defmodule App.Imgproxy do @prefix "https://imgproxy.mybiz.xyz" @key Base.decode16!("943b421c9eb07c830af81030552c86009268de4e532ba2ee2eab8247c6da0881", case: :lower) @salt Base.decode16!("520f986b998545b4785e0defbc4f3c1203f22de2374a3d53cb7a7fe9fea309c5", case: :lower) def build_url(img_url, opts) do path = build_path(img_url, opts) signature = gen_signature(path) Path.join([@prefix, signature, path]) end defp build_path(img_url, opts) do Path.join([ "/", "rs:#{opts.resize}:#{opts.width}:#{opts.height}:#{opts.enlarge}", "g:#{opts.gravity}", Base.url_encode64(img_url, padding: false) <> "." <> opts.extension ]) end defp gen_signature(path) do :sha256 |> :crypto.hmac(@key, @salt <> path) |> Base.url_encode64(padding: false) end end # Usage # # App.Imgproxy.build_url( # "https://myawesomedomain.com/raw-image.png", # %{resize: "fit", width: 1000, height: 400, gravity: "ce", enlarge: 0, extension: "jpg"} # )