Hello, an enquiry please, is there a method to get inside the containers using this kubernetes-client?

[DivyaYash]

I wanted to programmatically get inside the container and check if a certain process is up or not..Is that possible?

[silasbw]

kubernetes-client does not currently support this. We should support it. Do you want to try adding support for this?

[DivyaYash]

@silasbw, am very new to the whole development stuff, with my skill level, I do not think I can contribute :( But definitely in need of this feature..I do not want to use kubectl hence looking for other means..

[silasbw]

Understood: you can use kubectl exec for getting a nice interactive shell in the container running as part of a pod. We plan on adding exec support to kubernetes-client, but we we're working on other priorities right now.

[DivyaYash]

Yes, for now am going to use the kubectl exec to get the desired feature..Please let me know when this feature is added to kubernetes-client..Thank you!

[nick]

It took me a while to piece this together, so leaving it here to help others. The following code lets you run the equivalent of kube exec programatically. You may need to run the script with NODE_TLS_REJECT_UNAUTHORIZED=0 if there is a certificate error. You'll also need the ws package.

const WebSocket = require('ws');

function exec(apiUri, namespace, pod, cmd, callback) {
    var response = '', uri = '';

    uri += `wss://${apiUri}/api/v1/namespaces/${namespace}/pods/${pod}/exec?`;
    uri += 'stdout=1&stdin=1&stderr=1';
    cmd.forEach(subCmd => uri += `&command=${encodeURIComponent(subCmd)}`);

    var ws = new WebSocket(uri, "base64.channel.k8s.io")
    ws.on('message', (data) => {
        if (data[0].match(/^[0-3]$/)) {
            response += Buffer.from(data.slice(1), 'base64').toString("ascii");
        }
    });
    ws.on('close', () => callback(response));
}

exec(
    'user:pass@kubecluster:6443',
    'default',
    'pod-name',
    ['/bin/sh', '-c', 'df -h | grep device'],
    (response) => {
        console.log(response);
    }
)

[silasbw]

Oh wow, nice. Would love to see a PR for this :)