function _M.rewrite()

in apisix/plugins/redirect.lua [181:261]

• 68 lines of code
• 15 McCabe index (conditional complexity)

function _M.rewrite(conf, ctx)
    core.log.info("plugin rewrite phase, conf: ", core.json.delay_encode(conf))

    local ret_code = conf.ret_code

    local attr = plugin.plugin_attr(plugin_name)
    local ret_port = get_port(attr)

    local uri = conf.uri
    local regex_uri = conf.regex_uri

    local proxy_proto = core.request.header(ctx, "X-Forwarded-Proto")
    local _scheme = proxy_proto or core.request.get_scheme(ctx)
    if conf.http_to_https and _scheme == "http" then
        if ret_port == nil or ret_port == 443 or ret_port <= 0 or ret_port > 65535  then
            uri = "https://$host$request_uri"
        else
            uri = "https://$host:" .. ret_port .. "$request_uri"
        end

        local method_name = ngx.req.get_method()
        if method_name == "GET" or method_name == "HEAD" then
            ret_code = 301
        else
         
            ret_code = 308
        end
    end

    if ret_code then
        local new_uri
        if uri then
            local err
            new_uri, err = concat_new_uri(uri, ctx)
            if not new_uri then
                core.log.error("failed to generate new uri by: " .. uri .. err)
                return 500
            end
        elseif regex_uri then
            local n, err
            new_uri, n, err = re_sub(ctx.var.uri, regex_uri[1],
                                     regex_uri[2], "jo")
            if not new_uri then
                local msg = string_format("failed to substitute the uri:%s (%s) with %s, error:%s",
                                          ctx.var.uri, regex_uri[1], regex_uri[2], err)
                core.log.error(msg)
                return 500
            end

            if n < 1 then
                return
            end
        end

        if not new_uri then
            return
        end

        local index = str_find(new_uri, "?")
        if conf.encode_uri then
            if index then
                new_uri = core.utils.uri_safe_encode(str_sub(new_uri, 1, index-1)) ..
                          str_sub(new_uri, index)
            else
                new_uri = core.utils.uri_safe_encode(new_uri)
            end
        end

        if conf.append_query_string and ctx.var.is_args == "?" then
            if index then
                new_uri = new_uri .. "&" .. (ctx.var.args or "")
            else
                new_uri = new_uri .. "?" .. (ctx.var.args or "")
            end
        end

        core.response.set_header("Location", new_uri)
        return ret_code
    end

end