Kubeletctl is a command line tool that implement kubelet's API.
Part of kubelet's API is documented but most of it is not.
This tool covers all the documented and undocumented APIs.
The full list of all kubelet's API can be view through the tool or this API table.
A related blog post:
https://www.cyberark.com/resources/threat-research-blog/using-kubelet-client-to-attack-the-kubernetes-cluster
- Run any kubelet API call
- Scan for nodes with opened kubelet API
- Scan for containers with RCE
- Run a command on all the available containers by kubelet at the same time
- Get service account tokens from all available containers by kubelet
- Nice printing :)
On the releases page you will find the latest releases with links based on the operating system.
For the following examples, we will use the kubeletctl_linux_amd64 binary link. If you plan to use other link, change it accordingly.
wget https://github.com/cyberark/kubeletctl/releases/download/v1.13/kubeletctl_linux_amd64 && chmod a+x ./kubeletctl_linux_amd64 && mv ./kubeletctl_linux_amd64 /usr/local/bin/kubeletctl
curl -LO https://github.com/cyberark/kubeletctl/releases/download/v1.13/kubeletctl_linux_amd64 && chmod a+x ./kubeletctl_linux_amd64 && mv ./kubeletctl_linux_amd64 /usr/local/bin/kubeletctl
kubeletctl works similar to kubectl, use the following syntax to run commands:
Usage:
kubeletctl [flags]
kubeletctl [command]
Available Commands:
attach Attach to a container
checkpoint Taking a container snapshot
configz Return kubelet's configuration.
containerLogs Return container log
cri Run commands inside a container through the Container Runtime Interface (CRI)
debug Return debug information (pprof or flags)
exec Run commands inside a container
healthz Check the state of the node
help Help about any command
log Return the log from the node.
metrics Return resource usage metrics (such as container CPU, memory usage, etc.)
pid2pod That shows how Linux process IDs (PIDs) can be mapped to Kubernetes pod metadata
pods Get list of pods on the node
portForward Attach to a container
run Run commands inside a container
runningpods Returns all pods running on kubelet from looking at the container runtime cache.
scan Scans for nodes with opened kubelet API
spec Cached MachineInfo returned by cadvisor
stats Return statistical information for the resources in the node.
version Print the version of the kubeletctl
Flags:
--cacert string CA certificate (example: /etc/kubernetes/pki/ca.crt )
--cert string Private key (example: /var/lib/kubelet/pki/kubelet-client-current.pem)
--cidr string A network of IP addresses (Example: x.x.x.x/24)
-k, --config string KubeConfig file
-c, --container string Container name
-h, --help help for kubeletctl
--http Use HTTP (default is HTTPS)
-i, --ignoreconfig Ignore the default KUBECONFIG environment variable or location ~/.kube
--key string Digital certificate (example: /var/lib/kubelet/pki/kubelet-client-current.pem)
-n, --namespace string pod namespace
-p, --pod string Pod name
--port string Kubelet's port, default is 10250
-r, --raw Prints raw data
-s, --server string Server address (format: x.x.x.x. For Example: 123.123.123.123)
-t, --token string Service account Token (JWT) to insert
-f, --token-file string Service account Token (JWT) file path
-u, --uid string Pod UID
Use "kubeletctl [command] --help" for more information about a command.
To view the details on each command or subcommand use the -h\--help switch.
Prerequisite:
To build the project run:
# If some of the libraries are not installed
go mod tidy
make -j all
This will create build/kubeletctl_{{.OS}}_{{.Arch}} binaries.
For Windows users it is possible to use gox directly:
gox -ldflags "-s -w" -osarch linux/amd64 -osarch linux/386 -osarch windows/amd64 -osarch windows/386 -osarch="darwin/amd64"
You can use the attached release Dockerfile to build a local image by running:
make docker-release
Then run:
docker run -it --rm kubeletctl:release
This will fetch and unpack the latest release binary into the Dockerfile.
If you wish to build from source run:
make docker
Then run:
docker run -it --rm kubeletctl:latest
We welcome contributions of all kinds to this repository.
For instructions on how to get started and descriptions
of our development workflows, please see our contributing guide.
Copyright (c) 2020 CyberArk Software Ltd. All rights reserved
This repository is licensed under Apache License 2.0 - see LICENSE for more details.
For more comments, suggestions or questions, you can contact Eviatar Gerzi (@g3rzi) from CyberArk Labs. You can find more projects developed by us in https://github.com/cyberark/.