实现重写规则管理

pkg/serverconfigs/http_rewrite_rule.go

@@ -0,0 +1,126 @@
+package serverconfigs
+
+import (
+	"fmt"
+	"github.com/TeaOSLab/EdgeCommon/pkg/configutils"
+	"github.com/TeaOSLab/EdgeCommon/pkg/serverconfigs/shared"
+	"regexp"
+)
+
+type HTTPRewriteMode = string
+
+const (
+	HTTPRewriteTargetProxy = 1
+	HTTPRewriteTargetURL   = 2
+)
+
+const (
+	HTTPRewriteModeRedirect HTTPRewriteMode = "redirect" // 跳转
+	HTTPRewriteModeProxy    HTTPRewriteMode = "proxy"    // 代理
+)
+
+// 重写规则定义
+//
+// 参考
+// - http://nginx.org/en/docs/http/ngx_http_rewrite_module.html
+// - https://httpd.apache.org/docs/current/mod/mod_rewrite.html
+// - https://httpd.apache.org/docs/2.4/rewrite/flags.html
+type HTTPRewriteRule struct {
+	Id   int64 `yaml:"id" json:"id"`     // ID
+	IsOn bool  `yaml:"isOn" json:"isOn"` // 是否开启
+
+	// 开启的条件
+	// 语法为：cond param operator value 比如：
+	// - cond ${status} gte 200
+	// - cond ${arg.name} eq lily
+	// - cond ${requestPath} regexp .*\.png
+	CondGroups []*shared.HTTPRequestCondGroup `yaml:"condGroups" json:"condGroups"` // 匹配条件 TODO
+
+	// 规则
+	// 语法为：pattern regexp 比如：
+	// - pattern ^/article/(\d+).html
+	Pattern string `yaml:"pattern" json:"pattern"`
+
+	// 模式
+	Mode           HTTPRewriteMode `yaml:"mode" json:"mode"`
+	RedirectStatus int             `yaml:"redirectStatus" json:"redirectStatus"` // 跳转的状态码
+	ProxyHost      string          `yaml:"proxyHost" json:"proxyHost"`           // 代理模式下的Host
+
+	// TODO 实现对其他代理服务的引用
+
+	// 要替换成的URL
+	// 支持反向引用：${0}, ${1}, ...，也支持?P<NAME>语法
+	// - 如果以 proxy:// 开头，表示目标为代理，首先会尝试作为代理ID请求，如果找不到，会尝试作为代理Host请求
+	Replace string `yaml:"replace" json:"replace"`
+
+	IsBreak bool `yaml:"isBreak" json:"isBreak"` // 终止向下解析
+
+	reg *regexp.Regexp
+}
+
+// 校验
+func (this *HTTPRewriteRule) Init() error {
+	reg, err := regexp.Compile(this.Pattern)
+	if err != nil {
+		return err
+	}
+	this.reg = reg
+
+	// 校验条件
+	for _, condGroup := range this.CondGroups {
+		err := condGroup.Init()
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// 对某个请求执行规则
+func (this *HTTPRewriteRule) Match(requestPath string, formatter func(source string) string) (replace string, varMapping map[string]string, matched bool) {
+	if this.reg == nil {
+		return "", nil, false
+	}
+
+	matches := this.reg.FindStringSubmatch(requestPath)
+	if len(matches) == 0 {
+		return "", nil, false
+	}
+
+	// 判断条件
+	if len(this.CondGroups) > 0 {
+		for _, cond := range this.CondGroups {
+			if !cond.Match(formatter) {
+				return "", nil, false
+			}
+		}
+	}
+
+	varMapping = map[string]string{}
+	subNames := this.reg.SubexpNames()
+	for index, match := range matches {
+		varMapping[fmt.Sprintf("%d", index)] = match
+		subName := subNames[index]
+		if len(subName) > 0 {
+			varMapping[subName] = match
+		}
+	}
+
+	replace = configutils.ParseVariables(this.Replace, func(varName string) string {
+		v, ok := varMapping[varName]
+		if ok {
+			return v
+		}
+		return "${" + varName + "}"
+	})
+
+	replace = formatter(replace)
+
+	return replace, varMapping, true
+}
+
+// 判断是否是外部URL
+func (this *HTTPRewriteRule) IsExternalURL(url string) bool {
+	return shared.RegexpExternalURL.MatchString(url)
+}