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State Backends

This guide covers how to configure state storage for Pulumi, OpenTofu, and Terraform deployments. OpenMCF reads backend configuration from manifest labels and CLI flags, eliminating the need for separate backend configuration files.

For the conceptual overview of state management — what state is, why it matters, and how each engine handles it — see State Management.

Quick Reference

ProvisionerBackend Labels
Terraformterraform.openmcf.org/backend.type, backend.bucket, backend.key, backend.region, backend.endpoint
OpenTofutofu.openmcf.org/backend.type, backend.bucket, backend.key, backend.region, backend.endpoint
Pulumipulumi.openmcf.org/stack.name (uses Pulumi Cloud or local)

S3 Backend Labels (Complete Example)

metadata:
  labels:
    openmcf.org/provisioner: terraform
    terraform.openmcf.org/backend.type: s3
    terraform.openmcf.org/backend.bucket: my-terraform-state
    terraform.openmcf.org/backend.key: path/to/state.tfstate
    terraform.openmcf.org/backend.region: us-west-2

CLI Flags for Backend Configuration

In addition to manifest labels, you can configure backends using CLI flags. CLI flags take precedence over manifest labels, allowing you to override settings for CI/CD or testing.

Backend CLI Flags

FlagDescription
--backend-typeBackend type: local, s3, gcs, azurerm
--backend-bucketBucket/container name for state storage
--backend-keyState file path within the bucket
--backend-regionAWS region (use auto for S3-compatible backends)
--backend-endpointCustom S3-compatible endpoint URL (R2, MinIO, etc.)
--reconfigureForce backend reconfiguration

Example: CLI-Based Configuration

# Full CLI configuration
openmcf apply -f manifest.yaml \
    --backend-type s3 \
    --backend-bucket my-state-bucket \
    --backend-key env/prod/terraform.tfstate \
    --backend-region us-west-2

# Override just the bucket (other values from manifest)
openmcf apply -f manifest.yaml --backend-bucket different-bucket

Configuration Precedence

CLI Flags > Manifest Labels > Environment Variables > Interactive Prompts > Defaults

This means:

  1. CLI flags always win if provided
  2. Manifest labels override environment variables
  3. Environment variables provide defaults when manifest labels are absent
  4. If required values are missing, you'll be prompted interactively
  5. Local backend is used if nothing is configured

Environment Variables

For scenarios where CLI flags are cumbersome or manifests can't be modified, you can configure backend settings via environment variables. This is especially useful for CI/CD pipelines and 12-factor app patterns.

Supported Variables

VariableDescription
OPENMCF_BACKEND_TYPEBackend type: s3, gcs, azurerm, local
OPENMCF_BACKEND_BUCKETState bucket/container name
OPENMCF_BACKEND_REGIONAWS region (use auto for S3-compatible backends)
OPENMCF_BACKEND_ENDPOINTCustom S3-compatible endpoint URL (R2, MinIO, etc.)

Note: backend.key is intentionally NOT configurable via environment variable. State file paths should be explicit and traceable, so they must come from manifest labels or CLI flags.

Usage Example

# Set environment variables (e.g., in CI/CD pipeline)
export OPENMCF_BACKEND_TYPE=s3
export OPENMCF_BACKEND_BUCKET=my-state-bucket
export OPENMCF_BACKEND_REGION=auto
export OPENMCF_BACKEND_ENDPOINT=https://account-id.r2.cloudflarestorage.com

# Run with key from manifest
openmcf apply -f manifest.yaml

# Or provide key via CLI flag
openmcf apply -f manifest.yaml --backend-key env/prod/state.tfstate

CI/CD Example (GitHub Actions)

jobs:
  deploy:
    runs-on: ubuntu-latest
    env:
      OPENMCF_BACKEND_TYPE: s3
      OPENMCF_BACKEND_BUCKET: ${{ secrets.STATE_BUCKET }}
      OPENMCF_BACKEND_REGION: auto
      OPENMCF_BACKEND_ENDPOINT: ${{ secrets.R2_ENDPOINT }}
    steps:
      - uses: actions/checkout@v4
      - name: Deploy infrastructure
        run: openmcf apply -f manifest.yaml

Override Behavior

Environment variables serve as defaults that can be overridden:

# Environment sets bucket to "default-bucket"
export OPENMCF_BACKEND_BUCKET=default-bucket

# Manifest label overrides to "manifest-bucket"
# terraform.openmcf.org/backend.bucket: manifest-bucket

# CLI flag overrides to "cli-bucket" (highest priority)
openmcf apply -f manifest.yaml --backend-bucket cli-bucket

Pulumi State

Pulumi stores state either in Pulumi Cloud (default) or locally. The stack name label identifies where your state is stored.

Stack Name Label

apiVersion: kubernetes.openmcf.org/v1
kind: KubernetesPostgres
metadata:
  name: app-database
  labels:
    openmcf.org/provisioner: pulumi
    pulumi.openmcf.org/stack.name: prod.KubernetesPostgres.app-database
spec:
  container:
    replicas: 1

Stack Name Format

The stack name follows the pattern: <environment>.<project>.<stack>

  • environment: Deployment environment (prod, staging, dev)
  • project: Pulumi project name (usually matches the kind)
  • stack: Unique identifier for this deployment

Pulumi Backend Options

1. Pulumi Cloud (Recommended)

# Login to Pulumi Cloud
pulumi login

# State is automatically stored in Pulumi Cloud
openmcf apply -f database.yaml

2. Local Backend

# Use local filesystem for state
pulumi login --local

# State stored in ~/.pulumi/
openmcf apply -f database.yaml

3. Self-hosted Backend (S3, GCS, Azure)

# Use S3 for state
pulumi login s3://my-pulumi-state-bucket

# Or GCS
pulumi login gs://my-pulumi-state-bucket

# Or Azure Blob
pulumi login azblob://my-container

OpenTofu / Terraform State

OpenTofu and Terraform use a backend configuration to store state. OpenMCF reads this configuration from manifest labels.

Label Format

Each provisioner uses its own label prefix. The backend configuration requires these labels:

LabelDescriptionRequired
backend.typeBackend type: s3, gcs, azurerm, or localYes
backend.bucketBucket/container name for remote stateYes (for remote backends)
backend.keyState file path within the bucketYes
backend.regionAWS region (S3 only)Yes (for S3)

For Terraform (S3 backend):

metadata:
  labels:
    openmcf.org/provisioner: terraform
    terraform.openmcf.org/backend.type: s3
    terraform.openmcf.org/backend.bucket: my-terraform-state
    terraform.openmcf.org/backend.key: vpc/production.tfstate
    terraform.openmcf.org/backend.region: us-west-2

For OpenTofu (GCS backend):

metadata:
  labels:
    openmcf.org/provisioner: tofu
    tofu.openmcf.org/backend.type: gcs
    tofu.openmcf.org/backend.bucket: my-tofu-state
    tofu.openmcf.org/backend.key: vpc/production

Backward Compatibility

For backward compatibility:

  • OpenTofu accepts terraform.openmcf.org/* labels if provisioner-specific labels are not present
  • backend.object label is still supported but deprecated in favor of backend.key
metadata:
  labels:
    openmcf.org/provisioner: tofu
    # Legacy labels - still work
    terraform.openmcf.org/backend.type: s3
    terraform.openmcf.org/backend.bucket: my-bucket
    terraform.openmcf.org/backend.object: path/to/state.tfstate  # deprecated, use backend.key
    terraform.openmcf.org/backend.region: us-west-2

We recommend using provisioner-specific labels with backend.key for clarity.

Supported Backend Types

Amazon S3

Store state in an S3 bucket with optional DynamoDB locking.

apiVersion: aws.openmcf.org/v1
kind: AwsVpc
metadata:
  name: production-vpc
  labels:
    openmcf.org/provisioner: terraform
    terraform.openmcf.org/backend.type: s3
    terraform.openmcf.org/backend.bucket: my-terraform-state
    terraform.openmcf.org/backend.key: vpc/production.tfstate
    terraform.openmcf.org/backend.region: us-west-2
spec:
  cidrBlock: 10.0.0.0/16
  region: us-west-2

Required labels:

  • backend.type: s3
  • backend.bucket: S3 bucket name
  • backend.key: State file path within the bucket
  • backend.region: AWS region where the bucket is located

Prerequisites:

  • S3 bucket must exist
  • IAM permissions: s3:GetObject, s3:PutObject, s3:DeleteObject, s3:ListBucket
  • Optional: DynamoDB table for state locking (configured via environment)

S3-Compatible Backends (Cloudflare R2, MinIO)

OpenMCF supports S3-compatible backends like Cloudflare R2, MinIO, and other S3-compatible storage services. The CLI automatically detects these backends and configures the necessary compatibility flags.

Detection signals:

  • backend.region set to auto
  • backend.endpoint is specified

When an S3-compatible backend is detected, OpenMCF automatically adds:

  • skip_credentials_validation = true
  • skip_region_validation = true
  • skip_requesting_account_id = true
  • skip_metadata_api_check = true
  • skip_s3_checksum = true
  • use_path_style = true

Cloudflare R2 Example

apiVersion: aws.openmcf.org/v1
kind: AwsVpc
metadata:
  name: production-vpc
  labels:
    openmcf.org/provisioner: terraform
    terraform.openmcf.org/backend.type: s3
    terraform.openmcf.org/backend.bucket: my-r2-state-bucket
    terraform.openmcf.org/backend.key: vpc/production.tfstate
    terraform.openmcf.org/backend.region: auto
    terraform.openmcf.org/backend.endpoint: https://<account-id>.r2.cloudflarestorage.com
spec:
  cidrBlock: 10.0.0.0/16

CLI-Based R2 Configuration

openmcf apply -f manifest.yaml \
    --backend-type s3 \
    --backend-bucket my-r2-state-bucket \
    --backend-key vpc/production.tfstate \
    --backend-region auto \
    --backend-endpoint https://<account-id>.r2.cloudflarestorage.com

MinIO Example

metadata:
  labels:
    openmcf.org/provisioner: tofu
    tofu.openmcf.org/backend.type: s3
    tofu.openmcf.org/backend.bucket: terraform-state
    tofu.openmcf.org/backend.key: app/state.tfstate
    tofu.openmcf.org/backend.region: auto
    tofu.openmcf.org/backend.endpoint: https://minio.example.com:9000

Prerequisites for R2:

  • Cloudflare R2 bucket must exist
  • R2 API token with read/write permissions
  • Configure credentials via AWS CLI profile or environment variables: 
    export AWS_ACCESS_KEY_ID=<r2-access-key>
export AWS_SECRET_ACCESS_KEY=<r2-secret-key>

Google Cloud Storage

Store state in a GCS bucket.

apiVersion: gcp.openmcf.org/v1
kind: GkeCluster
metadata:
  name: staging-cluster
  labels:
    openmcf.org/provisioner: tofu
    tofu.openmcf.org/backend.type: gcs
    tofu.openmcf.org/backend.bucket: my-gcs-state-bucket
    tofu.openmcf.org/backend.key: gke/staging-cluster
spec:
  projectId: my-gcp-project
  region: us-central1

Required labels:

  • backend.type: gcs
  • backend.bucket: GCS bucket name
  • backend.key: State prefix/path within the bucket

Prerequisites:

  • GCS bucket must exist
  • IAM permissions: storage.objects.get, storage.objects.create, storage.objects.delete, storage.objects.list

Azure Storage

Store state in Azure Blob Storage.

apiVersion: azure.openmcf.org/v1
kind: AzureAksCluster
metadata:
  name: production-aks
  labels:
    openmcf.org/provisioner: terraform
    terraform.openmcf.org/backend.type: azurerm
    terraform.openmcf.org/backend.bucket: tfstate-container
    terraform.openmcf.org/backend.key: aks/production
spec:
  location: eastus
  nodeCount: 3

Required labels:

  • backend.type: azurerm
  • backend.bucket: Azure container name
  • backend.key: State file path within the container

Prerequisites:

  • Storage account and container must exist
  • Storage account name configured via environment
  • IAM permissions: Storage Blob Data Contributor

Local Backend

Store state on the local filesystem. Not recommended for production or team use.

apiVersion: kubernetes.openmcf.org/v1
kind: KubernetesDeployment
metadata:
  name: test-service
  labels:
    openmcf.org/provisioner: tofu
    tofu.openmcf.org/backend.type: local
    tofu.openmcf.org/backend.key: /tmp/test-service.tfstate
spec:
  replicas: 1

Required labels:

  • backend.type: local
  • backend.key: Local file path for state

Use cases:

  • Local development
  • Testing
  • Single-user scenarios

Limitations:

  • No state locking
  • Not shareable between team members
  • Lost if machine is wiped

Complete Examples

Example 1: AWS Infrastructure with S3 Backend

apiVersion: aws.openmcf.org/v1
kind: AwsRdsInstance
metadata:
  name: app-database
  labels:
    # Provisioner selection
    openmcf.org/provisioner: terraform
    
    # Backend configuration
    terraform.openmcf.org/backend.type: s3
    terraform.openmcf.org/backend.bucket: company-terraform-state
    terraform.openmcf.org/backend.key: rds/app-database/production.tfstate
    terraform.openmcf.org/backend.region: us-west-2
spec:
  engine: postgres
  engineVersion: "15"
  instanceClass: db.t3.medium
  allocatedStorage: 100
  region: us-west-2

Deploy:

openmcf apply -f database.yaml

Example 2: GCP Infrastructure with GCS Backend (OpenTofu)

apiVersion: gcp.openmcf.org/v1
kind: GcpCloudRun
metadata:
  name: api-service
  labels:
    # Provisioner selection
    openmcf.org/provisioner: tofu
    
    # Backend configuration (OpenTofu-specific)
    tofu.openmcf.org/backend.type: gcs
    tofu.openmcf.org/backend.bucket: company-tofu-state
    tofu.openmcf.org/backend.key: cloud-run/api-service/prod
spec:
  projectId: my-gcp-project
  region: us-central1
  image: gcr.io/my-project/api:latest

Deploy:

openmcf apply -f api-service.yaml

Example 3: Multi-Environment with Kustomize

Base manifest (base/database.yaml):

apiVersion: aws.openmcf.org/v1
kind: AwsRdsInstance
metadata:
  name: app-database
  labels:
    openmcf.org/provisioner: terraform
    terraform.openmcf.org/backend.type: s3
    terraform.openmcf.org/backend.bucket: company-terraform-state
    terraform.openmcf.org/backend.region: us-west-2
    # Key will be patched per environment
spec:
  engine: postgres
  instanceClass: db.t3.small

Production overlay (overlays/prod/kustomization.yaml):

patches:
  - patch: |
      - op: add
        path: /metadata/labels/terraform.openmcf.org~1backend.key
        value: rds/app-database/production.tfstate
      - op: replace
        path: /spec/instanceClass
        value: db.t3.large
    target:
      kind: AwsRdsInstance

Deploy:

openmcf apply --kustomize-dir . --overlay prod

Example 4: Pulumi with Stack Name

apiVersion: kubernetes.openmcf.org/v1
kind: KubernetesPostgres
metadata:
  name: analytics-db
  labels:
    # Provisioner selection
    openmcf.org/provisioner: pulumi
    
    # Stack name for state identification
    pulumi.openmcf.org/stack.name: production.KubernetesPostgres.analytics-db
spec:
  container:
    replicas: 3
    resources:
      limits:
        cpu: 2000m
        memory: 8Gi

Deploy:

# Ensure you're logged into Pulumi
pulumi login

# Deploy
openmcf apply -f analytics-db.yaml

Best Practices

1. Use Consistent Naming

Establish a naming convention for state paths:

<bucket>/<resource-type>/<resource-name>/<environment>

Example: terraform-state/rds/app-database/production

2. Separate State by Environment

Use different buckets or prefixes for different environments:

# Production
terraform.openmcf.org/backend.bucket: prod-terraform-state
terraform.openmcf.org/backend.key: vpc/main.tfstate

# Staging
terraform.openmcf.org/backend.bucket: staging-terraform-state
terraform.openmcf.org/backend.key: vpc/main.tfstate

# Development
terraform.openmcf.org/backend.bucket: dev-terraform-state
terraform.openmcf.org/backend.key: vpc/main.tfstate

3. Enable Versioning

Always enable versioning on your state bucket:

S3:

aws s3api put-bucket-versioning \
  --bucket my-terraform-state \
  --versioning-configuration Status=Enabled

GCS:

gsutil versioning set on gs://my-terraform-state

4. Enable Encryption

Encrypt state at rest:

S3:

aws s3api put-bucket-encryption \
  --bucket my-terraform-state \
  --server-side-encryption-configuration '{
    "Rules": [{"ApplyServerSideEncryptionByDefault": {"SSEAlgorithm": "AES256"}}]
  }'

5. Restrict Access

Implement least-privilege access to state files:

  • Use IAM roles/policies
  • Enable bucket logging
  • Consider using separate accounts for production state

6. Use State Locking

For S3, configure DynamoDB for state locking:

aws dynamodb create-table \
  --table-name terraform-state-lock \
  --attribute-definitions AttributeName=LockID,AttributeType=S \
  --key-schema AttributeName=LockID,KeyType=HASH \
  --billing-mode PAY_PER_REQUEST

Troubleshooting

"Backend configuration required"

Error: Backend type is specified but required labels are missing.

Solution: For remote backends, all required labels must be specified:

labels:
  # S3 backend - all four labels required
  terraform.openmcf.org/backend.type: s3
  terraform.openmcf.org/backend.bucket: my-terraform-state
  terraform.openmcf.org/backend.key: path/to/state.tfstate
  terraform.openmcf.org/backend.region: us-west-2

For GCS or Azure backends, backend.region is not required.

"Access Denied" to State Bucket

Error: Permission denied when accessing state.

Solutions:

  1. Verify IAM permissions on the bucket
  2. Check credential configuration
  3. Ensure bucket exists in the expected region
  4. Verify bucket policy allows access

State Lock Timeout

Error: Unable to acquire state lock.

Solutions:

  1. Check if another operation is running
  2. Force unlock if previous operation crashed: 
    terraform force-unlock <LOCK_ID>
  3. Verify DynamoDB table permissions (for S3 backend)

Wrong Provisioner Labels

Error: Backend not detected, using local backend.

Solution: Ensure labels match the provisioner:

# For Terraform (S3)
openmcf.org/provisioner: terraform
terraform.openmcf.org/backend.type: s3
terraform.openmcf.org/backend.bucket: my-state-bucket
terraform.openmcf.org/backend.key: path/to/state.tfstate
terraform.openmcf.org/backend.region: us-west-2

# For OpenTofu (GCS)
openmcf.org/provisioner: tofu
tofu.openmcf.org/backend.type: gcs
tofu.openmcf.org/backend.bucket: my-state-bucket
tofu.openmcf.org/backend.key: path/to/state

"Backend configuration changed"

Error: Terraform/Tofu prompts for backend reconfiguration.

Solution: Use the --reconfigure flag to accept the new backend configuration:

openmcf init -f manifest.yaml --reconfigure

# Or with other commands that run init internally
openmcf apply -f manifest.yaml --reconfigure

S3-Compatible Backend: "InvalidClientTokenId"

Error: error calling sts:GetCallerIdentity: InvalidClientTokenId

Cause: This error occurs when using S3-compatible backends (R2, MinIO) without the proper endpoint configuration. Terraform tries to validate credentials via AWS STS, which fails with non-AWS credentials.

Solution: Set region to auto and provide the endpoint:

metadata:
  labels:
    terraform.openmcf.org/backend.region: auto
    terraform.openmcf.org/backend.endpoint: https://<account-id>.r2.cloudflarestorage.com

Or via CLI:

openmcf apply -f manifest.yaml \
    --backend-region auto \
    --backend-endpoint https://<account-id>.r2.cloudflarestorage.com \
    --reconfigure

Incomplete Backend Configuration (Interactive Prompt)

Behavior: When required backend configuration is missing, OpenMCF prompts for values interactively:

ℹ  S3-Compatible Backend Detected
   Region is set to 'auto', indicating an S3-compatible backend

✗  Incomplete Backend Configuration

   S3 backend requires the following configuration:

   • Custom S3-compatible endpoint (required when region is 'auto')
     Flag:    --backend-endpoint
     Example: https://<account-id>.r2.cloudflarestorage.com

Enter endpoint: _

Solution: Either:

  1. Provide values at the prompt
  2. Add labels to your manifest
  3. Use CLI flags: --backend-endpoint https://...

In CI/CD (non-interactive): The CLI will exit with an error and show exactly which flags or labels are needed.

What's Next

  • State Management — Conceptual overview of state in OpenMCF
  • Unified Commands — Using apply, destroy, init, plan, refresh
  • Credentials — Setting up cloud provider credentials
  • Kustomize Integration — Multi-environment deployments with per-environment state
  • CLI Reference — Complete command and flag reference

Next article

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Credentials OpenMCF needs credentials to create and manage resources in your cloud accounts. This page explains how credentials are loaded and provides a quick reference for all supported providers. For detailed setup instructions for the three major clouds, see the dedicated provider guides: AWS Provider Setup GCP Provider Setup Azure Provider Setup How Credentials Are Loaded OpenMCF supports two methods for providing credentials. Both methods work with all IaC engines (Pulumi, OpenTofu,...
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