Dependency conflict errors when using Agones SDK in runtime module

Local Setup
3

Hi @jonbonazza. Thanks for the post on the forums to describe this use case. The error you posted can happen with Go-based Nakama projects so I thought it would be valuable to others to explain in detail.

“Could not open Go module”,“path”:“/nakama/data/modules/roa-nakama.so”,“error”:“plugin.Open("/nakama/data/modules/roa-nakama"): plugin was built with a different version of package The Go Programming Language”

The specific package named (i.e. “The Go Programming Language”) that cannot be loaded changes sometimes based on the dependencies in your plugin project code but the root cause is all for the same reason. When a project is built with Go as a plugin a copy of the Go runtime is bundled with the shared object; it’s covered in detail here.

The result is that Nakama’s copy of the Go runtime and the Go runtime bundled with the shared object of your plugin code must be an exact match with its list of dependencies (cached in the binaries via Go mod). This should be straightfoward to match dependencies but becomes trickier because Go mod dependency management uses minimal version selection. This means that it’s difficult to pin transitive dependencies to specific versions. This makes it hard to achieve an exact match of the deps tree.

We have found a useful workaround to pin a transitive dependency without a problem when the code is compiled. I’ve put together my example code.

The go.mod file looks like:

module github.com/heroiclabs/agones_nakama

go 1.13

require (
	agones.dev/agones v1.2.0
	github.com/grpc-ecosystem/grpc-gateway v1.11.1
	github.com/heroiclabs/nakama-common v1.3.0
	golang.org/x/net v0.0.0-20190827160401-ba9fcec4b297
	golang.org/x/text v0.3.2
)

The main file for the plugin code looks like:

package main

import (
	agones "agones.dev/agones/sdks/go"
	"context"
	"database/sql"
	"github.com/heroiclabs/nakama-common/runtime"

	// NOTE: Do not remove. These are required to pin as direct dependencies with Go modules.
	_ "golang.org/x/net/idna"
	_ "golang.org/x/text/transform"
	_ "github.com/grpc-ecosystem/grpc-gateway/utilities"
)

func InitModule(ctx context.Context, logger runtime.Logger, db *sql.DB, nk runtime.NakamaModule, initializer runtime.Initializer) error {
	_, err := agones.NewSDK()
	if err != nil {
		return err
	}
	return nil
}

I should note that I don’t know much about the Agones Go SDK so my code is just an example to check it all compiles and runs fine.

I can add more details if it’d help but let me know if this resolves the build issue with your code.

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