Remove mappings from the ServiceBinding resource

The existing mappings on the ServiceBinding resource were introduced as a way to make it easier for a user to enrich an existing Secret into a form appropriate for binding to an application workload. This approch had a few issues that can be better addressed by other resources that interoperate with the ServiceBiding resource. The issues include: - the ServiceBinding controller needs to be able to read and write Secrets - Go templates were used to compose new values, which worked for basic templating, but were limited in their capabilities - the capabilities of the Go templates are an implemenation detail of how the controller is built and could change over time independent of the speced behavior. The behavior applied by mappings can be reintroduced as dedicated resources that can themselves expose a Secret as a ProvisionedService, which can be consumed by a ServiceBinding. This change further separates the concerns of provisioning a service from binding a service. Refs servicebinding#145 Signed-off-by: Scott Andrews <[email protected]>
scothis · May 14, 2021 · 9c5594c · 9c5594c
1 parent 44c1d8e
commit 9c5594c
Show file tree

Hide file tree

Showing 3 changed files with 1 addition and 88 deletions.
diff --git a/README.md b/README.md
@@ -55,7 +55,6 @@ Behavior within the project is governed by the [Contributor Covenant Code of Con
   - [Resource Type Schema](#resource-type-schema-1)
   - [Minimal Example Resource](#minimal-example-resource)
   - [Label Selector Example Resource](#label-selector-example-resource)
-  - [Mappings Example Resource](#mappings-example-resource)
   - [Environment Variables Example Resource](#environment-variables-example-resource)
   - [Reconciler Implementation](#reconciler-implementation)
     - [Ready Condition Status](#ready-condition-status)
@@ -263,9 +262,7 @@ The Service Binding resource **MAY** define `.spec.application.containers`, as a
 - if the value is a string (`${containerString}`), a container or init container matching by name (`.spec.template.spec.containers[?(@.name=='${containerString}')]` or `.spec.template.spec.initContainers[?(@.name=='${containerString}')]`) **MUST** be bound
 - values that do not match a container or init container **SHOULD** be ignored
 
-A Service Binding Resource **MAY** define a `.spec.mappings` which is an array of `Mapping` objects.  A `Mapping` object **MUST** define `name` and `value` entries.  The `value` of a `Mapping` **MUST** be handled as a [Go Template][gt] exposing binding `Secret` keys for substitution. The executed output of the template **MUST** be added to the `Secret` exposed to the resource represented by `application` as the key specified by the `name` of the `Mapping`.  If the `name` of a `Mapping` matches that of a Provisioned Service `Secret` key, the value from `Mapping` **MUST** be used for binding.
-
-A Service Binding Resource **MAY** define a `.spec.env` which is an array of `EnvMapping`.  An `EnvMapping` object **MUST** define `name` and `key` entries.  The `key` of an `EnvMapping` **MUST** refer to a binding `Secret` key name including any key defined by a `Mapping`.  The value of this `Secret` entry **MUST** be configured as an environment variable on the resource represented by `application`.
+A Service Binding Resource **MAY** define a `.spec.env` which is an array of `EnvMapping`.  An `EnvMapping` object **MUST** define `name` and `key` entries.  The `key` of an `EnvMapping` **MUST** refer to a binding `Secret` key name.  The value of this `Secret` entry **MUST** be configured as an environment variable on the resource represented by `application`.
 
 A Service Binding resource **MUST** define `.status.conditions` which is an array of `Condition` objects as defined in [meta/v1 Condition][mv1c].  At least one condition containing a `type` of `Ready` **MUST** be defined.  The `Ready` condition **SHOULD** contain appropriate values defined by the implementation.  As label selectors are inherently queries that return zero-to-many resources, it is **RECOMMENDED** that `ServiceBinding` authors use a combination of labels that yield a single resource, but implementors **MUST** handle each matching resource as if it was specified by name in a distinct `ServiceBinding` resource. Partial failures **MUST** be aggregated and reported on the binding status's `Ready` condition. A Service Binding resource **SHOULD** reflect the secret projected into the application as `.status.binding.name`.
 
@@ -285,8 +282,6 @@ metadata:
   ...
 spec:
   name:                 # string, optional, default: .metadata.name
-  type:                 # string, optional
-  provider:             # string, optional
 
   application:          # ObjectReference-like
     apiVersion:         # string
@@ -300,10 +295,6 @@ spec:
     kind:               # string
     name:               # string
 
-  mappings:             # []Mapping, optional
-  - name:               # string
-    value:              # string
-
   env:                  # []EnvMapping, optional
   - name:               # string
     key:                # string
@@ -374,39 +365,6 @@ status:
     lastTransitionTime: '2021-01-20T17:00:00Z'
 ```
 
-## Mappings Example Resource
-
-```yaml
-apiVersion: service.binding/v1alpha2
-kind: ServiceBinding
-metadata:
-  name: account-service
-spec:
-  application:
-    apiVersion: apps/v1
-    kind:       Deployment
-    name:       online-banking
-
-  service:
-    apiVersion: com.example/v1alpha1
-    kind:       AccountService
-    name:       prod-account-service
-
-  mappings:
-  - name:  accountServiceUri
-    value: https://{{ urlquery .username }}:{{ urlquery .password }}@{{ .host }}:{{ .port }}/{{ .path }}
-
-status:
-  binding:
-    name: prod-account-service-projection
-  conditions:
-  - type:   Ready
-    status: 'True'
-    reason: 'Projected'
-    message: ''
-    lastTransitionTime: '2021-01-20T17:00:00Z'
-```
-
 ## Environment Variables Example Resource
 
 ```yaml
@@ -425,19 +383,13 @@ spec:
     kind:       AccountService
     name:       prod-account-service
 
-  mappings:
-  - name:  accountServiceUri
-    value: https://{{ urlquery .username }}:{{ urlquery .password }}@{{ .host }}:{{ .port }}/{{ .path }}
-
   env:
   - name: ACCOUNT_SERVICE_HOST
     key:  host
   - name: ACCOUNT_SERVICE_USERNAME
     key:  username
   - name: ACCOUNT_SERVICE_PASSWORD
     key:  password
-  - name: ACCOUNT_SERVICE_URI
-    key:  accountServiceUri
 
 status:
   binding:
@@ -460,8 +412,6 @@ If the `$SERVICE_BINDING_ROOT` environment variable has already been configured
 
 The `$SERVICE_BINDING_ROOT` environment variable **MUST NOT** be reset if it is already configured on the resource represented by `application`.
 
-If a `.spec.type` is set, the `type` entry in the binding `Secret` **MUST** be set to its value overriding any existing value.  If a `.spec.provider` is set, the `provider` entry in the binding `Secret` **MUST** be set to its value overriding any existing value.
-
 ### Ready Condition Status
 
 If the modification of the Application resource is completed successfully, the `Ready` condition status **MUST** be set to `True`.  If the modification of the Application resource is not completed successfully the `Ready` condition status **MUST NOT** be set to `True`.

diff --git a/internal/service.binding/v1alpha2/service_binding.go b/internal/service.binding/v1alpha2/service_binding.go
@@ -64,31 +64,16 @@ type EnvMapping struct {
 	Key string `json:"key"`
 }
 
-// ServiceBindingMapping defines a mapping from the existing collection of Secret values to a new Secret entry.
-type ServiceBindingMapping struct {
-	// Name is the name of the mapped Secret entry
-	Name string `json:"name"`
-	// Value is the value of the new Secret entry.  Contents may be a Go template and refer to the other secret entries
-	// by name.
-	Value string `json:"value"`
-}
-
 // ServiceBindingSpec defines the desired state of ServiceBinding
 type ServiceBindingSpec struct {
 	// Name is the name of the service as projected into the application container.  Defaults to .metadata.name.
 	Name string `json:"name,omitempty"`
-	// Type is the type of the service as projected into the application container
-	Type string `json:"type,omitempty"`
-	// Provider is the provider of the service as projected into the application container
-	Provider string `json:"provider,omitempty"`
 	// Application is a reference to an object
 	Application ServiceBindingApplicationReference `json:"application"`
 	// Service is a reference to an object that fulfills the ProvisionedService duck type
 	Service ServiceBindingServiceReference `json:"service"`
 	// Env is the collection of mappings from Secret entries to environment variables
 	Env []EnvMapping `json:"env,omitempty"`
-	// Mappings is the collection of mappings from existing Secret entries to new Secret entries
-	Mappings []ServiceBindingMapping `json:"mappings,omitempty"`
 }
 
 // These are valid conditions of ServiceBinding.

diff --git a/service.binding_servicebindings.yaml b/service.binding_servicebindings.yaml
@@ -112,28 +112,9 @@ spec:
                   - name
                   type: object
                 type: array
-              mappings:
-                description: Mappings is the collection of mappings from existing Secret entries to new Secret entries
-                items:
-                  description: ServiceBindingMapping defines a mapping from the existing collection of Secret values to a new Secret entry.
-                  properties:
-                    name:
-                      description: Name is the name of the mapped Secret entry
-                      type: string
-                    value:
-                      description: Value is the value of the new Secret entry.  Contents may be a Go template and refer to the other secret entries by name.
-                      type: string
-                  required:
-                  - name
-                  - value
-                  type: object
-                type: array
               name:
                 description: Name is the name of the service as projected into the application container.  Defaults to .metadata.name.
                 type: string
-              provider:
-                description: Provider is the provider of the service as projected into the application container
-                type: string
               service:
                 description: Service is a reference to an object that fulfills the ProvisionedService duck type
                 properties:
@@ -151,9 +132,6 @@ spec:
                 - kind
                 - name
                 type: object
-              type:
-                description: Type is the type of the service as projected into the application container
-                type: string
             required:
             - application
             - service