stdlib/aws: implemented ecr helper to get registry credentials

Signed-off-by: Sam Alba <sam.alba@gmail.com>

stdlib/aws/ecr/ecr.cue

@@ -0,0 +1,36 @@
+package ecr
+
+import (
+	"dagger.io/dagger"
+	"dagger.io/aws"
+)
+
+// Credentials retriever for ECR
+#Credentials: {
+
+	// AWS Config
+	config: aws.#Config
+
+	// Target is the ECR image
+	target: string
+
+	out: dagger.#Secret
+
+	// ECR credentials
+	credentials: dagger.#RegistryCredentials & {
+		username: "AWS"
+		secret: out
+	}
+
+	aws.#Script & {
+		"config": config
+		export: "/out"
+		code: """
+			aws ecr get-login-password > /out
+			"""
+	}
+
+	// Authentication for ECR Registries
+	auth: dagger.#RegistryAuth
+	auth: "\(target)": credentials
+}