GROW-662: Capture K8 related sub-counts for AWS (#9)

Author: laverion

README.md

@@ -133,6 +133,7 @@ Cloud Resource Counter (v0.7.0) running with:
 Activity
  * Retrieving Account ID...OK (240520192079)
  * Retrieving EC2 counts...................OK (5)
+ * Retrieving EC2 K8 related VMs Sub-instance counts...................OK (1)
  * Retrieving Spot instance counts...................OK (4)
  * Retrieving EBS volume counts...................OK (9)
  * Retrieving Unique container counts...................OK (3)
@@ -151,7 +152,7 @@ As you can see above, no command line arguments were necessary: it used my defau
 Here is what the CSV file looks like. It is important to mention that this tool was run TWICE to collect the results of two different accounts/profiles.
 
 ```csv
-Account ID,Timestamp,Region,# of EC2 Instances,# of Spot Instances,# of EBS Volumes,# of Unique Containers,# of Lambda Functions,# of RDS Instances,# of Lightsail Instances,# of S3 Buckets,# of EKS Nodes
+Account ID,Timestamp,Region,# of EC2 Instances,# of EC2 K8 related VMs Sub-instances,# of Spot Instances,# of EBS Volumes,# of Unique Containers,# of Lambda Functions,# of RDS Instances,# of Lightsail Instances,# of S3 Buckets,# of EKS Nodes
 896149672290,2020-10-20T16:29:39-04:00,ALL_REGIONS,2,3,7,3,2,3,2,2,2
 240520192079,2020-10-21T16:24:06-04:00,ALL_REGIONS,5,4,9,3,12,7,0,13,0
 ```
@@ -267,9 +268,10 @@ The `aws-resource-counter` examines the following resources:
 1. **EC2**. We count the number of EC2 **running** instances (both "normal" and Spot instances) across all regions.
 
    * For EC2 instances, we only count those _without_ an Instance Lifecycle tag (which is either `spot` or `scheduled`).
+   * For EC2 K8 related VMs sub-instances, we only count those with a tag of `aws:eks:cluster-name`.
    * For Spot instance, we only count those with an Instance Lifecycle tag of `spot`.
 
-   * This is stored in the generated CSV file under the "# of EC2 Instances" and "# of Spot Instances" columns.
+   * This is stored in the generated CSV file under the "# of EC2 Instances", "# of EC2 K8 related VMs Sub-instances", and "# of Spot Instances" columns.
 
 1. **EBS Volumes.** We count the number of "attached" EBS volumes across all regions.
 
@@ -348,7 +350,7 @@ To collect the total number of EC2 instances across all regions, we will need to
 ```bash
 $ aws ec2 describe-regions $aws_p \
    --filters Name=opt-in-status,Values=opt-in-not-required,opted-in \
-   --region us-east-1 --output text --query Regions[].RegionName
+   --region us-east-1 --output text --query 'Regions[].RegionName'
 eu-north-1    ap-south-1    eu-west-3 ...
 ```
 
@@ -364,7 +366,7 @@ We will be using the results of this command to "iterate" over all regions. To m
 ```bash
 $ ec2_r=$(aws ec2 describe-regions $aws_p \
    --filters Name=opt-in-status,Values=opt-in-not-required,opted-in \
-   --region us-east-1 --output text --query Regions[].RegionName )
+   --region us-east-1 --output text --query 'Regions[].RegionName' )
 ```
 
 You can show the list of regions for your account by using the `echo` command:
@@ -417,6 +419,32 @@ The second and third lines are our call to `describe-instances` (as shown above)
 
 In the fourth line, we paste all of the values into a long addition and use `bc` to sum the values.
 
+#### EC2 K8 Related VMs Subcount Instances
+
+Here is the command to count the number of _EC K8 related VMs subcount_ instances for a given region:
+
+```bash
+$ aws ec2 describe-instances $aws_p --no-paginate --region us-east-1 \
+      --filters Name=instance-state-name,Values=running \
+      --filters Name=tag-key,Values='aws:eks:cluster-name' \
+      --query 'length(Reservations[].Instances[?!not_null(InstanceLifecycle)].InstanceId[])'
+1
+```
+
+This command is similar to the normal EC2 query, but now explicitly checks for EC2 instances whose `Tags` have that key `aws:eks:cluster-name`.
+
+We will need to run this command over all regions. Here is what it looks like:
+
+```bash
+$ for reg in $ec2_r; do \
+   aws ec2 describe-instances $aws_p --no-paginate --region $reg \
+      --filters Name=instance-state-name,Values=running \
+      --filters Name=tag-key,Values='aws:eks:cluster-name' \
+      --query 'length(Reservations[].Instances[?!not_null(InstanceLifecycle)].InstanceId[])' ; \
+done | paste -s -d+ - | bc
+5
+```
+
 #### Spot Instances
 
 Here is the command to count the number of _Spot_ instances for a given region:

ec2_k8_subcount.go

@@ -0,0 +1,85 @@
+/******************************************************************************
+Cloud Resource Counter
+File: spot.go
+
+Summary: Provides a count of all Spot EC2 instances.
+******************************************************************************/
+
+package main
+
+import (
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/service/ec2"
+	color "github.com/logrusorgru/aurora"
+)
+
+// SpotInstances retrieves the count of all EC2 spot instances
+// either for all regions (allRegions is true) or the region
+// associated with the session.
+// This method gives status back to the user via the supplied
+// ActivityMonitor instance.
+func EC2K8SubInstances(sf ServiceFactory, am ActivityMonitor, allRegions bool) int {
+	// Indicate activity
+	am.StartAction("Retrieving EC2 K8 related VMs Sub-instance counts")
+
+	// Should we get the counts for all regions?
+	instanceCount := 0
+	if allRegions {
+		// Get the list of all enabled regions for this account
+		regionsSlice := GetEC2Regions(sf.GetEC2InstanceService(""), am)
+
+		// Loop through all of the regions
+		for _, regionName := range regionsSlice {
+			// Get the EC2 counts for a specific region
+			instanceCount += ec2K8SubInstancesForSingleRegion(sf.GetEC2InstanceService(regionName), am)
+		}
+	} else {
+		// Get the EC2 counts for the region selected by this session
+		instanceCount = ec2K8SubInstancesForSingleRegion(sf.GetEC2InstanceService(""), am)
+	}
+
+	// Indicate end of activity
+	am.EndAction("OK (%d)", color.Bold(instanceCount))
+
+	return instanceCount
+}
+
+func ec2K8SubInstancesForSingleRegion(ec2is *EC2InstanceService, am ActivityMonitor) int {
+	// Indicate activity
+	am.Message(".")
+
+	// Construct our input to find ONLY RUNNING EC2 instances that also have the "aws:eks:cluster-name" tag
+	input := &ec2.DescribeInstancesInput{
+		Filters: []*ec2.Filter{
+			{
+				Name: aws.String("tag-key"),
+				Values: []*string{
+					aws.String("aws:eks:cluster-name"),
+				},
+			},
+			{
+				Name: aws.String("instance-state-name"),
+				Values: []*string{
+					aws.String("running"),
+				},
+			},
+		},
+	}
+
+	// Invoke our service
+	instanceCount := 0
+	err := ec2is.InspectInstances(input, func(dio *ec2.DescribeInstancesOutput, lastPage bool) bool {
+		// Loop through each reservation
+		for _, reservation := range dio.Reservations {
+			// We assume that the AWS Service has properly filtered the list of returned instances
+			instanceCount += len(reservation.Instances)
+		}
+
+		return true
+	})
+
+	// Check for error
+	am.CheckError(err)
+
+	return instanceCount
+}

ec2_k8_subcount_test.go

@@ -0,0 +1,74 @@
+/******************************************************************************
+Cloud Resource Counter
+File: ec2_k8_subcount_test.go
+
+Summary: The Unit Test for EC2 K8 sub-count.
+******************************************************************************/
+
+package main
+
+import (
+	"testing"
+
+	"github.com/expel-io/aws-resource-counter/mock"
+)
+
+// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
+// Unit Test for EC2 K8 sub-count.
+// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
+
+func TestEC2K8SubInstances(t *testing.T) {
+	// Describe all of our test cases: 1 failure and 4 success cases
+	cases := []struct {
+		RegionName    string
+		AllRegions    bool
+		ExpectedCount int
+		ExpectError   bool
+	}{
+		{
+			RegionName:    "us-east-1",
+			ExpectedCount: 1,
+		}, {
+			RegionName:    "us-east-2",
+			ExpectedCount: 0,
+		}, {
+			RegionName:    "af-south-1",
+			ExpectedCount: 0,
+		}, {
+			RegionName:  "undefined-region",
+			ExpectError: true,
+		}, {
+			AllRegions:    true,
+			ExpectedCount: 1,
+		},
+	}
+
+	// Loop through each test case
+	for _, c := range cases {
+		// Create our fake service factory
+		sf := fakeEC2ServiceFactory{
+			RegionName: c.RegionName,
+			DRResponse: ec2Regions,
+		}
+
+		// Create a mock activity monitor
+		mon := &mock.ActivityMonitorImpl{}
+
+		// Invoke our EC K8 Subcount Instances function
+		actualCount := EC2K8SubInstances(sf, mon, c.AllRegions)
+
+		// Did we expect an error?
+		if c.ExpectError {
+			// Did it fail to arrive?
+			if !mon.ErrorOccured {
+				t.Error("Expected an error to occur, but it did not... :^(")
+			}
+		} else if mon.ErrorOccured {
+			t.Errorf("Unexpected error occurred: %s", mon.ErrorMessage)
+		} else if actualCount != c.ExpectedCount {
+			t.Errorf("Error: EC K8 SubcountInstances returned %d; expected %d", actualCount, c.ExpectedCount)
+		} else if mon.ProgramExited {
+			t.Errorf("Unexpected Exit: The program unexpected exited with status code=%d", mon.ExitCode)
+		}
+	}
+}

ec2_test.go

@@ -10,6 +10,7 @@ package main
 import (
 	"errors"
 	"reflect"
+	"slices"
 	"strings"
 	"testing"
 
@@ -50,7 +51,7 @@ var ec2Regions *ec2.DescribeRegionsOutput = &ec2.DescribeRegionsOutput{
 // This is our map of regions and the instances in each
 var ec2InstancesPerRegion = map[string][]*ec2.DescribeInstancesOutput{
 	// US-EAST-1 illustrates a case where DescribeInstancesPages returns two pages of results.
-	// First page: 2 different reservations (1 running instance, then 2 instances [1 is spot])
+	// First page: 2 different reservations (1 running instance, then 3 instances [1 is k8 related vm, 1 is a spot instance])
 	// Second page: 1 reservation (2 instances, 1 of which is stopped)
 	"us-east-1": {
 		&ec2.DescribeInstancesOutput{
@@ -71,6 +72,14 @@ var ec2InstancesPerRegion = map[string][]*ec2.DescribeInstancesOutput{
 								Name: aws.String("running"),
 							},
 						},
+						{
+							Tags: []*ec2.Tag{
+								{Key: aws.String("aws:eks:cluster-name"), Value: aws.String("cluster-name")},
+							},
+							State: &ec2.InstanceState{
+								Name: aws.String("running"),
+							},
+						},
 						{
 							InstanceLifecycle: aws.String("spot"),
 							State: &ec2.InstanceState{
@@ -276,13 +285,26 @@ func instanceSatisfiesFilter(reflectStruct reflect.Value, filter *ec2.Filter) bo
 
 	// Get our field value from the path
 	fieldValue, ok := resolvePathByReflection(reflectStruct, fieldNamePath)
-	if !ok {
+	if !ok && !slices.Contains(fieldNamePath, "TagKey") {
 		return false
 	}
 
 	// Does this match one of the filter values?
 	for _, value := range filter.Values {
-		// Does it match?
+		// if we get a filter for "tag-key", check the "Tags" portion of an ec2 instance
+		// loop through the tags slice checking each of the "Kay" values in the tags struct
+		// return true if we find any matching values
+		if slices.Contains(fieldNamePath, "TagKey") {
+			tags := reflectStruct.FieldByName("Tags")
+			if !tags.IsValid() || tags.IsNil() || tags.Kind() != reflect.Slice {
+				return false
+			}
+			for i := 0; i < tags.Len(); i++ {
+				if tagKey := tags.Index(i).Elem().FieldByName("Key").Elem(); tagKey.IsValid() && tagKey.Kind() == reflect.String && tagKey.String() == *value {
+					return true
+				}
+			}
+		}
 		if *value == fieldValue {
 			return true
 		}
@@ -455,7 +477,7 @@ func TestEC2Counts(t *testing.T) {
 	}{
 		{
 			RegionName:    "us-east-1",
-			ExpectedCount: 3,
+			ExpectedCount: 4,
 		}, {
 			RegionName:    "us-east-2",
 			ExpectedCount: 5,
@@ -467,7 +489,7 @@ func TestEC2Counts(t *testing.T) {
 			ExpectError: true,
 		}, {
 			AllRegions:    true,
-			ExpectedCount: 8,
+			ExpectedCount: 9,
 		},
 	}
 

main.go

@@ -30,7 +30,6 @@ var date string = "<<never built>>"
 //
 // This command requires access to a valid AWS Account. For now, it is assumed that
 // this is stored in the user's ".aws" folder (located in $HOME/.aws).
-//
 func main() {
 	/* =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
 	 * Command line processing
@@ -92,6 +91,7 @@ func main() {
 	results.Append("Timestamp", time.Now().Format(time.RFC3339))
 	results.Append("Region", displayRegion)
 	results.Append("# of EC2 Instances", EC2Counts(serviceFactory, monitor, settings.allRegions))
+	results.Append("# of EC2 K8 related VMs Sub-instances", EC2K8SubInstances(serviceFactory, monitor, settings.allRegions))
 	results.Append("# of Spot Instances", SpotInstances(serviceFactory, monitor, settings.allRegions))
 	results.Append("# of EBS Volumes", EBSVolumes(serviceFactory, monitor, settings.allRegions))
 	results.Append("# of Unique Containers", UniqueContainerImages(serviceFactory, monitor, settings.allRegions))