Refactor/config and logging (#5)

* config | Refactor about how to access configuration value
* logging | Refactor about how to get logger

Author: ardikabs

cmd/root.go

@@ -13,17 +13,9 @@ import (
 	"awssh/internal/logging"
 )
 
-var (
-	usePublicIP bool
-	appConfig   *config.Config
-)
-
 // MakeRoot used to create a root command functionality
 func MakeRoot() *cobra.Command {
-
-	appConfig = config.Get()
-
-	var command = &cobra.Command{
+	var cmd = &cobra.Command{
 		Use:   "awssh",
 		Short: "awssh is a simple CLI to ssh'ing EC2",
 		Long:  "awssh is a simple CLI providing an ssh access to EC2 utilizing ec2-instance-connect",
@@ -45,18 +37,11 @@ func MakeRoot() *cobra.Command {
 	`,
 	}
 
-	command.Args = cobra.MaximumNArgs(1)
-	command.Run = runSSHAccess
-
-	command.Flags().BoolVarP(&appConfig.Debug, "debug", "d", appConfig.Debug, "Enabled debug mode")
-	command.Flags().StringVar(&appConfig.Region, "region", appConfig.Region, "Default AWS region to be used. Either set AWS_REGION or AWS_DEFAULT_REGION")
-	command.Flags().StringVarP(&appConfig.Tags, "tags", "t", appConfig.Tags, "A comma-separated key-value pairs of EC2 tags. Ex: 'Name=ec2,Environment=staging'")
-	command.Flags().StringVarP(&appConfig.SSHUsername, "ssh-username", "u", appConfig.SSHUsername, "EC2 SSH username")
-	command.Flags().StringVarP(&appConfig.SSHPort, "ssh-port", "p", appConfig.SSHPort, "An EC2 instance ssh port")
-	command.Flags().StringVarP(&appConfig.SSHOpts, "ssh-opts", "o", appConfig.SSHOpts, "An additional ssh options")
-	command.Flags().BoolVarP(&usePublicIP, "use-public-ip", "", false, "Use public IP to access the EC2 instance")
+	cmd.Args = cobra.MaximumNArgs(1)
+	cmd.Run = runSSHAccess
 
-	return command
+	config.AddEC2AccessFlags(cmd.Flags())
+	return cmd
 }
 
 func validateInstanceIDArgs(args []string) (err error) {
@@ -70,7 +55,7 @@ func validateInstanceIDArgs(args []string) (err error) {
 }
 
 func runSSHAccess(cmd *cobra.Command, args []string) {
-	logging.NewLogger(appConfig.Debug)
+	logging.NewLogger(config.GetDebugMode())
 
 	err := validateInstanceIDArgs(args)
 
@@ -80,7 +65,7 @@ func runSSHAccess(cmd *cobra.Command, args []string) {
 
 	var target *aws.EC2Instance
 
-	session := aws.NewSession(appConfig.Region)
+	session := aws.NewSession(config.GetRegion())
 
 	if len(args) > 0 {
 		instances, err := aws.GetInstanceWithID(session, args[0])
@@ -90,7 +75,7 @@ func runSSHAccess(cmd *cobra.Command, args []string) {
 
 		target = instances[0]
 	} else {
-		instances, err := aws.GetInstanceWithTag(session, appConfig.Tags)
+		instances, err := aws.GetInstanceWithTag(session, config.GetEC2Tags())
 		if err != nil {
 			logging.ExitWithError(err)
 		}
@@ -101,7 +86,7 @@ func runSSHAccess(cmd *cobra.Command, args []string) {
 		}
 	}
 
-	err = target.Connect(usePublicIP)
+	err = target.Connect(config.GetUsePublicIP())
 	if err != nil {
 		logging.ExitWithError(err)
 	}

config/config.go

@@ -4,29 +4,71 @@ import (
 	"log"
 
 	"github.com/joeshaw/envdecode"
+	flag "github.com/spf13/pflag"
 )
 
 // Config represent the application configuration
-type Config struct {
+type config struct {
 	Debug       bool   `env:"AWSSH_DEBUG,default=0"`
-	Tags        string `env:"AWSS_TAGS,default=Name=*"`
+	Tags        string `env:"AWSSH_TAGS,default=Name=*"`
 	SSHUsername string `env:"AWSSH_SSH_USERNAME,default=ec2-user"`
 	SSHPort     string `env:"AWSSH_SSH_PORT,default=22"`
 	SSHOpts     string `env:"AWSSH_SSH_OPTS,default=-o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o ConnectTimeout=5"`
+	UsePublicIP bool   `env:"AWSSH_USE_PUBLIC_IP,default=0"`
 	Region      string `env:"AWS_DEFAULT_REGION"`
 }
 
-var appConfig Config
+var appConfig config
 
 // Load used to load the application configuration
 func Load() {
-
 	if err := envdecode.Decode(&appConfig); err != nil {
 		log.Fatal("Can't load config: ", err)
 	}
 }
 
-// Get used to get the application configuration
-func Get() *Config {
-	return &appConfig
+// AddEC2AccessFlags to populate flags used for accessing EC2
+func AddEC2AccessFlags(flagSet *flag.FlagSet) {
+	flagSet.BoolVarP(&appConfig.Debug, "debug", "d", appConfig.Debug, "Enabled debug mode")
+	flagSet.StringVar(&appConfig.Region, "region", appConfig.Region, "Default AWS region to be used. Either set AWS_REGION or AWS_DEFAULT_REGION")
+	flagSet.StringVarP(&appConfig.Tags, "tags", "t", appConfig.Tags, "A comma-separated key-value pairs of EC2 tags. Ex: 'Name=ec2,Environment=staging'")
+	flagSet.StringVarP(&appConfig.SSHUsername, "ssh-username", "u", appConfig.SSHUsername, "EC2 SSH username")
+	flagSet.StringVarP(&appConfig.SSHPort, "ssh-port", "p", appConfig.SSHPort, "An EC2 instance ssh port")
+	flagSet.StringVarP(&appConfig.SSHOpts, "ssh-opts", "o", appConfig.SSHOpts, "An additional ssh options")
+	flagSet.BoolVarP(&appConfig.UsePublicIP, "use-public-ip", "", appConfig.UsePublicIP, "Use public IP to access the EC2 instance")
+}
+
+// GetDebugMode get the debug mode flag
+func GetDebugMode() bool {
+	return appConfig.Debug
+}
+
+// GetRegion get AWS region
+func GetRegion() string {
+	return appConfig.Region
+}
+
+// GetEC2Tags get EC2 tags
+func GetEC2Tags() string {
+	return appConfig.Tags
+}
+
+// GetSSHUsername get SSH username
+func GetSSHUsername() string {
+	return appConfig.SSHUsername
+}
+
+// GetSSHPort get SSH port
+func GetSSHPort() string {
+	return appConfig.SSHPort
+}
+
+// GetSSHOpts get SSH optional argument
+func GetSSHOpts() string {
+	return appConfig.SSHOpts
+}
+
+// GetUsePublicIP get the flag to access EC2 for using public ip or not
+func GetUsePublicIP() bool {
+	return appConfig.UsePublicIP
 }

go.mod

@@ -9,6 +9,8 @@ require (
 	github.com/manifoldco/promptui v0.7.0
 	github.com/morikuni/aec v1.0.0
 	github.com/spf13/cobra v1.0.0
+	github.com/spf13/pflag v1.0.3
+	github.com/spf13/viper v1.4.0
 	go.uber.org/zap v1.10.0
 	golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2
 )

go.sum

@@ -28,6 +28,7 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
 github.com/dgryski/go-sip13 v0.0.0-20181026042036-e10d5fee7954/go.mod h1:vAd38F8PWV+bWy6jNmig1y/TA+kYO4g3RSRF0IAv0no=
+github.com/fsnotify/fsnotify v1.4.7 h1:IXs+QLmnXW2CcXuY+8Mzv/fWEsPGWxqefPtCP5CnV9I=
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
 github.com/ghodss/yaml v1.0.0/go.mod h1:4dBDuWmgqj2HViK6kFavaiC9ZROes6MMH2rRYeMEF04=
 github.com/go-kit/kit v0.8.0/go.mod h1:xBxKIO96dXMWWy0MnWVtmwkA9/13aqxPnvrjFYMA2as=
@@ -48,6 +49,7 @@ github.com/gorilla/websocket v1.4.0/go.mod h1:E7qHFY5m1UJ88s3WnNqhKjPHQ0heANvMoA
 github.com/grpc-ecosystem/go-grpc-middleware v1.0.0/go.mod h1:FiyG127CGDf3tlThmgyCl78X/SZQqEOJBCDaAfeWzPs=
 github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0/go.mod h1:8NvIoxWQoOIhqOTXgfV/d3M/q6VIi02HzZEHgUlZvzk=
 github.com/grpc-ecosystem/grpc-gateway v1.9.0/go.mod h1:vNeuVxBJEsws4ogUvrchl83t/GYV9WGTSLVdBhOQFDY=
+github.com/hashicorp/hcl v1.0.0 h1:0Anlzjpi4vEasTeNFn2mLJgTSwt0+6sfsiTG8qcWGx4=
 github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T20WEQ=
 github.com/inconshreveable/mousetrap v1.0.0 h1:Z8tu5sraLXCXIcARxBp/8cbvlwVa7Z1NHg9XEKhtSvM=
 github.com/inconshreveable/mousetrap v1.0.0/go.mod h1:PxqpIevigyE2G7u3NXJIT2ANytuPF1OarO4DADm73n8=
@@ -72,6 +74,7 @@ github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/lunixbochs/vtclean v0.0.0-20180621232353-2d01aacdc34a h1:weJVJJRzAJBFRlAiJQROKQs8oC9vOxvm4rZmBBk0ONw=
 github.com/lunixbochs/vtclean v0.0.0-20180621232353-2d01aacdc34a/go.mod h1:pHhQNgMf3btfWnGBVipUOjRYhoOsdGqdm/+2c2E2WMI=
+github.com/magiconair/properties v1.8.0 h1:LLgXmsheXeRoUOBOjtwPQCWIYqM/LU1ayDtDePerRcY=
 github.com/magiconair/properties v1.8.0/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
 github.com/manifoldco/promptui v0.7.0 h1:3l11YT8tm9MnwGFQ4kETwkzpAwY2Jt9lCrumCUW4+z4=
 github.com/manifoldco/promptui v0.7.0/go.mod h1:n4zTdgP0vr0S3w7/O/g98U+e0gwLScEXGwov2nIKuGQ=
@@ -81,11 +84,13 @@ github.com/mattn/go-isatty v0.0.4 h1:bnP0vzxcAdeI1zdubAl5PjU6zsERjGZb7raWodagDYs
 github.com/mattn/go-isatty v0.0.4/go.mod h1:M+lRXTBqGeGNdLjl/ufCoiOlB5xdOkqRJdNxMWT7Zi4=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
 github.com/mitchellh/go-homedir v1.1.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrkLzIz1N1q0pr0=
+github.com/mitchellh/mapstructure v1.1.2 h1:fmNYVwqnSfB9mZU6OS2O6GsXM+wcskZDuKQzvN1EDeE=
 github.com/mitchellh/mapstructure v1.1.2/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
 github.com/morikuni/aec v1.0.0 h1:nP9CBfwrvYnBRgY6qfDQkygYDmYwOilePFkwzv4dU8A=
 github.com/morikuni/aec v1.0.0/go.mod h1:BbKIizmSmc5MMPqRYbxO4ZU0S0+P200+tUnFx7PXmsc=
 github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
 github.com/oklog/ulid v1.3.1/go.mod h1:CirwcVhetQ6Lv90oh/F+FBtV6XMibvdAFo93nm5qn4U=
+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 v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
@@ -107,13 +112,17 @@ github.com/shurcooL/sanitized_anchor_name v1.0.0/go.mod h1:1NzhyTcUVG4SuEtjjoZeV
 github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
 github.com/soheilhy/cmux v0.1.4/go.mod h1:IM3LyeVVIOuxMH7sFAkER9+bJ4dT7Ms6E4xg4kGIyLM=
 github.com/spaolacci/murmur3 v0.0.0-20180118202830-f09979ecbc72/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
+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/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 v1.0.0 h1:6m/oheQuQ13N9ks4hubMG6BnvwOeaJrqSPLahSnczz8=
 github.com/spf13/cobra v1.0.0/go.mod h1:/6GTrnGXV9HjY+aR4k0oJ5tcvakLuG6EuKReYlHNrgE=
+github.com/spf13/jwalterweatherman v1.0.0 h1:XHEdyB+EcvlqZamSM4ZOMGlc93t6AcsBEu9Gc1vn7yk=
 github.com/spf13/jwalterweatherman v1.0.0/go.mod h1:cQK4TGJAtQXfYWX+Ddv3mKDzgVb68N+wFjFa4jdeBTo=
 github.com/spf13/pflag v1.0.3 h1:zPAT6CGy6wXeQ7NtTnaTerfKOsV6V6F8agHXFiazDkg=
 github.com/spf13/pflag v1.0.3/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
+github.com/spf13/viper v1.4.0 h1:yXHLWeravcrgGyFSyCgdYpXQ9dR9c/WED3pg1RhxqEU=
 github.com/spf13/viper v1.4.0/go.mod h1:PTJ7Z/lr49W6bUbkmS1V3by4uWynFiR9p7+dSq/yZzE=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=

internal/aws/aws.go

@@ -18,39 +18,31 @@ import (
 // in particularly when you need to use AWS_PROFILE located in ~/.aws/config
 // you need to set AWS_SDK_LOAD_CONFIG=1
 func NewSession(region string) (session *aws_session.Session) {
-	logger := logging.Get()
-
 	session = aws_session.Must(aws_session.NewSession(&aws.Config{
 		Region: aws.String(region),
 	}))
 
-	logger.Debugf("Region: %s", *session.Config.Region)
+	logging.Logger().Debugf("Region: %s", *session.Config.Region)
 
 	return
 }
 
 // GetInstanceWithID used to get instance with InstanceID input
 func GetInstanceWithID(session *aws_session.Session, instanceID string) (ec2Instances []*EC2Instance, err error) {
-
-	logger := logging.Get()
-
 	input := &ec2.DescribeInstancesInput{
 		InstanceIds: []*string{
 			aws.String(instanceID),
 		},
 	}
 
-	logger.Debugf("Filter EC2 instances with InstanceID: %s", instanceID)
+	logging.Logger().Debugf("Filter EC2 instances with InstanceID: %s", instanceID)
 	ec2Instances, err = getInstance(session, input)
 
 	return
 }
 
 // GetInstanceWithTag used to get instance with key-value pair tags input (ex: Environment=production,ProductDomain=VirtualProduct)
 func GetInstanceWithTag(session *aws_session.Session, tags string) (ec2Instances []*EC2Instance, err error) {
-
-	logger := logging.Get()
-
 	filters, err := prepareFilters(tags)
 
 	if err != nil {
@@ -61,7 +53,7 @@ func GetInstanceWithTag(session *aws_session.Session, tags string) (ec2Instances
 		Filters: filters,
 	}
 
-	logger.Debugf("Filter EC2 instances with tags: %s", tags)
+	logging.Logger().Debugf("Filter EC2 instances with tags: %s", tags)
 	ec2Instances, err = getInstance(session, input)
 
 	return
@@ -70,8 +62,6 @@ func GetInstanceWithTag(session *aws_session.Session, tags string) (ec2Instances
 // prepareFilters used to form a proper AWS filter tags format
 // from a raw tags input format
 func prepareFilters(rawTags string) (filters []*ec2.Filter, err error) {
-	logger := logging.Get()
-
 	awsTags := make(map[string][]*string)
 
 	splitTags := strings.Split(rawTags, ",")
@@ -103,17 +93,14 @@ func prepareFilters(rawTags string) (filters []*ec2.Filter, err error) {
 		filters = append(filters, f)
 	}
 
-	logger.Debugf("Use the following filters to filter EC2 instances: %v", filters)
+	logging.Logger().Debugf("Use the following filters to filter EC2 instances: %v", filters)
 
 	return
 }
 
 // getInstance handle the underlaying to gather the EC2 instances
 // following with the DescribeInstances method
 func getInstance(session *aws_session.Session, input *ec2.DescribeInstancesInput) (ec2Instances []*EC2Instance, err error) {
-
-	logger := logging.Get()
-
 	svc := ec2.New(session)
 	result, err := svc.DescribeInstances(input)
 
@@ -134,7 +121,7 @@ func getInstance(session *aws_session.Session, input *ec2.DescribeInstancesInput
 		}
 	}
 
-	logger.Debugf("Found %d EC2 instances on region %s", len(ec2Instances), *session.Config.Region)
+	logging.Logger().Debugf("Found %d EC2 instances on region %s", len(ec2Instances), *session.Config.Region)
 
 	return
 }

internal/aws/instance.go

@@ -57,18 +57,15 @@ func NewEC2Instance(session *aws_session.Session, instance *ec2.Instance) *EC2In
 // sendSSHPublicKey is an extend method to do ec2-instance-connect task
 // for sending SSH Public Key to the AWS API Server
 func (e *EC2Instance) sendSSHPublicKey(publicKey string) (err error) {
-	appConfig := config.Get()
-	logger := logging.Get()
-
 	svc := ec2instanceconnect.New(e.session)
 	input := &ec2instanceconnect.SendSSHPublicKeyInput{
 		InstanceId:       aws.String(e.InstanceID),
 		SSHPublicKey:     aws.String(publicKey),
-		InstanceOSUser:   aws.String(appConfig.SSHUsername),
+		InstanceOSUser:   aws.String(config.GetSSHUsername()),
 		AvailabilityZone: aws.String(e.AvailabilityZone),
 	}
 
-	logger.Debugf("Sending SSH Public Key for EC2 instance '%s' (%s)", e.Name, e.InstanceID)
+	logging.Logger().Debugf("Sending SSH Public Key for EC2 instance '%s' (%s)", e.Name, e.InstanceID)
 
 	_, err = svc.SendSSHPublicKey(input)
 	if err != nil {
@@ -103,10 +100,7 @@ func (e *EC2Instance) sendSSHPublicKey(publicKey string) (err error) {
 func (e *EC2Instance) Connect(usePublicIP bool) (err error) {
 	var ipAddr string
 
-	appConfig := config.Get()
-	logger := logging.Get()
-
-	logger.Debugf("Select EC2 instance '%s' (%s)", e.Name, e.InstanceID)
+	logging.Logger().Debugf("Select EC2 instance '%s' (%s)", e.Name, e.InstanceID)
 
 	sshSession, err := ssh.NewSession(e.InstanceID)
 
@@ -126,21 +120,21 @@ func (e *EC2Instance) Connect(usePublicIP bool) (err error) {
 			return fmt.Errorf("Could not find public IP for EC2 instance target '%s' (%s)", e.Name, e.InstanceID)
 		}
 
-		logger.Debugf("Use public IP to connect to the EC2 instance target '%s' (%s): %s", e.Name, e.InstanceID, e.PublicIP)
+		logging.Logger().Debugf("Use public IP to connect to the EC2 instance target '%s' (%s): %s", e.Name, e.InstanceID, e.PublicIP)
 		ipAddr = e.PublicIP
 	}
 
-	logger.Debugf("Establish an SSH connection to the EC2 instance target '%s' (%s)", e.Name, e.InstanceID)
+	logging.Logger().Debugf("Establish an SSH connection to the EC2 instance target '%s' (%s)", e.Name, e.InstanceID)
 
 	sshArgs := []string{
 		"-l",
-		appConfig.SSHUsername,
+		config.GetSSHUsername(),
 		"-p",
-		appConfig.SSHPort,
+		config.GetSSHPort(),
 		ipAddr,
 	}
 
-	sshOpts := strings.Split(appConfig.SSHOpts, " ")
+	sshOpts := strings.Split(config.GetSSHOpts(), " ")
 	sshArgs = append(sshArgs, sshOpts...)
 
 	fmt.Printf("Running command: ssh %s\n", strings.Join(sshArgs[:], " "))

internal/logging/logging.go

@@ -38,10 +38,10 @@ func NewLogger(debugMode bool) *zap.SugaredLogger {
 	return appLogger
 }
 
-// Get used to get the application logger
-func Get() *zap.SugaredLogger {
+// Logger used to get the application logger
+func Logger() (log *zap.SugaredLogger) {
 	defer appLogger.Sync() // nolint: errcheck
-	return appLogger
+	return
 }
 
 // ExitWithError will terminate execution with an error result