Support v2 exec-watch in v3 etcdctl

[wwyiwzhang]

Hi there,
I cannot use exec-watch in etcdctl api v3.
I wonder if it is going to be added as a feature soon or is there a command that can substitute it in v3?

Thanks!

[gyuho]

What's your use case? We don't have exec-watch command for v3, and no plan yet.

If you use v3 lock command, we have something similar

https://github.com/coreos/etcd/blob/b65435b86d80fd3e71c6411832e8cc7eb8fb8b44/etcdctl/ctlv3/command/lock_command.go#L34-L37

[wwyiwzhang]

In API v2, I can do something like,
etcdctl --no-sync --endpoints ${ENDPOINTS} exec-watch --recursive /${prefix} -- sh -c 'python <name of the script> -a "$ETCD_WATCH_ACTION" -ck "$ETCD_WATCH_KEY" -cv "$ETCD_WATCH_VALUE"
How can I replicate in API v3?

[wwyiwzhang]

Based on the offline chat, I think etcd watch seems to be the only option.
I am trying to replicate this,
etcdctl --no-sync --endpoints ${ENDPOINTS} exec-watch --recursive /${prefix} -- sh -c 'python <name of the script> -a "$ETCD_WATCH_ACTION" -ck "$ETCD_WATCH_KEY" -cv "$ETCD_WATCH_VALUE" in API v2
using API v3.
We rely on exec-watch to trigger events for the downstream applications. Could you provide any workaround or ideas?

[pldmgg]

Any news on this? From @wwyiwzhang 's comment, it seems like we use v2's exec-watch similarly.

I'm not sure I quite follow the lock example either...

[gyuho]

@pldmgg Currently, we don't have bandwidth to add this feature. Contributions are welcome!

[jiaxuanzhou]

@xiang90 I will effort on it

[gyuho]

@jiaxuanzhou @wwyiwzhang Can you try #8919? Thanks!