Graham McIntire
45fb9736fa
Add RemoteIp plug that extracts real client IP from X-Forwarded-For header (set by nginx/dokku proxy) and adds it to Logger metadata.
48 lines
1 KiB
Elixir
48 lines
1 KiB
Elixir
defmodule MicrowavepropWeb.Plugs.RemoteIp do
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@moduledoc """
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Extracts the client IP from X-Forwarded-For (set by nginx/dokku proxy)
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and assigns it to conn.remote_ip and Logger metadata.
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"""
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@behaviour Plug
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@impl true
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def init(opts), do: opts
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@impl true
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def call(conn, _opts) do
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ip =
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case Plug.Conn.get_req_header(conn, "x-forwarded-for") do
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[forwarded | _] ->
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forwarded
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|> String.split(",")
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|> hd()
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|> String.trim()
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|> parse_ip()
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_ ->
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nil
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end
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conn =
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if ip do
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%{conn | remote_ip: ip}
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else
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conn
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end
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Logger.metadata(remote_ip: format_ip(conn.remote_ip))
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conn
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end
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defp parse_ip(str) do
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case :inet.parse_address(String.to_charlist(str)) do
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{:ok, ip} -> ip
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_ -> nil
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end
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end
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defp format_ip({a, b, c, d}), do: "#{a}.#{b}.#{c}.#{d}"
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defp format_ip({a, b, c, d, e, f, g, h}), do: "#{a}:#{b}:#{c}:#{d}:#{e}:#{f}:#{g}:#{h}"
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defp format_ip(_), do: "unknown"
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end
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