenarios

HIGH

PENDING

1.6

Document unseal procedures for all nodes

MEDIUM

PENDING

1.7

Configure DNS round-robin or VIP for vault.inside.domusdigitalis.dev

MEDIUM

PENDING

4.3. Success Criteria

  • All 3 nodes in Raft cluster with quorum

  • Certificate issuance works from any node

  • Automatic leader election on failure

  • Documented failover runbook

5. Phase 2: dsec Integration with Vault

5.1. Objectives

  • Store dsec master keys in Vault KV secrets engine

  • Enable Vault Transit for dsec encryption operations

  • Migrate from age-based encryption to Vault-backed encryption

  • Maintain backwards compatibility with existing .age files

5.2. Architecture

dsec + Vault Integration

5.3. Tasks

# Task Priority

2.1

Enable Vault KV v2 secrets engine for dsec

HIGH

2.2

Enable Vault Transit engine for encryption operations

HIGH

2.3

Create dsec-specific Vault policies

HIGH

2.4

Implement Vault backend in dsec CLI

HIGH

2.5

Migration tool: .age → Vault KV

MEDIUM

2.6

Document hybrid mode (Vault + age fallback)

MEDIUM

5.4. Success Criteria

  • dsec source can read from Vault

  • dsec add can write to Vault

  • Existing .age files still work

  • Vault audit log captures all dsec operations

6. Phase 3: Let’s Encrypt Automation for External Services

6.1. Objectives

  • Automated certificate issuance for public-facing services

  • DNS-01 challenge via BIND DNS API

  • Certificate deployment to ISE Guest Portal

  • Renewal automation with zero downtime

6.2. Use Cases

Service Domain Notes

ISE Guest Portal

guest.domusdigitalis.dev

Public captive portal for guest WiFi

ISE Sponsor Portal

sponsor.domusdigitalis.dev

Employee sponsor interface

External APIs

api.domusdigitalis.dev

Public API endpoints

Documentation

docs.domusdigitalis.dev

Antora documentation site

6.3. Tasks

# Task Priority

3.1

Configure certbot with DNS-01 challenge

HIGH

3.2

Integrate BIND DNS API for challenge response (VyOS replaced pfSense)

HIGH

3.3

Create ISE certificate deployment script

HIGH

3.4

Set up renewal cron/systemd timer

MEDIUM

3.5

Monitoring for certificate expiration

MEDIUM

3.6

Document in domus-infra-ops runbook

MEDIUM

6.4. Certificate Deployment Flow

Let’s Encrypt Automation Flow

6.5. Success Criteria

  • Automated cert issuance for guest.domusdigitalis.dev

  • ISE Guest Portal using Let’s Encrypt cert

  • No browser warnings for guests

  • Auto-renewal 30 days before expiry

7. Phase 4: Certificate Lifecycle Management

7.1. Objectives

  • Centralized certificate inventory

  • Expiration monitoring and alerting

  • Automated renewal workflows

  • Audit trail for compliance

7.2. Tasks

# Task Priority

4.1

Build certificate inventory (Vault + Let’s Encrypt)

MEDIUM

4.2

Expiration monitoring (Prometheus/Alertmanager)

MEDIUM

4.3

Slack/email alerts for upcoming expirations

LOW

4.4

Compliance reporting (cert validity, algorithms)

LOW

8. Work Applicability

This roadmap directly supports work enterprise requirements:

  • Internal PKI: Same Vault architecture for work environment

  • Let’s Encrypt: Guest/visitor WiFi portals

  • dsec integration: Secrets management for network infrastructure

  • HA/DR: Production-ready certificate infrastructure

Patterns validated in home enterprise are directly deployable to work.

10. Revision History

Date Author Changes

2026-02-22

EvanusModestus

Updated certmgr-01/02 → vault-01/02/03, added SSH CA status, 3-node HA plan

2026-02-11

EvanusModestus

Initial roadmap creation