SpoddyCoder Kube Tools

scube-tools is a suite of simple but useful Kubernetes helper tools.

These should all be considered beta, only my setups / systems have been tested so far. PR's welcome!

Requirements / Assumptions

• kubectl installed
• ~/.kube/config exists
• All commands use the current-context defined in ~/.kube/config
  • If you manage multiple clusters, check you are using the right context!
• You have correct permissions for the namespaces + resources you want to query / modify

Usage + Optional Installation

The tools can be run directly, so just copy wherever you need and run, eg:

./find-pod-and bash my-app

If you want them available system wide, do something like this...

sudo cp find-pod-and /usr/local/bin/scube-find-pod-and
sudo cp launch-dashboard /usr/local/bin/scube-launch-dashboard

Then run the commands as you would any other on your system (assuming /usr/local/bin/ is in your $PATH)...

scube-find-pod-and tail my-app

scube-launch-dashboard

find-pod-and

Because who hasn't had enough of using kubectl to query running pods?... Then copy-pasting auto-generated deployment id's into a second kubectl command... which you often forget the exact syntax for... Only to find out it has multiple containers... which you need to kubectl query... And then rerun th... FML!

Usage

./find-pod-and [command] [searchterm] [namespace]

Search running pods by [searchterm] and list matches, select one from the list and do [command]. If a pod has multiple containers, each is shown. eg:

./find-pod-and describe my-app -A

• [command]:

  • bash - /bin/bash into container
  • sh - /bin/sh into container
  • log - show container logs (logs also works)
  • tail - tail container logs
  • describe - describe the pod
  • help - show usage info (--help also works)

• [searchterm]:

  • somestring - search for pods matching somestring (also searches namespaces)
  • - - match-all, return all pods in selected namespace

• [namespace] (optional):

  • no value - search the current namespace in the current context
  • -A - search across all namespaces
  • mynamespace - search in mynamespace

Examples

Shell into a container...

scube-find-pod-and bash example

Searching for containers matching 'example' in namespace: default

1) default: example-app-1-deployment-1d23456789-9876 -> nginx

Select container number (or Enter to exit): 1

root@example-app-1-deployment-1d23456789-9876:/# service nginx status
nginx is running.

Tail application logs...

scube-find-pod-and tail app-1 my-app

Searching for containers matching 'app-1' in namespace: my-app

1) my-app: app-1-mysql-deployment-1298379231-1298 -> mysql
2) my-app: example-app-1-deployment-1d23456789-9876 -> varnish
3) my-app: example-app-1-deployment-1d23456789-9876 -> nginx

Select container number (or Enter to exit): 3

1000.99.99.99 - - [12/Jun/2022:22:31:52 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/102.0.0.0 Safari/537.36" "999.22.33.44"
2022/06/12 22:31:59 [error] 30#30: *1 open() "/usr/share/nginx/html/howaboutthis" failed (2: No such file or directory), client: 999.22.33.44, server: localhost, request: "GET /howaboutthis HTTP/1.1", host: "test.example.com"
1000.99.99.99 - - [12/Jun/2022:22:31:59 +0000] "GET /howaboutthis HTTP/1.1" 404 555 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/102.0.0.0 Safari/537.36" "999.22.33.44"

Get logs from kube-system core components...

scube-find-pod-and log kube -A

Searching for containers matching 'kube' across all namespaces

1) kube-system: coredns-123454567-99999 -> coredns
2) kube-system: coredns-786543211-99998 -> coredns
3) kube-system: etcd-k-master -> etcd
4) kube-system: kube-apiserver-k-master -> kube-apiserver
5) kube-system: kube-controller-manager-k-master -> kube-controller-manager
6) kube-system: kube-flannel-ds-12345 -> kube-flannel
7) kube-system: kube-proxy-4321 -> kube-proxy
8) kube-system: kube-scheduler-k-master -> kube-scheduler

Select container number (or Enter to exit): 2

.:53
[INFO] plugin/reload: Running configuration MD5 = f4304ahahahahahahahacf234m439
CoreDNS-55.5.5
linux/amd64, go5.55.5, 555555

launch-dashboard

Frugal dashboardery! Why have pods running when no-one's looking? This makes accessing the kubernetes dashboard as simple as it can possibly get...

scube-launch-dashboard

Scube is a good boi! Does all this for you...

• Get a new token for dashboard login and copy it to clipboard
  • Mac only - will print to STDOUT if pbcopy not found
  • Service account for the token generation is configurable
• Redeploy the dashboard pods
  • Scale is configurable
• Start the kubectl proxy
• Open the kube dashbaord url with default query workloads?all-namepsaces=&namespace=_all
  • Browser app is configurable
  • Kube proxy dash URL is configurable
  • Default query is configurable
• Listen for CTRL+C quit and cleans up
  • Stop the kubectl proxy
  • Undeploy the dashboard pods
• If the kubectl proxy is already running...
  • Just copy new token to the clipboard (or print to STDOUT)
  • Useful if your dashboard browser session times out

Kubernetes Dashboard Service Acccounts

By default this tool generates a token for the k8s-dashboard-admin service account. You can generate a token for a different service account by using the configuration options.

Example yaml to create a k8s-dashboard-admin service account with a cluster-admin rolebinding...

apiVersion: v1
kind: ServiceAccount
metadata:
  name: k8s-dashboard-admin
  namespace: kubernetes-dashboard
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: k8s-dashboard-admin-crb
subjects:
- kind: ServiceAccount
  name: k8s-dashboard-admin
  namespace: kubernetes-dashboard
roleRef:
  kind: ClusterRole
  name: cluster-admin
  apiGroup: rbac.authorization.k8s.io

Warning: ensure you understand the consequences, this gives the k8s-dashboard-admin service account full access to your cluster.

Configuration

Available settings;

• service name for token generation
  • default: k8s-dashboard-admin
• browser app
  • default: /Applications/Google Chrome.app (mac chrome)
• proxy dashboard url
  • default: http://localhost:8001/api/v1/namespaces/kubernetes-dashboard/services/https:kubernetes-dashboard:/proxy/
• browser query
  • default: "workloads?all-namepsaces=&namespace=_all
• kubernetes-dashboard pods deployment scale
  • default: 1

The tool looks for config files at different locations, they are applied in the following order, each overriding values in the previous...

• Default config: tool source code, eg: /usr/local/bin/scube-launch-dashboard
• System config: /etc/scube-tools/launch-dashboard.conf
• User config: ~/.scube-tools/launch-dashboard.conf
• Directory config: .launch-dashboard.conf or .scube-launch-dashboard.conf

See the tool for the user config variable names and their descriptions.

Contributing

Contributions very welcome! Something wrong? Could be better? Additional use-cases? Please post in the issues forum or submit a PR. See the tool source code for outstanding ideas / todo's.