luet/pkg/api/core/image/delta_test.go

// Copyright © 2021 Ettore Di Giacinto <mudler@gentoo.org>
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License along
// with this program; if not, see <http://www.gnu.org/licenses/>.

package image_test

import (
	"io/ioutil"
	"os"
	"path/filepath"

	"github.com/google/go-containerregistry/pkg/name"
	v1 "github.com/google/go-containerregistry/pkg/v1"
	daemon "github.com/google/go-containerregistry/pkg/v1/daemon"
	"github.com/mudler/luet/pkg/api/core/context"
	. "github.com/mudler/luet/pkg/api/core/image"
	"github.com/mudler/luet/pkg/helpers/file"
	. "github.com/onsi/ginkgo/v2"
	. "github.com/onsi/gomega"
)

var _ = Describe("Delta", func() {
	Context("Generates deltas of images", func() {
		It("computes delta", func() {
			ref, err := name.ParseReference("alpine")
			Expect(err).ToNot(HaveOccurred())

			img, err := daemon.Image(ref)
			Expect(err).ToNot(HaveOccurred())

			layers, err := Delta(img, img)
			Expect(err).ToNot(HaveOccurred())
			Expect(len(layers.Changes)).To(Equal(0))
			Expect(len(layers.Additions)).To(Equal(0))
			Expect(len(layers.Deletions)).To(Equal(0))
		})

		Context("ExtractDeltaFiles", func() {
			ctx := context.NewContext()
			var tmpfile *os.File
			var ref, ref2 name.Reference
			var img, img2 v1.Image
			var err error

			BeforeEach(func() {
				ctx = context.NewContext()
				ctx.Config.General.Debug = true

				tmpfile, err = ioutil.TempFile("", "delta")
				Expect(err).ToNot(HaveOccurred())
				defer os.RemoveAll(tmpfile.Name()) // clean up

				ref, _ = name.ParseReference("alpine")
				ref2, _ = name.ParseReference("golang:1.16-alpine3.14")
				img, _ = daemon.Image(ref)
				img2, _ = daemon.Image(ref2)
			})

			It("Extract all deltas", func() {

				f, err := ExtractDeltaAdditionsFiles(ctx, img, []string{}, []string{})
				Expect(err).ToNot(HaveOccurred())

				_, tmpdir, err := Extract(
					ctx,
					img2,
					f,
				)
				Expect(err).ToNot(HaveOccurred())
				defer os.RemoveAll(tmpdir) // clean up

				// No extra dirs are present
				Expect(file.Exists(filepath.Join(tmpdir, "home"))).To(BeFalse())
				// Cache from go
				Expect(file.Exists(filepath.Join(tmpdir, "root", ".cache"))).To(BeTrue())
				// sh is present from alpine, hence not in the result
				Expect(file.Exists(filepath.Join(tmpdir, "bin", "sh"))).To(BeFalse())
				// /usr/local/go is part of golang:alpine
				Expect(file.Exists(filepath.Join(tmpdir, "usr", "local", "go"))).To(BeTrue())
				Expect(file.Exists(filepath.Join(tmpdir, "usr", "local", "go", "bin"))).To(BeTrue())
			})

			It("Extract deltas and excludes /usr/local/go", func() {
				f, err := ExtractDeltaAdditionsFiles(ctx, img, []string{}, []string{"usr/local/go"})
				Expect(err).ToNot(HaveOccurred())

				Expect(err).ToNot(HaveOccurred())
				_, tmpdir, err := Extract(
					ctx,
					img2,
					f,
				)
				Expect(err).ToNot(HaveOccurred())
				defer os.RemoveAll(tmpdir) // clean up
				Expect(file.Exists(filepath.Join(tmpdir, "usr", "local", "go"))).To(BeFalse())
			})

			It("Extract deltas and excludes /usr/local/go/bin, but includes /usr/local/go", func() {
				f, err := ExtractDeltaAdditionsFiles(ctx, img, []string{"usr/local/go"}, []string{"usr/local/go/bin"})
				Expect(err).ToNot(HaveOccurred())

				_, tmpdir, err := Extract(
					ctx,
					img2,
					f,
				)
				Expect(err).ToNot(HaveOccurred())
				defer os.RemoveAll(tmpdir) // clean up
				Expect(file.Exists(filepath.Join(tmpdir, "usr", "local", "go"))).To(BeTrue())
				Expect(file.Exists(filepath.Join(tmpdir, "usr", "local", "go", "bin"))).To(BeFalse())
			})

			It("Extract deltas and includes /usr/local/go", func() {
				f, err := ExtractDeltaAdditionsFiles(ctx, img, []string{"usr/local/go"}, []string{})
				Expect(err).ToNot(HaveOccurred())
				_, tmpdir, err := Extract(
					ctx,
					img2,
					f,
				)
				Expect(err).ToNot(HaveOccurred())
				defer os.RemoveAll(tmpdir) // clean up

				Expect(file.Exists(filepath.Join(tmpdir, "usr", "local", "go"))).To(BeTrue())
				Expect(file.Exists(filepath.Join(tmpdir, "root", ".cache"))).To(BeFalse())
			})
		})
	})
})