x/build/cmd/buildlet: Reverse Dial Fails in Local devMode

[hydernaqvi]

What version of Go are you using (go version)?

$ go version
go1.19

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

go env Output

$ go env

linux/amd64

What did you do?

Followed instructions at https://github.com/golang/build/tree/master/cmd/coordinator

1. ran go run . -mode=dev -listen-http=localhost:8119
2. followed by go run golang.org/x/build/cmd/buildlet -halt=false -reverse-type=host-linux-amd64-localdev

What did you expect to see?

Messages confirming reverse mode connection between coordinator and buildlet such as:

Registering reverse mode with coordinator...
Connected to coordinator; reverse dialing active

What did you see instead?

Error dialing coordinator: failed to handshake with coordinator: tls: first record does not look like a TLS handshake

[mknyszek]

CC @golang/release

[dmitshur]

Thanks for reporting. We can choose to improve coordinator's local dev mode if that's a good path to implementing and testing some change, and I think @prattmic helped make this work better most recently, but in general local development mode of coordinator is best effort and doesn't make any guarantees.

[prattmic]

https://go.dev/cl/354309 and https://go.dev/cl/354310 are what I was using to get local reverse buildlets working.