Redirect /api/* to /api/v1/*

Question

In a Rails project, there's a namespace called api. I'm looking into making the API versioned so that api/v1 would be the preferred namespace.

For the routing, I was thinking of doing this:

namespace :api do
  redirect_api_path_to_api_v1_path
  namespace :v1 do
    ...
  end
end

Its a large project, so I was thinking that I would still support the v1 endpoint and just redirect people to v1. Then slowly add v2 and at a point in time, do a v2 redirect.

What I've tried:

namespace :api do
  namespace :v1 do
    ...

    resources :countries

    ...
  end

  match "*", to: redirect(-> (params, request) {
    "https://#{request.host_with_port}/api/v1#{request.path.split("/api").last}"
  }), via: [:get, :post, :put, :post]
end

Specs return:

it "should redirect to v1" do
  get "/api/countries"
  expect(response).to have_http_status 302
end

Failures:

  1) Version /api should redirect to v1
     Failure/Error: get "/api/countries"
     ActionController::RoutingError:
       No route matches [GET] "/api/countries"