Display Resources
Introduction to Resources
Managing multiple clusters effectively requires a centralized location for viewing a summary of all the deployed resources. Below are some of the key reasons why it is important.
- Centralized Visibility: A central location provides a unified view of resource summaries. It allows monitoring and visualisation of the health of every cluster in one place. It simplifies issue detection, trend identification, and problem troubleshooting across multiple clusters.
- Efficient Troubleshooting and Issue Resolution: With a centralized resource view, we can swiftly identify the affected clusters when an issue arises, compare it with others, and narrow down potential causes. This comprehensive overview of resource states and dependencies enables efficient troubleshooting and quicker problem resolution.
- Enhanced Security and Compliance: Centralized resource visibility strengthens security and compliance monitoring. It enables monitoring of the cluster configurations, identify security vulnerabilities, and ensures consistent adherence to compliance standards across all clusters. We can easily track and manage access controls, network policies, and other security-related aspects from a single location.
Using Projectsveltos can facilitate the display of information about all the resources resources in the managed clusters.
Example: Display Deployment Replicas Managed Clusters
To showcase information about the deployments in every managed cluster, we can utilize a combination of a ClusterHealthCheck and a HealthCheck.
Follow the steps below to set up Projectsveltos to display deployment replicas from the managed clusters.
- Create a
HealthCheckinstance that contains a Lua script responsible for examining all the deployments in the managed clusters. In the example below, deployments with a difference between the number of available replicas and requested replicas are identified asdegraded.
apiVersion: lib.projectsveltos.io/v1alpha1
kind: HealthCheck
metadata:
name: deployment-replicas
spec:
collectResources: true
resourceSelectors:
- group: "apps"
version: v1
kind: Deployment
evaluateHealth: |
function evaluate()
local statuses = {}
status = "Progressing"
message = ""
for _,resource in ipairs(resources) do
if resource.spec.replicas == 0 then
continue
end
if resource.status ~= nil then
if resource.status.availableReplicas ~= nil then
if resource.status.availableReplicas == resource.spec.replicas then
status = "Healthy"
message = "All replicas " .. resource.spec.replicas .. " are healthy"
else
status = "Progressing"
message = "expected replicas: " .. resource.spec.replicas .. " available: " .. resource.status.availableReplicas
end
end
if resource.status.unavailableReplicas ~= nil then
status = "Degraded"
message = "deployments have unavailable replicas"
end
end
table.insert(statuses, {resource=resource, status = status, message = message})
end
local hs = {}
if #statuses > 0 then
hs.resources = statuses
end
return hs
end
- Use the
ClusterHealthCheckand set theclusterSelectorfield to filter the managed cluster deployments that should be examined. In the below example, all managed clusters that match the cluster label selectorenv=fvare considered.
apiVersion: lib.projectsveltos.io/v1alpha1
kind: ClusterHealthCheck
metadata:
name: production
spec:
clusterSelector: env=fv
livenessChecks:
- name: deployment
type: HealthCheck
livenessSourceRef:
kind: HealthCheck
apiVersion: lib.projectsveltos.io/v1alpha1
name: deployment-replicas
notifications:
- name: event
type: KubernetesEvent
The approach describe above enables us to display information about all the deployments across specific managed clusters effectively.
To obtain a consolidated view of resource information, the sveltosctl show resources command can be used.
$ sveltosctl show resources --kind=deployment
+-----------------------------+--------------------------+----------------+-----------------------------------------+----------------------------+
| CLUSTER | GVK | NAMESPACE | NAME | MESSAGE |
+-----------------------------+--------------------------+----------------+-----------------------------------------+----------------------------+
| default/clusterapi-workload | apps/v1, Kind=Deployment | kube-system | calico-kube-controllers | All replicas 1 are healthy |
| | | kube-system | coredns | All replicas 2 are healthy |
| | | kyverno | kyverno-admission-controller | All replicas 1 are healthy |
| | | kyverno | kyverno-background-controller | All replicas 1 are healthy |
| | | kyverno | kyverno-cleanup-controller | All replicas 1 are healthy |
| | | kyverno | kyverno-reports-controller | All replicas 1 are healthy |
| | | projectsveltos | sveltos-agent-manager | All replicas 1 are healthy |
| gke/pre-production | | gke-gmp-system | gmp-operator | All replicas 1 are healthy |
| | | gke-gmp-system | rule-evaluator | All replicas 1 are healthy |
| | | kube-system | antrea-controller-horizontal-autoscaler | All replicas 1 are healthy |
| | | kube-system | egress-nat-controller | All replicas 1 are healthy |
| | | kube-system | event-exporter-gke | All replicas 1 are healthy |
| | | kube-system | konnectivity-agent | All replicas 4 are healthy |
| | | kube-system | konnectivity-agent-autoscaler | All replicas 1 are healthy |
| | | kube-system | kube-dns | All replicas 2 are healthy |
| | | kube-system | kube-dns-autoscaler | All replicas 1 are healthy |
| | | kube-system | l7-default-backend | All replicas 1 are healthy |
| | | kube-system | metrics-server-v0.5.2 | All replicas 1 are healthy |
| | | kyverno | kyverno-admission-controller | All replicas 1 are healthy |
| | | kyverno | kyverno-background-controller | All replicas 1 are healthy |
| | | kyverno | kyverno-cleanup-controller | All replicas 1 are healthy |
| | | kyverno | kyverno-reports-controller | All replicas 1 are healthy |
| | | nginx | nginx-deployment | All replicas 2 are healthy |
| | | projectsveltos | sveltos-agent-manager | All replicas 1 are healthy |
| gke/production | | gke-gmp-system | gmp-operator | All replicas 1 are healthy |
| | | gke-gmp-system | rule-evaluator | All replicas 1 are healthy |
| | | kube-system | antrea-controller-horizontal-autoscaler | All replicas 1 are healthy |
| | | kube-system | egress-nat-controller | All replicas 1 are healthy |
| | | kube-system | event-exporter-gke | All replicas 1 are healthy |
| | | kube-system | konnectivity-agent | All replicas 3 are healthy |
| | | kube-system | konnectivity-agent-autoscaler | All replicas 1 are healthy |
| | | kube-system | kube-dns | All replicas 2 are healthy |
| | | kube-system | kube-dns-autoscaler | All replicas 1 are healthy |
| | | kube-system | l7-default-backend | All replicas 1 are healthy |
| | | kube-system | metrics-server-v0.5.2 | All replicas 1 are healthy |
| | | kyverno | kyverno-admission-controller | All replicas 1 are healthy |
| | | kyverno | kyverno-background-controller | All replicas 1 are healthy |
| | | kyverno | kyverno-cleanup-controller | All replicas 1 are healthy |
| | | kyverno | kyverno-reports-controller | All replicas 1 are healthy |
| | | projectsveltos | sveltos-agent-manager | All replicas 1 are healthy |
+-----------------------------+--------------------------+----------------+-----------------------------------------+----------------------------+
Below are all the available options to filter what the show resources output displays.
--group=<group>: Show Kubernetes resources deployed in clusters matching this group. If not specified, all groups are considered.
--kind=<kind>: Show Kubernetes resources deployed in clusters matching this Kind. If not specified, all kinds are considered.
--namespace=<namespace>: Show Kubernetes resources in this namespace. If not specified, all namespaces are considered.
--cluster-namespace=<name>: Show Kubernetes resources in clusters in this namespace. If not specified, all namespaces are considered.
--cluster=<name>: Show Kubernetes resources in the cluster with the specified name. If not specified, all cluster names are considered.
Additionally, with the use of the --full option, we can display the complete details of the resources.
$ sveltosctl show resources --full
Cluster: default/clusterapi-workload
Object: object:
apiVersion: apps/v1
kind: Deployment
metadata:
annotations:
deployment.kubernetes.io/revision: "1"
creationTimestamp: "2023-07-11T14:03:15Z"
...
Example: Display Deployment Images Managed Clusters
The below HealthCheck instance will instruct Sveltos to collect and display the deployment images from every managed cluster.
apiVersion: lib.projectsveltos.io/v1alpha1
kind: HealthCheck
metadata:
name: deployment-replicas
spec:
collectResources: true
group: "apps"
version: v1
kind: Deployment
namespace: nginx
script: |
function evaluate()
hs = {}
hs.status = "Progressing"
hs.message = ""
if obj.status ~= nil then
if obj.status.availableReplicas ~= nil then
if obj.status.availableReplicas == obj.spec.replicas then
hs.status = "Healthy"
else
hs.status = "Progressing"
end
end
if obj.status.unavailableReplicas ~= nil then
hs.status = "Degraded"
end
end
for i, container in ipairs(obj.spec.template.spec.containers) do
hs.message = "Image: " .. container.image
end
return hs
end
$ sveltosctl show resources
+-----------------------------+--------------------------+-----------+------------------+---------------------+
| CLUSTER | GVK | NAMESPACE | NAME | MESSAGE |
+-----------------------------+--------------------------+-----------+------------------+---------------------+
| default/clusterapi-workload | apps/v1, Kind=Deployment | nginx | nginx-deployment | Image: nginx:1.14.2 |
| gke/pre-production | | nginx | nginx-deployment | Image: nginx:latest |
| gke/production | | nginx | nginx-deployment | Image: nginx:1.14.2 |
+-----------------------------+--------------------------+-----------+------------------+---------------------+
Example: Display Pod Names Based on Deployment
The below HealthCheck instance will instruct Sveltos to collect and display the pod names based on a specified Deployment name.
apiVersion: lib.projectsveltos.io/v1alpha1
kind: HealthCheck
metadata:
name: pod-in-deployment
spec:
collectResources: true
group: ""
version: v1
kind: Pod
script: |
function setContains(set, key)
return set[key] ~= nil
end
function evaluate()
hs = {}
hs.status = "Healthy"
hs.message = ""
hs.ignore = true
if obj.metadata.labels ~= nil then
if setContains(obj.metadata.labels, "app") then
if obj.status.phase == "Running" then
hs.ignore = false
hs.message = "Deployment: " .. obj.metadata.labels["app"]
end
end
end
return hs
end
$ sveltosctl show resources --kind=pod --namespace=nginx
+-----------------------------+---------------+-----------+-----------------------------------+-------------------+
| CLUSTER | GVK | NAMESPACE | NAME | MESSAGE |
+-----------------------------+---------------+-----------+-----------------------------------+-------------------+
| default/clusterapi-workload | /v1, Kind=Pod | nginx | nginx-deployment-85996f8dbd-7tctq | Deployment: nginx |
| | | nginx | nginx-deployment-85996f8dbd-tz4gd | Deployment: nginx |
| gke/pre-production | | nginx | nginx-deployment-c4f7848dc-6jtwg | Deployment: nginx |
| | | nginx | nginx-deployment-c4f7848dc-trllk | Deployment: nginx |
| gke/production | | nginx | nginx-deployment-676cf9b46d-k84pb | Deployment: nginx |
| | | nginx | nginx-deployment-676cf9b46d-mmbl4 | Deployment: nginx |
+-----------------------------+---------------+-----------+-----------------------------------+-------------------+
Example: Display Kyverno PolicyReports
In this example we will define an HealthCheck instance with a Lua script that will:
- Examine all the Kyverno PolicyReports;
- Will report all the resources in violation of the policy and the rules defined
apiVersion: lib.projectsveltos.io/v1alpha1
kind: HealthCheck
metadata:
name: deployment-replicas
spec:
collectResources: true
resourceSelectors:
- group: wgpolicyk8s.io
version: v1alpha2
kind: PolicyReport
evaluateHealth: |
function evaluate()
local statuses = {}
status = "Healthy"
message = ""
for _,resource in ipairs(resources) do
for i, result in ipairs(resource.results) do
if result.result == "fail" then
status = "Degraded"
for j, r in ipairs(result.resources) do
message = message .. " " .. r.namespace .. "/" .. r.name
end
end
end
if status ~= "Healthy" then
table.insert(statuses, {resource=resource, status = status, message = message})
end
end
local hs = {}
if #statuses > 0 then
hs.resources = statuses
end
return hs
end
As before, we need to have a ClusterHealthCheck instance to instruct Sveltos which clusters to watch for.
apiVersion: lib.projectsveltos.io/v1alpha1
kind: ClusterHealthCheck
metadata:
name: production
spec:
clusterSelector: env=fv
livenessChecks:
- name: kyverno-policy-reports
type: HealthCheck
livenessSourceRef:
kind: HealthCheck
apiVersion: lib.projectsveltos.io/v1alpha1
name: kyverno-policy-reports
notifications:
- name: event
type: KubernetesEvent
We assume we have deployed an nginx deployment using the latest image in the managed cluster1
$ sveltosctl show resources
+-------------------------------------+--------------------------------+-----------+--------------------------+-----------------------------------------+
| CLUSTER | GVK | NAMESPACE | NAME | MESSAGE |
+-------------------------------------+--------------------------------+-----------+--------------------------+-----------------------------------------+
| default/sveltos-management-workload | wgpolicyk8s.io/v1alpha2, | nginx | cpol-disallow-latest-tag | nginx/nginx-deployment |
| | Kind=PolicyReport | | | nginx/nginx-deployment-6b7f675859 |
| | | | | nginx/nginx-deployment-6b7f675859-fp6tm |
| | | | | nginx/nginx-deployment-6b7f675859-kkft8 |
+-------------------------------------+--------------------------------+-----------+--------------------------+-----------------------------------------+
apiVersion: config.projectsveltos.io/v1alpha1
kind: ClusterProfile
metadata:
name: kyverno
spec:
clusterSelector: env=fv
helmCharts:
- chartName: kyverno/kyverno
chartVersion: v3.0.1
helmChartAction: Install
releaseName: kyverno-latest
releaseNamespace: kyverno
repositoryName: kyverno
repositoryURL: https://kyverno.github.io/kyverno/
policyRefs:
- deploymentType: Remote
kind: ConfigMap
name: kyverno-latest
namespace: default
$ wget https://github.com/kyverno/policies/raw/main//best-practices/disallow-latest-tag/disallow-latest-tag.yaml
$ kubectl create configmap kyverno-latest --from-file disallow-latest-tag.yaml
-
To deploy Kyverno and a ClusterPolicy in each managed cluster matching the label selector env=fv we can use the below
ClusterProfiledefinition. ↩