Scripting

Custom-logic scripts use hooks and helpers to trigger actions, supported by the available integrations, and based on programmatic decisions and/or on a schedule.

Kubeshark scripting language is based on Javascript ES5.

The following script example calculates the number of packets and overall traffic processed per minute using an L4 network hook (onPacketCaptured), some helpers and a job.

var packetCount = 0;
var totalKB = 0;

function onPacketCaptured(info) {
  packetCount++;
  totalKB += info.length / 1000;
}

function logPacketCountTotalBytes() {
  console.log("Captured packet count per minute:", packetCount);
  packetCount = 0;
  console.log("Total KB captured per minute:", totalKB);
  totalKB = 0;
}

jobs.schedule("log-packet-count-total-bytes", "0 */1 * * * *", logPacketCountTotalBytes);

Scripts Development

Develope your scripts locally in your environment (e.g. VS Code, GitHub) and simply add your scripts folder to the scripts section in Kubeshark’s configuration file .

scripting:
  source: "/path/to/scripts/folder/"

Scripts Runtime

All scripts are transmitted to the workers and executed inside the K8s cluster at the node-level.

Local Scripts Folder

Kubeshark provides the option to view and make temporary changes to the scripts currently executed by the workers.

You can edit, add, delete scripts directly in the workers. Any changes you make are not persistent and will apply for as long Kubeshark is running.

Scripting Editor

To access the dashboard’s script editor and edit the scripts in the workers, press the scrips button located at the top right corner. Scripting Button

The CLI monitors the scripts folder by default and updates the workers on any changes. You can use the kubeshark scripts command to explicitly monitor the folder for changes, especially if you don’t use the CLI.

The following command wil transmit the content of any folder to the workers:

kubeshark scripts --set scripting.source="/path/to/scripts/folder/"

Environment Variables

You can use the env configuration directive to provide environment variables for your scripts to use.

scripting:
  env:
    SLACK_AUTH_TOKEN: "xo.."
    SLACK_CHANNEL_ID: "C0.."
    WEBHOOK_URL: "https://webh.."
    INFLUXDB_URL: "https://us-e.."
    INFLUXDB_TOKEN: "_9r.."
    INFLUXDB_MEASUREMENT: "st.."
    INFLUXDB_ORGANIZATION: "a.."
    INFLUXDB_BUCKET: "al.."
  source: "/User.."

To use any of the env variables in a script, use the prefix: env.*. For example:

vendor.influxdb(
  env.INFLUXDB_URL,
  env.INFLUXDB_TOKEN,
  env.INFLUXDB_ORGANIZATION,
  env.INFLUXDB_BUCKET,
  "Example Measurement",        // Measurement
  data,                         // Payload
  {"example":"tag"}
);

Scopes

Kubeshark scripts supports the following scopes:

  • Function: When variables and functions are declared within a function.
  • Script: When variables and functions are declared outside functions , at the specific script level and can maintain a state across the specific script’s functions.
  • Global When you use the object this you can decares scrips and function at the global level accessible by all scripts.

Script Examples Dropdown

Kubeshark comes with numerous script examples representing certain use-cases as part of its dashboard. Use the Examples dropdown list to access the list of script examples.

Script Examples