config.go

package main

import (
	"archive/zip"
	"bytes"
	"context"
	"crypto/md5"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"io/ioutil"
	"net/http"
	"os"
	"os/exec"
	"os/user"
	"path"
	"path/filepath"
	"reflect"
	"regexp"
	"strings"
	"time"

	"github.com/aws/aws-sdk-go-v2/aws"
	awsConfig "github.com/aws/aws-sdk-go-v2/config"
	"github.com/aws/aws-sdk-go-v2/credentials/stscreds"
	"github.com/aws/aws-sdk-go-v2/service/iam"
	"github.com/aws/aws-sdk-go-v2/service/ssm"
	"github.com/aws/aws-sdk-go-v2/service/sts"
	"github.com/blang/semver/v4"
	"github.com/coveooss/gotemplate/v3/collections"
	"github.com/fatih/color"
	"github.com/hashicorp/go-getter"
	"github.com/minio/selfupdate"
	yaml "gopkg.in/yaml.v2"
)

const (
	// ssm configuration
	defaultSSMParameterFolder = "/default/tgf"

	// ssm configuration used to fetch configs from a remote location
	remoteDefaultConfigPath       = "TGFConfig"
	remoteConfigLocationParameter = "config-location"
	remoteConfigPathsParameter    = "config-paths"

	// configuration files
	configFile     = ".tgf.config"
	userConfigFile = "tgf.user.config"

	tagSeparator = "-"
)

// TGFConfig contains the resulting configuration that will be applied
type TGFConfig struct {
	Image                   string            `yaml:"docker-image,omitempty" json:"docker-image,omitempty" hcl:"docker-image,omitempty"`
	ImageVersion            *string           `yaml:"docker-image-version,omitempty" json:"docker-image-version,omitempty" hcl:"docker-image-version,omitempty"`
	ImageTag                *string           `yaml:"docker-image-tag,omitempty" json:"docker-image-tag,omitempty" hcl:"docker-image-tag,omitempty"`
	ImageBuild              string            `yaml:"docker-image-build,omitempty" json:"docker-image-build,omitempty" hcl:"docker-image-build,omitempty"`
	ImageBuildFolder        string            `yaml:"docker-image-build-folder,omitempty" json:"docker-image-build-folder,omitempty" hcl:"docker-image-build-folder,omitempty"`
	ImageBuildTag           string            `yaml:"docker-image-build-tag,omitempty" json:"docker-image-build-tag,omitempty" hcl:"docker-image-build-tag,omitempty"`
	LogLevel                string            `yaml:"logging-level,omitempty" json:"logging-level,omitempty" hcl:"logging-level,omitempty"`
	EntryPoint              string            `yaml:"entry-point,omitempty" json:"entry-point,omitempty" hcl:"entry-point,omitempty"`
	Refresh                 time.Duration     `yaml:"docker-refresh,omitempty" json:"docker-refresh,omitempty" hcl:"docker-refresh,omitempty"`
	DockerOptions           []string          `yaml:"docker-options,omitempty" json:"docker-options,omitempty" hcl:"docker-options,omitempty"`
	RecommendedImageVersion string            `yaml:"recommended-image-version,omitempty" json:"recommended-image-version,omitempty" hcl:"recommended-image-version,omitempty"`
	RequiredVersionRange    string            `yaml:"required-image-version,omitempty" json:"required-image-version,omitempty" hcl:"required-image-version,omitempty"`
	RecommendedTGFVersion   string            `yaml:"tgf-recommended-version,omitempty" json:"tgf-recommended-version,omitempty" hcl:"tgf-recommended-version,omitempty"`
	Environment             map[string]string `yaml:"environment,omitempty" json:"environment,omitempty" hcl:"environment,omitempty"`
	RunBefore               string            `yaml:"run-before,omitempty" json:"run-before,omitempty" hcl:"run-before,omitempty"`
	RunAfter                string            `yaml:"run-after,omitempty" json:"run-after,omitempty" hcl:"run-after,omitempty"`
	Aliases                 map[string]string `yaml:"alias,omitempty" json:"alias,omitempty" hcl:"alias,omitempty"`
	UpdateVersion           string            `yaml:"update-version,omitempty" json:"update-version,omitempty" hcl:"update-version,omitempty"`
	AutoUpdateDelay         time.Duration     `yaml:"auto-update-delay,omitempty" json:"auto-update-delay,omitempty" hcl:"auto-update-delay,omitempty"`
	AutoUpdate              bool              `yaml:"auto-update,omitempty" json:"auto-update,omitempty" hcl:"auto-update,omitempty"`

	runBeforeCommands, runAfterCommands []string
	imageBuildConfigs                   []TGFConfigBuild // List of config built from previous build configs
	tgf                                 *TGFApplication
}

// TGFConfigBuild contains an entry specifying how to customize the current docker image
type TGFConfigBuild struct {
	Instructions string
	Folder       string
	Tag          string
	source       string
}

var (
	cachedAWSConfigExistCheck *bool
)

func resetCache() {
	cachedAWSConfigExistCheck = nil
	cachedAwsConfig = nil
}

func (cb TGFConfigBuild) hash() string {
	h := md5.New()
	io.WriteString(h, filepath.Base(filepath.Dir(cb.source)))
	io.WriteString(h, cb.Instructions)
	if cb.Folder != "" {
		filepath.Walk(cb.Dir(), func(path string, info os.FileInfo, err error) error {
			if info == nil || info.IsDir() || err != nil {
				return nil
			}
			if !strings.Contains(path, dockerfilePattern) {
				io.WriteString(h, fmt.Sprintf("%v", info.ModTime()))
			}
			return nil
		})
	}
	return fmt.Sprintf("%x", h.Sum(nil))
}

// Dir returns the folder name relative to the source
func (cb TGFConfigBuild) Dir() string {
	if cb.Folder == "" {
		return filepath.Dir(cb.source)
	}
	if filepath.IsAbs(cb.Folder) {
		return cb.Folder
	}
	return must(filepath.Abs(filepath.Join(filepath.Dir(cb.source), cb.Folder))).(string)
}

// GetTag returns the tag name that should be added to the image
func (cb TGFConfigBuild) GetTag() string {
	tag := cb.Tag
	if tag == "" {
		tag = fmt.Sprintf("%s-%s", filepath.Base(filepath.Dir(cb.source)), cb.hash())
	}
	tagRegex := regexp.MustCompile(`[^a-zA-Z0-9\._-]`)
	return tagRegex.ReplaceAllString(tag, "")
}

// InitConfig returns a properly initialized TGF configuration struct
func InitConfig(app *TGFApplication) *TGFConfig {
	config := TGFConfig{Image: "coveo/tgf",
		tgf:               app,
		Refresh:           1 * time.Hour,
		AutoUpdateDelay:   2 * time.Hour,
		AutoUpdate:        true,
		EntryPoint:        "terragrunt",
		LogLevel:          "notice",
		Environment:       make(map[string]string),
		imageBuildConfigs: []TGFConfigBuild{},
	}
	config.setDefaultValues()
	config.ParseAliases()
	return &config
}

func (config TGFConfig) String() string {
	bytes, err := yaml.Marshal(config)
	if err != nil {
		return fmt.Sprintf("Error parsing TGFConfig: %v", err)
	}
	return string(bytes)
}

var cachedAwsConfig *aws.Config

func (tgfConfig *TGFConfig) loadDefaultConfig(assumeRoleDuration time.Duration) (aws.Config, error) {
	log.Debugf("Creating new AWS config (assumeRoleDuration=%s)", assumeRoleDuration)
	return awsConfig.LoadDefaultConfig(
		context.TODO(),
		awsConfig.WithSharedConfigProfile(tgfConfig.tgf.AwsProfile),
		awsConfig.WithLogger(awsLogger),
		// The logger level controlled by the --aws-debug flag controls whether the logs are shown.
		// With that in mind, we just let the AWS SDK blindly log and rely on the logger to decide if it should print or not.
		awsConfig.WithClientLogMode(
			aws.LogRetries|
				aws.LogRequestWithBody|
				aws.LogRequestEventMessage|
				aws.LogResponseWithBody|
				aws.LogResponseEventMessage,
		),
		awsConfig.WithAssumeRoleCredentialOptions(func(o *stscreds.AssumeRoleOptions) {
			o.TokenProvider = stscreds.StdinTokenProvider
			if assumeRoleDuration > 0 {
				o.Duration = assumeRoleDuration
			}
		}),
	)
}

func (tgfConfig *TGFConfig) getAwsConfig(assumeRoleDuration time.Duration) (aws.Config, error) {
	if cachedAwsConfig != nil {
		log.Debug("Using cached AWS config")
		return *cachedAwsConfig, nil
	}

	config, err := tgfConfig.loadDefaultConfig(assumeRoleDuration)
	if err != nil {
		return config, err
	}

	log.Debug("Fetching credentials for current AWS config")
	creds, err := config.Credentials.Retrieve(context.TODO())
	if err != nil {
		return config, err
	}

	expiresIn := time.Until(creds.Expires)
	if creds.CanExpire && expiresIn < (1*time.Hour) {
		newDuration := guessAwsMaxAssumeRoleDuration(config)

		log.Warningf(
			"Credentials for current AWS session are set to expire in less than one hour (%s). Will extend to %s.",
			expiresIn,
			newDuration,
		)

		log.Warningf(
			color.WhiteString("You should consider defining %s in your AWS config profile %s"),
			color.HiBlueString("duration_seconds = %d", newDuration/time.Second),
			color.HiBlueString(getPrettyAwsProfileName(*tgfConfig)),
		)

		shortConfig := config
		config, err = tgfConfig.loadDefaultConfig(assumeRoleDuration)
		if err != nil {
			log.Warning("Failed to extend current AWS session, will use the current short duration.", err)
			config = shortConfig
		}
	}

	log.Debug("Caching newly created AWS config for future calls")
	cachedAwsConfig = &config

	return config, nil
}

func guessAwsMaxAssumeRoleDuration(awsConfig aws.Config) time.Duration {
	fallback := 1 * time.Hour
	log.Debugf("Trying to figure out the max duration of an AWS assume role operation (fallback=%s)", fallback)

	roleRegex := regexp.MustCompile(".*:assumed-role/(.*)/.*")

	identity, err := sts.NewFromConfig(awsConfig).GetCallerIdentity(context.TODO(), &sts.GetCallerIdentityInput{})
	if err != nil {
		log.Debug("Failed, using fallback:", err)
		return fallback
	}

	matches := roleRegex.FindStringSubmatch(*identity.Arn)
	if len(matches) == 0 {
		log.Debug("Failed, using fallback: Current role is not an assumed role")
		return fallback
	}

	role, err := iam.NewFromConfig(awsConfig).GetRole(
		context.TODO(),
		&iam.GetRoleInput{
			RoleName: &matches[1],
		},
	)
	if err != nil {
		log.Debug("Failed, using fallback:", err)
		return fallback
	}

	maxDuration := time.Duration(*role.Role.MaxSessionDuration) * time.Second
	log.Debugf("Max duration for current role (%s) is %s", *role.Role.Arn, maxDuration)
	return maxDuration
}

func getPrettyAwsProfileName(tgfConfig TGFConfig) string {
	if profile := tgfConfig.tgf.AwsProfile; profile != "" {
		return profile
	}

	if profile := os.Getenv("AWS_PROFILE"); profile != "" {
		return profile
	}

	return "default"
}

// InitAWS tries to open an AWS session and init AWS environment variable on success
func (config *TGFConfig) InitAWS() error {
	if config.tgf.AwsProfile == "" && os.Getenv("AWS_ACCESS_KEY_ID") != "" && os.Getenv("AWS_PROFILE") != "" {
		log.Warning("You set both AWS_ACCESS_KEY_ID and AWS_PROFILE, AWS_PROFILE will be ignored")
	}
	awsConfig, err := config.getAwsConfig(0)
	if err != nil {
		return err
	}
	creds, err := awsConfig.Credentials.Retrieve(context.TODO())
	if err != nil {
		return err
	}
	os.Unsetenv("AWS_PROFILE")
	os.Unsetenv("AWS_DEFAULT_PROFILE")
	for key, value := range map[string]string{
		"AWS_ACCESS_KEY_ID":     creds.AccessKeyID,
		"AWS_SECRET_ACCESS_KEY": creds.SecretAccessKey,
		"AWS_SESSION_TOKEN":     creds.SessionToken,
		"AWS_REGION":            awsConfig.Region,
	} {
		os.Setenv(key, value)
		if !config.tgf.ConfigDump {
			// If we are saving the current configuration, we do not want to save the current credentials
			config.Environment[key] = value
		}
	}
	return nil
}

// setDefaultValues sets the uninitialized values from the config files and the parameter store
// Priorities (Higher overwrites lower values):
// 1. Configuration location files
// 2. SSM Parameter Config
// 3. tgf.user.config
// 4. .tgf.config
func (config *TGFConfig) setDefaultValues() {
	app := config.tgf

	//app.PsPath, app.ConfigLocation, app.ConfigFiles
	type configData struct {
		Name   string
		Raw    string
		Config *TGFConfig
	}
	configsData := []configData{}

	// --config-dump output must not contain any logs to be valid YAML
	// so make sure logs go to stderr in this case
	if config.tgf.ConfigDump {
		log.SetStdout(os.Stdout)
	}

	// Fetch SSM configs
	if config.awsConfigExist() {
		if err := config.InitAWS(); err != nil {
			log.Fatal(err)
		}

		if app.ConfigLocation == "" {
			values := config.readSSMParameterStore(app.PsPath)
			app.ConfigLocation = values[remoteConfigLocationParameter]
			if app.ConfigFiles == "" {
				app.ConfigFiles = values[remoteConfigPathsParameter]
			}
		}
	}

	for _, configFile := range config.findRemoteConfigFiles(app.ConfigLocation, app.ConfigFiles) {
		configsData = append(configsData, configData{Name: "RemoteConfigFile", Raw: configFile})
	}

	if config.awsConfigExist() {
		// Only fetch SSM parameters if no ConfigFile was found
		if len(configsData) == 0 {
			ssmConfig := parseSsmConfig(config.readSSMParameterStore(app.PsPath))
			if ssmConfig != "" {
				configsData = append(configsData, configData{Name: "AWS/ParametersStore", Raw: ssmConfig})
			}
		}
	}

	// Fetch file configs
	for _, configFile := range config.findConfigFiles(must(os.Getwd()).(string)) {
		log.Debugln("Reading configuration from", configFile)
		bytes, err := ioutil.ReadFile(configFile)

		if err != nil {
			log.Errorf("Error while loading configuration file %s\n%v", configFile, err)
			continue
		}
		configsData = append(configsData, configData{Name: configFile, Raw: string(bytes)})
	}

	// Parse/Unmarshal configs
	for i := range configsData {
		configData := &configsData[i]
		if err := collections.ConvertData(configData.Raw, config); err != nil {
			log.Errorf("Error while loading configuration from %s\nConfiguration file must be valid YAML, JSON or HCL\n%v\nContent:\n%s", configData.Name, err, configData.Raw)
		}
		collections.ConvertData(configData.Raw, &configData.Config)
	}

	// Special case for image build configs and run before/after, we must build a list of instructions from all configs
	for i := range configsData {
		configData := &configsData[i]
		if configData.Config == nil {
			log.Errorf("Config from %s is nil. It did not load correctly", configData.Name)
			continue
		}
		if configData.Config.ImageBuild != "" {
			config.imageBuildConfigs = append([]TGFConfigBuild{{
				Instructions: configData.Config.ImageBuild,
				Folder:       configData.Config.ImageBuildFolder,
				Tag:          configData.Config.ImageBuildTag,
				source:       configData.Name,
			}}, config.imageBuildConfigs...)
		}
		if configData.Config.RunBefore != "" {
			config.runBeforeCommands = append(config.runBeforeCommands, configData.Config.RunBefore)
		}
		if configData.Config.RunAfter != "" {
			config.runAfterCommands = append(config.runAfterCommands, configData.Config.RunAfter)
		}
	}
	// We reverse the execution of before scripts to ensure that more specific commands are executed last
	config.runBeforeCommands = collections.AsList(config.runBeforeCommands).Reverse().Strings()
}

var reVersion = regexp.MustCompile(`(?P<version>\d+\.\d+(?:\.\d+){0,1})`)
var reVersionWithEndMarkers = regexp.MustCompile(`^` + reVersion.String() + `$`)

// https://regex101.com/r/ZKt4OP/5
var reImage = regexp.MustCompile(`^(?P<image>.*?)(?::(?:` + reVersion.String() + `(?:(?P<sep>[\.-])(?P<spec>.+))?|(?P<fix>.+)))?$`)

func (config *TGFConfig) validate() (errors []error) {
	if strings.Contains(config.Image, ":") {
		// It is possible that the : is there because we do not use a standard registry port, so we remove the port from the config.Image and
		// check again if there is still a : in the image name before returning a warning
		portRemoved := regexp.MustCompile(`.*:\d+/`).ReplaceAllString(config.Image, "")
		if strings.Contains(portRemoved, ":") {
			errors = append(errors, ConfigWarning(fmt.Sprintf("Image should not contain the version: %s", config.Image)))
		}
	}

	if config.ImageVersion != nil && strings.ContainsAny(*config.ImageVersion, ":-") {
		errors = append(errors, ConfigWarning(fmt.Sprintf("Image version parameter should not contain the image name nor the specialized version: %s", *config.ImageVersion)))
	}

	if config.ImageTag != nil && strings.ContainsAny(*config.ImageTag, ":") {
		errors = append(errors, ConfigWarning(fmt.Sprintf("Image tag parameter should not contain the image name: %s", *config.ImageTag)))
	}

	if config.RecommendedTGFVersion != "" && version != locallyBuilt {
		if valid, err := CheckVersionRange(version, config.RecommendedTGFVersion); err != nil {
			errors = append(errors, fmt.Errorf("unable to check recommended tgf version %s vs %s: %v", version, config.RecommendedTGFVersion, err))
		} else if !valid {
			errors = append(errors, ConfigWarning(fmt.Sprintf("TGF v%s does not meet the recommended version range %s", version, config.RecommendedTGFVersion)))
		}
	}

	if config.RequiredVersionRange != "" && config.ImageVersion != nil && *config.ImageVersion != "" && reVersion.MatchString(*config.ImageVersion) {
		if valid, err := CheckVersionRange(*config.ImageVersion, config.RequiredVersionRange); err != nil {
			errors = append(errors, fmt.Errorf("unable to check recommended image version %s vs %s: %v", *config.ImageVersion, config.RequiredVersionRange, err))
			return
		} else if !valid {
			errors = append(errors, VersionMistmatchError(fmt.Sprintf("Image %s does not meet the required version range %s", config.GetImageName(), config.RequiredVersionRange)))
			return
		}
	}

	if config.RecommendedImageVersion != "" && config.ImageVersion != nil && *config.ImageVersion != "" && reVersion.MatchString(*config.ImageVersion) {
		if valid, err := CheckVersionRange(*config.ImageVersion, config.RecommendedImageVersion); err != nil {
			errors = append(errors, fmt.Errorf("unable to check recommended image version %s vs %s: %v", *config.ImageVersion, config.RecommendedImageVersion, err))
		} else if !valid {
			errors = append(errors, ConfigWarning(fmt.Sprintf("Image %s does not meet the recommended version range %s", config.GetImageName(), config.RecommendedImageVersion)))
		}
	}

	return
}

// ValidateVersion ensures that the current version is compliant with the setting (mainly those in the parameter store1)
func (config *TGFConfig) ValidateVersion() bool {
	version := config.tgf.ImageVersion
	for _, err := range config.validate() {
		switch err := err.(type) {
		case ConfigWarning:
			log.Warning(err)
		case VersionMistmatchError:
			log.Error(err)
			if version == "-" {
				// We consider this as a fatal error only if the version has not been explicitly specified on the command line
				return false
			}
		default:
			log.Error(err)
			return false
		}
	}
	return true
}

// IsPartialVersion returns true if the given version is partial (x.x instead of semver's x.x.x)
func (config *TGFConfig) IsPartialVersion() bool {
	return config.ImageVersion != nil &&
		reVersionWithEndMarkers.MatchString(*config.ImageVersion) &&
		strings.Count(*config.ImageVersion, ".") == 1
}

// GetImageName returns the actual image name
func (config *TGFConfig) GetImageName() string {
	var suffix string
	if config.ImageVersion != nil {
		suffix += *config.ImageVersion
	}
	if config.ImageTag != nil {
		if suffix != "" && *config.ImageTag != "" {
			suffix += tagSeparator
		}
		suffix += *config.ImageTag
	}
	if len(suffix) > 1 {
		return fmt.Sprintf("%s:%s", config.Image, suffix)
	}
	return config.Image
}

// parseAliases will parse the original argument list and replace aliases only in the first argument.
func (config *TGFConfig) parseAliases(args []string) []string {
	if len(args) > 0 {
		if replace := String(config.Aliases[args[0]]); replace != "" {
			var result collections.StringArray
			replace, quoted := replace.Protect()
			result = replace.Fields()
			if len(quoted) > 0 {
				for i := range result {
					result[i] = result[i].RestoreProtected(quoted).ReplaceN(`="`, "=", 1).Trim(`"`)
				}
			}
			return append(config.parseAliases(result.Strings()), args[1:]...)
		}
	}
	return args
}

// ParseAliases checks if the actual command matches an alias and set the options according to the configuration
func (config *TGFConfig) ParseAliases() {
	args := config.tgf.Unmanaged
	if alias := config.parseAliases(args); len(alias) > 0 && len(args) > 0 && alias[0] != args[0] {
		config.tgf.Unmanaged = nil
		must(config.tgf.Application.Parse(alias))
	}
}

func (config *TGFConfig) readSSMParameterStore(ssmParameterFolder string) map[string]string {
	values := make(map[string]string)
	awsConfig, err := config.getAwsConfig(0)
	log.Debugf("Reading configuration from SSM %s in %s", ssmParameterFolder, awsConfig.Region)
	if err != nil {
		log.Warningf("Caught an error while creating an AWS session: %v", err)
		return values
	}
	svc := ssm.NewFromConfig(awsConfig)
	response, err := svc.GetParametersByPath(context.TODO(), &ssm.GetParametersByPathInput{
		Path:           aws.String(ssmParameterFolder),
		Recursive:      aws.Bool(true),
		WithDecryption: aws.Bool(true),
	})
	if err != nil {
		log.Warningf("Caught an error while reading from `%s` in SSM: %v", ssmParameterFolder, err)
		return values
	}
	for _, parameter := range response.Parameters {
		key := strings.TrimLeft(strings.Replace(*parameter.Name, ssmParameterFolder, "", 1), "/")
		values[key] = *parameter.Value
	}
	return values
}

func (config *TGFConfig) findRemoteConfigFiles(location, files string) []string {
	if location == "" {
		return []string{}
	}

	if !strings.HasSuffix(location, "/") {
		location += "/"
	}

	if files == "" {
		files = remoteDefaultConfigPath
	}
	configPaths := strings.Split(files, ":")

	tempDir := must(ioutil.TempDir("", "tgf-config-files")).(string)
	defer os.RemoveAll(tempDir)

	configs := []string{}
	for _, configPath := range configPaths {
		fullConfigPath := location + configPath
		destConfigPath := path.Join(tempDir, configPath)
		log.Debugln("Reading configuration from", fullConfigPath)
		source := must(getter.Detect(fullConfigPath, must(os.Getwd()).(string), getter.Detectors)).(string)

		err := getter.GetFile(destConfigPath, source)
		if err == nil {
			_, err = os.Stat(destConfigPath)
			if os.IsNotExist(err) {
				err = errors.New("config file was not found at the source")
			}
		}

		if err != nil {
			log.Warningf("Error fetching config at %s: %v", source, err)
			continue
		}

		if content, err := ioutil.ReadFile(destConfigPath); err != nil {
			log.Warningf("Error reading fetched config file %s: %v", configPath, err)
		} else {
			contentString := string(content)
			if contentString != "" {
				configs = append(configs, contentString)
			}
		}
	}

	return configs
}

func parseSsmConfig(parameterValues map[string]string) string {
	ssmConfig := ""
	for key, value := range parameterValues {
		isDict := strings.HasPrefix(value, "{") && strings.HasSuffix(value, "}")
		isList := strings.HasPrefix(value, "[") && strings.HasSuffix(value, "]")
		if !isDict && !isList {
			value = fmt.Sprintf("\"%s\"", value)
		}
		ssmConfig += fmt.Sprintf("%s: %s\n", key, value)
	}
	return ssmConfig
}

// Check if there is an AWS configuration available.
//
// We call this function before trying to init an AWS session. This avoid trying to init a session in a non AWS context
// and having to wait for metadata resolution or generating an error.
func (config TGFConfig) awsConfigExist() (result bool) {
	if cachedAWSConfigExistCheck != nil {
		return *cachedAWSConfigExistCheck
	}
	defer func() { cachedAWSConfigExistCheck = &result }()
	app := config.tgf
	if !app.UseAWS {
		log.Debugln("Not trying to read the config from AWS. It is disabled")
		return false
	}

	log.Debugln("Checking if the TGF configuration should be read from AWS SSM. This will happen if any of the following are true:")

	environmentVariablesExist := os.Getenv("AWS_PROFILE")+os.Getenv("AWS_ACCESS_KEY_ID")+os.Getenv("AWS_CONFIG_FILE")+os.Getenv("TGF_USE_AWS_CONFIG") != ""
	log.Debugln(" - One of these env variables exist (AWS_PROFILE, AWS_ACCESS_KEY_ID, AWS_CONFIG_FILE, TGF_USE_AWS_CONFIG):", environmentVariablesExist)
	if environmentVariablesExist {
		// If any AWS identification variable is defined, we consider that we are in an AWS environment.
		return true
	}

	_, err := exec.LookPath("aws")
	awsCliIsInstalled := err == nil
	log.Debugln(" - The AWS CLI is installed:", awsCliIsInstalled)
	if awsCliIsInstalled {
		// If aws program is installed, we also consider that we are in an AWS environment.
		return true
	}

	// Otherwise, we check if the current user has a folder named .aws defined under its home directory.
	awsFolderExists := false
	if currentUser, _ := user.Current(); currentUser != nil {
		if awsFolder, err := os.Stat(filepath.Join(currentUser.HomeDir, ".aws")); err == nil {
			awsFolderExists = awsFolder.IsDir()
		}
	}
	log.Debugln(" - The ~/.aws folder exists:", awsFolderExists)

	return awsFolderExists
}

// Return the list of configuration files found from the current working directory up to the root folder
func (config TGFConfig) findConfigFiles(folder string) (result []string) {
	app := config.tgf
	configFiles := []string{userConfigFile, configFile}
	if app.DisableUserConfig {
		configFiles = []string{configFile}
	}
	for _, file := range configFiles {
		file = filepath.Join(folder, file)
		if _, err := os.Stat(file); !os.IsNotExist(err) {
			result = append(result, file)
		}
	}

	if parent := filepath.Dir(folder); parent != folder {
		result = append(config.findConfigFiles(parent), result...)
	}

	return
}

func getTgfConfigFields() []string {
	fields := []string{}
	classType := reflect.ValueOf(TGFConfig{}).Type()
	for i := 0; i < classType.NumField(); i++ {
		tagValue := classType.Field(i).Tag.Get("yaml")
		if tagValue != "" {
			fields = append(fields, color.GreenString(strings.Replace(tagValue, ",omitempty", "", -1)))
		}
	}
	return fields
}

// CheckVersionRange compare a version with a range of values
// Check https://github.com/blang/semver/blob/master/README.md for more information
func CheckVersionRange(version, compare string) (bool, error) {
	if strings.Count(version, ".") == 1 {
		version = version + ".9999" // Patch is irrelevant if major and minor are OK
	}
	v, err := semver.Make(version)
	if err != nil {
		return false, err
	}

	comp, err := semver.ParseRange(compare)
	if err != nil {
		return false, err
	}

	return comp(v), nil
}

// ConfigWarning is used to represent messages that should not be considered as critical error
type ConfigWarning string

func (e ConfigWarning) Error() string {
	return string(e)
}

// VersionMistmatchError is used to describe an out of range version
type VersionMistmatchError string

func (e VersionMistmatchError) Error() string {
	return string(e)
}

// Restart re-run the app with all the arguments passed
func (config *TGFConfig) Restart() int {
	cmd := exec.Command(os.Args[0], os.Args[1:]...)
	cmd.Stdin, cmd.Stdout, cmd.Stderr = os.Stdin, os.Stdout, os.Stderr
	if err := cmd.Run(); err != nil {
		log.Errorln("Error on restart:", err)
		return 1
	}
	return 0
}

// GetUpdateVersion fetches the latest tgf version number from the GITHUB_API
func (config *TGFConfig) GetUpdateVersion() (string, error) {
	if config.UpdateVersion != "" {
		// The target version number has been specified in the configuration to avoid
		// hammering GitHub
		return config.UpdateVersion, nil
	}
	resp, err := http.Get("https://api.github.com/repos/coveooss/tgf/releases/latest")
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()

	var jsonResponse map[string]string
	json.NewDecoder(resp.Body).Decode(&jsonResponse)
	latestVersion := jsonResponse["tag_name"]
	if latestVersion == "" {
		return "", errors.New("Error parsing json response")
	}
	return latestVersion[1:], nil
}

// ShouldUpdate evaluate wether tgf updater should run or not depending on cli options and config file
func (config *TGFConfig) ShouldUpdate() bool {
	app := config.tgf
	if app.AutoUpdateSet {
		if app.AutoUpdate {
			if version == locallyBuilt {
				version = "0.0.0"
				log.Debug("Auto update is forced locally. Checking version...")
			} else {
				log.Debug("Auto update is forced. Checking version...")
			}
		} else {
			log.Debug("Auto update is force disabled. Bypassing update version check.")
			return false
		}
	} else {
		if !config.AutoUpdate {
			log.Debug("Auto update is disabled in the config. Bypassing update version check.")
			return false
		} else if config.GetLastRefresh(autoUpdateFile) < config.AutoUpdateDelay {
			log.Debugf("Less than %v since last check. Bypassing update version check.", config.AutoUpdateDelay.String())
			return false
		} else {
			if version == locallyBuilt {
				log.Debug("Running locally. Bypassing update version check.")
				return false
			}
			log.Debug("An update is due. Checking version...")
		}
	}

	return true
}

func (config *TGFConfig) getTgfFile(url string) (tgfFile io.ReadCloser, err error) {
	// request the new zip file
	resp, err := http.Get(url)
	if err != nil {
		return
	} else if resp.StatusCode != 200 {
		err = fmt.Errorf("HTTP status error %v", resp.StatusCode)
		return
	}
	defer resp.Body.Close()

	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return
	}

	zipReader, err := zip.NewReader(bytes.NewReader(body), int64(len(body)))
	if err != nil {
		return
	}

	tgfFile, err = zipReader.File[0].Open()
	if err != nil {
		log.Errorln("Failed to read new version rollback from bad update:", err)
		return
	}
	return
}

// DoUpdate fetch the executable from the link, unzip it and replace it with the current
func (config *TGFConfig) DoUpdate(url string) (err error) {
	savePath, err := ioutil.TempFile("", "tgf.previous-version")
	if err != nil {
		return
	}

	tgfFile, err := config.getTgfFile(url)
	if err != nil {
		return
	}

	if err = selfupdate.Apply(tgfFile, selfupdate.Options{OldSavePath: savePath.Name()}); err != nil {
		if err := selfupdate.RollbackError(err); err != nil {
			log.Errorln("Failed to rollback from bad update:", err)
		}
	}
	return
}

// GetLastRefresh get the lastime the tgf update file was updated
func (config *TGFConfig) GetLastRefresh(autoUpdateFile string) time.Duration {
	return lastRefresh(autoUpdateFile)
}

// SetLastRefresh set the lastime the tgf update file was updated
func (config *TGFConfig) SetLastRefresh(autoUpdateFile string) {
	touchImageRefresh(autoUpdateFile)
}