engine: exec: add mount service tests

Signed-off-by: Andrea Luzzardi <aluzzardi@gmail.com>

tests/tasks.bats

@@ -35,6 +35,7 @@ setup() {
     "$DAGGER" --europa up ./mount_fs.cue
     TESTSECRET="hello world" "$DAGGER" --europa up ./mount_secret.cue
     "$DAGGER" --europa up ./mount_tmp.cue
+    "$DAGGER" --europa up ./mount_service.cue
 
     "$DAGGER" --europa up ./user.cue
     "$DAGGER" --europa up ./workdir.cue

tests/tasks/exec/mount_service.cue

@@ -0,0 +1,29 @@
+package main
+
+import (
+	"alpha.dagger.io/europa/dagger/engine"
+)
+
+engine.#Plan & {
+	context: services: dockerSocket: unix: "/var/run/docker.sock"
+
+	actions: {
+		image: engine.#Pull & {
+			source: "alpine:3.15.0@sha256:e7d88de73db3d3fd9b2d63aa7f447a10fd0220b7cbf39803c803f2af9ba256b3"
+		}
+
+		imageWithDocker: engine.#Exec & {
+			input: image.output
+			args: ["apk", "add", "--no-cache", "docker-cli"]
+		}
+
+		verify: engine.#Exec & {
+			input: imageWithDocker.output
+			mounts: docker: {
+				dest:     "/var/run/docker.sock"
+				contents: context.services.dockerSocket.service
+			}
+			args: ["docker", "info"]
+		}
+	}
+}