constellation/cli/internal/cloudcmd/tfupgrade.go

/*
Copyright (c) Edgeless Systems GmbH

SPDX-License-Identifier: AGPL-3.0-only
*/

package cloudcmd

import (
	"context"
	"fmt"
	"io"
	"os"

	"github.com/edgelesssys/constellation/v2/cli/internal/terraform"
	"github.com/edgelesssys/constellation/v2/internal/file"
)

// planUpgrade prepares a workspace and plans the possible Terraform migrations.
// In case of possible migrations, the diff is written to outWriter and this function returns true.
func planUpgrade(
	ctx context.Context, tfClient tfUpgradePlanner, fileHandler file.Handler,
	outWriter io.Writer, logLevel terraform.LogLevel, vars terraform.Variables,
	templateDir, existingWorkspace, backupDir string,
) (bool, error) {
	if err := ensureFileNotExist(fileHandler, backupDir); err != nil {
		return false, fmt.Errorf("workspace is not clean: %w", err)
	}

	// Prepare the new Terraform workspace and backup the old one
	err := tfClient.PrepareUpgradeWorkspace(
		templateDir,
		existingWorkspace,
		backupDir,
		vars,
	)
	if err != nil {
		return false, fmt.Errorf("preparing terraform workspace: %w", err)
	}

	hasDiff, err := tfClient.Plan(ctx, logLevel)
	if err != nil {
		return false, fmt.Errorf("terraform plan: %w", err)
	}

	if hasDiff {
		if err := tfClient.ShowPlan(ctx, logLevel, outWriter); err != nil {
			return false, fmt.Errorf("terraform show plan: %w", err)
		}
	}

	return hasDiff, nil
}

// moveUpgradeToCurrent replaces the an existing Terraform workspace with a workspace holding migrated Terraform resources.
func moveUpgradeToCurrent(fileHandler file.Handler, existingWorkspace, upgradeWorkingDir string) error {
	if err := fileHandler.RemoveAll(existingWorkspace); err != nil {
		return fmt.Errorf("removing old terraform directory: %w", err)
	}
	if err := fileHandler.CopyDir(
		upgradeWorkingDir,
		existingWorkspace,
	); err != nil {
		return fmt.Errorf("replacing old terraform directory with new one: %w", err)
	}

	if err := fileHandler.RemoveAll(upgradeWorkingDir); err != nil {
		return fmt.Errorf("removing terraform upgrade directory: %w", err)
	}
	return nil
}

// ensureFileNotExist checks if a single file or directory does not exist, returning an error if it does.
func ensureFileNotExist(fileHandler file.Handler, fileName string) error {
	if _, err := fileHandler.Stat(fileName); err != nil {
		if !os.IsNotExist(err) {
			return fmt.Errorf("checking %q: %w", fileName, err)
		}
		return nil
	}
	return fmt.Errorf("%q already exists", fileName)
}