function _M.rewrite()

in apisix/plugins/proxy-rewrite.lua [271:393]

• 102 lines of code
• 24 McCabe index (conditional complexity)

function _M.rewrite(conf, ctx)
    for _, name in ipairs(upstream_names) do
        if conf[name] then
            ctx.var[upstream_vars[name]] = conf[name]
        end
    end

    local upstream_uri = ctx.var.uri
    local separator_escaped = false
    if conf.use_real_request_uri_unsafe then
        upstream_uri = ctx.var.real_request_uri
    end

    if conf.uri ~= nil then
        separator_escaped = true
        upstream_uri = core.utils.resolve_var(conf.uri, ctx.var, escape_separator)

    elseif conf.regex_uri ~= nil then
        if not str_find(upstream_uri, "?") then
            separator_escaped = true
        end

        local error_msg
        for i = 1, #conf.regex_uri, 2 do
            local captures, err = re_match(upstream_uri, conf.regex_uri[i], "jo")
            if err then
                error_msg = "failed to match the uri " .. ctx.var.uri ..
                    " (" .. conf.regex_uri[i] .. ") " .. " : " .. err
                break
            end

            if captures then
                ctx.proxy_rewrite_regex_uri_captures = captures

                local uri, _, err = re_sub(upstream_uri,
                    conf.regex_uri[i], conf.regex_uri[i + 1], "jo")
                if uri then
                    upstream_uri = uri
                else
                    error_msg = "failed to substitute the uri " .. ngx.var.uri ..
                        " (" .. conf.regex_uri[i] .. ") with " ..
                        conf.regex_uri[i + 1] .. " : " .. err
                end

                break
            end
        end

        if error_msg ~= nil then
            core.log.error(error_msg)
            return 500, { error_msg = error_msg }
        end
    end

    if not conf.use_real_request_uri_unsafe then
        local index
        if separator_escaped then
            index = str_find(upstream_uri, "?")
        end

        if index then
            upstream_uri = core.utils.uri_safe_encode(sub_str(upstream_uri, 1, index - 1)) ..
                sub_str(upstream_uri, index)
        else
            
            
            upstream_uri = core.utils.uri_safe_encode(upstream_uri)
        end

        req_set_uri(upstream_uri)

        if ctx.var.is_args == "?" then
            if index then
                ctx.var.upstream_uri = upstream_uri .. "&" .. (ctx.var.args or "")
            else
                ctx.var.upstream_uri = upstream_uri .. "?" .. (ctx.var.args or "")
            end
        else
            ctx.var.upstream_uri = upstream_uri
        end
    else
        ctx.var.upstream_uri = upstream_uri
    end

    if conf.headers then
        local hdr_op, err = core.lrucache.plugin_ctx(lrucache, ctx, nil,
                                    create_header_operation, conf.headers)
        if not hdr_op then
            core.log.error("failed to create header operation: ", err)
            return
        end

        local field_cnt = #hdr_op.add
        for i = 1, field_cnt, 2 do
            local val = core.utils.resolve_var_with_captures(hdr_op.add[i + 1],
                                            ctx.proxy_rewrite_regex_uri_captures)
            val = core.utils.resolve_var(val, ctx.var)
            
            if val then
                local header = hdr_op.add[i]
                core.request.add_header(ctx, header, val)
            end
        end

        local field_cnt = #hdr_op.set
        for i = 1, field_cnt, 2 do
            local val = core.utils.resolve_var_with_captures(hdr_op.set[i + 1],
                                            ctx.proxy_rewrite_regex_uri_captures)
            val = core.utils.resolve_var(val, ctx.var)
            core.request.set_header(ctx, hdr_op.set[i], val)
        end

        local field_cnt = #hdr_op.remove
        for i = 1, field_cnt do
            core.request.set_header(ctx, hdr_op.remove[i], nil)
        end

    end

    if conf.method then
        ngx.req.set_method(switch_map[conf.method])
    end
end