Add --pull option to build command

Signed-off-by: David Son <[email protected]>

Author: sondavidb

cmd/nerdctl/builder_build.go

@@ -51,6 +51,7 @@ If Dockerfile is not present and -f is not specified, it will look for Container
 	buildCommand.Flags().StringP("output", "o", "", "Output destination (format: type=local,dest=path)")
 	buildCommand.Flags().String("progress", "auto", "Set type of progress output (auto, plain, tty). Use plain to show container output")
 	buildCommand.Flags().String("provenance", "", "Shorthand for \"--attest=type=provenance\"")
+	buildCommand.Flags().Bool("pull", false, "On true, always attempt to pull latest image version from remote. Default uses buildkit's default.")
 	buildCommand.Flags().StringArray("secret", nil, "Secret file to expose to the build: id=mysecret,src=/local/secret")
 	buildCommand.Flags().StringArray("allow", nil, "Allow extra privileged entitlement, e.g. network.host, security.insecure")
 	buildCommand.RegisterFlagCompletionFunc("allow", func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
@@ -133,6 +134,14 @@ func processBuildCommandFlag(cmd *cobra.Command, args []string) (types.BuilderBu
 	if err != nil {
 		return types.BuilderBuildOptions{}, err
 	}
+	var pull *bool
+	if cmd.Flags().Changed("pull") {
+		pullFlag, err := cmd.Flags().GetBool("pull")
+		if err != nil {
+			return types.BuilderBuildOptions{}, err
+		}
+		pull = &pullFlag
+	}
 	secret, err := cmd.Flags().GetStringArray("secret")
 	if err != nil {
 		return types.BuilderBuildOptions{}, err
@@ -205,6 +214,7 @@ func processBuildCommandFlag(cmd *cobra.Command, args []string) (types.BuilderBu
 		BuildArgs:            buildArgs,
 		Label:                label,
 		NoCache:              noCache,
+		Pull:                 pull,
 		Secret:               secret,
 		Allow:                allow,
 		Attest:               attest,

cmd/nerdctl/builder_linux_test.go

@@ -19,9 +19,13 @@ package main
 import (
 	"bytes"
 	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
 	"testing"
 
 	"github.com/containerd/nerdctl/v2/pkg/testutil"
+	"gotest.tools/v3/assert"
 )
 
 func TestBuilderDebug(t *testing.T) {
@@ -36,3 +40,89 @@ CMD ["echo", "nerdctl-builder-debug-test-string"]
 
 	base.Cmd("builder", "debug", buildCtx).CmdOption(testutil.WithStdin(bytes.NewReader([]byte("c\n")))).AssertOK()
 }
+
+func TestBuildWithPull(t *testing.T) {
+	testutil.DockerIncompatible(t)
+	testutil.RequiresBuild(t)
+
+	oldImage := testutil.BusyboxImage
+	oldImageSha := "141c253bc4c3fd0a201d32dc1f493bcf3fff003b6df416dea4f41046e0f37d47"
+	newImage := testutil.AlpineImage
+
+	buildkitConfig := fmt.Sprintf(`[worker.oci]
+enabled = false
+
+[worker.containerd]
+enabled = true
+namespace = "%s"`, testutil.Namespace)
+
+	cleanup := useBuildkitConfig(t, buildkitConfig)
+	defer cleanup()
+
+	testCases := []struct {
+		name string
+		pull string
+	}{
+		{
+			name: "build with local image",
+			pull: "false",
+		},
+		{
+			name: "build with newest image",
+			pull: "true",
+		},
+		{
+			name: "build with buildkit default",
+			// buildkit default pulls from remote
+			pull: "default",
+		},
+	}
+
+	for _, tc := range testCases {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			base := testutil.NewBase(t)
+			defer base.Cmd("builder", "prune").AssertOK()
+			base.Cmd("image", "prune", "--force", "--all").AssertOK()
+
+			base.Cmd("pull", oldImage).Run()
+			base.Cmd("tag", oldImage, newImage).Run()
+
+			dockerfile := fmt.Sprintf(`FROM %s`, newImage)
+			tmpDir := t.TempDir()
+			err := os.WriteFile(filepath.Join(tmpDir, "Dockerfile"), []byte(dockerfile), 0644)
+			assert.NilError(t, err)
+
+			buildCtx := createBuildContext(t, dockerfile)
+
+			buildCmd := []string{"build", buildCtx}
+			switch tc.pull {
+			case "false":
+				buildCmd = append(buildCmd, "--pull=false")
+				base.Cmd(buildCmd...).AssertErrContains(oldImageSha)
+			case "true":
+				buildCmd = append(buildCmd, "--pull=true")
+				base.Cmd(buildCmd...).AssertErrNotContains(oldImageSha)
+			case "default":
+				base.Cmd(buildCmd...).AssertErrNotContains(oldImageSha)
+			}
+		})
+	}
+}
+
+func useBuildkitConfig(t *testing.T, config string) (cleanup func()) {
+	buildkitConfigPath := "/etc/buildkit/buildkitd.toml"
+
+	currConfig, err := exec.Command("cat", buildkitConfigPath).Output()
+	assert.NilError(t, err)
+
+	os.WriteFile(buildkitConfigPath, []byte(config), 0644)
+	_, err = exec.Command("systemctl", "restart", "buildkit").Output()
+	assert.NilError(t, err)
+
+	return func() {
+		assert.NilError(t, os.WriteFile(buildkitConfigPath, currConfig, 0644))
+		_, err = exec.Command("systemctl", "restart", "buildkit").Output()
+		assert.NilError(t, err)
+	}
+}

docs/command-reference.md

@@ -692,6 +692,7 @@ Flags:
   - :whale: `type=image,name=example.com/image,push=true`: Push to a registry (see [`buildctl build`](https://github.com/moby/buildkit/tree/v0.9.0#imageregistry) documentation)
 - :whale: `--progress=(auto|plain|tty)`: Set type of progress output (auto, plain, tty). Use plain to show container output
 - :whale: `--provenance`: Shorthand for \"--attest=type=provenance\", see [`buildx_build.md`](https://github.com/docker/buildx/blob/v0.12.1/docs/reference/buildx_build.md#provenance) documentation
+- :whale: `--pull=(true|false)`: On true, always attempt to pull latest image version from remote. Default uses buildkit's default.
 - :whale: `--secret`: Secret file to expose to the build: id=mysecret,src=/local/secret
 - :whale: `--allow`: Allow extra privileged entitlement, e.g. network.host, security.insecure  (It’s required to configure the buildkitd to enable the feature, see [`buildkitd.toml`](https://github.com/moby/buildkit/blob/master/docs/buildkitd.toml.md) documentation)
 - :whale: `--attest`: Attestation parameters (format: "type=sbom,generator=image"), see [`buildx_build.md`](https://github.com/docker/buildx/blob/v0.12.1/docs/reference/buildx_build.md#attest) documentation

pkg/api/types/builder_types.go

@@ -69,6 +69,8 @@ type BuilderBuildOptions struct {
 	ExtendedBuildContext []string
 	// NetworkMode mode for the build context
 	NetworkMode string
+	// Pull determines if we should try to pull latest image from remote. Default is buildkit's default.
+	Pull *bool
 }
 
 // BuilderPruneOptions specifies options for `nerdctl builder prune`.

pkg/cmd/builder/build.go

@@ -367,6 +367,15 @@ func generateBuildctlArgs(ctx context.Context, client *containerd.Client, option
 		buildctlArgs = append(buildctlArgs, "--no-cache")
 	}
 
+	if options.Pull != nil {
+		switch *options.Pull {
+		case true:
+			buildctlArgs = append(buildctlArgs, "--opt=image-resolve-mode=pull")
+		case false:
+			buildctlArgs = append(buildctlArgs, "--opt=image-resolve-mode=local")
+		}
+	}
+
 	for _, s := range strutil.DedupeStrSlice(options.Secret) {
 		buildctlArgs = append(buildctlArgs, "--secret="+s)
 	}