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Updated enforcement design to align with the issue 151
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Implementing enforcement for the NonAdminBackupStorageLocation requires
revisit of the enforcement behavior. This design should align with it's
requirements and allow other parts of the enforcement functionality.

The enforcement levels are described in the:
#151

Signed-off-by: Michal Pryc <[email protected]>
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@mpryc
mpryc committed Jan 29, 2025
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215 changes: 127 additions & 88 deletions docs/design/admin_control_over_spec.md
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# Admin users control over non admin objects' spec
# Admin users control over non admin objects' spec

## Abstract

Non Admin Controller (NAC) restricts the usage of OADP operator with NonAdminBackups and NonAdminRestores.
Admin users may want to further restrict this by restricting NonAdminBackup/NonAdminRestore spec fields values.

Non Admin Controller (NAC) restricts the usage of OADP operator with NonAdminBackups, NonAdminRestores and NonAdminBackupStorageLocations.
Admin users may want to further restrict this by restricting relevant spec fields values.
## Background

Non Admin Controller (NAC) adds the ability to admin users restrict the use of OADP operator for non admin users, by only allowing them to create backup/restores from their namespaces with NonAdminBackups/NonAdminRestores.
Admin users may want to further restrict non admin users operations, like forcing a specific time to live (TTL) for NonAdminBackups associated Velero Backups.
This design enables admin users to set custom default values for NonAdminBackup/NonAdminRestore spec fields, which can not be overridden by non-admin users.
The Non Admin Controller (NAC) restricts how non-admin users interact with the OADP operator. It allows them to create backups, restores, and backup storage locations only within their own namespaces using `NonAdminBackup`, `NonAdminRestore`, and `NonAdminBackupStorageLocation`, while enforcing additional restrictions and policies.

The NAC Controller enforces two types of controls: **restrictions** and **enforcements**.

- **Controller Restrictions** define policies that neither users nor cluster administrators can override.
- **Controller Enforcements** define policies that administrators can override if needed.

This design allows system administrators to manage **Controller Enforcements**, enabling them to set custom default values for the `NonAdminBackup`, `NonAdminRestore`, and `NonAdminBackupStorageLocation` spec fields, which non-admin users cannot override.

For example, administrators may want to enforce specific rules on non-admin user operations, such as:

- Enforcing a specific time to live (TTL) for Velero Backups associated with `NonAdminBackup`.
- Limiting the region that users can select within Velero `BackupStorageLocation`.
- Controlling which resource types can be restored in a `NonAdminRestore` request.

## Goals

Enable admin users to
- set custom default values for NonAdminBackup spec.backupSpec fields, which can not be overridden
- set custom default values for NonAdminRestore spec.restoreSpec fields, which can not be overridden
- set custom enforced values for NonAdminBackup spec.backupSpec fields, which can not be overridden
- set custom enforced values for NonAdminRestore spec.restoreSpec fields, which can not be overridden
- set custom enforced values for NonAdminBackupStorageLocation spec.backupStorageLocationSpec fields, which can not be overridden

Also
- Show custom default values validation errors in NAC object statuses and in NAC logs
- Show custom enforced values validation errors in NAC object statuses and in NAC logs
- Each enforced value is associated with a specific spec field. If a spec field is a map or a list, enforcing one key/value pair will not override the whole map/list
- Custom enforced values are overriding the Spec default values
- Non Admin users must define all fields that are within the enforced spec field

## Non Goals

- Show NonAdminBackup spec.backupSpec fields/NonAdminRestore spec.restoreSpec fields custom default values to non admin users
- Prevent non admin users to create NonAdminBackup/NonAdminRestore with overridden defaults
- Allow admin users to set second level defaults (for example, NonAdminBackup `spec.backupSpec.labelSelector` can have a custom default value, but not just `spec.backupSpec.labelSelector.matchLabels`)
- Prevent non admin users to create NonAdminBackup/NonAdminRestore/NonAdminBackupStorageLocation objects with overridden defaults. During reconciliation, NAC will check if the object has different values than enforced ones and will error if it does.
- Show NonAdminBackup spec.backupSpec fields/NonAdminRestore spec.restoreSpec fields/NonAdminBackupStorageLocation spec.backupStorageLocationSpec fields enforced values to the non admin users
- Check if there are on-going NAC operations prior to recreating NAC Pod
- Allow admin users to enforce falsy values (like empty maps or empty lists) for NonAdminBackup spec.backupSpec fields/NonAdminRestore spec.restoreSpec fields
- Allow admin users to enforce falsy values (like empty maps or empty lists) for NonAdminBackup spec.backupSpec fields/NonAdminRestore spec.restoreSpec fields/NonAdminBackupStorageLocation spec.backupStorageLocationSpec fields

## High-Level Design

A field will be added to OADP DPA object. With it, admin users will be able to select which NonAdminBackup `spec.backupSpec` fields have custom default (and enforced) values. NAC will respect the set values. If a NonAdminBackup is created with fields overriding any enforced values, it will fail validation prior to creating an associated Velero Backup.
Additional fields will be added to the OADP DPA object:
- `spec.nonAdmin.enforceBackupSpec`
- `spec.nonAdmin.enforceRestoreSpec`
- `spec.nonAdmin.enforceBackupStorageLocationSpec`

Another field will be added to OADP DPA object. With it, admin users will be able to select which NonAdminRestore `spec.restoreSpec` fields have custom default (and enforced) values. NAC will respect the set values. If a NonAdminRestore is created with fields overriding any enforced values, it will fail validation prior to creating an associated Velero Restore.

If admin user changes any enforced field value, NAC Pod is recreated to always be up to date with admin user enforcements.
These fields allow admin users to define custom enforced values for the `spec.backupSpec`, `spec.restoreSpec`, and `spec.backupStorageLocationSpec` fields within NonAdminBackup, NonAdminRestore, and NonAdminBackupStorageLocation objects, respectively. The Non Admin Controller (NAC) will ensure compliance with these values, and any NonAdmin object that attempts to override them will fail validation before the creation of the associated Velero object, whether it be a Backup, Restore, or BackupStorageLocation. Furthermore, if an admin user updates any enforced field value, the NAC Pod will be automatically recreated to reflect the latest administrative settings, ensuring that the system consistently enforces the specified policies and maintains operational integrity within the OADP operator.

> **Note:** if there are on-going NAC operations prior to recreating NAC Pod, reconcile progress might get lost for NAC objects.
## Detailed Design

Field `spec.nonAdmin.enforceBackupSpec`, of the same type as the Velero Backup Spec, will be added to OADP DPA object.

With it, admin users will be able to select which NonAdminBackup `spec.backupSpec` fields have custom default (and enforced) values.
With it, admin users will be able to select which NonAdminBackup `spec.backupSpec` fields have custom enforced (new default) values.

To avoid mistakes, not all fields will be able to be enforced, like `IncludedNamespaces`, that could break NAC usage.
To avoid mistakes, not all fields will be able to be enforced, like `IncludedNamespaces` which is within **Controller Restrictions** fields and admin users should not enforce it, which could break NAC usage.

NAC will respect the set values by reading DPA field during startup.If admin user changes any enforced field value, NAC Pod is recreated (and only NAC Pod) to always be up to date with admin user enforcements.

Expand All @@ -54,8 +68,14 @@ If NonAdminBackup respects enforcement, the created associated Velero Backup wil

Enforcement is done dynamically. If new field is added to Velero Backup Spec, it will be presented to user without code changes. If a field changes type/or default value, tests will warn us.

Similar enforcement is done for NonAdminRestore and NonAdminBackupStorageLocation.

It is important to note that the enforcement of one field will not override the whole map/list.

### Example workflows

#### Admin user configures NAC with enforced spec fields

In this example, admin user has configured NAC with the following OADP DPA options
```yaml
...
Expand All @@ -65,35 +85,84 @@ spec:
enable: true
enforceBackupSpecs:
snapshotVolumes: false
unsupportedOverrides:
tech-preview-ack: 'true'
```
That means, that the 2 following NonAdminBackup will be accepted by NAC validation
That means, that the following NonAdminBackup will be accepted by NAC validation
```yaml
...
spec:
backupSpec:
snapshotVolumes: false
ttl: 3h
```
> **Note:** the related Velero Backup for this NonAdminBackup will have `spec.snapshotVolumes` set to false, ttl set to 3h and other fields set to their default values.

But this NonAdminBackup will not be accepted by NAC validation
```yaml
...
spec:
backupSpec:
ttl: 3h
snapshotVolumes: true
```
> **Note:** the related Velero Backup for this NonAdminBackup will have `spec.snapshotVolumes` set to false
NonAdminBackup status and NAC log will have the following message:
> spec.backupSpec.snapshotVolumes field value is enforced by admin user, can not override it

But this NonAdminBackup will not be accepted by NAC validation
Also the following NonAdminBackup will be rejected, because user did not define all fields that are within the enforced spec field:
```yaml
...
spec:
backupSpec:
snapshotVolumes: true
ttl: 3h
```

NonAdminBackup status and NAC log will have the following message:
> spec.backupSpec.snapshotVolumes field value is enforced by admin user, can not override it
> spec.backupSpec.ttl field value is enforced by admin user, can not override it

#### Admin user configures NAC with enforced spec map/list fields

In this example, admin user has configured NAC with the following OADP DPA options, from which only `config.region` and `objectStorage.prefix` are enforced and the `config` is a map
```yaml
...
spec:
...
nonAdmin:
enable: true
enforceBackupStorageLocationSpec:
config:
region: eu-central-1
objectStorage:
prefix: non-admin-buckets
provider: aws
```

That means, that the following NonAdminBackupStorageLocation will be accepted by NAC validation
```yaml
...
spec:
backupStorageLocationSpec:
config:
serverSideEncryption: AES256
region: eu-central-1
objectStorage:
prefix: non-admin-buckets
provider: aws
```

The following NonAdminBackupStorageLocation will be rejected, because user did not define all fields that are within the enforced spec field:
```yaml
...
spec:
backupStorageLocationSpec:
config:
serverSideEncryption: AES256
objectStorage:
prefix: non-admin-buckets
provider: aws
```

NonAdminBackupStorageLocation status and NAC log will have the following message:
> spec.backupStorageLocationSpec.config.region field value is enforced by admin user, can not override it

## Alternatives Considered

Expand Down Expand Up @@ -127,18 +196,30 @@ type NonAdmin struct {
}
```

Store previous `EnforceBackupSpec` and `EnforceRestoreSpec` value, so when admin user changes it, Deployment is also changed to trigger a Pod recreation
Add `EnforceBackupStorageLocationSpec` struct to OADP DPA `NonAdmin` struct
```go
type NonAdmin struct {
// which backupStorageLocation spec field values to enforce
// +optional
EnforceBackupStorageLocationSpec *velero.BackupStorageLocationSpec `json:"enforceBackupStorageLocationSpec,omitempty"`
}
```

Store previous `EnforceBackupSpec`, `EnforceRestoreSpec` and `EnforceBackupStorageLocationSpec` value, so when admin user changes it, Deployment is also changed to trigger a Pod recreation
```go
const (
enforcedBackupSpecKey = "enforced-backup-spec"
enforcedRestoreSpecKey = "enforced-restore-spec"
enforcedBackupStorageLocationSpecKey = "enforced-backup-storage-location-spec"
)

var (
previousEnforcedBackupSpec *velero.BackupSpec = nil
dpaBackupSpecResourceVersion = ""
previousEnforcedRestoreSpec *velero.RestoreSpec = nil
dpaRestoreSpecResourceVersion = ""
previousEnforcedBackupStorageLocationSpec *velero.BackupStorageLocationSpec = nil
dpaBackupStorageLocationSpecResourceVersion = ""
)

func ensureRequiredSpecs(deploymentObject *appsv1.Deployment, dpa *oadpv1alpha1.DataProtectionApplication, image string, imagePullPolicy corev1.PullPolicy) error {
Expand All @@ -150,9 +231,14 @@ func ensureRequiredSpecs(deploymentObject *appsv1.Deployment, dpa *oadpv1alpha1.
dpaRestoreSpecResourceVersion = dpa.GetResourceVersion()
}
previousEnforcedRestoreSpec = dpa.Spec.NonAdmin.EnforceRestoreSpec
if len(dpaBackupStorageLocationSpecResourceVersion) == 0 || !reflect.DeepEqual(dpa.Spec.NonAdmin.EnforceBackupStorageLocationSpec, previousEnforcedBackupStorageLocationSpec) {
dpaBackupStorageLocationSpecResourceVersion = dpa.GetResourceVersion()
}
previousEnforcedBackupStorageLocationSpec = dpa.Spec.NonAdmin.EnforceBackupStorageLocationSpec
enforcedSpecAnnotation := map[string]string{
enforcedBackupSpecKey: dpaBackupSpecResourceVersion,
enforcedRestoreSpecKey: dpaRestoreSpecResourceVersion,
enforcedBackupStorageLocationSpecKey: dpaBackupStorageLocationSpecResourceVersion,
}

templateObjectAnnotations := deploymentObject.Spec.Template.GetAnnotations()
Expand All @@ -161,6 +247,7 @@ func ensureRequiredSpecs(deploymentObject *appsv1.Deployment, dpa *oadpv1alpha1.
} else {
templateObjectAnnotations[enforcedBackupSpecKey] = enforcedSpecAnnotation[enforcedBackupSpecKey]
templateObjectAnnotations[enforcedRestoreSpecKey] = enforcedSpecAnnotation[enforcedRestoreSpecKey]
templateObjectAnnotations[enforcedBackupStorageLocationSpecKey] = enforcedSpecAnnotation[enforcedBackupStorageLocationSpecKey]
deploymentObject.Spec.Template.SetAnnotations(templateObjectAnnotations)
}
}
Expand All @@ -187,71 +274,23 @@ During NAC startup, read OADP DPA, to be able to apply admin user enforcement
}
```

Modify ValidateBackupSpec function to use `EnforceBackupSpec` and apply that to non admin users' NonAdminBackup request
Implement `EnforceNacSpec` function to validate NonAdminBackup/NonAdminRestore/NonAdminBackupStorageLocation spec from Validation functions:
```go
func ValidateBackupSpec(nonAdminBackup *nacv1alpha1.NonAdminBackup, enforcedBackupSpec *velerov1.BackupSpec) error {
enforcedSpec := reflect.ValueOf(enforcedBackupSpec).Elem()
for index := range enforcedSpec.NumField() {
enforcedField := enforcedSpec.Field(index)
enforcedFieldName := enforcedSpec.Type().Field(index).Name
currentField := reflect.ValueOf(nonAdminBackup.Spec.BackupSpec).Elem().FieldByName(enforcedFieldName)
if !enforcedField.IsZero() && !currentField.IsZero() && !reflect.DeepEqual(enforcedField.Interface(), currentField.Interface()) {
field, _ := reflect.TypeOf(nonAdminBackup.Spec.BackupSpec).Elem().FieldByName(enforcedFieldName)
tagName, _, _ := strings.Cut(field.Tag.Get("json"), ",")
return fmt.Errorf(
"NonAdminBackup spec.backupSpec.%v field value is enforced by admin user, can not override it",
tagName,
)
}
}
}
```

Before creating NonAdminBackup's related Velero Backup, apply any missing fields to it that admin user has enforced
```go
enforcedSpec := reflect.ValueOf(r.EnforcedBackupSpec).Elem()
for index := range enforcedSpec.NumField() {
enforcedField := enforcedSpec.Field(index)
enforcedFieldName := enforcedSpec.Type().Field(index).Name
currentField := reflect.ValueOf(backupSpec).Elem().FieldByName(enforcedFieldName)
if !enforcedField.IsZero() && currentField.IsZero() {
currentField.Set(enforcedField)
}
}
```
func EnforceNacSpec(currentSpec, enforcedSpec any) error {
// Implementation not part of the design
}

Modify ValidateRestoreSpec function to use `EnforceRestoreSpec` and apply that to non admin users' NonAdminBackup request
```go
enforcedSpec := reflect.ValueOf(enforcedRestoreSpec).Elem()
for index := range enforcedSpec.NumField() {
enforcedField := enforcedSpec.Field(index)
enforcedFieldName := enforcedSpec.Type().Field(index).Name
currentField := reflect.ValueOf(nonAdminRestore.Spec.RestoreSpec).Elem().FieldByName(enforcedFieldName)
if !enforcedField.IsZero() && !currentField.IsZero() && !reflect.DeepEqual(enforcedField.Interface(), currentField.Interface()) {
field, _ := reflect.TypeOf(nonAdminRestore.Spec.RestoreSpec).Elem().FieldByName(enforcedFieldName)
tagName, _, _ := strings.Cut(field.Tag.Get("json"), ",")
return fmt.Errorf(
"NonAdminRestore spec.restoreSpec.%v field value is enforced by admin user, can not override it",
tagName,
)
}
}
```
// Validate NonAdminBackup/NonAdminRestore/NonAdminBackupStorageLocation spec from ValidateBackupSpec/ValidateRestoreSpec/ValidateBackupStorageLocationSpec functions. Example on the RestoreSpec validation:
err = EnforceNacSpec(nonAdminRestore.Spec.RestoreSpec, enforcedRestoreSpec)
if err != nil {
return err
}

Before creating NonAdminRestore's related Velero Restore, apply any missing fields to it that admin user has enforced
```go
enforcedSpec := reflect.ValueOf(r.EnforcedRestoreSpec).Elem()
for index := range enforcedSpec.NumField() {
enforcedField := enforcedSpec.Field(index)
enforcedFieldName := enforcedSpec.Type().Field(index).Name
currentField := reflect.ValueOf(restoreSpec).Elem().FieldByName(enforcedFieldName)
if !enforcedField.IsZero() && currentField.IsZero() {
currentField.Set(enforcedField)
}
}
return nil
```

For more details, check https://github.com/openshift/oadp-operator/pull/1584, https://github.com/migtools/oadp-non-admin/pull/110, https://github.com/openshift/oadp-operator/pull/1600 and https://github.com/migtools/oadp-non-admin/pull/122.
For more details, check [Issue 151](https://github.com/migtools/oadp-non-admin/issues/151) and [PR 1584](https://github.com/openshift/oadp-operator/pull/1584), [PR 110](https://github.com/migtools/oadp-non-admin/pull/110), [PR 1600](https://github.com/openshift/oadp-operator/pull/1600) and [PR 122](https://github.com/migtools/oadp-non-admin/pull/122).

## Open Issues

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