Add workspace pkg for managing local configuration

go.mod

@@ -14,6 +14,8 @@ require (
 	github.com/hinshun/vt10x v0.0.0-20180809195222-d55458df857c
 	github.com/onsi/ginkgo v1.10.1
 	github.com/onsi/gomega v1.7.0
+	github.com/pkg/errors v0.8.1 // indirect
+	github.com/spf13/afero v1.2.2
 	github.com/spf13/cobra v0.0.5
 	github.com/stretchr/testify v1.4.0
 	gopkg.in/yaml.v3 v3.0.0-20190905181640-827449938966

go.sum

@@ -77,6 +77,7 @@ github.com/onsi/gomega v1.7.0 h1:XPnZz8VVBHjVsy1vzJmRwIcSwiUO+JFfrv/xGiigmME=
 github.com/onsi/gomega v1.7.0/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1CpauHY=
 github.com/pelletier/go-toml v1.2.0 h1:T5zMGML61Wp+FlcbWjRDT7yAxhJNAiPPLOFECq181zc=
 github.com/pelletier/go-toml v1.2.0/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/94hg7ilaic=
+github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/rogpeppe/go-internal v1.1.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
@@ -87,6 +88,8 @@ github.com/sirupsen/logrus v1.4.2 h1:SPIRibHv4MatM3XXNO2BJeFLZwZ2LvZgfQ5+UNI2im4
 github.com/sirupsen/logrus v1.4.2/go.mod h1:tLMulIdttU9McNUspp0xgXVQah82FyeX6MwdIuYE2rE=
 github.com/spf13/afero v1.1.2 h1:m8/z1t7/fwjysjQRYbP0RD+bUIF/8tJwPdEZsI83ACI=
 github.com/spf13/afero v1.1.2/go.mod h1:j4pytiNVoe2o6bmDsKpLACNPDBIoEAkihy7loJ1B0CQ=
+github.com/spf13/afero v1.2.2 h1:5jhuqJyZCZf2JRofRvN/nIFgIWNzPa3/Vz8mYylgbWc=
+github.com/spf13/afero v1.2.2/go.mod h1:9ZxEEn6pIJ8Rxe320qSDBk6AsU0r9pR7Q4OcevTdifk=
 github.com/spf13/cast v1.3.0 h1:oget//CVOEoFewqQxwr0Ej5yjygnqGkvggSE/gB35Q8=
 github.com/spf13/cast v1.3.0/go.mod h1:Qx5cxh0v+4UWYiBimWS+eyWzqEqokIECu5etghLkUJE=
 github.com/spf13/cobra v0.0.5 h1:f0B+LkLX6DtmRH1isoNA9VTtNUK9K8xYd28JNNfOv/s=

internal/pkg/archer/workspace.go

@@ -0,0 +1,24 @@
+// Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package archer
+
+// WorkspaceSummary is a description of what's associated with this workspace.
+type WorkspaceSummary struct {
+	ProjectName string `yaml:"project"`
+}
+
+// Workspace can bootstrap a workspace with a manifest directory and workspace summary
+// and it can manage manifest files.
+type Workspace interface {
+	ManifestIO
+	Create(projectName string) error
+	Summary() (*WorkspaceSummary, error)
+}
+
+// ManifestIO can read, write and list local manifest files.
+type ManifestIO interface {
+	WriteManifest(manifestBlob []byte, applicationName string) error
+	ReadManifestFile(manifestFileName string) ([]byte, error)
+	ListManifestFiles() ([]string, error)
+}

internal/pkg/workspace/errors.go

@@ -0,0 +1,46 @@
+// Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package workspace
+
+import "fmt"
+
+// ErrWorkspaceNotFound means we couldn't locate a workspace root.
+type ErrWorkspaceNotFound struct {
+	CurrentDirectory      string
+	ManifestDirectoryName string
+	NumberOfLevelsChecked int
+}
+
+func (e *ErrWorkspaceNotFound) Error() string {
+	return fmt.Sprintf("couldn't find a directory called %s up to %d levels up from %s",
+		e.ManifestDirectoryName,
+		e.NumberOfLevelsChecked,
+		e.CurrentDirectory)
+}
+
+// ErrNoProjectAssociated means we couldn't locate a workspace summary file.
+type ErrNoProjectAssociated struct{}
+
+func (e *ErrNoProjectAssociated) Error() string {
+	return fmt.Sprint("couldn't find a project associated with this workspace")
+}
+
+// ErrWorkspaceHasExistingProject means we tried to create a workspace for a project
+// but it already belongs to another project.
+type ErrWorkspaceHasExistingProject struct {
+	ExistingProjectName string
+}
+
+func (e *ErrWorkspaceHasExistingProject) Error() string {
+	return fmt.Sprintf("this workspace is already registered with project %s", e.ExistingProjectName)
+}
+
+// ErrManifestNotFound means we we couldn't find a manifest in the manifest root.
+type ErrManifestNotFound struct {
+	ManifestName string
+}
+
+func (e *ErrManifestNotFound) Error() string {
+	return fmt.Sprintf("manifest file %s does not exists", e.ManifestName)
+}

internal/pkg/workspace/workspace.go

@@ -0,0 +1,234 @@
+// Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+// Package workspace contains the service to manage a user's local workspace. This includes
+// creating a manifest directory, reading and writing a summary file
+// to that directory and managing manifest files (reading, writing and listing).
+// The typical workspace will be structured like:
+//  .
+//  ├── ecs             (manifest directory)
+//  │   ├── .project    (workspace summary)
+//  │   └── my-app.yml  (manifest)
+//  └── my-app          (customer application)
+//
+package workspace
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/aws/PRIVATE-amazon-ecs-archer/internal/pkg/archer"
+	"github.com/spf13/afero"
+	"gopkg.in/yaml.v3"
+)
+
+const (
+	workspaceSummaryFileName  = ".project"
+	manifestDirectoryName     = "ecs"
+	maximumParentDirsToSearch = 5
+	manifestFileSuffix        = "-app.yml"
+)
+
+// Service manages a local workspace, including creating and managing manifest files.
+type Service struct {
+	workingDir  string
+	manifestDir string
+	fsUtils     *afero.Afero
+}
+
+// New returns a workspace Service, used for reading and writing to
+// user's local workspace.
+func New() (*Service, error) {
+	appFs := afero.NewOsFs()
+	fsUtils := &afero.Afero{Fs: appFs}
+
+	workingDir, err := os.Getwd()
+	if err != nil {
+		return nil, err
+	}
+	ws := Service{
+		workingDir: workingDir,
+		fsUtils:    fsUtils,
+	}
+
+	return &ws, nil
+}
+
+// Create creates the manifest directory (if it doesn't already exist) in
+// the current working directory, and saves a summary in the manifest
+// directory with the project name.
+func (ws *Service) Create(projectName string) error {
+	// Create a manifest directory, if one doesn't exist
+	if createDirErr := ws.createManifestDirectory(); createDirErr != nil {
+		return createDirErr
+	}
+
+	// Grab an existing workspace summary, if one exists.
+	existingWorkspaceSummary, existingWorkspaceSummaryErr := ws.Summary()
+
+	if existingWorkspaceSummaryErr == nil {
+		// If a summary exists, but is registered to a different project, throw an error.
+		if existingWorkspaceSummary.ProjectName != projectName {
+			return &ErrWorkspaceHasExistingProject{ExistingProjectName: existingWorkspaceSummary.ProjectName}
+		}
+		// Otherwise our work is all done.
+		return nil
+	}
+
+	// If there isn't an existing workspace summary, create it.
+	var noProjectFound *ErrNoProjectAssociated
+	if errors.As(existingWorkspaceSummaryErr, &noProjectFound) {
+		return ws.writeSummary(projectName)
+	}
+
+	return existingWorkspaceSummaryErr
+}
+
+// Summary returns a summary of the workspace - including the project name.
+func (ws *Service) Summary() (*archer.WorkspaceSummary, error) {
+	summaryPath, err := ws.summaryPath()
+	if err != nil {
+		return nil, err
+	}
+	summaryFileExists, err := ws.fsUtils.Exists(summaryPath)
+	if summaryFileExists {
+		value, err := ws.fsUtils.ReadFile(summaryPath)
+		if err != nil {
+			return nil, err
+		}
+		wsSummary := archer.WorkspaceSummary{}
+		return &wsSummary, yaml.Unmarshal(value, &wsSummary)
+	}
+	return nil, &ErrNoProjectAssociated{}
+}
+
+func (ws *Service) writeSummary(projectName string) error {
+	summaryPath, err := ws.summaryPath()
+	if err != nil {
+		return err
+	}
+
+	workspaceSummary := archer.WorkspaceSummary{
+		ProjectName: projectName,
+	}
+
+	serializedWorkspaceSummary, err := yaml.Marshal(workspaceSummary)
+
+	if err != nil {
+		return err
+	}
+	return ws.fsUtils.WriteFile(summaryPath, serializedWorkspaceSummary, 0644)
+}
+
+func (ws *Service) summaryPath() (string, error) {
+	manifestPath, err := ws.manifestDirectoryPath()
+	if err != nil {
+		return "", err
+	}
+	workspaceSummaryPath := filepath.Join(manifestPath, workspaceSummaryFileName)
+	return workspaceSummaryPath, nil
+}
+
+func (ws *Service) createManifestDirectory() error {
+	// First check to see if a manifest directory already exists
+	dirExists, err := ws.fsUtils.DirExists(filepath.Join(ws.workingDir, manifestDirectoryName))
+	if err != nil {
+		return err
+	}
+	// If a manifest directory doesn't exist, create it - otherwise fast succeed
+	if !dirExists {
+		return ws.fsUtils.Mkdir(manifestDirectoryName, 0755)
+	}
+	return nil
+}
+
+func (ws *Service) manifestDirectoryPath() (string, error) {
+	if ws.manifestDir != "" {
+		return ws.manifestDir, nil
+	}
+	// Are we in the manifest directory?
+	inEcsDir := filepath.Base(ws.workingDir) == manifestDirectoryName
+	if inEcsDir {
+		ws.manifestDir = ws.workingDir
+		return ws.manifestDir, nil
+	}
+
+	searchingDir := ws.workingDir
+	for try := 0; try < maximumParentDirsToSearch; try++ {
+		currentDirectoryPath := filepath.Join(searchingDir, manifestDirectoryName)
+		inCurrentDirPath, err := ws.fsUtils.DirExists(currentDirectoryPath)
+		if err != nil {
+			return "", err
+		}
+		if inCurrentDirPath {
+			ws.manifestDir = currentDirectoryPath
+			return ws.manifestDir, nil
+		}
+		searchingDir = filepath.Dir(searchingDir)
+	}
+	return "", &ErrWorkspaceNotFound{
+		CurrentDirectory:      ws.workingDir,
+		ManifestDirectoryName: manifestDirectoryName,
+		NumberOfLevelsChecked: maximumParentDirsToSearch,
+	}
+}
+
+// ListManifestFiles returns a list of all the local manifests filenames.
+func (ws *Service) ListManifestFiles() ([]string, error) {
+	manifestDir, err := ws.manifestDirectoryPath()
+	if err != nil {
+		return nil, err
+	}
+	manifestDirFiles, err := ws.fsUtils.ReadDir(manifestDir)
+	if err != nil {
+		return nil, err
+	}
+
+	var manifestFiles []string
+	for _, file := range manifestDirFiles {
+		if !file.IsDir() && strings.HasSuffix(file.Name(), manifestFileSuffix) {
+			manifestFiles = append(manifestFiles, file.Name())
+		}
+	}
+
+	return manifestFiles, nil
+}
+
+// ReadManifestFile takes in a manifest file (e.g. frontend-app.yml) and returns
+// the read bytes.
+func (ws *Service) ReadManifestFile(manifestFile string) ([]byte, error) {
+	manifestDirPath, err := ws.manifestDirectoryPath()
+	if err != nil {
+		return nil, err
+	}
+	manifestPath := filepath.Join(manifestDirPath, manifestFile)
+	manifestFileExists, err := ws.fsUtils.Exists(manifestPath)
+
+	if err != nil {
+		return nil, err
+	}
+
+	if !manifestFileExists {
+		return nil, &ErrManifestNotFound{ManifestName: manifestFile}
+	}
+
+	value, err := ws.fsUtils.ReadFile(manifestPath)
+	if err != nil {
+		return nil, err
+	}
+
+	return value, nil
+}
+
+// WriteManifest takes a manifest blob and writes it to the manifest directory.
+func (ws *Service) WriteManifest(manifestBlob []byte, applicationName string) error {
+	manifestPath, err := ws.manifestDirectoryPath()
+	if err != nil {
+		return err
+	}
+	manifestFileName := fmt.Sprintf("%s%s", applicationName, manifestFileSuffix)
+	return ws.fsUtils.WriteFile(filepath.Join(manifestPath, manifestFileName), manifestBlob, 0644)
+}