Templating Functions & HCL Variables for Artifacts, Deploys

builtin/docker/builder.go

@@ -3,9 +3,11 @@ package docker
 import (
 	"bytes"
 	"context"
+	"crypto/rand"
 	"fmt"
 	"os"
-	"path"
+	"path/filepath"
+	"strings"
 
 	"github.com/docker/cli/cli/command/image/build"
 	"github.com/docker/docker/api/types"
@@ -16,6 +18,7 @@ import (
 	"github.com/hashicorp/waypoint-plugin-sdk/component"
 	"github.com/hashicorp/waypoint-plugin-sdk/docs"
 	"github.com/hashicorp/waypoint-plugin-sdk/terminal"
+	"github.com/oklog/ulid/v2"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 
@@ -125,8 +128,26 @@ func (b *Builder) Build(
 	cli.NegotiateAPIVersion(ctx)
 
 	dockerfile := b.config.Dockerfile
-	if dockerfile != "" {
-		dockerfile = path.Join(src.Path, dockerfile)
+	if !filepath.IsAbs(dockerfile) {
+		dockerfile = filepath.Join(src.Path, dockerfile)
+	}
+
+	// If the dockerfile is outside of our build context, then we copy it
+	// into our build context.
+	relDockerfile, err := filepath.Rel(src.Path, dockerfile)
+	if err != nil || strings.HasPrefix(relDockerfile, "..") {
+		id, err := ulid.New(ulid.Now(), rand.Reader)
+		if err != nil {
+			return nil, err
+		}
+
+		newPath := filepath.Join(src.Path, fmt.Sprintf("Dockerfile-%s", id.String()))
+		if err := copyFile(dockerfile, newPath); err != nil {
+			return nil, err
+		}
+		defer os.Remove(newPath)
+
+		dockerfile = newPath
 	}
 
 	contextDir, relDockerfile, err := build.GetContextFromLocalDir(src.Path, dockerfile)

builtin/docker/copy.go

@@ -0,0 +1,52 @@
+package docker
+
+import (
+	"io"
+	"os"
+)
+
+// From: https://gist.github.com/m4ng0squ4sh/92462b38df26839a3ca324697c8cba04
+
+// copyFile copies the contents of the file named src to the file named
+// by dst. The file will be created if it does not already exist. If the
+// destination file exists, all it's contents will be replaced by the contents
+// of the source file. The file mode will be copied from the source and
+// the copied data is synced/flushed to stable storage.
+func copyFile(src, dst string) (err error) {
+	in, err := os.Open(src)
+	if err != nil {
+		return
+	}
+	defer in.Close()
+
+	out, err := os.Create(dst)
+	if err != nil {
+		return
+	}
+	defer func() {
+		if e := out.Close(); e != nil {
+			err = e
+		}
+	}()
+
+	_, err = io.Copy(out, in)
+	if err != nil {
+		return
+	}
+
+	err = out.Sync()
+	if err != nil {
+		return
+	}
+
+	si, err := os.Stat(src)
+	if err != nil {
+		return
+	}
+	err = os.Chmod(dst, si.Mode())
+	if err != nil {
+		return
+	}
+
+	return
+}