feat: add client/server version check mechanism to gRPC calls (#260)

* Add version check mechanism to gRPC calls

* Use semver not semver/v3

* Give dev builds a special "infinite" version number (999.0.0-dev)

* Handle no metadata on grpc call correctly for version check

* Move versioncheck package to root pkg/ from pkg/api/ since it is shared by both pkg/api/ and pkg/client/

* Only show "no daemon version" warning once

* Append version headers to metadata, not overwrite...

* Unit tests on versioncheck logic

* Move SetHeader to the ServerStream in ServerStreamInterceptor

* Go modernizer nits: interface{} -> any

* Use more conventional gRPC header names for version/min-versions

* Add TODO notes on checkDaemonVersionInResponse and related code that can be removed eventually after transition to version checking client/daemons

* Use testify for testing assertions

* Add explanatory comments on MinCLIVersion and MinDaemonVersion

---------

Co-authored-by: Pasha Sviderski <me@psviderski.name>

pkg/client/connector/unix.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 
+	"github.com/psviderski/uncloud/pkg/versioncheck"
 	"golang.org/x/net/proxy"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials/insecure"
@@ -26,6 +27,8 @@ func (c *UnixConnector) Connect(_ context.Context) (*grpc.ClientConn, error) {
 		target,
 		grpc.WithTransportCredentials(insecure.NewCredentials()),
 		grpc.WithDefaultServiceConfig(defaultServiceConfig),
+		grpc.WithUnaryInterceptor(versioncheck.ClientUnaryInterceptor),
+		grpc.WithStreamInterceptor(versioncheck.ClientStreamInterceptor),
 	)
 	if err != nil {
 		return nil, fmt.Errorf("create machine API client: %w", err)