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kswitch

Hooks

Hooks

Section titled “Hooks”

By providing a configuration file, the kswitch tool can call arbitrary hooks (an executable or inline shell command).

switch hooks help
Usage:
  --config-path path to the configuration file. (default "~/.kube/switch-config.yaml")
  --state-directory path to the state directory. (default "~/.kube/switch-state")
  --hook-name the name of the hook that should be run.
  --run-hooks-immediately run hooks right away. Do not respect the hooks execution configuration. (default "true").

Hooks are executed prior to the fuzzy search via $ switch or can be called directly via $ switch hooks --hook-name=<name>.

The default location for the config file is at ~/.kube/switch-config.yaml or can be set with --hook-config-path.

You can find several demo configuration files here.

See configured Hooks

Section titled “See configured Hooks”

This shows an overview of all configured hooks including their type, interval and when the next execution will be.

$ switch hooks ls


+---------------------------+------------+----------+----------------+
| NAME                      | TYPE       | INTERVAL | NEXT EXECUTION |
+---------------------------+------------+----------+----------------+
| sync-local-landscape      | Executable | 24h0m0s  | 3h48m0s        |
| sync-dev-landscape        | Executable | 6h0m0s   | 4h39m0s        |
| sync-ns2-canary-landscape | Executable | 12h0m0s  | 3h57m0s        |
| sync-live-landscape       | Executable | 24h0m0s  | 3h47m0s        |
| sync-ns2-live-landscape   | Executable | 48h0m0s  | 27h47m0s       |
| sync-canary-landscape     | Executable | 48h0m0s  | 27h47m0s       |
+---------------------------+------------+----------+----------------+
| TOTAL                     | 6          |          |                |
+---------------------------+------------+----------+----------------+

Hook calling an executable

Section titled “Hook calling an executable”

Hooks can call an arbitrary executable and pass arguments.

Below is the configuration to use with Gardener installations. The Hook gardener-landscape-sync downloads the kubeconfig files for all available Kubernetes clusters to the local filesystem. The hook is executed every 6 hours. Not specifying an execution interval means that the hook shall only be run on demand via switch hooks --hook-name <name>.

kind: SwitchConfig
hooks:
  - name: sync-dev-landscape
    type: Executable
    path: /Users/<your-user>/go/src/github.com/MichaelSp/kswitch/hack/hooks/hook-gardener-landscape-sync
    arguments:
      - "sync"
      - "--garden-kubeconfig-path"
      - "/Users/<your-user>/.kube/switch/dev/dev-virtual-garden/config"
      - "--export-path"
      - "/Users/<your-user>/.kube/gardener-landscapes"
      - "--landscape-name"
      - "dev"
      - "--clean-directory=true"
    execution:
      interval: 6h

Hook with inline command

Section titled “Hook with inline command”

A hook can also just execute shell commands directly. For example, the below configuration uses an inline command to garbage collection temporary kubeconfig files every 6 hours.

kind: SwitchConfig
hooks:
  - name: inline
    type: InlineCommand
    execution:
      interval: 6h
    arguments:
      - "/Users/<your-user>/go/src/github.com/MichaelSp/kswitch/hack/switch/kswitch clean && echo ' Garbage collection complete.'"

Hook State

Section titled “Hook State”

To remember the last execution time for hooks, a file is written into the state directory. The default location for the hook state files are at ~/.kube/switch-state or can be set with --state-directory.