Merge pull request #128 from stevendborrelli/write-context

Function Context support

README.md

@@ -166,6 +166,44 @@ example:
 {{- end }}
 ```
 
+### Writing to the Context
+
+This function can write to the Composition [Context](https://docs.crossplane.io/latest/concepts/compositions/#function-pipeline-context). Subsequent pipeline steps will be able to access the data.
+
+```yaml
+---
+apiVersion: meta.gotemplating.fn.crossplane.io/v1alpha1
+kind: Context
+data:
+  region: {{ $spec.region }}
+  id: field
+  array:
+  - "1" 
+  - "2"
+```
+
+To update Context data, match an existing key. For example, [function-environment-configs](https://github.com/crossplane-contrib/function-environment-configs)
+stores data under the key `apiextensions.crossplane.io/environment`.
+
+In this case, Environment fields `update` and `nestedEnvUpdate.hello` would be updated with new values.
+
+```yaml
+---
+apiVersion: meta.gotemplating.fn.crossplane.io/v1alpha1
+kind: Context
+data:
+  "apiextensions.crossplane.io/environment":
+      kind: Environment
+      apiVersion: internal.crossplane.io/v1alpha1
+      update: environment
+      nestedEnvUpdate:
+        hello: world
+  otherContextData:
+    test: field
+```
+
+For more information, see the example in [context](example/context).
+
 ## Additional functions
 
 | Name                                                             | Description                                                  |

context.go

@@ -0,0 +1,19 @@
+package main
+
+import (
+	"dario.cat/mergo"
+	"github.com/crossplane/function-sdk-go/errors"
+	fnv1beta1 "github.com/crossplane/function-sdk-go/proto/v1beta1"
+)
+
+// MergeContext merges existing Context with new values provided
+func (f *Function) MergeContext(req *fnv1beta1.RunFunctionRequest, val map[string]interface{}) (map[string]interface{}, error) {
+	mergedContext := req.GetContext().AsMap()
+	if len(val) == 0 {
+		return mergedContext, nil
+	}
+	if err := mergo.Merge(&mergedContext, val, mergo.WithOverride); err != nil {
+		return mergedContext, errors.Wrapf(err, "cannot merge data %T", req)
+	}
+	return mergedContext, nil
+}

context_test.go

@@ -0,0 +1,93 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/crossplane/crossplane-runtime/pkg/logging"
+	fnv1beta1 "github.com/crossplane/function-sdk-go/proto/v1beta1"
+	"github.com/crossplane/function-sdk-go/resource"
+	"github.com/google/go-cmp/cmp"
+	"github.com/google/go-cmp/cmp/cmpopts"
+	"google.golang.org/protobuf/testing/protocmp"
+)
+
+func TestMergeContext(t *testing.T) {
+	type args struct {
+		val map[string]interface{}
+		req *fnv1beta1.RunFunctionRequest
+	}
+	type want struct {
+		us  map[string]any
+		err error
+	}
+
+	cases := map[string]struct {
+		reason string
+		args   args
+		want   want
+	}{
+		"NoContextAtKey": {
+			reason: "When there is no existing context data at the key to merge, return the value",
+			args: args{
+				req: &fnv1beta1.RunFunctionRequest{
+					Context: nil,
+				},
+				val: map[string]interface{}{"hello": "world"},
+			},
+			want: want{
+				us:  map[string]interface{}{"hello": "world"},
+				err: nil,
+			},
+		},
+		"SuccessfulMerge": {
+			reason: "Confirm that keys are merged with source overwriting destination",
+			args: args{
+				req: &fnv1beta1.RunFunctionRequest{
+					Context: resource.MustStructJSON(`{"apiextensions.crossplane.io/environment":{"complex":{"a":"b","c":{"d":"e","f":"1","overWrite": "fromContext"}}}}`),
+				},
+				val: map[string]interface{}{
+					"newKey": "newValue",
+					"apiextensions.crossplane.io/environment": map[string]any{
+						"complex": map[string]any{
+							"c": map[string]any{
+								"overWrite": "fromFunction",
+							},
+						},
+					},
+				},
+			},
+			want: want{
+				us: map[string]interface{}{
+					"apiextensions.crossplane.io/environment": map[string]any{
+						"complex": map[string]any{
+							"a": "b",
+							"c": map[string]any{
+								"d":         "e",
+								"f":         "1",
+								"overWrite": "fromFunction",
+							},
+						},
+					},
+					"newKey": "newValue"},
+				err: nil,
+			},
+		},
+	}
+	for name, tc := range cases {
+		t.Run(name, func(t *testing.T) {
+			f := &Function{
+				log: logging.NewNopLogger(),
+			}
+			rsp, err := f.MergeContext(tc.args.req, tc.args.val)
+
+			if diff := cmp.Diff(tc.want.us, rsp, protocmp.Transform()); diff != "" {
+				t.Errorf("%s\nf.MergeContext(...): -want rsp, +got rsp:\n%s", tc.reason, diff)
+			}
+
+			if diff := cmp.Diff(tc.want.err, err, cmpopts.EquateErrors()); diff != "" {
+				t.Errorf("%s\nf.RunFunction(...): -want err, +got err:\n%s", tc.reason, diff)
+			}
+		})
+	}
+
+}

example/context/README.md

@@ -0,0 +1,84 @@
+# Writing to the Function Context
+
+function-go-templating can write to the Function Context
+
+## Testing This Function Locally
+
+You can run your function locally and test it using [`crossplane render`](https://docs.crossplane.io/latest/cli/command-reference/#render)
+with these example manifests.
+
+```shell
+crossplane render \
+  --extra-resources environmentConfigs.yaml \
+  --include-context \
+  xr.yaml composition.yaml functions.yaml
+```
+
+Will produce an output like:
+
+```shell
+---
+apiVersion: example.crossplane.io/v1
+kind: XR
+metadata:
+  name: example-xr
+status:
+  conditions:
+  - lastTransitionTime: "2024-01-01T00:00:00Z"
+    reason: Available
+    status: "True"
+    type: Ready
+  fromEnv: e
+---
+apiVersion: render.crossplane.io/v1beta1
+fields:
+  apiextensions.crossplane.io/environment:
+    apiVersion: internal.crossplane.io/v1alpha1
+    array:
+    - "1"
+    - "2"
+    complex:
+      a: b
+      c:
+        d: e
+        f: "1"
+    kind: Environment
+    nestedEnvUpdate:
+      hello: world
+    update: environment
+  newkey:
+    hello: world
+  other-context-key:
+    complex:
+      a: b
+      c:
+        d: e
+        f: "1"
+kind: Context
+```
+
+## Debugging This Function
+
+First we need to run the command in debug mode. In a terminal Window Run:
+
+```shell
+# Run the function locally
+$ go run . --insecure --debug
+```
+
+Next, set the go-templating function `render.crossplane.io/runtime: Development` annotation so that
+`crossplane render` communicates with the local process instead of downloading an image:
+
+```yaml
+apiVersion: pkg.crossplane.io/v1beta1
+kind: Function
+metadata:
+  name: crossplane-contrib-function-go-templating
+  annotations: 
+    render.crossplane.io/runtime: Development
+spec:
+  package: xpkg.upbound.io/crossplane-contrib/function-go-templating:v0.6.0
+```
+
+While the function is running in one terminal, open another terminal window and run `crossplane render`.
+The function should output debug-level logs in the terminal.

example/context/composition.yaml

@@ -0,0 +1,58 @@
+apiVersion: apiextensions.crossplane.io/v1
+kind: Composition
+metadata:
+  name: go-template-context.example.crossplane.io
+spec:
+  compositeTypeRef:
+    apiVersion: example.crossplane.io/v1
+    kind: XR
+  mode: Pipeline
+  pipeline:
+  - step: environmentConfigs
+    functionRef:
+      name: crossplane-contrib-function-environment-configs
+    input:
+      apiVersion: environmentconfigs.fn.crossplane.io/v1beta1
+      kind: Input
+      spec:
+        environmentConfigs:
+          - type: Reference
+            ref:
+              name: example-config
+  - step: go-templating-update-context
+    functionRef:
+      name: crossplane-contrib-function-go-templating
+    input:
+      apiVersion: gotemplating.fn.crossplane.io/v1beta1
+      kind: GoTemplate
+      source: Inline
+      inline:
+        template: |
+          ---
+          apiVersion: meta.gotemplating.fn.crossplane.io/v1alpha1
+          kind: Context
+          data:
+            # update existing EnvironmentConfig by using the "apiextensions.crossplane.io/environment" key
+            "apiextensions.crossplane.io/environment":
+               kind: Environment
+               apiVersion: internal.crossplane.io/v1alpha1
+               update: environment
+               nestedEnvUpdate:
+                 hello: world
+               array:
+               - "1"
+               - "2"
+            # read existing context and move it to another key
+            "other-context-key":
+              complex: {{ index .context "apiextensions.crossplane.io/environment" "complex" | toYaml | nindent 6 }}
+            # Create a new Context key and populate it with data
+            newkey:
+              hello: world
+          ---
+          apiVersion: example.crossplane.io/v1
+          kind: XR
+          status:
+            fromEnv: {{ index .context "apiextensions.crossplane.io/environment" "complex" "c" "d" }} 
+  - step: automatically-detect-ready-composed-resources
+    functionRef:
+      name: crossplane-contrib-function-auto-ready

example/context/environmentConfigs.yaml

@@ -0,0 +1,10 @@
+apiVersion: apiextensions.crossplane.io/v1alpha1
+kind: EnvironmentConfig
+metadata:
+  name: example-config
+data:
+  complex:
+    a: b
+    c:
+      d: e
+      f: "1"

example/context/functions.yaml

@@ -0,0 +1,25 @@
+---
+apiVersion: pkg.crossplane.io/v1beta1
+kind: Function
+metadata:
+  name: crossplane-contrib-function-environment-configs
+spec:
+  # This is ignored when using the Development runtime.
+  package: xpkg.upbound.io/crossplane-contrib/function-environment-configs:v0.0.7
+---
+apiVersion: pkg.crossplane.io/v1beta1
+kind: Function
+metadata:
+  name: crossplane-contrib-function-go-templating
+  annotations: 
+    # This tells crossplane beta render to connect to the function locally.
+    render.crossplane.io/runtime: Development
+spec:
+  package: xpkg.upbound.io/crossplane-contrib/function-go-templating:v0.6.0
+---
+apiVersion: pkg.crossplane.io/v1beta1
+kind: Function
+metadata:
+  name: crossplane-contrib-function-auto-ready
+spec:
+  package: xpkg.upbound.io/crossplane-contrib/function-auto-ready:v0.2.1

example/context/xr.yaml

@@ -0,0 +1,5 @@
+apiVersion: example.crossplane.io/v1
+kind: XR
+metadata:
+  name: example-xr
+spec: {}

example/context/xrd.yaml

@@ -0,0 +1,25 @@
+---
+apiVersion: apiextensions.crossplane.io/v1
+kind: CompositeResourceDefinition
+metadata:
+  name: xrs.example.crossplane.io
+spec:
+  group: example.crossplane.io
+  names:
+    kind: XR
+    plural: xrs
+  connectionSecretKeys:
+    - test
+  versions:
+    - name: v1
+      served: true
+      referenceable: true
+      schema:
+        openAPIV3Schema:
+          type: object
+          properties:
+            status:
+              type: object
+              properties:
+                fromEnv:
+                  type: string