keycloak openresty authentication

keycloak_openresty_auth.conf

set $session_check_ssi off;
set $session_secret Eeko7aeb6iu5Wohch9Loo1aitha0ahd1;
set $session_storage cookie;

access_by_lua_block {
  local opts = {
    redirect_uri_path = "/auth",
    discovery = "https://keycloak.freevision.sk/auth/realms/rancher-elk/.well-known/openid-configuration",
    client_id = "nginx",
    client_secret = "2cfde6f9-4283-456a-9f13-1b803482db9a"
  }

  -- call authenticate for OpenID Connect user authentication
  local res, err = require("resty.openidc").authenticate(opts)

  if err then
    ngx.status = 500
    ngx.say(err)
    ngx.exit(ngx.HTTP_INTERNAL_SERVER_ERROR)
  end

  ngx.req.set_header("X-User", res.id_token.sub)
}