implemented #DecodeSecret as engine task

Signed-off-by: Richard Jones <richard@dagger.io>

pkg/dagger.io/dagger/engine/secret.cue

@@ -15,18 +15,31 @@ package engine
 }
 
 // Securely apply a CUE transformation on the contents of a secret
-#TransformSecret: {
-	$dagger: task: _name: "TransformSecret"
-	// The original secret
+// FIXME: disabled due to data race associated with filling #function.input
+// #TransformSecret: {
+//  $dagger: task: _name: "TransformSecret"
+//  // The original secret
+//  input: #Secret
+//  // A new secret or (map of secrets) with the transformation applied
+//  output: #Secret | {[string]: output}
+//  // Transformation function
+//  #function: {
+//   // Full contents of the input secret (only available to the function)
+//   input:           string
+//   _functionOutput: string | {[string]: _functionOutput}
+//   // New contents of the output secret (must provided by the caller)
+//   output: _functionOutput
+//  }
+// }
+
+#DecodeSecret: {
+	$dagger: task: _name: "DecodeSecret"
+
+	// A #Secret whose plain text is a JSON or YAML string
 	input: #Secret
-	// A new secret or (map of secrets) with the transformation applied
+
+	format: "json" | "yaml"
+
+	// A new secret or (map of secrets) derived from unmarshaling the input secret's plain text
 	output: #Secret | {[string]: output}
-	// Transformation function
-	#function: {
-		// Full contents of the input secret (only available to the function)
-		input:           string
-		_functionOutput: string | {[string]: _functionOutput}
-		// New contents of the output secret (must provided by the caller)
-		output: _functionOutput
-	}
 }

pkg/dagger.io/dagger/utils.cue

@@ -1,8 +1,8 @@
 package dagger
 
 import (
-	"encoding/yaml"
-	"encoding/json"
+	// "encoding/json"
+	// "encoding/yaml"
 	"dagger.io/dagger/engine"
 )
 
@@ -38,23 +38,24 @@ import (
 }
 
 // DecodeSecret is a convenience wrapper around #TransformSecret. The plain text contents of input is expected to match the format
-#DecodeSecret: {
-	{
-		format: "json"
-		engine.#TransformSecret & {
-			#function: {
-				input:  _
-				output: json.Unmarshal(input)
-			}
-		}
-	} | {
-		format: "yaml"
-		engine.#TransformSecret & {
-			#function: {
-				input:  _
-				output: yaml.Unmarshal(input)
-			}
-		}
-	}
+// #DecodeSecret: {
+//  {
+//   format: "json"
+//   engine.#TransformSecret & {
+//    #function: {
+//     input:  _
+//     output: json.Unmarshal(input)
+//    }
+//   }
+//  } | {
+//   format: "yaml"
+//   engine.#TransformSecret & {
+//    #function: {
+//     input:  _
+//     output: yaml.Unmarshal(input)
+//    }
+//   }
+//  }
+// }
 
-}
+#DecodeSecret: engine.#DecodeSecret

pkg/universe.dagger.io/netlify/test/netlify-test.cue

@@ -1,8 +1,6 @@
 package yarn
 
 import (
-	"encoding/yaml"
-
 	"dagger.io/dagger"
 	"dagger.io/dagger/engine"
 
@@ -18,12 +16,9 @@ dagger.#Plan & {
 	}
 
 	actions: {
-		testSecrets: engine.#TransformSecret & {
+		testSecrets: dagger.#DecodeSecret & {
 			input:  inputs.secrets.test.contents
-			#function: {
-				input:  _
-				output: yaml.Unmarshal(input)
-			}
+			format: "yaml"
 		}
 
 		marker: "hello world"

plan/task/decodesecret.go

@@ -0,0 +1,80 @@
+package task
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+
+	"cuelang.org/go/cue"
+	"github.com/rs/zerolog/log"
+	"go.dagger.io/dagger/compiler"
+	"go.dagger.io/dagger/plancontext"
+	"go.dagger.io/dagger/solver"
+	"gopkg.in/yaml.v3"
+)
+
+func init() {
+	Register("DecodeSecret", func() Task { return &decodeSecretTask{} })
+}
+
+type decodeSecretTask struct {
+}
+
+func (c *decodeSecretTask) Run(ctx context.Context, pctx *plancontext.Context, _ solver.Solver, v *compiler.Value) (*compiler.Value, error) {
+	lg := log.Ctx(ctx)
+	lg.Debug().Msg("decoding secret")
+
+	input := v.Lookup("input")
+
+	inputSecret, err := pctx.Secrets.FromValue(input)
+	if err != nil {
+		return nil, err
+	}
+
+	format, err := v.Lookup("format").String()
+	if err != nil {
+		return nil, err
+	}
+
+	lg.Debug().Str("format", format).Msg("unmarshaling secret")
+
+	inputSecretPlaintext := inputSecret.PlainText()
+
+	var unmarshaled map[string]interface{}
+
+	switch format {
+	case "json":
+		err = json.Unmarshal([]byte(inputSecretPlaintext), &unmarshaled)
+	case "yaml":
+		err = yaml.Unmarshal([]byte(inputSecretPlaintext), &unmarshaled)
+	}
+
+	if err != nil {
+		// returning err here could expose secret plaintext!
+		return nil, errors.New("could not unmarshal secret")
+	}
+
+	output := compiler.NewValue()
+
+	// recurse over unmarshaled to convert string values to secrets
+	var convert func(p []cue.Selector, i interface{})
+	convert = func(p []cue.Selector, i interface{}) {
+		switch entry := i.(type) {
+		case string:
+			secret := pctx.Secrets.New(entry)
+			path := cue.MakePath(append(p, cue.ParsePath("contents").Selectors()...)...)
+			pathSelectors := path.Selectors()
+			logPath := cue.MakePath(pathSelectors[1 : len(pathSelectors)-1]...)
+			lg.Debug().Str("path", logPath.String()).Str("type", "string").Msg("found secret")
+			output.FillPath(path, secret.MarshalCUE())
+		case map[string]interface{}:
+			for k, v := range entry {
+				convert(append(p, cue.ParsePath(k).Selectors()...), v)
+			}
+		}
+	}
+
+	convert(cue.ParsePath("output").Selectors(), unmarshaled)
+
+	return output, nil
+}