feat: Intent-Based Node Types Implementation (Full, Validator, Archive, Gateway)

[mvleandro]

📝 Description

This PR introduces a significant architectural change to the blockchain-operator, moving from manual flag-based configuration to an Intent-Based approach.

The EthereumNode CRD now supports the nodeType field. Based on this field, the Operator automatically:

• Infers the synchronization strategy (syncMode)
• Adjusts Geth flags
• Dynamically modifies the Pod topology (including conditional sidecar
  injection)

This drastically simplifies node provisioning while improving safety, consistency, and maintainability.

---

✨ Key Changes

✅ NodeType Abstraction

• Added NodeType enum to the API with the following values:
  • full
  • archive
  • validator
  • gateway
• syncMode is now optional and automatically inferred:
  • archive → archive sync
  • all others → snap sync

✅ Dynamic Pod Topology

• Full refactor of the desiredStatefulSet method.

🧱 Validators

• When nodeType: validator is set:
  • The Operator automatically injects the validator-client
    container (Prysm)
  • Required secret volumes for validator keys are mounted
    automatically

🌐 Gateways

• RPC optimization flags are applied
• API limits and resource allocations are increased for
  high-performance traffic

🗃️ Archives

• Automatically configures:

  --gcmode=archive
  

✅ Security & RBAC

• Fixed Controller permissions:
  • The Operator now has permission to list and read Secrets
    (core/secrets)
  • Required for validator key mounting and JWT management

✅ Documentation

• README.md updated with:
  • New architecture overview
  • Revised Mermaid diagram (showing optional containers)
  • New manifest examples for each nodeType

---

🏗️ Implementation Details

📁 Modified File: api/v1/ethereumnode_types.go

• Added the NodeType struct and constants

📁 Modified File: internal/controller/ethereumnode_controller.go

• Argument inference logic
• Conditional injection of containers and volumes
• Updated RBAC markers (//+kubebuilder:rbac...)

---

🧪 How to Test

1️⃣ Deploy the Updated Operator

make docker-build IMG=blockchain-operator:v2
kind load docker-image blockchain-operator:v2 --name blockchain-operator
make deploy IMG=blockchain-operator:v2

---

2️⃣ Full Node Test (Default Snap Sync)

Apply the manifest:

apiVersion: infra.blockchain.corp/v1
kind: EthereumNode
metadata:
  name: test-full
  namespace: blockchain-operator-system
spec:
  nodeType: full
  network: sepolia
  replicas: 1
  storageSize: 500Gi

✅ Expected Result:
The Pod should start with 2 containers (execution + consensus).

---

3️⃣ Validator Node Test

Create a mock secret:

kubectl create secret generic test-validator-validator-keys \
  --from-literal=password.txt=123 \
  -n blockchain-operator-system

Apply the manifest with nodeType: validator.

✅ Expected Result:
The Pod should start with 3 containers, including the
validator-client, and the secret must be mounted at:

/secrets/validator

---

✅ Checklist

• Code compiles successfully (make build)
• Manual Kind tests executed successfully
• Manifests generated and updated (make manifests)
• Documentation (README.md) updated
• Linting verified