feat(sftp): DDS integration into the rover (DHEI-20905)

common/pkg/config/feature.go

@@ -49,6 +49,7 @@ var (
 	FeatureSecretManager Feature = NewFeature("secret_manager", true) // Secret Manager feature enabled by default
 	FeatureFileManager   Feature = NewFeature("file_manager", true)   // File Manager feature enabled by default
 	FeatureAiGateway     Feature = NewFeature("ai_gateway", false)    // AI Gateway (MCP) feature disabled by default
+	FeatureFile          Feature = NewFeature("file", true)
 )
 
 // SetFeatureEnabled sets the enabled state for a feature. Intended for tests.

docs/docs/architecture/rover.mdx

@@ -25,10 +25,26 @@ Users interact with the Rover domain through three paths:
 - **Application domain** — Creates Application resources.
 - **API domain** — Creates Api, ApiExposure, and ApiSubscription resources.
 - **Event domain** — Creates EventExposure and EventSubscription resources.
+- **File domain (SFTP)** — Creates the SFTP user (shared space) from a `FileSpecification` and registers producer/consumer SSH public keys for `fileType` exposures and subscriptions. Gated behind the `file` feature flag.
 - **Gateway domain** — Configures traffic management settings.
 - **Identity domain** — Configures authentication settings.
 - **Approval domain** — Integrates approval requirements for exposures.
 
+## File Types (SFTP)
+
+Rover can configure an external SFTP file-transfer service without changing the customer-facing Rover file:
+
+- A `FileSpecification` (`metadata.name` must equal `spec.type`) provisions an SFTP user with a default shared space.
+- A `fileType` **exposure** (producer) or **subscription** (consumer) with `variant: sftp` and one or more `publicKeys` registers those SSH keys on the matching SFTP user.
+
+Validation rules enforced by the Rover webhook:
+
+- `fileType` exposures/subscriptions are only allowed on the `cetus` and `canis` zones.
+- `variant: sftp` is optional.
+- At least one public key is required; both the key `label` and `key` value must be unique per `fileType`.
+
+Because file transfer happens directly over SFTP, a Rover that only exposes/subscribes to file types yields a **logical** Application (`needsClient` and `needsConsumer` are `false`). If the same Rover also has an API or event subscription, a client is still required.
+
 ## Related Pages
 
 - [User Journey: Onboarding](../user-journey/onboarding.md)

file/api/go.mod

@@ -0,0 +1,74 @@
+// Copyright 2026 Deutsche Telekom IT GmbH
+//
+// SPDX-License-Identifier: Apache-2.0
+
+module github.com/telekom/controlplane/file/api
+
+go 1.26.5
+
+require (
+	github.com/onsi/ginkgo/v2 v2.32.0
+	github.com/onsi/gomega v1.42.1
+	github.com/telekom/controlplane/common v0.0.0
+	k8s.io/apiextensions-apiserver v0.36.2
+	k8s.io/apimachinery v0.36.2
+	sigs.k8s.io/controller-runtime v0.24.1
+)
+
+require (
+	github.com/Masterminds/semver/v3 v3.4.0 // indirect
+	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
+	github.com/emicklei/go-restful/v3 v3.13.0 // indirect
+	github.com/evanphx/json-patch/v5 v5.9.11 // indirect
+	github.com/fsnotify/fsnotify v1.9.0 // indirect
+	github.com/fxamacker/cbor/v2 v2.9.0 // indirect
+	github.com/go-logr/logr v1.4.3 // indirect
+	github.com/go-openapi/jsonpointer v0.21.0 // indirect
+	github.com/go-openapi/jsonreference v0.20.2 // indirect
+	github.com/go-openapi/swag v0.23.0 // indirect
+	github.com/go-task/slim-sprig/v3 v3.0.0 // indirect
+	github.com/go-viper/mapstructure/v2 v2.5.0 // indirect
+	github.com/google/gnostic-models v0.7.0 // indirect
+	github.com/google/go-cmp v0.7.0 // indirect
+	github.com/google/pprof v0.0.0-20260402051712-545e8a4df936 // indirect
+	github.com/google/uuid v1.6.0 // indirect
+	github.com/josharian/intern v1.0.0 // indirect
+	github.com/json-iterator/go v1.1.12 // indirect
+	github.com/mailru/easyjson v0.7.7 // indirect
+	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
+	github.com/modern-go/reflect2 v1.0.3-0.20250322232337-35a7c28c31ee // indirect
+	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
+	github.com/pelletier/go-toml/v2 v2.2.4 // indirect
+	github.com/sagikazarmark/locafero v0.12.0 // indirect
+	github.com/spf13/afero v1.15.0 // indirect
+	github.com/spf13/cast v1.10.0 // indirect
+	github.com/spf13/pflag v1.0.10 // indirect
+	github.com/spf13/viper v1.21.0 // indirect
+	github.com/subosito/gotenv v1.6.0 // indirect
+	github.com/x448/float16 v0.8.4 // indirect
+	go.yaml.in/yaml/v2 v2.4.4 // indirect
+	go.yaml.in/yaml/v3 v3.0.4 // indirect
+	golang.org/x/mod v0.38.0 // indirect
+	golang.org/x/net v0.56.0 // indirect
+	golang.org/x/oauth2 v0.36.0 // indirect
+	golang.org/x/sync v0.21.0 // indirect
+	golang.org/x/sys v0.46.0 // indirect
+	golang.org/x/term v0.44.0 // indirect
+	golang.org/x/text v0.39.0 // indirect
+	golang.org/x/time v0.15.0 // indirect
+	golang.org/x/tools v0.47.0 // indirect
+	google.golang.org/protobuf v1.36.12-0.20260120151049-f2248ac996af // indirect
+	gopkg.in/inf.v0 v0.9.1 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+	k8s.io/api v0.36.2 // indirect
+	k8s.io/client-go v0.36.2 // indirect
+	k8s.io/klog/v2 v2.140.0 // indirect
+	k8s.io/kube-openapi v0.0.0-20260317180543-43fb72c5454a // indirect
+	k8s.io/utils v0.0.0-20260210185600-b8788abfbbc2 // indirect
+	sigs.k8s.io/json v0.0.0-20250730193827-2d320260d730 // indirect
+	sigs.k8s.io/randfill v1.0.0 // indirect
+	sigs.k8s.io/structured-merge-diff/v6 v6.3.2 // indirect
+	sigs.k8s.io/yaml v1.6.0 // indirect
+)
+
+replace github.com/telekom/controlplane/common => ../../common