Done handler gets called twice when watch aborts

[mariusziemke]

When trying to do a continuous watch on kubernetes resources I noticed that the done handler gets called twice when the connection to the kubernetes api server aborts unexpectedly.

I don't have time to look deeper into this at the moment, but I guess it's because the error and close events both get fired on the request and both of them trigger the callback function.

Currently I just use a debounce function as a workaround, but we should find a better way of handling this.

Reference:

https://github.com/kubernetes-client/javascript/blob/master/src/watch.ts#L82
https://github.com/kubernetes-client/javascript/blob/master/src/watch.ts#L92

My code:

watchFunction(): void {
    this.watchClient.watch(
      '/api/v1/nodes',
      {},
      async (phase: string, node: V1Node) => {
        // do some magic
      },
      (err) => {
        console.log(`Failed to watch nodes.. restarting watch`);
        this.watchFunction()
      },
    );
}

Workaround:

watchFunction(): void {
    this.watchClient.watch(
      '/api/v1/nodes',
      {},
      async (phase: string, node: V1Node) => {
        // do some magic
      },
      debounce(() => {
        console.log(`Failed to watch nodes.. restarting watch`);
        this.watchFunction();
      }, 1000),
    );
}

[brendandburns]

There was the beginning of a fix here:
#505

I should revisit it.

I believe this is the root cause of #494 also.

[brendandburns]

Also, the trick is that what if someone only registers close shouldn't that also be called if it is closed b/c of an error?

[mariusziemke]

Good point. But close is called after an error anyways isn't it? Can we just save the error in a local variable and check if it is set after the connection got closed?

[brendandburns]

I think I'm just going to split the callback out and make it explicit that there is a done and an error callback and let the client handle the difference

[brendandburns]

Please have a look at #555

[mariusziemke]

LGTM! Thank you!