EphemeralMongo is a set of multiple NuGet packages wrapping the binaries of MongoDB 4, 5, 6 and 7. Each package targets .NET Standard 2.0, which means you can use it with .NET Framework 4.5.2 up to .NET 6 and later.
The supported operating systems are Linux, macOS and Windows on their x64 architecture versions only. Each package provides access to:
This project is very much inspired from Mongo2Go but contains several improvements:
ManualResetEventSlim
.Use the static MongoRunner.Run()
method to create a disposable instance that provides access to a MongoDB connection string, import and export tools:
// All properties below are optional. The whole "options" instance is optional too!
var options = new MongoRunnerOptions
{
UseSingleNodeReplicaSet = true, // Default: false
StandardOuputLogger = line => Console.WriteLine(line), // Default: null
StandardErrorLogger = line => Console.WriteLine(line), // Default: null
DataDirectory = "/path/to/data/", // Default: null
BinaryDirectory = "/path/to/mongo/bin/", // Default: null
ConnectionTimeout = TimeSpan.FromSeconds(10), // Default: 30 seconds
ReplicaSetSetupTimeout = TimeSpan.FromSeconds(5), // Default: 10 seconds
AdditionalArguments = "--quiet", // Default: null
MongoPort = 27017, // Default: random available port
// EXPERIMENTAL - Only works on Windows and modern .NET (netcoreapp3.1, net5.0, net6.0, net7.0 and so on):
// Ensures that all MongoDB child processes are killed when the current process is prematurely killed,
// for instance when killed from the task manager or the IDE unit tests window. Processes are managed as a unit using
// job objects: https://learn.microsoft.com/en-us/windows/win32/procthread/job-objects
KillMongoProcessesWhenCurrentProcessExits = true // Default: false
};
// Disposing the runner will kill the MongoDB process (mongod) and delete the associated data directory
using (var runner = MongoRunner.Run(options))
{
var database = new MongoClient(runner.ConnectionString).GetDatabase("default");
// Do something with the database
database.CreateCollection("people");
// Export a collection. Full method signature:
// Export(string database, string collection, string outputFilePath, string? additionalArguments = null)
runner.Export("default", "people", "/path/to/default.json");
// Import a collection. Full method signature:
// Import(string database, string collection, string inputFilePath, string? additionalArguments = null, bool drop = false)
runner.Import("default", "people", "/path/to/default.json");
}
mongod
, mongoimport
and mongoexport
) are copied to your project output directory,MongoRunner.Run
always starts a new mongod
process with a random available port,UseSingleNodeReplicaSet
and AdditionalArguments
),EphemeralMongo4, 5, 6 and 7 are NuGet metapackages that reference dedicated runtime packages for both Linux, macOS and Windows. As of now, there isn't a way to optimize NuGet package downloads for a specific operating system (see #2). However, one can still avoid referencing the metapackage and directly reference the dependencies instead. Add MSBuild OS platform conditions and you'll get optimized NuGet imports for your OS and less downloads.
Instead of doing this:
<PackageReference Include="EphemeralMongo6" Version="1.0.0" />
Do this:
<PackageReference Include="EphemeralMongo.Core" Version="1.0.0" />
<PackageReference Include="EphemeralMongo6.runtime.linux-x64" Version="1.0.0" Condition="$([MSBuild]::IsOSPlatform('Linux'))" />
<PackageReference Include="EphemeralMongo6.runtime.osx-x64" Version="1.0.0" Condition="$([MSBuild]::IsOSPlatform('OSX'))" />
<PackageReference Include="EphemeralMongo6.runtime.win-x64" Version="1.0.0" Condition="$([MSBuild]::IsOSPlatform('Windows'))" />
On Windows, you might get a Windows Defender Firewall prompt.
This is because this EphemeralMongo starts the mongod.exe
process from your build output directory, and mongod.exe
tries to open an available port.
Avoid calling MongoRunner.Run
concurrently, as this will create many mongod
processes and make your operating system slower.
Instead, try to use a single instance and reuse it - create as many databases as you need, one per test for example.
Check out this gist for an implementation of a reusable IMongoRunner
.