constellation/cli/internal/cloudcmd/tfplan.go
Daniel Weiße 625dc26644
cli: unify cloudcmd create and upgrade code (#2513)
* Unify cloudcmd create and upgrade code
* Make libvirt runner code a bit more idempotent

---------

Signed-off-by: Daniel Weiße <dw@edgeless.systems>
2023-10-31 12:46:40 +01:00

97 lines
2.8 KiB
Go

/*
Copyright (c) Edgeless Systems GmbH
SPDX-License-Identifier: AGPL-3.0-only
*/
package cloudcmd
import (
"context"
"errors"
"fmt"
"io"
"os"
"github.com/edgelesssys/constellation/v2/cli/internal/terraform"
"github.com/edgelesssys/constellation/v2/internal/file"
)
// plan prepares a workspace and plans the possible Terraform actions.
// This will either create a new workspace or update an existing one.
// In case of possible migrations, the diff is written to outWriter and this function returns true.
func plan(
ctx context.Context, tfClient tfPlanner, fileHandler file.Handler,
outWriter io.Writer, logLevel terraform.LogLevel, vars terraform.Variables,
templateDir, existingWorkspace, backupDir string,
) (bool, error) {
isNewWorkspace, err := fileHandler.IsEmpty(existingWorkspace)
if err != nil {
if !errors.Is(err, os.ErrNotExist) {
return false, fmt.Errorf("checking if workspace is empty: %w", err)
}
isNewWorkspace = true
}
// Backup old workspace if it exists
if !isNewWorkspace {
if err := ensureFileNotExist(fileHandler, backupDir); err != nil {
return false, fmt.Errorf("backup directory %s already exists: %w", backupDir, err)
}
if err := fileHandler.CopyDir(existingWorkspace, backupDir); err != nil {
return false, fmt.Errorf("backing up old workspace: %w", err)
}
}
// Move the new embedded Terraform files into the workspace.
if err := tfClient.PrepareWorkspace(templateDir, vars); 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 we are planning in a new workspace, we don't want to show a diff
if isNewWorkspace {
return false, nil
}
if hasDiff {
if err := tfClient.ShowPlan(ctx, logLevel, outWriter); err != nil {
return false, fmt.Errorf("terraform show plan: %w", err)
}
}
return hasDiff, nil
}
// restoreBackup replaces the existing Terraform workspace with the backup.
func restoreBackup(fileHandler file.Handler, workingDir, backupDir string) error {
if err := fileHandler.RemoveAll(workingDir); err != nil {
return fmt.Errorf("removing existing workspace: %w", err)
}
if err := fileHandler.CopyDir(
backupDir,
workingDir,
); err != nil {
return fmt.Errorf("replacing terraform workspace with backup: %w", err)
}
if err := fileHandler.RemoveAll(backupDir); err != nil {
return fmt.Errorf("removing backup 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)
}