From 3db629e2ca3757f1c7d415cc9fe0b0584b6ed8b3 Mon Sep 17 00:00:00 2001
From: Michael Hohn <hohn@github.com>
Date: Wed, 27 Nov 2024 22:56:47 -0800
Subject: [PATCH] A go version of hepc-serve

---
 client/qldbtools/bin/hepc-serve.go | 104 +++++++++++++++++++++++++++++
 1 file changed, 104 insertions(+)
 create mode 100755 client/qldbtools/bin/hepc-serve.go

diff --git a/client/qldbtools/bin/hepc-serve.go b/client/qldbtools/bin/hepc-serve.go
new file mode 100755
index 0000000..9f5b38b
--- /dev/null
+++ b/client/qldbtools/bin/hepc-serve.go
@@ -0,0 +1,104 @@
+/*
+   dependencies
+   go get -u golang.org/x/exp/slog
+
+   on-the-fly
+   go run bin/hepc-serve.go --codeql-db-dir  db-collection-py-1
+
+   compiled
+   cd ~/work-gh/mrva/mrvacommander/client/qldbtools/
+   go build -o ./bin/hepc-serve.bin ./bin/hepc-serve.go
+
+   test
+   curl http://127.0.0.1:8080/api/v1/latest_results/codeql-all -o foo
+   curl $(head -1 foo | jq  -r ".result_url" |sed 's|hepc|127.0.0.1:8080/db|g;') -o foo.zip
+
+*/
+package main
+
+import (
+	"flag"
+	"fmt"
+	"net/http"
+	"os"
+	"path/filepath"
+
+	"golang.org/x/exp/slog"
+)
+
+var dbDir string
+
+func serveFile(w http.ResponseWriter, r *http.Request) {
+	fullPath := r.URL.Path[len("/db/"):]
+
+	resolvedPath, err := filepath.EvalSymlinks(fullPath)
+	if err != nil {
+		slog.Warn("failed to resolve symlink", slog.String("fullPath", fullPath),
+			slog.String("error", err.Error()))
+		http.Error(w, "File not found", http.StatusNotFound)
+		return
+	}
+
+	if fileInfo, err := os.Stat(resolvedPath); err != nil || fileInfo.IsDir() {
+		slog.Warn("file not found or is a directory", slog.String("resolvedPath", resolvedPath))
+		http.Error(w, "File not found", http.StatusNotFound)
+		return
+	}
+
+	slog.Info("serving file", slog.String("resolvedPath", resolvedPath))
+	http.ServeFile(w, r, resolvedPath)
+}
+
+func serveMetadata(w http.ResponseWriter, r *http.Request) {
+	metadataPath := filepath.Join(dbDir, "metadata.json")
+	if fileInfo, err := os.Stat(metadataPath); err != nil || fileInfo.IsDir() {
+		slog.Warn("metadata.json not found", slog.String("metadataPath", metadataPath))
+		http.Error(w, "metadata.json not found", http.StatusNotFound)
+		return
+	}
+
+	slog.Info("serving metadata.json", slog.String("metadataPath", metadataPath))
+	http.ServeFile(w, r, metadataPath)
+}
+
+func logMiddleware(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		slog.Info("incoming request", slog.String("method", r.Method), slog.String("url", r.URL.Path))
+		next.ServeHTTP(w, r)
+	})
+}
+
+func main() {
+	var host string
+	var port int
+
+	flag.StringVar(&dbDir, "codeql-db-dir", "", "Directory containing CodeQL database files (required)")
+	flag.StringVar(&host, "host", "127.0.0.1", "Host address for the HTTP server")
+	flag.IntVar(&port, "port", 8080, "Port for the HTTP server")
+	flag.Parse()
+
+	if dbDir == "" {
+		slog.Error("missing required flag", slog.String("flag", "--codeql-db-dir"))
+		os.Exit(1)
+	}
+
+	if _, err := os.Stat(dbDir); os.IsNotExist(err) {
+		slog.Error("invalid directory", slog.String("dbDir", dbDir))
+		os.Exit(1)
+	}
+
+	slog.Info("starting server", slog.String("host", host), slog.Int("port", port), slog.String("dbDir", dbDir))
+
+	mux := http.NewServeMux()
+	mux.HandleFunc("/db/", serveFile)
+	mux.HandleFunc("/index", serveMetadata)
+	mux.HandleFunc("/api/v1/latest_results/codeql-all", serveMetadata)
+
+	loggedHandler := logMiddleware(mux)
+
+	addr := fmt.Sprintf("%s:%d", host, port)
+	slog.Info("server listening", slog.String("address", addr))
+	if err := http.ListenAndServe(addr, loggedHandler); err != nil {
+		slog.Error("server error", slog.String("error", err.Error()))
+	}
+}