Warden MongoDb Watcher

OPEN SOURCE & CROSS-PLATFORM TOOL FOR SIMPLIFIED MONITORING

getwarden.net

Branch	Build status
master
develop

MongoDbWatcher can be used either for simple database monitoring (e.g. checking if a connection can be made) or more advanced one which may include running a specialized query.

Installation:

Available as a NuGet package.

dotnet add package Warden.Watchers.MongoDb

Configuration:

• WithQuery() - executes the specified query on a selected database.
• WithTimeout() - timeout after which the invalid result will be returned.
• EnsureThat() - predicate containing a received query result of type IEnumerable that has to be met in order to return a valid result.
• EnsureThatAsync() - async - predicate containing a received query result of type IEnumerable that has to be met in order to return a valid result
• WithConnectionProvider() - provide a custom IMongoDbConnection which is responsible for making a connection to the database.
• WithMongoDbProvider() - provide a custom IMongoDb which is responsible for executing a query on a database.

MongoDbWatcher can be configured by using the MongoDbWatcherWatcherConfiguration class or via the lambda expression passed to a specialized constructor.

Please note that either WithConnectionProvider() or WithDatabaseProvider() methods can be used to achieve the same goal, which is getting the IMongoDb instance.

Example of configuring the watcher via provided configuration class:

var configuration = MongoDbWatcherConfiguration
    .Create("MyDatabase", "mongodb://localhost:27017", timeout: TimeSpan.FromSeconds(3))
    .WithQuery("Users", "{\"name\": \"admin\"}")
    .EnsureThat(users => users.Any(user => user.role == "admin"))
    .Build();
var mongoDbWatcher = MongoDbWatcher.Create("My MongoDB watcher", configuration);

var wardenConfiguration = WardenConfiguration
    .Create()
    .AddWatcher(mongoDbWatcher)
    //Configure other watchers, hooks etc.

Example of adding the watcher directly to the Warden via one of the extension methods:

var wardenConfiguration = WardenConfiguration
    .Create()
    .AddMongoDbWatcher("mongodb://localhost:27017", "MyDatabase", cfg =>
    {
        cfg.WithQuery("Users", "{\"name\": \"admin\"}")
           .EnsureThat(users => users.Any(user => user.role == "admin"));
    }, timeout: TimeSpan.FromSeconds(3))
    //Configure other watchers, hooks etc.

Please note that you may either use the lambda expression for configuring the watcher or pass the configuration instance directly. You may also configure the hooks by using another lambda expression available in the extension methods.

Check result type:

MongoDbWatcher provides a custom MongoDbWatcherCheckResult type which contains additional values.

public class MongoDbWatcherCheckResult : WatcherCheckResult
{
    public string Database { get; }
    public string ConnectionString { get; }
    public string Query { get; }
    public IEnumerable<dynamic> QueryResult { get; }
}

Custom interfaces:

public interface IMongoDbConnection
{
    string Database { get; }
    string ConnectionString { get; }
    TimeSpan Timeout { get; }
    Task<IMongoDb> GetDatabaseAsync();
}

IMongoDbConnection is responsible for making a connection to the database. It can be configured via the WithConnectionProvider() method. By default it is based on the MongoDB Driver.

public interface IMongoDb
{
    Task<IEnumerable<dynamic>> QueryAsync(string collection, string query);
}

IMongoDb is responsible for executing the query on a database. It can be configured via the WithMongoDbProvider() method. By default it is based on the MongoDB Driver.