Create an example for starting mongodb as a replica set

[makesbuckets]

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Describe your problem

I use dockertest/v3 extensively in my testing of api servers in go.

I am getting to the point where I want to do more interesting things the backing mongodb database (e.g. change streams, transactions) and still would like to containerize the mongo instance for tests. I feel like I'm close to figuring this out but I'd like to successfully run rs.initiate() inside the mongodb container after creating the test resource, but have been running into issues successfully using the resource.Exec function.

Describe your ideal solution

Spin up a mongodb container, programmatically in go, with replica set configuration and execute the rs.initiate() command so that the repl set is connectable in code. Was hoping something like this would work:

.Exec([]string{`echo "rs.initiate().ok || rs.status().ok" | mongo`}

Workarounds or alternatives

While troubleshooting, I have tried removing the "pipe to mongo shell" at first with no success, so I think I am just going about resource.Exec incorrectly here.

When calling: .Exec([]string{echo "rs.initiate().ok || rs.status().ok"}, I see output:

OCI runtime exec failed: exec failed: unable to start container process: exec: "echo \"rs.initiate().ok || rs.status().ok\"": executable file not found in $PATH: unknown

When adding "/bin/bash" in front: Exec([]string{"/bin/bash", echo "rs.initiate().ok || rs.status().ok"}:

/bin/bash: echo "rs.initiate().ok || rs.status().ok": No such file or directory

Version

github.com/ory/dockertest/v3 v3.10.0

Additional Context

No response

[makesbuckets]

Updated context: when originally posting this, I ran with the options:

var out bytes.Buffer
dockertest.ExecOptions{
	StdOut: &out,
	StdErr: &out,
}

I have since tried adding TTY: true and see a new error:

Start exec failed: Unrecognized input header: 47

Again, I feel I am close here, just missing probably one or two (obvious) things here

[t2y]

I am trying to initialize a replica set for testing, too. Does anyone have a good solution?

[t2y]

IIRC, --keyFile also is needed to specify with a replica set together.

• https://www.mongodb.com/docs/manual/reference/program/mongod/#std-option-mongod.--keyFile