map $http_upgrade
    $req_connection
{
    default  upgrade;
    ""       "";
}

map $http_user_agent
    $req_user_agent
{
    default  $http_user_agent;
{%- if env.NGX_HTTP_FAKE_UA %}
    ## merely fake
    ""  {{ env.NGX_HTTP_FAKE_UA | ngx_esc }};
{%- else %}
    ""  "Angie/$angie_version";
{%- endif %}
}

map $http_accept
    $req_accept
{
    volatile;
    default  $http_accept;
    ""       "*/*";
}