Release 0.2.0 (#4)

* Merge branch 'develop' of github.com:darkraiden/sigmund into develop

# Conflicts:
#	.gitignore
#	go.mod
#	pkg/autoscaling/execPolicy.go

* add salvatore to contributors

* add changelog

.gitignore

@@ -1,2 +1,2 @@
-/.vscode
-/vendor
+.vscode
+vendor

CHANGELOG.md

@@ -0,0 +1,9 @@
+## 0.2.0 (May 29, 2019)
+
+ADDITIONS:
+
+-   checks if either `Memory` or `CPU` are in an `OK` state, rather than just `Low`
+
+CHANGES:
+
+-   Minor code improvements

contributors.md

@@ -1 +1,2 @@
 -   [Davide Di Mauro](https://github.com/darkraiden)
+-   [Salvatore Tards](https://github.com/Stakct)

go.mod

@@ -3,5 +3,5 @@ module github.com/darkraiden/sigmund
 require (
 	github.com/aws/aws-lambda-go v1.8.0
 	github.com/aws/aws-sdk-go v1.15.89
-	github.com/jmespath/go-jmespath v0.0.0-20160202185014-0b12d6b521d8
+	github.com/sirupsen/logrus v1.4.2
 )

go.sum

@@ -2,5 +2,18 @@ github.com/aws/aws-lambda-go v1.8.0 h1:YMCzi9FP7MNVVj9AkGpYyaqh/mvFOjhqiDtnNlWtK
 github.com/aws/aws-lambda-go v1.8.0/go.mod h1:zUsUQhAUjYzR8AuduJPCfhBuKWUaDbQiPOG+ouzmE1A=
 github.com/aws/aws-sdk-go v1.15.89 h1:T5xLl6ePbLhTdKWoeRhwIV58OfXPSLu2s4GMNDpRLu0=
 github.com/aws/aws-sdk-go v1.15.89/go.mod h1:es1KtYUFs7le0xQ3rOihkuoVD90z7D0fR2Qm4S00/gU=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/jmespath/go-jmespath v0.0.0-20160202185014-0b12d6b521d8 h1:12VvqtR6Aowv3l/EQUlocDHW2Cp4G9WJVH7uyH8QFJE=
 github.com/jmespath/go-jmespath v0.0.0-20160202185014-0b12d6b521d8/go.mod h1:Nht3zPeWKUH0NzdCt2Blrr5ys8VGpn0CEB0cQHVjt7k=
+github.com/konsorten/go-windows-terminal-sequences v1.0.1 h1:mweAR1A6xJ3oS2pRaGiHgQ4OO8tzTaLawm8vnODuwDk=
+github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
+github.com/magefile/mage v1.8.0/go.mod h1:IUDi13rsHje59lecXokTfGX0QIzO45uVPlXnJYsXepA=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/sirupsen/logrus v1.4.2 h1:SPIRibHv4MatM3XXNO2BJeFLZwZ2LvZgfQ5+UNI2im4=
+github.com/sirupsen/logrus v1.4.2/go.mod h1:tLMulIdttU9McNUspp0xgXVQah82FyeX6MwdIuYE2rE=
+github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+golang.org/x/net v0.0.0-20181207154023-610586996380/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/sys v0.0.0-20190422165155-953cdadca894 h1:Cz4ceDQGXuKRnVBDTS23GTn/pU5OE2C0WrNTOYK1Uuc=
+golang.org/x/sys v0.0.0-20190422165155-953cdadca894/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=

metrics.go

@@ -1,19 +1,65 @@
 package sigmund
 
 import (
-	"fmt"
+	log "github.com/sirupsen/logrus"
 )
 
-func identifyMetric(m string) (string, error) {
-	var k string
-	var err error
-	switch {
-	case m == "memory":
-		k = "isLowMemory"
-	case m == "cpu":
-		k = "isLowCPU"
-	default:
-		err = fmt.Errorf("%v is an invalid parameter. Please provide either 'memory' or 'cpu' keys", m)
+// Metric is a type that will be used to serialise the metric types received from SNS
+type Metric int
+
+type dbKey struct {
+	metric string
+	value  bool
+}
+
+const (
+	// LowMemory is a metric that indicates low memory
+	LowMemory Metric = iota
+	// LowCPU is a metric that indicates low CPU
+	LowCPU
+	// OkMemory is a metric that indicates the absence of memory issues
+	OkMemory
+	// OkCPU is a metric that indicates the absence of CPU issues
+	OkCPU
+)
+
+var stringsToMetrics = map[string]Metric{
+	"LowMemory": LowMemory,
+	"LowCPU":    LowCPU,
+	"OkMemory":  OkMemory,
+	"OkCPU":     OkCPU,
+}
+
+func (m Metric) String() string {
+	metricNames := [...]string{
+		"LowMemory",
+		"LowCPU",
+		"OkMemory",
+		"OkCPU",
+	}
+
+	if m < 0 || m > 3 {
+		log.WithField("integer", m).Panic("Value cannot be interpreted as a metric")
 	}
-	return k, err
+
+	return metricNames[m]
+}
+
+var metricsTodbKey = map[Metric]dbKey{
+	LowMemory: {
+		metric: "isLowMemory",
+		value:  true,
+	},
+	LowCPU: {
+		metric: "isLowCPU",
+		value:  true,
+	},
+	OkMemory: {
+		metric: "isLowMemory",
+		value:  false,
+	},
+	OkCPU: {
+		metric: "isLowCPU",
+		value:  false,
+	},
 }

pkg/autoscaling/errorHandlers.go

@@ -0,0 +1,28 @@
+package autoscaling
+
+import (
+	"fmt"
+
+	"github.com/aws/aws-sdk-go/aws/awserr"
+	"github.com/aws/aws-sdk-go/service/autoscaling"
+)
+
+func checkAutoscalingError(err error) error {
+	if err != nil {
+		if aerr, ok := err.(awserr.Error); ok {
+			switch aerr.Code() {
+			case autoscaling.ErrCodeScalingActivityInProgressFault:
+				return fmt.Errorf("%v: %v", autoscaling.ErrCodeScalingActivityInProgressFault, aerr.Error())
+			case autoscaling.ErrCodeResourceContentionFault:
+				return fmt.Errorf("%v: %v", autoscaling.ErrCodeResourceContentionFault, aerr.Error())
+			default:
+				return fmt.Errorf("%v", aerr.Error())
+			}
+		} else {
+			// Print the error, cast err to awserr.Error to get the Code and
+			// Message from an error.
+			return err
+		}
+	}
+	return nil
+}

pkg/autoscaling/execPolicy.go

@@ -4,7 +4,6 @@ import (
 	"fmt"
 
 	"github.com/aws/aws-sdk-go/aws"
-	"github.com/aws/aws-sdk-go/aws/awserr"
 	"github.com/aws/aws-sdk-go/service/autoscaling"
 )
 
@@ -16,30 +15,9 @@ func (client *Client) TriggerPolicy(asg *Autoscaling) error {
 		PolicyName:           aws.String(asg.PolicyName),
 	}
 
-	_, err := client.ExecutePolicy(input)
+	result, err := client.ExecutePolicy(input)
 	awsErr := checkAutoscalingError(err)
 
+	fmt.Println(result)
 	return awsErr
 }
-
-func checkAutoscalingError(err error) error {
-	if err != nil {
-		if aerr, ok := err.(awserr.Error); ok {
-			switch aerr.Code() {
-			case autoscaling.ErrCodeScalingActivityInProgressFault:
-				return fmt.Errorf("%v: %v", autoscaling.ErrCodeScalingActivityInProgressFault, aerr.Error())
-			case autoscaling.ErrCodeResourceContentionFault:
-				return fmt.Errorf("%v: %v", autoscaling.ErrCodeResourceContentionFault, aerr.Error())
-			default:
-				return fmt.Errorf("%v", aerr.Error())
-			}
-		} else {
-			// Print the error, cast err to awserr.Error to get the Code and
-			// Message from an error.//^
-			//I would probably rewrite this to make the default be to return error and handle the specific cases you're interested in here.
-			//Wrapping a switch in an if is tough to read.
-			return err
-		}
-	}
-	return nil
-}

shrinker.go

@@ -1,61 +1,83 @@
 package sigmund
 
 import (
+	log "github.com/sirupsen/logrus"
+
 	"github.com/darkraiden/sigmund/pkg/autoscaling"
 	"github.com/darkraiden/sigmund/pkg/storage/dynamo"
 )
 
 // Shrink is the core function of the package
 // which Executes an Autoscaling Group Policy
 // when requirements are met
-func (s *Sigmund) Shrink() error {
-	var item *DBItem
-	dbClient, err := s.newDBClient()
+func (s *Sigmund) Shrink() {
+	dbClient, err := s.newDBClient(metricsTodbKey[s.Key].metric)
+  
 	if err != nil {
-		return err
+		s.Log.WithError(err).Panic("Could not connect to DynamoDB")
 	}
 
 	// Run a Select query
 	item, err = s.readDynamo(dbClient)
 	if err != nil {
-		return err
+		s.Log.WithError(err).Panic("Could not read from DynamoDB")
 	}
 
-	switch s.Dynamo.Key {
-	case "isLowCPU":
-		if !item.IsLowCPU {
-			err = dbClient.WriteToTable(s.Dynamo.TableName, s.Dynamo.Key, true)
-			if err != nil {
-				return err
-			}
-			item.IsLowCPU = true
+	switch s.Dynamo.Key.String() {
+	case "LowMemory":
+		err := dbClient.WriteToTable(s.Dynamo.TableName, "isLowMemory", true)
+		if err != nil {
+			s.Log.WithError(err).WithFields(log.Fields{
+				"table name": s.Dynamo.TableName,
+				"metric":     "isLowMemory == true",
+			}).Panic()
+		}
+		item.IsLowMemory = true
+	case "OkMemory":
+		err := dbClient.WriteToTable(s.Dynamo.TableName, "isLowMemory", false)
+		if err != nil {
+			s.Log.WithError(err).WithFields(log.Fields{
+				"table name": s.Dynamo.TableName,
+				"metric":     "isLowMemory == false",
+			}).Panic()
 		}
-	case "isLowMemory":
-		if !item.IsLowMemory {
-			err = dbClient.WriteToTable(s.Dynamo.TableName, s.Dynamo.Key, true)
-			if err != nil {
-				return err
-			}
-			item.IsLowMemory = true
+		item.IsLowMemory = false
+	case "LowCPU":
+		err := dbClient.WriteToTable(s.Dynamo.TableName, "isLowCPU", true)
+		if err != nil {
+			s.Log.WithError(err).WithFields(log.Fields{
+				"table name": s.Dynamo.TableName,
+				"metric":     "isLowCPU == true",
+			}).Panic()
+		}
+		item.IsLowCPU = true
+	case "OkCPU":
+		err := dbClient.WriteToTable(s.Dynamo.TableName, "isLowCPU", false)
+		if err != nil {
+			s.Log.WithError(err).WithFields(log.Fields{
+				"table name": s.Dynamo.TableName,
+				"metric":     "isLowCPU == false",
+			}).Panic()
 		}
 	}
 
 	if item.IsLowCPU && item.IsLowMemory {
 		err = dbClient.WriteToTable(s.Dynamo.TableName, "isLowCPU", false)
 		if err != nil {
-			return err
+			s.Log.WithError(err).WithFields(log.Fields{
+				"table name": s.Dynamo.TableName,
+				"metric":     "isLowCPU == false",
+			}).Panic()
 		}
 		err = dbClient.WriteToTable(s.Dynamo.TableName, "isLowMemory", false)
 		if err != nil {
-			return err
-		}
-		err = s.execASGPolicy()
-		if err != nil {
-			return err
+			s.Log.WithError(err).WithFields(log.Fields{
+				"table name": s.Dynamo.TableName,
+				"metric":     "isLowMemory == false",
+			}).Panic()
 		}
+		s.execASGPolicy()
 	}
-
-	return nil
 }
 
 func (s *Sigmund) newDBClient() (*dynamo.Client, error) {
@@ -85,22 +107,24 @@ func (s *Sigmund) readDynamo(cli *dynamo.Client) (*DBItem, error) {
 	}, nil
 }
 
-func (s *Sigmund) execASGPolicy() error {
+func (s *Sigmund) execASGPolicy() {
 	var client *autoscaling.Client
 	asg, err := autoscaling.New(s.Autoscaling.AutoScalingGroupName, s.Autoscaling.PolicyName, s.Autoscaling.Region)
 	if err != nil {
-		return err
+		s.Log.WithError(err).WithFields(log.Fields{
+			"asg name":    s.Autoscaling.AutoScalingGroupName,
+			"policy name": s.Autoscaling.PolicyName,
+			"region":      s.Autoscaling.Region,
+		}).Panic("Failed to create autoscaling config")
 	}
 
 	client, err = asg.NewClient()
 	if err != nil {
-		return err
+		s.Log.WithError(err).Panic("Failed to create autoscaling client")
 	}
 
 	err = client.TriggerPolicy(asg)
 	if err != nil {
-		return err
+		s.Log.WithError(err).Panic("Failed to trigger asg policy")
 	}
-
-	return nil
 }