feat(browser-fetch): add lightpanda-backed fetch service and knowledge URL fallback

Adds a new browser-fetch microservice that wraps Lightpanda for rendering
JS-heavy pages, and wires it into the knowledge URL parser as a fallback
when the upstream link reader returns 403/429/5xx for an allow-listed
domain (e.g. zhuanlan.zhihu.com). Includes config/env plumbing, hot-reload
diff support, and full deploy assets (Dockerfile target, docker-compose,
k3s manifests, image-build/package scripts).
This commit is contained in:
2026-05-11 11:11:21 +08:00
parent 708a45ba16
commit 7f08d92958
22 changed files with 1770 additions and 8 deletions
@@ -4,12 +4,16 @@ import (
"bytes"
"context"
"encoding/json"
"errors"
"fmt"
"io"
"net/http"
"net/url"
"strconv"
"strings"
"time"
"github.com/geo-platform/tenant-api/internal/shared/config"
"github.com/geo-platform/tenant-api/internal/shared/llm"
"github.com/geo-platform/tenant-api/internal/tenant/prompts"
"go.uber.org/zap"
@@ -23,6 +27,37 @@ const (
defaultKnowledgeURLMarkdownOutputToken = 12000
)
var errBrowserFetchNotAvailable = fmt.Errorf("browser fetch fallback is not available")
type sourceFetchRestrictedError struct {
URL string
Status int
Cause error
}
func (e sourceFetchRestrictedError) Error() string {
cause := ""
if e.Cause != nil {
cause = strings.TrimSpace(e.Cause.Error())
}
if cause == "" {
cause = "source website requires browser rendering or blocks server-side fetch"
}
if e.Status > 0 {
return fmt.Sprintf("source website fetch restricted status=%d: %s", e.Status, cause)
}
return "source website fetch restricted: " + cause
}
func (e sourceFetchRestrictedError) Unwrap() error {
return e.Cause
}
func isSourceFetchRestrictedError(err error) bool {
var restricted sourceFetchRestrictedError
return errors.As(err, &restricted)
}
type arkToolExecuteRequest struct {
ActionName string `json:"action_name"`
ToolName string `json:"tool_name"`
@@ -50,7 +85,20 @@ type arkWebDataItem struct {
func (s *KnowledgeService) parseWebsiteKnowledge(ctx context.Context, rawURL string) (*knowledgeParsedContent, error) {
item, err := s.executeLinkReader(ctx, rawURL)
if err != nil {
return nil, err
if !s.shouldTryBrowserFetchFallback(rawURL, err) {
return nil, classifySourceFetchError(rawURL, err)
}
fallback, fallbackErr := s.parseWebsiteKnowledgeWithBrowserFetch(ctx, rawURL)
if fallbackErr == nil {
return fallback, nil
}
if s.logger != nil {
s.logger.Warn("knowledge browser fetch fallback failed",
zap.String("url", rawURL),
zap.Error(fallbackErr),
)
}
return nil, classifySourceFetchError(rawURL, err)
}
text := normalizeKnowledgeText(item.Content)
@@ -76,6 +124,65 @@ func (s *KnowledgeService) parseWebsiteKnowledge(ctx context.Context, rawURL str
}, nil
}
func (s *KnowledgeService) parseWebsiteKnowledgeWithBrowserFetch(ctx context.Context, rawURL string) (*knowledgeParsedContent, error) {
runtimeCfg := s.runtimeConfig()
browserCfg := runtimeCfg.BrowserFetch
config.NormalizeBrowserFetchConfig(&browserCfg)
if !browserCfg.Enabled {
return nil, errBrowserFetchNotAvailable
}
provider := strings.ToLower(strings.TrimSpace(browserCfg.Provider))
if provider != "lightpanda" && provider != "lightpanda_service" {
return nil, fmt.Errorf("unsupported browser fetch provider %q", browserCfg.Provider)
}
if strings.TrimSpace(browserCfg.ServiceURL) == "" {
return nil, fmt.Errorf("%w: browser_fetch.service_url is empty", errBrowserFetchNotAvailable)
}
callCtx := ctx
if browserCfg.RequestTimeout > 0 {
var cancel context.CancelFunc
callCtx, cancel = context.WithTimeout(ctx, browserCfg.RequestTimeout)
defer cancel()
}
result, err := s.browserFetchQueue(browserCfg).Fetch(callCtx, rawURL, browserCfg)
if err != nil {
return nil, err
}
text := normalizeKnowledgeText(result.Text)
if text == "" {
text = normalizeKnowledgeText(result.Markdown)
}
if text == "" {
return nil, fmt.Errorf("browser fetch returned empty content")
}
title := strings.TrimSpace(result.Title)
markdown := strings.TrimSpace(result.Markdown)
if markdown == "" {
var err error
markdown, err = s.formatWebsiteMarkdown(ctx, title, text, rawURL)
if err != nil {
if s.logger != nil {
s.logger.Warn("knowledge browser fetch markdown formatting failed, fallback to local markdown",
zap.String("url", rawURL),
zap.Error(err),
)
}
markdown = buildKnowledgeMarkdownFromText(title, text)
}
}
return &knowledgeParsedContent{
Text: text,
Markdown: markdown,
}, nil
}
func (s *KnowledgeService) executeLinkReader(ctx context.Context, rawURL string) (*arkWebDataItem, error) {
runtimeCfg := s.runtimeConfig()
baseURL := strings.TrimRight(strings.TrimSpace(runtimeCfg.ArkBaseURL), "/")
@@ -135,6 +242,90 @@ func (s *KnowledgeService) executeLinkReader(ctx context.Context, rawURL string)
return &item, nil
}
func classifySourceFetchError(rawURL string, err error) error {
if err == nil {
return nil
}
status := extractHTTPStatusFromError(err)
if status == http.StatusForbidden || status == http.StatusTooManyRequests || status >= http.StatusInternalServerError {
return sourceFetchRestrictedError{URL: rawURL, Status: status, Cause: err}
}
return err
}
func extractHTTPStatusFromError(err error) int {
if err == nil {
return 0
}
message := err.Error()
idx := strings.Index(message, "status=")
if idx < 0 {
return 0
}
value := message[idx+len("status="):]
end := 0
for end < len(value) && value[end] >= '0' && value[end] <= '9' {
end++
}
if end == 0 {
return 0
}
status, parseErr := strconv.Atoi(value[:end])
if parseErr != nil {
return 0
}
return status
}
func (s *KnowledgeService) shouldTryBrowserFetchFallback(rawURL string, err error) bool {
if s == nil {
return false
}
runtimeCfg := s.runtimeConfig()
browserCfg := runtimeCfg.BrowserFetch
config.NormalizeBrowserFetchConfig(&browserCfg)
if !browserCfg.Enabled {
return false
}
if !browserFetchDomainAllowed(rawURL, browserCfg.AllowedDomains) {
return false
}
status := extractHTTPStatusFromError(err)
if status <= 0 {
return false
}
for _, trigger := range browserCfg.TriggerStatus {
if status == trigger {
return true
}
}
return false
}
func browserFetchDomainAllowed(rawURL string, allowedDomains []string) bool {
if len(allowedDomains) == 0 {
return false
}
parsed, err := url.Parse(rawURL)
if err != nil {
return false
}
host := strings.ToLower(strings.TrimSpace(parsed.Hostname()))
if host == "" {
return false
}
for _, domain := range allowedDomains {
domain = strings.ToLower(strings.TrimPrefix(strings.TrimSpace(domain), "."))
if domain == "" {
continue
}
if host == domain || strings.HasSuffix(host, "."+domain) {
return true
}
}
return false
}
func (s *KnowledgeService) formatWebsiteMarkdown(ctx context.Context, title, content, rawURL string) (string, error) {
content = strings.TrimSpace(content)
if content == "" {