Deploying Apps in an Independent EU Cloud: A Step-by-Step DevOps Guide

Hook: Why moving to an EU sovereign cloud is unavoidable — and hard

If you’re responsible for deploying and operating cloud-native apps for EU customers, you’ve probably felt the pressure: regulatory requirements, customer contracts demanding local control, and procurement teams insisting on on‑shore data residency. The launch of independent EU sovereign clouds in late 2025 and early 2026 means you can meet sovereignty guarantees — but only if your networking, identity, encryption, and CI/CD are rethought for an environment that is physically and logically separate from standard AWS regions.

The most important guidance up front

Key takeaway: Treat an EU sovereign region like a separate cloud provider. Reconfigure network paths, rebuild IAM trust boundaries, rekey encryption and place Terraform state and CI runners inside the sovereign region. Any dependency that crosses into global AWS control planes or external SaaS must be evaluated or replaced with an in‑region alternative.

Context: Why 2026 matters for sovereign cloud deployments

By 2026, major cloud vendors (including AWS) launched explicit European sovereign regions to meet EU digital sovereignty requirements. This trend accelerated after updated EU rules (NIS2 expansion, ongoing GDPR enforcement, and national data residency policies in finance and public sectors) and increased demand from regulated customers in late 2025. The result: architects must now design for logical separation, legal protections, and in‑region control of keys and identity.

Step-by-step migration and deployment plan (high level)

1. Discovery & inventory — list VPCs, IAM principals, KMS keys, S3 buckets, ECR repos, DNS records, CI/CD flows, and external integrations.
2. Network plan — design VPC addressing, transit, private connectivity, and egress policies for the sovereign region.
3. Identity & IAM migration — map and rebuild roles, OIDC providers and SSO inside the sovereign control plane.
4. Encryption strategy — create new CMKs/CloudHSM in-region, plan key rotation and re-encryption flights for data at rest.
5. CI/CD adaptation — place runners/agents in-region, relocate artifact stores and Terraform state, and reconfigure secrets management.
6. Staged cutover — test with canary workloads, validate compliance checks, then cut traffic with DNS/Load Balancer swap.

1) Discovery & inventory — the essential preflight checklist

Start by cataloging everything with high precision. Use infrastructure scans and asset inventories. Focus on:

• Network: VPC CIDRs, peering, Transit Gateway attachments, VPN/Direct Connect links.
• Identity: IAM principals, roles, trust policies, OIDC providers and SSO configuration.
• Encryption: KMS keys, CloudHSM clusters, and which services use CMK vs service-managed encryption.
• CI/CD: Runners, artifact storage (S3/ECR), secrets stores, and external integrations (Slack, PagerDuty, third‑party SaaS).
• Terraform & state: S3 buckets used for state, DynamoDB locks, and any remote backends or CI integrations.

2) Networking — design patterns for a sovereign region

Principle: Keep east‑west traffic inside the sovereign region and provide controlled, auditable egress for third‑party services that cannot be moved.

VPC & subnet layout

Use a predictable multi‑AZ VPC layout. Example:

• Public subnets for ALBs and NAT gateways
• Private application subnets for app services
• Isolated data subnets for databases and analytics
• Management subnets for bastion hosts and CI runners

Private connectivity: Direct Connect / Partner and VPN

If you currently use Direct Connect to an EU general region, provision a new Direct Connect or partner link into the sovereign region. Understand that the sovereign region may require new partner validation and different AWS Direct Connect locations.

Transit patterns

Use a regional Transit Gateway or equivalent to centralize routing. Avoid cross-region peering to non-sovereign regions. If you must access global services (e.g., payment gateways), place a hardened egress proxy in the sovereign region and log all traffic for audit.

DNS and routing

Route 53 private hosted zones can be recreated in region — but be aware: the global Route 53 control plane remains outside sovereign scopes in some implementations. Plan DNS records carefully and consider running in-region DNS servers for private names.

Practical networking checklist

• Allocate VPC CIDR block ranges that avoid clashes with corporate networks.
• Deploy Transit Gateway in-region and reattach VPCs.
• Provision Direct Connect or partner interconnect into the sovereign region.
• Run NAT gateways and egress proxies in-region for controlled outbound traffic.

3) IAM & identity — rebuilding trust boundaries

Principle: Recreate identity trusts inside the sovereign control plane. Do not rely on cross‑region IAM configurations that expose control to non‑sovereign control planes.

Accounts and organizational units

Create new accounts in your AWS Organization that are explicitly placed and managed for the sovereign region. Use SCPs (Service Control Policies) to enforce in‑region resource creation.

Identity providers & SSO

If you use the cloud provider’s centralized identity (like AWS IAM Identity Center), verify that it supports the sovereign control plane. You may need to deploy an identity bridge or run an on‑prem idP (SAML/OIDC) to keep everything fully auditable and in-region.

Cross-account roles & OIDC for CI

Recreate role trust relationships for your CI system. For example, if using GitHub Actions with OIDC, configure a new OIDC provider and role in the sovereign account. If GitHub public OIDC cannot be used due to compliance, deploy self-hosted runners and use short‑lived credentials issued by your internal idP.

Permissions boundaries & least privilege

Apply permissions boundaries and IAM policies that reflect the stricter compliance posture of the sovereign region. Add resource tagging enforcement so that audit tools can automatically classify data and workloads.

4) Encryption — keys are the crown jewels

Principle: Keep key management and HSM control inside the sovereign boundary. Re‑encrypt data with new in-region keys where required.

CMKs and CloudHSM

Create new Customer Master Keys (CMKs) in the sovereign region’s KMS. For the highest assurance workloads, provision CloudHSM clusters in-region and back KMS keys with them. Verify that key policies and IAM principals are limited to sovereign accounts.

Data migration & re-encryption strategy

For S3 buckets, RDS, EBS snapshots and encrypted volumes, use a re-encryption flight:

1. Create in-region CMKs / HSM clusters.
2. Copy objects from source buckets to destination buckets using SSE-KMS with the new key.
3. For databases, run logical dumps and imports using encrypted transport, or use database-native replication with in-region keys.

Encryption in transit

Ensure mTLS between services and terminate TLS at Ingress in-region load balancers. For service mesh deployments, run control plane components inside the sovereign region and store certificates in an in-region certificate manager.

5) CI/CD — the most practical adjustments

CI/CD workflows usually require the most operational changes when moving to a sovereign region because they touch artifacts, secrets and identity.

CI runner placement

Options:

• Self-hosted runners inside sovereign region VPC: Best for full sovereignty and low-latency access to in-region resources.
• Managed runners with OIDC: Only acceptable if the OIDC provider and token exchange meet your sovereign requirements.
• Privileged proxies: If some external SaaS is required, put a hardened proxy in-region that mediates and audits access.

Artifact stores and Terraform state

Move all artifact stores (S3 buckets, ECR repos) to the sovereign region. For Terraform, host your remote backend in‑region:

# Example Terraform backend block for S3 in the sovereign region
  terraform {
    backend "s3" {
      bucket = "my-terraform-state-eu-sovereign"
      key    = "team/app/terraform.tfstate"
      region = "eu-sovereign-1"
      dynamodb_table = "terraform-locks-eu-sovereign"
      encrypt = true
    }
  }
  

Ensure the DynamoDB locking table and S3 bucket are created in the sovereign account and protected by bucket policies and KMS CMKs in-region. Treat your Terraform backend migration like any enterprise tool consolidation: plan rollback and access controls carefully.

Secrets management

Relocate secrets to in-region secrets managers (e.g., Secrets Manager, Parameter Store) backed by in-region CMKs. Update your pipeline to fetch secrets from the new store, or use short-lived certs issued by your in-region idP.

Sample GitHub Actions pattern — self-hosted runner

# Simplified job that runs on a self-hosted runner in the sovereign region
  name: Deploy to EU Sovereign
  on: [push]
  jobs:
    build-and-deploy:
      runs-on: [self-hosted, eu-sovereign]
      steps:
        - uses: actions/checkout@v4
        - name: Authenticate to in-region secrets
          run: |
            aws ssm get-parameter --name /prod/db/password --with-decryption --region eu-sovereign-1
        - name: Terraform apply
          run: terraform apply -auto-approve
  

6) Terraform & IaC considerations

Principle: Your IaC should be explicit about region and account. Avoid implicit providers and cross-region resources unless specifically audited.

Provider pinning and multiple providers

Use multiple provider blocks to manage resources in the sovereign region and the global control plane where necessary:

provider "aws" {
    alias  = "sovereign"
    region = "eu-sovereign-1"
    # Use explicit credentials tied to sovereign account
  }

  resource "aws_vpc" "app" {
    provider = aws.sovereign
    cidr_block = "10.10.0.0/16"
    # ...
  }
  

State migration strategy

1. Export current Terraform state and plan a mapping between old resource IDs and new ones.
2. Use terraform state mv to move resources you will manage from the old backend to the new in-region backend, when possible.
3. For resources that must be recreated (e.g., KMS CMKs), plan replacements with minimal downtime and data re-encryption windows. Treat rekeying and re-encryption like a data-management project with clear audits and reconciliation.

7) Testing, canary rollout and cutover

Set up a staged approach to reduce risk:

1. Deploy a canary service in the sovereign region and run synthetic tests.
2. Perform security scans, compliance checks and key audits.
3. Use traffic shifting at the load balancer or DNS level (weighted DNS) for gradual migration.
4. Plan rollback paths and data reconciliation for eventual consistency issues.

8) Observability & logging in-region

Ensure all logs, traces and metrics are stored in-region. Move log aggregation (CloudWatch / alternative) and SIEM collectors inside the sovereign environment. Apply retention and access controls to satisfy auditors — follow an observability & incident response playbook for logging pipelines and alerting.

Real-world example: Moving a SaaS 3‑tier app from eu-west-1 to eu-sovereign-1

Scenario: A SaaS company with customers in finance needs to migrate app components (API, backend, Postgres, Redis) into the EU sovereign region. High-level steps we executed:

1. Inventoryed all resources and identified that RDS and S3 data must be re-encrypted due to key residency rules.
2. Provisioned new accounts and a Transit Gateway in eu-sovereign-1, created VPCs with matching subnet architecture, and established Direct Connect via a partner edge.
3. Created in-region CMKs and CloudHSM cluster, re-encrypted S3 and EBS snapshots using a phased copy with minimal impact.
4. Deployed self-hosted GitHub Actions runners into the sovereign VPC and relocated Terraform state to an S3 backend with DynamoDB locking secured by the new CMK.
5. Validated OIDC token exchange by configuring an internal OIDC bridge for legacy CI jobs, then gradually cut traffic using DNS weight shifting over 48 hours.
6. Completed a full audit for legal and compliance teams and put monitoring alerts for cross-boundary egress attempts.

Result: Successful migration with zero exposure of keys outside the sovereign control plane and minimal downtime for customers.

2026 trends & future predictions

• More vendors will offer “sovereign-ready” managed services with clear in‑region control plane assurances.
• CI/CD tooling will mature to support ephemeral, compliant runners tailored for sovereign clouds.
• Organizations will shift to envelope encryption patterns and local HSMs as default for regulated data.
• Expect more standardized APIs and compliance attestations for sovereign clouds from late 2026 onwards.

Common pitfalls and how to avoid them

• Assuming global control plane parity — verify which services remain global and plan alternates.
• Not rekeying data — if regulations require in-region keys, leaving old keys violates contracts.
• CI secret leakage — move secrets stores and runners in-region before cutover.
• DNS surprises — check how your provider implements private hosted zones in sovereign regions.

Actionable checklist — what to do this week

1. Run an inventory and tag all sovereignty-sensitive resources.
2. Create a new sovereign AWS Organization unit and accounts for workloads you’ll migrate.
3. Stand up a minimal VPC, Transit Gateway and dedicated Direct Connect/partner link in the sovereign region.
4. Deploy a single self-hosted CI runner and test pipeline runs against in-region resources.
5. Create CMKs and test object re-encryption for a small bucket.

“Treat the sovereign region as a second cloud provider — plan, test, and move identity, keys and CI first.”

Closing recommendations

Moving to an EU sovereign cloud is not a simple region switch. It’s an organizational and technical transformation that affects core primitives: networking, identity, encryption and CI/CD. The safest approach is staged, auditable, and minimizes cross-boundary dependencies. Use Terraform and IaC to capture the migration reproducibly, run CI runners and secrets in the sovereign region, and maintain strict key residency and access controls.

Next steps & call to action

If you’re evaluating migration to an EU sovereign region in 2026, start with a 2‑week assessment: inventory, a connectivity POC, and a CI runner smoke test inside the sovereign region. If you want help building the plan or running the POC, our DevOps engineers at pows.cloud specialize in sovereign cloud migrations — we can run a tailored workshop and provide ready-to-run Terraform modules and secure CI templates to get you production-ready faster.

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