AWS S3 upload manager /lib/myapp/upload_manager/s3.ex

s3.ex

defmodule App.UploadManager.S3 do

  @behaviour App.UploadManager.Behavior

  @config Application.get_env(:App, :file_manager)[:s3]

  alias ExAws.S3

  @doc """
  Check if file exists on S3 bucket
  """
  def exists?(key) do
    case S3.head_object(@config[:bucket], key) |> ExAws.request do
      {:ok, _body} -> :ok
      {:error, error} -> {:error, error}
    end
  end

  @doc """
    Save file to s3 bucket
  """
  def save_from_file!(source_file, key, opts \\ %{}) do
    opts = if (Map.get(opts, :acl) == nil), do: Map.put(opts, :acl, :public_read)

    source_file = File.read!(source_file)

    {:ok, response} = S3.put_object(@config[:bucket], key, source_file, opts) |> ExAws.request
    case response.status_code do
      200 -> :ok
      _ -> {:error, response.body}
    end
  end

  def save_from_content!(source, key, opts \\ %{}) do
    opts = if (Map.get(opts, :acl) == nil), do: Map.put(opts, :acl, :public_read)

    {:ok, response} = S3.put_object(@config[:bucket], key, source, opts) |> ExAws.request
    case response.status_code do
      200 -> :ok
      _ -> {:error, response.body}
    end
  end


  @doc """
  Delete file from S3
  """
  def delete!(key) do
    {:ok, response} = S3.delete_object(@config[:bucket], key) |> ExAws.request
    case response.status_code do
      204 -> :ok
      _ -> {:error, response.body}
    end
  end

  @doc """
  return URL for file
  """
  def url(key) do
    # todo add ability to return URL with expired param
    bucket = @config[:bucket]
    bucket_host = Application.get_env(:ex_aws, :s3)
    bucket_host = bucket_host[:host]
    "https://#{bucket_host}/#{bucket}/#{key}"
  end

  @doc """
  Saves object to local file
  """
  def save_to_local_file!(key, local_path) do
    {:ok, response} = S3.get_object(@config[:bucket], key) |> ExAws.request
    case response.status_code do
      200 ->
        File.write!(local_path, response.body)
      {:error, error} -> {:error, error}
    end
  end


end