Simulator

The accumulate repository includes a simulator. The simulator runs a fully functional Accumulate engine and API, though it does not simulate Tendermint. It does simulate multiple nodes with a basic consensus mechanism, so it will catch most potential consensus failures.

Run the simulator

The easiest way to run the simulator is via Docker:

docker run -p 26660:26660 -v /path/to/data:/data registry.gitlab.com/accumulatenetwork/accumulate/simulator

Alternatively, --net=host can be used instead of -p 26660:26660. Without -v, all history will be lost if the simulator is stopped or restarted. The data directory (/data) can be bound to an arbitrary host directory, or to a docker volume, but it must be bound to something outside of the container if the simulator's state is to be persisted.

Using the simulator in Go programs

simulator.New requires four parameters: a logger, database provider, network definition, and snapshot provider. These parameters are structs, functions, or simple interfaces, so the caller may provide custom inputs if they wish, though the simulator package includes implementations.

For the database provider, the simulator package includes MemoryDatabase, which opens transient in-memory databases, and BadgerDatabaseFromDirectory, which opens persistent Badger databases in the given directory.

For the network definition, the simulator package includes SimpleNetwork, which defines an N x M network with N BVNs, each with M nodes; and LocalNetwork, which defines an N x M network with IP addresses, which allows the simulator to be made network accessible.

For the snapshot provider, the simulator package includes Genesis and friends, which construct genesis snapshots; SnapshotMap, which returns snapshots from a map provided by the caller; and SnapshotFromDirectory, which returns snapshots read from a directory.

simulator.Simulator has a number of methods to submit messages, and hook into and modify the inner workings of the systems (for testing purposes), as well as a full implementation of API v3.

The simulator must be manually stepped. simulator.Simulator has a Step method that must be called to execute blocks.

Using the simulator in Go tests

The test/harness package defines a test harness that simplifies writing tests using the simulator. See simulator_test.go for an example of how this can be used.

Using the simulator via the API

simulator.Simulator has a ListenAndServe method that serves API v2 and/or v3 on its various interfaces.

Alternatively, the tools/cmd/simulator command can be used to run the simulator and serve API v2 and v3.