Provider gRPC client logging causes failures.

[liamawhite]

I'm trying to write my own provider using the boilerplate template but I think there is a breaking bug. From what I can tell the provider is expected to output to stdout the port it is listening on, but what appears to happen is that grpc logging beats it to it.

When I run Pulumi up I get:

pulumi:providers:tsb (tsb):
    error: tsb (resource) plugin [/Users/liamwhite/go/bin/pulumi-resource-tsb] wrote a non-numeric port to stdout ('2021-05-27T13:44:04.073942Z	info	[core]parsed scheme: ""'): strconv.Atoi: parsing "2021-05-27T13:44:04.073942Z\tinfo\t[core]parsed scheme: \"\"": invalid syntax

I can fix this by manually configuring the grpc logger to either info log to stderr (or discard).

// NewHostClient dials the target address, connects over gRPC, and returns a client interface.
func NewHostClient(addr string) (*HostClient, error) {
	grpclog.SetLoggerV2(grpclog.NewLoggerV2(os.Stderr, os.Stderr, os.Stderr)) // <-----------
	conn, err := grpc.Dial(
		addr,
		grpc.WithInsecure(),
		grpc.WithUnaryInterceptor(rpcutil.OpenTracingClientInterceptor()),
		rpcutil.GrpcChannelOptions(),
	)
...

The only problem with sending to stderr is that it shows up in diagnostics so it may be preferable to io.Discard instead.

[lukehoban]

From what I can tell the provider is expected to output to stdout the port it is listening on, but what appears to happen is that grpc logging beats it to it.

Yes - a requirement for a Pulumi plugin is that the first output to stdout is the port to use to connect to its gRPC server. That is part of the contract of what it means to be a Pulumi Plugin. You will need to ensure that you don't log anything to stdout ahead of that.

[liamawhite]

@lukehoban I wasn't logging anything this just happened using the standard boilerplate that imports the Main function @3.3.1.

[lukehoban]

I wasn't logging anything this just happened using the standard boilerplate that imports the Main function @3.3.1.

I just tried out cloning https://github.com/pulumi/pulumi-provider-boilerplate, updating go.mod to use github.com/pulumi/pulumi/pkg/v3 v3.3.1, building the provider, and then running an example using the provider, and I am not seeing this issue. Do you have repro steps for what additional changes you are making that might potentially impact this?

[liamawhite]

I did some more investigating and after deleting my go mod cache and re-downloading everything it appears to not be an issue. I have no idea what was causing it.

[liamawhite]

I noticed this hadn't actually gone away (we just hadn't rebuilt it recently). Having rebuilt without the logging changed I mentioned it still occurs. I have opened up a PR to solve the issue.