How can I retrieve Amazon EKS control plane logs from Amazon CloudWatch Logs?

Last updated: 2021-11-12

I'm troubleshooting an Amazon Elastic Kubernetes Service (Amazon EKS) issue and I need to collect logs from the components that run on the EKS control plane.

Short description

To view the logs in Amazon CloudWatch Logs, you must enable Amazon EKS control plane logging. You can find EKS control plane logs in the /aws/eks/cluster-name/cluster log group. For more information, see Viewing cluster control plane logs.

Note: Replace cluster name with your cluster's name.

You can use CloudWatch Logs Insights to search through the EKS control plane log data. For more information, see Analyzing log data with CloudWatch Insights.

Important: You can view log events in CloudWatch Logs only after you enabled control plane logging in a cluster. Before you select a time range to run queries in CloudWatch Logs Insights, verify that you enabled control plane logging.

Resolution

Search CloudWatch Insights

1.    Open the CloudWatch Logs Insights console.

2.    On the log group(s) menu, select the cluster log group that you want to query.

3.    Choose Run query to view the results.

Note: To export the results as a .csv file or to copy the results to the clipboard, choose Export results. You can change the sample query to get data for a specific use case. See the following sample queries for common EKS use cases.

Sample queries for common EKS use cases

To find the cluster creator, search for the IAM entity that's mapped to the kubernetes-admin user.

Query:

fields @logStream, @timestamp, @message
|  @timestamp desc
|  @logStream like /authenticator/
|  @message like "username=kubernetes-admin"
|  limit 50

Example output:

@logStream, @timestamp @message
authenticator-71976 ca11bea5d3083393f7d32dab75b,2021-08-11-10:09:49.020,"time=""2021-08-11T10:09:43Z"" level=info msg=""access granted"" arn=""arn:aws:iam::12345678910:user/awscli"" client=""127.0.0.1:51326"" groups=""[system:masters]"" method=POST path=/authenticate sts=sts.eu-west-1.amazonaws.com uid=""heptio-authenticator-aws:12345678910:ABCDEFGHIJKLMNOP"" username=kubernetes-admin"

In the preceding output, IAM user arn:aws:iam::12345678910:user/awscli is mapped to user kubernetes-admin.

To find requests that a specific user performed, search for operations that the kubernetes-admin user performed.

Example query:

fields @logStream, @timestamp, @message
| filter @logStream like /^kube-apiserver-audit/
| filter strcontains(user.username,"kubernetes-admin")
| sort @timestamp desc
| limit 50

Example output:

@logStream,@timestamp,@message
kube-apiserver-audit-71976ca11bea5d3083393f7d32dab75b,2021-08-11 09:29:13.095,"{...""requestURI"":""/api/v1/namespaces/kube-system/endpoints?limit=500";","string""verb"":""list"",""user"":{""username"":""kubernetes-admin"",""uid"":""heptio-authenticator-aws:12345678910:ABCDEFGHIJKLMNOP"",""groups"":[""system:masters"",""system:authenticated""],""extra"":{""accessKeyId"":[""ABCDEFGHIJKLMNOP""],""arn"":[""arn:aws:iam::12345678910:user/awscli""],""canonicalArn"":[""arn:aws:iam::12345678910:user/awscli""],""sessionName"":[""""]}},""sourceIPs"":[""12.34.56.78""],""userAgent"":""kubectl/v1.22.0 (darwin/amd64) kubernetes/c2b5237"",""objectRef"":{""resource"":""endpoints"",""namespace"":""kube-system"",""apiVersion"":""v1""}...}"

To find API calls that a specific userAgent made, you can use the following example query:

fields @logStream, @timestamp, userAgent, verb, requestURI, @message
| @logStream like /kube-apiserver-audit/
| userAgent like /kubectl\/v1.22.0/
| sort @timestamp desc
| filter verb like /(get)/

Shortened example output:

@logStream,@timestamp,userAgent,verb,requestURI,@message
kube-apiserver-audit-71976ca11bea5d3083393f7d32dab75b,2021-08-11 14:06:47.068,kubectl/v1.22.0 (darwin/amd64) kubernetes/c2b5237,get,/apis/metrics.k8s.io/v1beta1?timeout=32s,"{""kind"":""Event"",""apiVersion"":""audit.k8s.io/v1"",""level"":""Metadata"",""auditID"":""863d9353-61a2-4255-a243-afaeb9183524"",""stage"":""ResponseComplete"",""requestURI"":""/apis/metrics.k8s.io/v1beta1?timeout=32s"",""verb"":""get"",""user"":{""username"":""kubernetes-admin"",""uid"":""heptio-authenticator-aws:12345678910:AIDAUQGC5HFOHXON7M22F"",""groups"":[""system:masters"",""system:authenticated""],""extra"":{""accessKeyId"":[""ABCDEFGHIJKLMNOP""],""arn"":[""arn:aws:iam::12345678910:user/awscli""],""canonicalArn"":[""arn:aws:iam::12345678910:user/awscli""],""sourceIPs"":[""12.34.56.78""],""userAgent"":""kubectl/v1.22.0 (darwin/amd64) kubernetes/c2b5237""...}"

To find mutating changes made to the aws-auth ConfigMap, you can use the following example query:

fields @logStream, @timestamp, @message
| filter @logStream like /^kube-apiserver-audit/
| filter requestURI like /\/api\/v1\/namespaces\/kube-system\/configmaps/
| filter objectRef.name = "aws-auth"
| filter verb like /(create|delete|patch)/
| sort @timestamp desc
| limit 50

Shortened example output:

@logStream,@timestamp,@message
kube-apiserver-audit-f01c77ed8078a670a2eb63af6f127163,2021-10-27 05:43:01.850,{""kind"":""Event"",""apiVersion"":""audit.k8s.io/v1"",""level"":""RequestResponse"",""auditID"":""8f9a5a16-f115-4bb8-912f-ee2b1d737ff1"",""stage"":""ResponseComplete"",""requestURI"":""/api/v1/namespaces/kube-system/configmaps/aws-auth?timeout=19s"",""verb"":""patch"",""responseStatus"": {""metadata"": {},""code"": 200 },""requestObject"": {""data"": { contents of aws-auth ConfigMap } },""requestReceivedTimestamp"":""2021-10-27T05:43:01.033516Z"",""stageTimestamp"":""2021-10-27T05:43:01.042364Z"" }

To find requests that were denied, you can use the following example query:

fields @logStream, @timestamp, @message
| filter @logStream like /^authenticator/
| filter @message like "denied"
| sort @timestamp desc
| limit 50

Example output:

@logStream,@timestamp,@message
authenticator-8c0c570ea5676c62c44d98da6189a02b,2021-08-08 20:04:46.282,"time=""2021-08-08T20:04:44Z"" level=warning msg=""access denied"" client=""127.0.0.1:52856"" error=""sts getCallerIdentity failed: error from AWS (expected 200, got 403)"" method=POST path=/authenticate"

To find the node that a pod was scheduled on, query the kube-scheduler logs.

Example query:

fields @logStream, @timestamp, @message
| sort @timestamp desc
| filter @logStream like /kube-scheduler/
| filter @message like "aws-6799fc88d8-jqc2r"
| limit 50

Example output:

@logStream,@timestamp,@message
kube-scheduler-bb3ea89d63fd2b9735ba06b144377db6,2021-08-15 12:19:43.000,"I0915 12:19:43.933124       1 scheduler.go:604] ""Successfully bound pod to node"" pod=""kube-system/aws-6799fc88d8-jqc2r"" node=""ip-192-168-66-187.eu-west-1.compute.internal"" evaluatedNodes=3 feasibleNodes=2"

In the preceding example output, pod aws-6799fc88d8-jqc2r was scheduled on node ip-192-168-66-187.eu-west-1.compute.internal.

To find HTTP 5xx server errors for Kubernetes API server requests, you can use the following example query:

fields @logStream, @timestamp, responseStatus.code, @message
| filter @logStream like /^kube-apiserver-audit/
| filter responseStatus.code = 500
| limit 50

Shortened example output:

@logStream,@timestamp,responseStatus.code,@message
kube-apiserver-audit-4d5145b53c40d10c276ad08fa36d1f11,2021-08-04 07:22:06.518,503,"...""requestURI"":""/apis/metrics.k8s.io/v1beta1?timeout=32s"",""verb"":""get"",""user"":{""username"":""system:serviceaccount:kube-system:resourcequota-controller"",""uid"":""36d9c3dd-f1fd-4cae-9266-900d64d6a754"",""groups"":[""system:serviceaccounts"",""system:serviceaccounts:kube-system"",""system:authenticated""]},""sourceIPs"":[""12.34.56.78""],""userAgent"":""kube-controller-manager/v1.21.2 (linux/amd64) kubernetes/d2965f0/system:serviceaccount:kube-system:resourcequota-controller"",""responseStatus"":{""metadata"":{},""code"":503},..."}}"

To troubleshoot a CronJob activation, search for API calls that the cronjob-controller made.

Example query:

fields @logStream, @timestamp, @message
| filter @logStream like /kube-apiserver-audit/
| filter user.username like "system:serviceaccount:kube-system:cronjob-controller"
| display @logStream, @timestamp, @message, objectRef.namespace, objectRef.name
| sort @timestamp desc
| limit 50

Shortened example output:

{ "kind": "Event", "apiVersion": "audit.k8s.io/v1", "objectRef": { "resource": "cronjobs", "namespace": "default", "name": "hello", "apiGroup": "batch", "apiVersion": "v1" }, "responseObject": { "kind": "CronJob", "apiVersion": "batch/v1", "spec": { "schedule": "*/1 * * * *" }, "status": { "lastScheduleTime": "2021-08-09T07:19:00Z" } } }

In the preceding example output, the hello job in the default namespace runs every minute and was last scheduled at 2021-08-09T07:19:00Z.

To find API calls that the replicaset-controller made, you can use the following example query:

fields @logStream, @timestamp, @message
| filter @logStream like /kube-apiserver-audit/
| filter user.username like "system:serviceaccount:kube-system:replicaset-controller"
| display @logStream, @timestamp, requestURI, verb, user.username
| sort @timestamp desc
| limit 50

Example output:

@logStream,@timestamp,requestURI,verb,user.username
kube-apiserver-audit-8c0c570ea5676c62c44d98da6189a02b,2021-08-10 17:13:53.281,/api/v1/namespaces/kube-system/pods,create,system:serviceaccount:kube-system:replicaset-controller
kube-apiserver-audit-4d5145b53c40d10c276ad08fa36d1f11,2021-08-04 0718:44.561,/apis/apps/v1/namespaces/kube-system/replicasets/coredns-6496b6c8b9/status,update,system:serviceaccount:kube-system:replicaset-controller

To find operations that are made against a Kubernetes resource, you can use the following example query:

fields @logStream, @timestamp, @message
| filter @logStream like /^kube-apiserver-audit/
| filter verb == "delete" and requestURI like "/api/v1/namespaces/default/pods/my-app"
| sort @timestamp desc
| limit 10

The preceding example query filters for delete API calls on the default namespace for pod my-app.

Shortened example output:

@logStream,@timestamp,@message
kube-apiserver-audit-e7b3cb08c0296daf439493a6fc9aff8c,2021-08-11 14:09:47.813,"...""requestURI"":""/api/v1/namespaces/default/pods/my-app"",""verb"":""delete"",""user"":{""username""""kubernetes-admin"",""uid"":""heptio-authenticator-aws:12345678910:ABCDEFGHIJKLMNOP"",""groups"":[""system:masters"",""system:authenticated""],""extra"":{""accessKeyId"":[""ABCDEFGHIJKLMNOP""],""arn"":[""arn:aws:iam::12345678910:user/awscli""],""canonicalArn"":[""arn:aws:iam::12345678910:user/awscli""],""sessionName"":[""""]}},""sourceIPs"":[""12.34.56.78""],""userAgent"":""kubectl/v1.22.0 (darwin/amd64) kubernetes/c2b5237"",""objectRef"":{""resource"":""pods"",""namespace"":""default"",""name"":""my-app"",""apiVersion"":""v1""},""responseStatus"":{""metadata"":{},""code"":200},""requestObject"":{""kind"":""DeleteOptions"",""apiVersion"":""v1"",""propagationPolicy"":""Background""},
..."

To retrieve a count of HTTP response codes for calls made to the Kubernetes API server, you can use the following example query:

fields @logStream, @timestamp, @message
| filter @logStream like /^kube-apiserver-audit/
| stats count(*) as count by responseStatus.code
| sort count desc

Example output:

responseStatus.code,count
200,35066
201,525
403,125
404,116
101,2

To find changes that are made to DaemonSets/Addons in the kube-system namespace, you can use the following example query:

filter @logStream like /^kube-apiserver-audit/
| fields @logStream, @timestamp, @message
| filter verb like /(create|update|delete)/ and strcontains(requestURI,"/apis/apps/v1/namespaces/kube-system/daemonsets")
| sort @timestamp desc
| limit 50

Example output:

{ "kind": "Event", "apiVersion": "audit.k8s.io/v1", "level": "RequestResponse", "auditID": "93e24148-0aa6-4166-8086-a689b0031612", "stage": "ResponseComplete", "requestURI": "/apis/apps/v1/namespaces/kube-system/daemonsets/aws-node?fieldManager=kubectl-set", "verb": "patch", "user": { "username": "kubernetes-admin", "groups": [ "system:masters", "system:authenticated" ] }, "userAgent": "kubectl/v1.22.2 (darwin/amd64) kubernetes/8b5a191", "objectRef": { "resource": "daemonsets", "namespace": "kube-system", "name": "aws-node", "apiGroup": "apps", "apiVersion": "v1" }, "requestObject": { "REDACTED": "REDACTED" }, "requestReceivedTimestamp": "2021-08-09T08:07:21.868376Z", "stageTimestamp": "2021-08-09T08:07:21.883489Z", "annotations": { "authorization.k8s.io/decision": "allow", "authorization.k8s.io/reason": "" } }

In the preceding example output, the kubernetes-admin user used kubectl v1.22.2 to patch the aws-node DaemonSet.


Did this article help?


Do you need billing or technical support?