Correctly ignore files from .dockerignore (#508)

* Exclude files from dockerignore when uploading context tarball

* clean up ignore patterns

* Refactor ignorePatterns into separate function. Fix dockerignore path bug in hash function.

* dockerignore details

* unskipping dotnet test

* Do not ignore Dockerfile

* Improve readability for dockerfile exists condition

* address review feedback

* undo excluding Dockerfiles

* Do not dockerignore  and

* Add . to includeFiles

* Add warning for build files potentially being copied to an image when running in buildkit mode and attempting to dockerignore

* use length of ignorefiles to send warning to user

* tone down message

examples/examples_dotnet_test.go

@@ -33,7 +33,6 @@ func TestNginxCs(t *testing.T) {
 }
 
 func TestDotNet(t *testing.T) {
-
 	test := getCsharpBaseOptions(t).
 		With(integration.ProgramTestOptions{
 			Dir: path.Join(getCwd(t), "dotnet"),

examples/examples_nodejs_test.go

@@ -54,7 +54,6 @@ func TestNginx(t *testing.T) {
 }
 
 func TestDockerfileWithMultipleTargets(t *testing.T) {
-
 	test := getJsOptions(t).
 		With(integration.ProgramTestOptions{
 			Dir: path.Join(getCwd(t), "dockerfile-with-targets"),

provider/image.go

@@ -6,11 +6,11 @@ import (
 	"encoding/base64"
 	"encoding/json"
 	"fmt"
-	"net"
-
 	"github.com/docker/distribution/reference"
 	"github.com/moby/buildkit/session"
 	"github.com/moby/moby/registry"
+	"net"
+	"path/filepath"
 
 	"github.com/docker/cli/cli/config"
 	"github.com/docker/cli/cli/config/configfile"
@@ -23,6 +23,8 @@ import (
 	controlapi "github.com/moby/buildkit/api/services/control"
 	"github.com/pulumi/pulumi/sdk/v3/go/common/resource"
 	"github.com/pulumi/pulumi/sdk/v3/go/common/resource/plugin"
+
+	buildCmd "github.com/docker/cli/cli/command/image/build"
 )
 
 const defaultDockerfile = "Dockerfile"
@@ -90,8 +92,34 @@ func (p *dockerNativeProvider) dockerBuild(ctx context.Context,
 		return "", nil, err
 	}
 
-	// make the build context
-	tar, err := archive.TarWithOptions(img.Build.Context, &archive.TarOptions{})
+	// make the build context and ensure to exclude dockerignore file patterns
+	dockerIgnorePath := filepath.Join(build.Context, ".dockerignore")
+	initialIgnorePatterns, err := getIgnore(dockerIgnorePath)
+	// un-ignore build files so the docker daemon can use them
+	ignorePatterns := buildCmd.TrimBuildFilesFromExcludes(
+		initialIgnorePatterns,
+		img.Build.Dockerfile,
+		false,
+	)
+
+	// warn user about accidentally copying build files
+	if build.BuilderVersion == defaultBuilder && len(initialIgnorePatterns) != len(ignorePatterns) {
+		msg := "It looks like you are trying to dockerignore a build file such as `Dockerfile` or `.dockerignore`. " +
+			"To avoid accidentally copying these files to your image, please ensure any copied file systems do not " +
+			"include `Dockerfile` or `.dockerignore`."
+		err = p.host.Log(ctx, "warning", urn, msg)
+		if err != nil {
+			return "", nil, err
+		}
+	}
+
+	if err != nil {
+		return "", nil, err
+	}
+
+	tar, err := archive.TarWithOptions(img.Build.Context, &archive.TarOptions{
+		ExcludePatterns: ignorePatterns,
+	})
 	if err != nil {
 		return "", nil, err
 	}

provider/provider.go

@@ -483,22 +483,10 @@ func (accumulator *contextHashAccumulator) hexSumContext() string {
 
 func hashContext(dockerContextPath string, dockerfile string) (string, error) {
 	// exclude all files listed in dockerignore
-	dockerIgnorePath := dockerfile + ".dockerignore"
-	dockerIgnore, err := os.ReadFile(dockerIgnorePath)
-	if err != nil {
-		if os.IsNotExist(err) {
-			dockerIgnorePath = filepath.Join(dockerContextPath, ".dockerignore")
-			dockerIgnore, err = os.ReadFile(dockerIgnorePath)
-			if err != nil && !os.IsNotExist(err) {
-				return "", fmt.Errorf("unable to read %s file: %w", dockerIgnorePath, err)
-			}
-		} else {
-			return "", fmt.Errorf("unable to read %s file: %w", dockerIgnorePath, err)
-		}
-	}
-	ignorePatterns, err := dockerignore.ReadAll(bytes.NewReader(dockerIgnore))
+	dockerIgnorePath := filepath.Join(dockerContextPath, ".dockerignore")
+	ignorePatterns, err := getIgnore(dockerIgnorePath)
 	if err != nil {
-		return "", fmt.Errorf("unable to parse %s file: %w", dockerIgnorePath, err)
+		return "", err
 	}
 	ignoreMatcher, err := fileutils.NewPatternMatcher(ignorePatterns)
 	if err != nil {
@@ -554,3 +542,20 @@ func hashContext(dockerContextPath string, dockerfile string) (string, error) {
 	// create a hash of the entire input of the hash accumulator
 	return accumulator.hexSumContext(), nil
 }
+
+func getIgnore(dockerIgnorePath string) ([]string, error) {
+	var ignorePatterns []string
+	dockerIgnore, err := os.ReadFile(dockerIgnorePath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			// .dockerignore files are optional
+			return ignorePatterns, nil
+		}
+		return ignorePatterns, fmt.Errorf("unable to read %s file: %w", dockerIgnorePath, err)
+	}
+	ignorePatterns, err = dockerignore.ReadAll(bytes.NewReader(dockerIgnore))
+	if err != nil {
+		return ignorePatterns, fmt.Errorf("unable to parse %s file: %w", ".dockerignore", err)
+	}
+	return ignorePatterns, nil
+}