Grpc - Authorization Header

wwaldner · August 20, 2021, 3:21pm

Looks like the the stub has a way to pass headers. This does not appear to be documented. Had to do a bit of spelunking in the code.

github.com/elixir-grpc/grpc

Add mechanism to set headers in Stub.connect/3 (#112)

committed 08:08AM - 24 Dec 19 UTC

zph

+78 -10

* Add mechanism to set headers in Stub.connect/3 This patch provides a generi…c way to set headers that will be attached to each request from this `channel` by re-using append_custom_metadata/2. The use case is to provide a location for setting authorization headers that does not require manually adding it to each Stub fn call. With this change, headers can be set as: ``` channel = Stub.connect(host, port, headers: [{"authorization", "Bearer TOKEN"}]) ``` On the receiving server side they can be accessed using existing getter function. For the authorization example, this can be done in an Interceptor: ```elixir defmodule Authenticator do def init(_), do: [] def call(req, stream, next, opts) do with headers when is_map(headers) <- GRPC.Stream.get_headers(stream), token when not is_nil(token) <- Map.get(headers, "authorization") do .... # use token .... # if authenticated next.(req, stream) end end end ``` Adds two tests, one to verify on client side that headers can be set and accessible, a second test is for integration to verify the roundtrip of a header from client to server, then encode the header into a GRPC message response for test verification. * Avoid compilation warning about uniform_real/0 missing on Elixir 1.9 Co-authored-by: Tony Han <h.bing612@gmail.com>