New hidden install-pipelines-cli command that creates pipelines symlink to databricks

acceptance/dlt/install-dlt/output.txt

@@ -0,0 +1,25 @@
+
+=== install dlt
+>>> errcode [CLI] install-dlt -o json
+dlt successfully installed in directory "[BUILD_DIR]"
+
+>>> [BUILD_DIR]/dlt
+DLT command verified
+
+=== dlt already installed
+>>> errcode [CLI] install-dlt
+dlt already installed in directory "[BUILD_DIR]"
+
+=== dlt file exists, should not overwrite
+>>> errcode [CLI] install-dlt -d tmpdir -o json
+cannot install dlt CLI: "tmpdir/dlt" already exists
+Error: installation failed
+
+Exit code: 1
+
+=== Executable not called as databricks
+>>> errcode ./notdatabricks install-dlt -o json
+dlt successfully installed in directory "[TEST_TMP_DIR]"
+
+>>> [TEST_TMP_DIR]/dlt
+DLT command verified

acceptance/dlt/install-dlt/script

@@ -0,0 +1,20 @@
+title "install dlt"
+dlt=$(trace errcode $CLI install-dlt -o json | jq -r .symlink_path)
+trace $dlt | head -n1 | grep -q "DLT CLI" && echo "DLT command verified" || echo "DLT command failed"
+
+title "dlt already installed"
+trace errcode $CLI install-dlt
+rm -f "$(dirname $CLI)/dlt"
+
+title "dlt file exists, should not overwrite"
+mkdir -p tmpdir
+touch tmpdir/dlt
+trace errcode $CLI install-dlt -d tmpdir -o json | jq -r .symlink_path
+rm -rf tmpdir
+
+title "Executable not called as databricks"
+cp $CLI notdatabricks
+dlt=$(trace errcode ./notdatabricks install-dlt -o json | jq -r .symlink_path)
+trace $dlt | head -n1 | grep -q "DLT CLI" && echo "DLT command verified" || echo "DLT command failed"
+rm -f notdatabricks
+rm -f dlt

acceptance/dlt/install-dlt/test.toml

@@ -0,0 +1,8 @@
+# Fix path with reverse slashes in the output for Windows.
+[[Repls]]
+Old = '\\\\'
+New = '/'
+
+[[Repls]]
+Old = '\\'
+New = '/'

cmd/cmd.go

@@ -9,6 +9,7 @@ import (
 	"github.com/databricks/cli/cmd/auth"
 	"github.com/databricks/cli/cmd/bundle"
 	"github.com/databricks/cli/cmd/configure"
+	"github.com/databricks/cli/cmd/dlt"
 	"github.com/databricks/cli/cmd/fs"
 	"github.com/databricks/cli/cmd/labs"
 	"github.com/databricks/cli/cmd/root"
@@ -106,6 +107,7 @@ func New(ctx context.Context) *cobra.Command {
 	cli.AddCommand(sync.New())
 	cli.AddCommand(version.New())
 	cli.AddCommand(selftest.New())
+	cli.AddCommand(dlt.InstallDLT())
 
 	// Add workspace command groups, filtering out empty groups or groups with only hidden commands.
 	allGroups := workspace.Groups()

cmd/dlt/dlt.go

@@ -0,0 +1,18 @@
+package dlt
+
+import (
+	"github.com/spf13/cobra"
+)
+
+func New() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "dlt",
+		Short: "DLT CLI",
+		Long:  "DLT CLI (stub, to be filled in)",
+		Run: func(cmd *cobra.Command, args []string) {
+			_ = cmd.Help()
+		},
+	}
+
+	return cmd
+}

cmd/dlt/install_dlt.go

@@ -0,0 +1,85 @@
+package dlt
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/databricks/cli/cmd/root"
+	"github.com/databricks/cli/libs/cmdio"
+	"github.com/databricks/cli/libs/flags"
+	"github.com/spf13/cobra"
+)
+
+type installDLTResponse struct {
+	SymlinkPath string `json:"symlink_path"`
+}
+
+func installDLTSymlink(directory string) (string, error) {
+	path, err := os.Executable()
+	if err != nil {
+		return "", err
+	}
+	realPath, err := filepath.EvalSymlinks(path)
+	if err != nil {
+		return "", err
+	}
+
+	dir := directory
+	if dir == "" {
+		dir = filepath.Dir(path)
+	}
+	dltPath := filepath.Join(dir, "dlt")
+
+	_, err = os.Lstat(dltPath)
+	if err != nil {
+		if !errors.Is(err, os.ErrNotExist) {
+			return "", err
+		}
+		err = os.Symlink(realPath, dltPath)
+		if err != nil {
+			return "", err
+		}
+		cmdio.LogString(context.Background(), fmt.Sprintf("dlt successfully installed in directory %q", dir))
+		return dltPath, nil
+	}
+
+	target, err := filepath.EvalSymlinks(dltPath)
+	if err != nil {
+		return "", err
+	}
+	if realPath == target {
+		cmdio.LogString(context.Background(), fmt.Sprintf("dlt already installed in directory %q", dir))
+		return dltPath, nil
+	}
+	cmdio.LogString(context.Background(), fmt.Sprintf("cannot install dlt CLI: %q already exists", dltPath))
+	return "", errors.New("installation failed")
+}
+
+func InstallDLT() *cobra.Command {
+	var directory string
+	cmd := &cobra.Command{
+		Use:    "install-dlt",
+		Short:  "Install DLT",
+		Hidden: true,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			dltPath, err := installDLTSymlink(directory)
+			if err != nil {
+				return err
+			}
+			response := installDLTResponse{
+				SymlinkPath: dltPath,
+			}
+			switch root.OutputType(cmd) {
+			case flags.OutputJSON:
+				return cmdio.Render(cmd.Context(), response)
+			default:
+				return nil
+			}
+		},
+	}
+	cmd.Flags().StringVarP(&directory, "directory", "d", "", "Directory in which to install dlt CLI (defaults to databricks CLI's directory)")
+	return cmd
+}

main.go

@@ -3,14 +3,30 @@ package main
 import (
 	"context"
 	"os"
+	"path/filepath"
+	"runtime"
 
 	"github.com/databricks/cli/cmd"
+	"github.com/databricks/cli/cmd/dlt"
 	"github.com/databricks/cli/cmd/root"
+	"github.com/spf13/cobra"
 )
 
+// If invoked as 'dlt' (or 'dlt.exe' on Windows), returns DLT-specific commands,
+// otherwise returns the databricks CLI commands. This is used to allow the same
+// binary to be used for both DLT and databricks CLI commands.
+func getCommand(ctx context.Context) *cobra.Command {
+	invokedAs := filepath.Base(os.Args[0])
+	if invokedAs == "dlt" || (runtime.GOOS == "windows" && invokedAs == "dlt.exe") {
+		return dlt.New()
+	}
+	return cmd.New(ctx)
+}
+
 func main() {
 	ctx := context.Background()
-	err := root.Execute(ctx, cmd.New(ctx))
+	command := getCommand(ctx)
+	err := root.Execute(ctx, command)
 	if err != nil {
 		os.Exit(1)
 	}