ngx_postgres.conf

location ~ ^/(\w\w\w\w\w\w\w\w-\w\w\w\w-\w\w\w\w-\w\w\w\w-\w\w\w\w\w\w\w\w\w\w\w\w)/?$ {
    add_header Content-Type text/plain;

    postgres_pass   database;
    postgres_output value;

    postgres_escape $ip $remote_addr;
    postgres_escape $agent =$http_user_agent;
    postgres_escape $body =$request_body;

    postgres_query "
        WITH t AS (
            UPDATE api_check
            SET last_ping=now()
            WHERE code='$1'
            RETURNING id, last_ping
        )
        INSERT INTO api_ping
            (created, remote_addr, method, ua, body, owner_id, scheme)
        SELECT
            last_ping, $ip, '$request_method', $agent, $body, id, '$scheme'
        FROM t
        RETURNING 'OK'
    ";

    postgres_rewrite no_changes 400;
}