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fix: check limits mutation. #53

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merged 1 commit into from
Aug 12, 2024
Merged

fix: check limits mutation. #53

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11 changes: 10 additions & 1 deletion e2e.bats
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Original file line number Diff line number Diff line change
Expand Up @@ -63,7 +63,7 @@

@test "mutate deployment with limits but no request resources" {
run kwctl run annotated-policy.wasm -r test_data/deployment_with_limits_admission_request.json \
--settings-json '{"cpu": {"maxLimit": "4", "defaultRequest" : "2", "defaultLimit" : "2"}, "memory" : {"maxLimit": "4G", "defaultRequest" : "2G", "defaultLimit" : "2G"}}'
--settings-json '{"cpu": {"maxLimit": "4", "defaultRequest" : "1", "defaultLimit" : "1"}, "memory" : {"maxLimit": "4G", "defaultRequest" : "1G", "defaultLimit" : "1G"}}'

[ "$status" -eq 0 ]
[ $(expr "$output" : '.*allowed":true') -ne 0 ]
Expand Down Expand Up @@ -158,3 +158,12 @@
[ $(expr "$output" : '.*invalid cpu settings.*') -ne 0 ]
[ $(expr "$output" : '.*invalid memory settings.*') -ne 0 ]
}

@test "policy fails when the request resource is greater than the limit set by the policy" {
run kwctl run annotated-policy.wasm -r test_data/deployment_with_requests_no_limit_resources_admission_request.json \
--settings-json '{"cpu": {"maxLimit": 2, "defaultRequest": 1, "defaultLimit": 1, "ignoreValues":false}, "memory" : {"maxLimit": "1Gi", "defaultRequest" : "200Mi", "defaultLimit" : "200Mi", "ignoreValues":false}, "ignoreImages": ["image:latest"]}'

[ "$status" -eq 0 ]
[ $(expr "$output" : '.*allowed":false') -ne 0 ]
[ $(expr "$output" : ".*memory limit '200Mi' is less than the requested '250Mi' value.*") -ne 0 ]
}
4 changes: 2 additions & 2 deletions settings.go
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Original file line number Diff line number Diff line change
Expand Up @@ -74,8 +74,8 @@ func (s *Settings) Valid() error {
}
if cpuError != nil || memoryError != nil {
// user want to validate only one type of resource. The other one should be ignored
if (cpuError == nil && errors.Is(memoryError, AllValuesAreZeroError{})) || (memoryError == nil && errors.Is(cpuError, AllValuesAreZeroError{})) {
return nil
if (cpuError == nil && errors.Is(memoryError, AllValuesAreZeroError{})) || (memoryError == nil && errors.Is(cpuError, AllValuesAreZeroError{})) {
return nil
}
return errors.Join(cpuError, memoryError)
}
Expand Down
178 changes: 178 additions & 0 deletions test_data/deployment_with_requests_no_limit_resources_admission_request.json
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Original file line number Diff line number Diff line change
@@ -0,0 +1,178 @@
{
"dryRun": false,
"kind": {
"group": "apps",
"kind": "Deployment",
"version": "v1"
},
"name": "nginx",
"namespace": "default",
"object": {
"apiVersion": "apps/v1",
"kind": "Deployment",
"metadata": {
"annotations": {
"io.kubewarden.policy.echo.create": "true",
"kubectl.kubernetes.io/last-applied-configuration": "{\"apiVersion\":\"apps/v1\",\"kind\":\"Deployment\",\"metadata\":{\"annotations\":{\"io.kubewarden.policy.echo.create\":\"true\"},\"name\":\"nginx\",\"namespace\":\"default\"},\"spec\":{\"replicas\":0,\"selector\":{\"matchLabels\":{\"app\":\"nginx\"}},\"template\":{\"metadata\":{\"labels\":{\"app\":\"nginx\"}},\"spec\":{\"containers\":[{\"image\":\"nginx:latest\",\"name\":\"nginx\",\"ports\":[{\"containerPort\":80}]}]}}}}\n"
},
"creationTimestamp": "2024-01-11T12:25:50Z",
"generation": 1,
"managedFields": [
{
"apiVersion": "apps/v1",
"fieldsType": "FieldsV1",
"fieldsV1": {
"f:metadata": {
"f:annotations": {
".": {},
"f:io.kubewarden.policy.echo.create": {},
"f:kubectl.kubernetes.io/last-applied-configuration": {}
}
},
"f:spec": {
"f:progressDeadlineSeconds": {},
"f:replicas": {},
"f:revisionHistoryLimit": {},
"f:selector": {},
"f:strategy": {
"f:rollingUpdate": {
".": {},
"f:maxSurge": {},
"f:maxUnavailable": {}
},
"f:type": {}
},
"f:template": {
"f:metadata": {
"f:labels": {
".": {},
"f:app": {}
}
},
"f:spec": {
"f:containers": {
"k:{\"name\":\"nginx\"}": {
".": {},
"f:image": {},
"f:imagePullPolicy": {},
"f:name": {},
"f:ports": {
".": {},
"k:{\"containerPort\":80,\"protocol\":\"TCP\"}": {
".": {},
"f:containerPort": {},
"f:protocol": {}
}
},
"f:resources": {},
"f:terminationMessagePath": {},
"f:terminationMessagePolicy": {}
}
},
"f:dnsPolicy": {},
"f:restartPolicy": {},
"f:schedulerName": {},
"f:securityContext": {},
"f:terminationGracePeriodSeconds": {}
}
}
}
},
"manager": "kubectl-client-side-apply",
"operation": "Update",
"time": "2024-01-11T12:25:50Z"
}
],
"name": "nginx",
"namespace": "default",
"uid": "0663a366-270c-4d7c-a483-6f59d200fb22"
},
"spec": {
"progressDeadlineSeconds": 600,
"replicas": 0,
"revisionHistoryLimit": 10,
"selector": {
"matchLabels": {
"app": "nginx"
}
},
"strategy": {
"rollingUpdate": {
"maxSurge": "25%",
"maxUnavailable": "25%"
},
"type": "RollingUpdate"
},
"template": {
"metadata": {
"creationTimestamp": null,
"labels": {
"app": "nginx"
}
},
"spec": {
"containers": [
{
"image": "nginx:latest",
"imagePullPolicy": "Always",
"name": "nginx",
"ports": [
{
"containerPort": 80,
"protocol": "TCP"
}
],
"resources": {
"requests": {
"cpu": "1",
"memory": "250Mi"
},
"limits": {
"cpu": "1"
}
},
"terminationMessagePath": "/dev/termination-log",
"terminationMessagePolicy": "File"
}
],
"dnsPolicy": "ClusterFirst",
"restartPolicy": "Always",
"schedulerName": "default-scheduler",
"securityContext": {},
"terminationGracePeriodSeconds": 30
}
}
},
"status": {}
},
"operation": "CREATE",
"options": {
"apiVersion": "meta.k8s.io/v1",
"fieldManager": "kubectl-client-side-apply",
"fieldValidation": "Strict",
"kind": "CreateOptions"
},
"requestKind": {
"group": "apps",
"kind": "Deployment",
"version": "v1"
},
"requestResource": {
"group": "apps",
"resource": "deployments",
"version": "v1"
},
"resource": {
"group": "apps",
"resource": "deployments",
"version": "v1"
},
"uid": "31403b86-f972-423e-8adb-c4bd79dc15cc",
"userInfo": {
"groups": [
"system:masters",
"system:authenticated"
],
"username": "system:admin"
}
}
39 changes: 38 additions & 1 deletion validate.go
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Original file line number Diff line number Diff line change
Expand Up @@ -2,6 +2,7 @@ package main

import (
"encoding/json"
"errors"
"fmt"
"strings"

Expand Down Expand Up @@ -66,7 +67,7 @@ func validateContainerResourceRequests(container *corev1.Container, settings *Se
// We only check for the presence of the limits/requests, not their values.
// Returns an error if the limits/requests are not set and IgnoreValues is set to true.
func validateContainerResources(container *corev1.Container, settings *Settings) error {
if container.Resources == nil && ( settings.shouldIgnoreCpuValues() || settings.shouldIgnoreMemoryValues()) {
if container.Resources == nil && (settings.shouldIgnoreCpuValues() || settings.shouldIgnoreMemoryValues()) {
missing := fmt.Sprintf("required Cpu:%t, Memory:%t", settings.shouldIgnoreCpuValues(), settings.shouldIgnoreMemoryValues())
return fmt.Errorf("container does not have any resource limits or requests: %s", missing)
}
Expand All @@ -93,6 +94,26 @@ func validateAndAdjustContainerResourceRequests(container *corev1.Container, set
return mutated
}

// Ensure that the limit is greater than or equal to the request
func isResourceLimitGreaterThanRequest(container *corev1.Container, resourceName string) error {
if !missingResourceQuantity(container.Resources.Requests, resourceName) && !missingResourceQuantity(container.Resources.Limits, resourceName) {
resourceStr := container.Resources.Limits[resourceName]
resourceLimit, err := resource.ParseQuantity(string(*resourceStr))
if err != nil {
return errors.Join(fmt.Errorf("invalid %s limit", resourceName), err)
}
resourceStr = container.Resources.Requests[resourceName]
resourceRequest, err := resource.ParseQuantity(string(*resourceStr))
if err != nil {
return errors.Join(fmt.Errorf("invalid %s request", resourceName), err)
}
if resourceLimit.Cmp(resourceRequest) < 0 {
return fmt.Errorf("%s limit '%s' is less than the requested '%s' value. Please, change the resource configuration or change the policy settings to accommodate the requested value.", resourceName, resourceLimit.String(), resourceRequest.String())
}
}
return nil
}

// validateAndAdjustContainerResourceLimit validates the container against the passed resourceConfig // and mutates it if the validation didn't pass.
// Returns true when it mutates the container.
func validateAndAdjustContainerResourceLimit(container *corev1.Container, resourceName string, resourceConfig *ResourceConfiguration) (bool, error) {
Expand Down Expand Up @@ -164,6 +185,22 @@ func validateAndAdjustContainer(container *corev1.Container, settings *Settings)
return false, err
}
requestsMutation := validateAndAdjustContainerResourceRequests(container, settings)
if limitsMutation || requestsMutation {
// If the container has been mutated, we need to check that the limit is greater than the request
// for both CPU and Memory. If the limit is less than the request, we reject the request.
// Because the user need to adjust the resource or change the policy configuration. Otherwise,
// Kubernetes will not accept the resource mutated by the policy.
errorMsg := "There is an issue after resource limits mutation"
if requestsMutation {
errorMsg = "There is an issue after resource requests mutation"
}
if err := isResourceLimitGreaterThanRequest(container, "memory"); err != nil {
return false, errors.Join(errors.New(errorMsg), err)
}
if err := isResourceLimitGreaterThanRequest(container, "cpu"); err != nil {
return false, errors.Join(errors.New(errorMsg), err)
}
}
return limitsMutation || requestsMutation, nil
}

Expand Down
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