this.resource("posts", { path: "/posts" }, function() {
  this.resource("show", { path: "/:post_id" });
});

this.resource("posts", { path: "/posts" }, function() {
  this.resource("post", { path: "/:post_id" });
});

this.resource("posts", { path: "/posts" });
this.resource("post", { path: "/posts/:post_id" });