This is a simple CLI that provides an overview of the resource requests, limits, and utilization in a Kubernetes cluster. It attempts to combine the best parts of the output from kubectl top
and kubectl describe
into an easy to use CLI focused on cluster resources.
Go binaries are automatically built with each release by GoReleaser. These can be accessed on the GitHub releases page for this project.
This project can also be installed with Homebrew:
brew tap robscott/tap
brew install robscott/tap/kube-capacity
By default, kube-capacity will output a list of nodes with the total CPU and Memory resource requests and limits for all the pods running on them. For clusters with more than one node, the first line will also include cluster wide totals. That output will look something like this:
kube-capacity
NODE CPU REQUESTS CPU LIMITS MEMORY REQUESTS MEMORY LIMITS
* 560m (28%) 130m (7%) 572Mi (9%) 770Mi (13%)
example-node-1 220m (22%) 10m (1%) 192Mi (6%) 360Mi (12%)
example-node-2 340m (34%) 120m (12%) 380Mi (13%) 410Mi (14%)
For more detailed output, kube-capacity can include pods in the output. When -p
or --pods
are passed to kube-capacity, it will include pod specific output that looks like this:
kube-capacity --pods
NODE NAMESPACE POD CPU REQUESTS CPU LIMITS MEMORY REQUESTS MEMORY LIMITS
* * * 560m (28%) 780m (38%) 572Mi (9%) 770Mi (13%)
example-node-1 * * 220m (22%) 320m (32%) 192Mi (6%) 360Mi (12%)
example-node-1 kube-system metrics-server-lwc6z 100m (10%) 200m (20%) 100Mi (3%) 200Mi (7%)
example-node-1 kube-system coredns-7b5bcb98f8 120m (12%) 120m (12%) 92Mi (3%) 160Mi (5%)
example-node-2 * * 340m (34%) 460m (46%) 380Mi (13%) 410Mi (14%)
example-node-2 kube-system kube-proxy-3ki7 200m (20%) 280m (28%) 210Mi (7%) 210Mi (7%)
example-node-2 tiller tiller-deploy 140m (14%) 180m (18%) 170Mi (5%) 200Mi (7%)
To help understand how resource utilization compares to configured requests and limits, kube-capacity can include utilization metrics in the output. It's important to note that this output relies on metrics-server functioning correctly in your cluster. When -u
or --util
are passed to kube-capacity, it will include resource utilization information that looks like this:
kube-capacity --util
NODE CPU REQUESTS CPU LIMITS CPU UTIL MEMORY REQUESTS MEMORY LIMITS MEMORY UTIL
* 560m (28%) 130m (7%) 40m (2%) 572Mi (9%) 770Mi (13%) 470Mi (8%)
example-node-1 220m (22%) 10m (1%) 10m (1%) 192Mi (6%) 360Mi (12%) 210Mi (7%)
example-node-2 340m (34%) 120m (12%) 30m (3%) 380Mi (13%) 410Mi (14%) 260Mi (9%)
For more detailed output, kube-capacity can include both pods and resource utilization in the output. When --util
and --pods
are passed to kube-capacity, it will result in a wide output that looks like this:
kube-capacity --pods --util
NODE NAMESPACE POD CPU REQUESTS CPU LIMITS CPU UTIL MEMORY REQUESTS MEMORY LIMITS MEMORY UTIL
* * * 560m (28%) 780m (38%) 340m (17%) 572Mi (9%) 770Mi (13%) 470Mi (8%)
example-node-1 * * 220m (22%) 320m (32%) 160m (16%) 192Mi (6%) 360Mi (12%) 210Mi (7%)
example-node-1 kube-system metrics-server-lwc6z 100m (10%) 200m (20%) 70m (7%) 100Mi (3%) 200Mi (7%) 120Mi (4%)
example-node-1 kube-system coredns-7b5bcb98f8 120m (12%) 120m (12%) 90m (9%) 92Mi (3%) 160Mi (5%) 90Mi (3%)
example-node-2 * * 340m (34%) 460m (46%) 180m (18%) 380Mi (13%) 410Mi (14%) 260Mi (9%)
example-node-2 kube-system kube-proxy-3ki7 200m (20%) 280m (28%) 110m (11%) 210Mi (7%) 210Mi (7%) 120Mi (4%)
example-node-2 tiller tiller-deploy 140m (14%) 180m (18%) 70m (7%) 170Mi (6%) 200Mi (7%) 140Mi (5%)
It's worth noting that utilization numbers from pods will likely not add up to the total node utilization numbers. Unlike request and limit numbers where node and cluster level numbers represent a sum of pod values, node metrics come directly from metrics-server and will likely include other forms of resource utilization.
Any commands requesting cluster utilization are dependent on metrics-server running on your cluster. If it's not already installed, you can install it with the official helm chart.
If a KUBECONFIG
environment variable is specified, kube-capacity will attempt to use the config at that path, otherwise it will default to ~/.kube/config
.
There are already some great projects out there that have similar goals.
- kube-resource-report: generates HTML/CSS report for resource requests and limits across multiple clusters.
- kubetop: a CLI similar to top for Kubernetes, focused on resource utilization (not requests and limits).
Apache License 2.0