fix(images): 服务器镜像在创建时固定到仓库 digest，更换镜像需确认备份，安装器重建前先固定旧服并推送不可变版本标签

internal/api/images_pin_test.go

@@ -0,0 +1,162 @@
+package api
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/http"
+	"testing"
+
+	"felis.lolicon.best/internal/imagepin"
+)
+
+const pinnedDigest = "sha256:1111111111111111111111111111111111111111111111111111111111111111"
+
+// fakePinner pins every unpinned ref to pinnedDigest, or fails with err. A ref
+// that already names a digest comes back as is, like imagepin.Resolver.
+type fakePinner struct {
+	err  error
+	seen []string
+}
+
+func (f *fakePinner) Pin(_ context.Context, ref string) (string, error) {
+	f.seen = append(f.seen, ref)
+	if f.err != nil {
+		return "", f.err
+	}
+	if imagepin.Pinned(ref) {
+		return ref, nil
+	}
+	return ref + "@" + pinnedDigest, nil
+}
+
+// TestCreateServerStoresPinnedImage: the spec a server is created with names the
+// digest its tag resolved to, so a later push over the tag cannot move it.
+func TestCreateServerStoresPinnedImage(t *testing.T) {
+	api, _, cl, _ := newCreateAPI()
+	pin := &fakePinner{}
+	api.Images = pin
+
+	w := do(api.ExternalHandler(), "POST", "/api/v1/servers", validCreateBody, nil)
+	if w.Code != http.StatusCreated {
+		t.Fatalf("code = %d, want 201 (%s)", w.Code, w.Body.String())
+	}
+	if got, want := cl.created["survival"].Image, admittedImage+"@"+pinnedDigest; got != want {
+		t.Errorf("created image = %q, want %q", got, want)
+	}
+	if len(pin.seen) != 1 || pin.seen[0] != admittedImage {
+		t.Errorf("pinned refs = %v, want the admitted ref once", pin.seen)
+	}
+}
+
+// TestCreateServerPinErrors: a tag the registry does not hold is the caller's
+// problem (400); a registry that cannot answer is the platform's (503). Neither
+// creates anything.
+func TestCreateServerPinErrors(t *testing.T) {
+	for _, tc := range []struct {
+		err      error
+		code     int
+		wantCode string
+	}{
+		{fmt.Errorf("resolve: %w", imagepin.ErrNotFound), http.StatusBadRequest, "image_not_in_registry"},
+		{errors.New("dial tcp: connection refused"), http.StatusServiceUnavailable, "registry_unavailable"},
+	} {
+		api, _, cl, _ := newCreateAPI()
+		api.Images = &fakePinner{err: tc.err}
+
+		w := do(api.ExternalHandler(), "POST", "/api/v1/servers", validCreateBody, nil)
+		if w.Code != tc.code || decodeErr(t, w) != tc.wantCode {
+			t.Errorf("%v: got %d %s, want %d %s", tc.err, w.Code, w.Body.String(), tc.code, tc.wantCode)
+		}
+		if _, ok := cl.created["survival"]; ok {
+			t.Errorf("%v: server created despite the pin failure", tc.err)
+		}
+	}
+}
+
+// TestPatchServerImageChangeUnconfirmed: moving a world to another build is
+// refused until the caller acknowledges the chunk upgrade cannot be undone.
+func TestPatchServerImageChangeUnconfirmed(t *testing.T) {
+	api, repo, cl, _ := newPatchAPI()
+	cl.byName["survival"].Image = "registry.felis.svc:5000/mc:0@" + pinnedDigest
+	api.Images = &fakePinner{}
+
+	w := patchSurvival(api, `{"image":"`+admittedImage+`"}`)
+	if w.Code != http.StatusConflict || decodeErr(t, w) != "image_change_unconfirmed" {
+		t.Fatalf("got %d %s, want 409 image_change_unconfirmed", w.Code, w.Body.String())
+	}
+	if _, ok := cl.patched["survival"]; ok {
+		t.Error("spec patched without confirmation")
+	}
+	if len(repo.audits) != 0 {
+		t.Errorf("refused change audited: %+v", repo.audits)
+	}
+}
+
+// TestPatchServerImageConfirmedAudited: a confirmed change stores the pinned ref
+// and the audit row names both builds.
+func TestPatchServerImageConfirmedAudited(t *testing.T) {
+	api, repo, cl, _ := newPatchAPI()
+	from := "registry.felis.svc:5000/mc:0@" + pinnedDigest
+	cl.byName["survival"].Image = from
+	api.Images = &fakePinner{}
+
+	w := patchSurvival(api, `{"image":"`+admittedImage+`","confirmImageChange":true}`)
+	if w.Code != http.StatusOK {
+		t.Fatalf("code = %d, want 200 (%s)", w.Code, w.Body.String())
+	}
+	to := admittedImage + "@" + pinnedDigest
+	if p := cl.patched["survival"]; p.Image == nil || *p.Image != to {
+		t.Fatalf("patched image = %v, want %q", p.Image, to)
+	}
+	if len(repo.audits) != 1 || repo.audits[0].Action != "server.patch" {
+		t.Fatalf("audits = %+v, want one server.patch", repo.audits)
+	}
+	var payload map[string]string
+	if err := json.Unmarshal(repo.audits[0].Payload, &payload); err != nil {
+		t.Fatalf("audit payload %q: %v", repo.audits[0].Payload, err)
+	}
+	if payload["image_from"] != from || payload["image_to"] != to {
+		t.Errorf("audit payload = %v, want image_from %q image_to %q", payload, from, to)
+	}
+}
+
+// TestPatchServerImageSamePinIsNoChange: re-picking the tag a server runs, while
+// the tag still names the same build, changes nothing and needs no confirmation.
+func TestPatchServerImageSamePinIsNoChange(t *testing.T) {
+	api, repo, cl, _ := newPatchAPI()
+	cl.byName["survival"].Image = admittedImage + "@" + pinnedDigest
+	api.Images = &fakePinner{}
+
+	w := patchSurvival(api, `{"image":"`+admittedImage+`"}`)
+	if w.Code != http.StatusOK {
+		t.Fatalf("code = %d, want 200 (%s)", w.Code, w.Body.String())
+	}
+	if p := cl.patched["survival"]; p.Image != nil {
+		t.Errorf("patched image = %q, want no image change", *p.Image)
+	}
+	if len(repo.audits) != 1 || repo.audits[0].Payload != nil {
+		t.Errorf("audits = %+v, want a plain server.patch", repo.audits)
+	}
+}
+
+// TestPatchServerImageRestoresPinnedBuild: the exact build an earlier change
+// replaced is admitted by its tag and set as is, so a world restored from a
+// backup can go back to the build that wrote it.
+func TestPatchServerImageRestoresPinnedBuild(t *testing.T) {
+	api, _, cl, fb := newPatchAPI()
+	cl.byName["survival"].Image = admittedImage + "@" + pinnedDigest
+	pin := &fakePinner{}
+	api.Images = pin
+	old := admittedImage + "@sha256:" + fmt.Sprintf("%064d", 0)
+	fb.admitted[old] = true
+
+	w := patchSurvival(api, `{"image":"`+old+`","confirmImageChange":true}`)
+	if w.Code != http.StatusOK {
+		t.Fatalf("code = %d, want 200 (%s)", w.Code, w.Body.String())
+	}
+	if p := cl.patched["survival"]; p.Image == nil || *p.Image != old {
+		t.Errorf("patched image = %v, want %q", p.Image, old)
+	}
+}