add observer

ingress/plugin/http.go

@@ -0,0 +1,135 @@
+package ingress
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"net/http"
+
+	"github.com/go-gost/core/ingress"
+	"github.com/go-gost/core/logger"
+	"github.com/go-gost/x/internal/plugin"
+)
+
+type httpPluginGetRuleRequest struct {
+	Host string `json:"host"`
+}
+
+type httpPluginGetRuleResponse struct {
+	Endpoint string `json:"endpoint"`
+}
+
+type httpPluginSetRuleRequest struct {
+	Host     string `json:"host"`
+	Endpoint string `json:"endpoint"`
+}
+
+type httpPluginSetRuleResponse struct {
+	OK bool `json:"ok"`
+}
+
+type httpPlugin struct {
+	url    string
+	client *http.Client
+	header http.Header
+	log    logger.Logger
+}
+
+// NewHTTPPlugin creates an Ingress plugin based on HTTP.
+func NewHTTPPlugin(name string, url string, opts ...plugin.Option) ingress.Ingress {
+	var options plugin.Options
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	return &httpPlugin{
+		url:    url,
+		client: plugin.NewHTTPClient(&options),
+		header: options.Header,
+		log: logger.Default().WithFields(map[string]any{
+			"kind":    "ingress",
+			"ingress": name,
+		}),
+	}
+}
+
+func (p *httpPlugin) GetRule(ctx context.Context, host string, opts ...ingress.Option) *ingress.Rule {
+	if p.client == nil {
+		return nil
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, p.url, nil)
+	if err != nil {
+		return nil
+	}
+	if p.header != nil {
+		req.Header = p.header.Clone()
+	}
+	req.Header.Set("Content-Type", "application/json")
+
+	q := req.URL.Query()
+	q.Set("host", host)
+	req.URL.RawQuery = q.Encode()
+
+	resp, err := p.client.Do(req)
+	if err != nil {
+		return nil
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil
+	}
+
+	res := httpPluginGetRuleResponse{}
+	if err := json.NewDecoder(resp.Body).Decode(&res); err != nil {
+		return nil
+	}
+	if res.Endpoint == "" {
+		return nil
+	}
+	return &ingress.Rule{
+		Hostname: host,
+		Endpoint: res.Endpoint,
+	}
+}
+
+func (p *httpPlugin) SetRule(ctx context.Context, rule *ingress.Rule, opts ...ingress.Option) bool {
+	if p.client == nil || rule == nil {
+		return false
+	}
+
+	rb := httpPluginSetRuleRequest{
+		Host:     rule.Hostname,
+		Endpoint: rule.Endpoint,
+	}
+	v, err := json.Marshal(&rb)
+	if err != nil {
+		return false
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPut, p.url, bytes.NewReader(v))
+	if err != nil {
+		return false
+	}
+
+	if p.header != nil {
+		req.Header = p.header.Clone()
+	}
+	req.Header.Set("Content-Type", "application/json")
+	resp, err := p.client.Do(req)
+	if err != nil {
+		return false
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return false
+	}
+
+	res := httpPluginSetRuleResponse{}
+	if err := json.NewDecoder(resp.Body).Decode(&res); err != nil {
+		return false
+	}
+	return res.OK
+}