server: implement Nix binary cache HTTP handler with zero-copy NAR streaming

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: Ibcafdb7084453ee4f8a8b76b1ee222466a6a6964

internal/server/server_test.go

@@ -0,0 +1,153 @@
+package server_test
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"strings"
+	"testing"
+	"time"
+
+	"notashelf.dev/ncro/internal/cache"
+	"notashelf.dev/ncro/internal/config"
+	"notashelf.dev/ncro/internal/prober"
+	"notashelf.dev/ncro/internal/router"
+	"notashelf.dev/ncro/internal/server"
+)
+
+func makeTestServer(t *testing.T, upstreams ...string) *httptest.Server {
+	t.Helper()
+	f, _ := os.CreateTemp("", "ncro-srv-*.db")
+	f.Close()
+	t.Cleanup(func() { os.Remove(f.Name()) })
+
+	db, err := cache.Open(f.Name(), 1000)
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { db.Close() })
+
+	p := prober.New(0.3)
+	for _, u := range upstreams {
+		p.RecordLatency(u, 10)
+	}
+
+	upsCfg := make([]config.UpstreamConfig, len(upstreams))
+	for i, u := range upstreams {
+		upsCfg[i] = config.UpstreamConfig{URL: u}
+	}
+
+	r := router.New(db, p, time.Hour, 5*time.Second)
+	return httptest.NewServer(server.New(r, p, upsCfg))
+}
+
+func TestNixCacheInfo(t *testing.T) {
+	ts := makeTestServer(t)
+	defer ts.Close()
+
+	resp, err := http.Get(ts.URL + "/nix-cache-info")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 200 {
+		t.Errorf("status = %d, want 200", resp.StatusCode)
+	}
+	body, _ := io.ReadAll(resp.Body)
+	if !strings.Contains(string(body), "StoreDir:") {
+		t.Errorf("body missing StoreDir: %q", body)
+	}
+}
+
+func TestHealthEndpoint(t *testing.T) {
+	ts := makeTestServer(t)
+	defer ts.Close()
+
+	resp, err := http.Get(ts.URL + "/health")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if resp.StatusCode != 200 {
+		t.Errorf("status = %d, want 200", resp.StatusCode)
+	}
+}
+
+func TestNarinfoProxy(t *testing.T) {
+	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if strings.HasSuffix(r.URL.Path, ".narinfo") {
+			w.Header().Set("Content-Type", "text/x-nix-narinfo")
+			fmt.Fprint(w, "StorePath: /nix/store/abc123-hello-2.12\nURL: nar/abc123.nar\nCompression: none\n")
+			return
+		}
+		w.WriteHeader(404)
+	}))
+	defer upstream.Close()
+
+	ts := makeTestServer(t, upstream.URL)
+	defer ts.Close()
+
+	resp, err := http.Get(ts.URL + "/abc123def456.narinfo")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 200 {
+		t.Errorf("narinfo status = %d, want 200", resp.StatusCode)
+	}
+	body, _ := io.ReadAll(resp.Body)
+	if !strings.Contains(string(body), "StorePath:") {
+		t.Errorf("expected narinfo body, got: %q", body)
+	}
+}
+
+func TestNarinfoNotFound(t *testing.T) {
+	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(404)
+	}))
+	defer upstream.Close()
+
+	ts := makeTestServer(t, upstream.URL)
+	defer ts.Close()
+
+	resp, _ := http.Get(ts.URL + "/notfound000000.narinfo")
+	if resp.StatusCode != 404 {
+		t.Errorf("status = %d, want 404", resp.StatusCode)
+	}
+}
+
+func TestNARStreamingPassthrough(t *testing.T) {
+	narContent := []byte("fake-nar-content-bytes")
+	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if strings.HasPrefix(r.URL.Path, "/nar/") {
+			w.Header().Set("Content-Type", "application/x-nix-archive")
+			w.Write(narContent)
+			return
+		}
+		if strings.HasSuffix(r.URL.Path, ".narinfo") {
+			w.WriteHeader(200)
+			return
+		}
+		w.WriteHeader(404)
+	}))
+	defer upstream.Close()
+
+	ts := makeTestServer(t, upstream.URL)
+	defer ts.Close()
+
+	resp, err := http.Get(ts.URL + "/nar/abc123.nar")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != 200 {
+		t.Errorf("NAR status = %d, want 200", resp.StatusCode)
+	}
+	body, _ := io.ReadAll(resp.Body)
+	if string(body) != string(narContent) {
+		t.Errorf("NAR body mismatch: got %q, want %q", body, narContent)
+	}
+}