Docker Compose

With Docker Compose, you can spin up local testnets with a single command.

Requirements

1. Install tendermint
2. Install docker (opens new window)
3. Install docker-compose (opens new window)

Build

Build the tendermint binary and, optionally, the tendermint/localnode docker image.

Note the binary will be mounted into the container so it can be updated without rebuilding the image.

Copy # Build the linux binary in ./build make build-linux # (optionally) Build tendermint/localnode image make build-docker-localnode

Run a testnet

To start a 4 node testnet run:

Copy make localnet-start

The nodes bind their RPC servers to ports 26657, 26660, 26662, and 26664 on the host.

This file creates a 4-node network using the localnode image.

The nodes of the network expose their P2P and RPC endpoints to the host machine on ports 26656-26657, 26659-26660, 26661-26662, and 26663-26664 respectively.

To update the binary, just rebuild it and restart the nodes:

Copy make build-linux make localnet-start

Configuration

The make localnet-start creates files for a 4-node testnet in ./build by calling the tendermint testnet command.

The ./build directory is mounted to the /tendermint mount point to attach the binary and config files to the container.

To change the number of validators / non-validators change the localnet-start Makefile target here:

Copy localnet-start: localnet-stop @if ! [ -f build/node0/config/genesis.json ]; then docker run --rm -v $(CURDIR)/build:/tendermint:Z tendermint/localnode testnet --v 5 --n 3 --o . --populate-persistent-peers --starting-ip-address 192.167.10.2 ; fi docker-compose up

The command now will generate config files for 5 validators and 3 non-validators. Along with generating new config files the docker-compose file needs to be edited. Adding 4 more nodes is required in order to fully utilize the config files that were generated.

Copy node3: # bump by 1 for every node container_name: node3 # bump by 1 for every node image: "tendermint/localnode" environment: - ID=3 - LOG=${LOG:-tendermint.log} ports: - "26663-26664:26656-26657" # Bump 26663-26664 by one for every node volumes: - ./build:/tendermint:Z networks: localnet: ipv4_address: 192.167.10.5 # bump the final digit by 1 for every node

Before running it, don't forget to cleanup the old files:

Copy # Clear the build folder rm -rf ./build/node*

Configuring ABCI containers

To use your own ABCI applications with 4-node setup edit the docker-compose.yaml (opens new window) file and add image to your ABCI application.

Copy abci0: container_name: abci0 image: "abci-image" build: context: . dockerfile: abci.Dockerfile command: <insert command to run your abci application> networks: localnet: ipv4_address: 192.167.10.6 abci1: container_name: abci1 image: "abci-image" build: context: . dockerfile: abci.Dockerfile command: <insert command to run your abci application> networks: localnet: ipv4_address: 192.167.10.7 abci2: container_name: abci2 image: "abci-image" build: context: . dockerfile: abci.Dockerfile command: <insert command to run your abci application> networks: localnet: ipv4_address: 192.167.10.8 abci3: container_name: abci3 image: "abci-image" build: context: . dockerfile: abci.Dockerfile command: <insert command to run your abci application> networks: localnet: ipv4_address: 192.167.10.9

Override the command (opens new window) in each node to connect to it's ABCI.

Copy node0: container_name: node0 image: "tendermint/localnode" ports: - "26656-26657:26656-26657" environment: - ID=0 - LOG=$${LOG:-tendermint.log} volumes: - ./build:/tendermint:Z command: node --proxy_app=tcp://abci0:26658 networks: localnet: ipv4_address: 192.167.10.2

Similarly do for node1, node2 and node3 then run testnet (opens new window)

Logging

Log is saved under the attached volume, in the tendermint.log file. If the LOG environment variable is set to stdout at start, the log is not saved, but printed on the screen.

Special binaries

If you have multiple binaries with different names, you can specify which one to run with the BINARY environment variable. The path of the binary is relative to the attached volume.