If you are developing with the combination of an M1 MacBook + golang + memongo, you will run into the error message below and start searching for how to fix it. Since I forget the setup steps every time a new team member joins, I'm writing this down again.
When you run memongo on an M1, you'll see that it throws an error during the memongo download process saying the system architecture does not match, and it fails to run.
=== RUN TestMongoTestSuite
{"time":"2023-02-25T17:15:24.374615+09:00","level":"FATAL","prefix":"-","file":"db.go","line":"17","message":"memongo does not support automatic downloading on your system: your architecture, arm64, is not supported"}
There are two solutions. Personally, rather than having to remember the option every time, I find it a bit more convenient to leave the default settings as they are and use the downloaded MongoDB binary, so I recommend running it with the second approach.
1. Configuring Memongo Options
You can run it on an M1 by providing the URL to download when the architecture is arm64.
opts := &memongo.Options{
ShouldUseReplica: true,
MongoVersion: "4.2.1",
LogLevel: 2,
}
if runtime.GOARCH == "arm64" {
if runtime.GOOS == "darwin" {
// Only set the custom url as workaround for arm64 macs
opts.DownloadURL = "https://fastdl.mongodb.org/osx/mongodb-macos-x86_64-4.2.1.tgz"
}
}
mongoServer, err := memongo.StartWithOptions(opts)
2. Using a Custom MongoDB Binary
If you download the MongoDB binary and set the environment variables MEMONGO_MONGOD_BIN and PATH, you can make it use the already installed binary instead of downloading one. If you happen to run into problems when running it, very occasionally you may need to kill mongod with pkill.
Install mongodb with brew.
$ brew tap mongodb/brew
$ brew update
$ brew install mongodb-community@4.2
Verify that MongoDB is installed properly.
$ mongo --version
MongoDB shell version v4.2.21
git version: b0aeed9445ff41af07449fa757e1f231bce990b3
allocator: system
modules: none
build environment:
distarch: x86_64
target_arch: x86_64
Add the required environment variables to your shell's configuration. Note that if you run it from GoLand, you need to restart the application after modifying the shell settings.
$ vim ~/.zshrc
export MEMONGO_MONGOD_BIN=/opt/homebrew/opt/mongodb-community@4.2/bin/mongod
export PATH=$PATH:/opt/homebrew/opt/mongodb-community@4.2/bin
If you run memongo_test.go again, you can confirm that it runs fine.
=== RUN TestMongoTestSuite
[memongo] [INFO] Starting MongoDB with options &memongo.Options{ShouldUseReplica:true, Port:57585, CachePath:"", MongoVersion:"4.2.1", DownloadURL:"", MongodBin:"/opt/homebrew/opt/mongodb-community@4.2/bin/mongod", Logger:(*log.Logger)(nil), LogLevel:0, StartupTimeout:10000000000, Auth:false}
--- PASS: TestMongoTestSuite (2.21s)
=== RUN TestMongoTestSuite/TestQuery
[{_id ObjectID("63f9c767d1ef4a0debb6f01a")} {type Oolong} {rating 7} {vendor [C]}]
--- PASS: TestMongoTestSuite/TestQuery (0.00s)
PASS