implemented ability to pass #Secret as env var

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

tests/tasks.bats

@@ -39,6 +39,7 @@ setup() {
     cd "$TESTDIR"/tasks/exec
     "$DAGGER" --europa up ./args.cue
     "$DAGGER" --europa up ./env.cue
+    "$DAGGER" --europa up ./env_secret.cue
     "$DAGGER" --europa up ./hosts.cue
 
     "$DAGGER" --europa up ./mount_cache.cue

tests/tasks/exec/env_secret.cue

@@ -0,0 +1,25 @@
+package main
+
+import (
+	"dagger.io/dagger/engine"
+)
+
+engine.#Plan & {
+	inputs: secrets: testSecret: path: "secret.txt"
+	actions: {
+		image: engine.#Pull & {
+			source: "alpine:3.15.0@sha256:e7d88de73db3d3fd9b2d63aa7f447a10fd0220b7cbf39803c803f2af9ba256b3"
+		}
+
+		verify: engine.#Exec & {
+			input: image.output
+			env: TEST: inputs.secrets.testSecret.contents
+			args: [
+				"sh", "-c",
+				#"""
+					test "$TEST" = "hello world"
+					"""#,
+			]
+		}
+	}
+}

tests/tasks/exec/secret.txt

@@ -0,0 +1 @@
+hello world