# Docker Compose With Docker Compose, you can spin up local testnets with a single command. ## Requirements 1. [Install tendermint](../introduction/install.md) 2. [Install docker](https://docs.docker.com/engine/installation/) 3. [Install docker-compose](https://docs.docker.com/compose/install/) ## 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. ``` cd $GOPATH/src/github.com/tendermint/tendermint # 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: ``` 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: ``` make build-linux make localnet-stop 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: ``` 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 network. Before running it, don't forget to cleanup the old files: ``` cd $GOPATH/src/github.com/tendermint/tendermint # 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](https://github.com/tendermint/tendermint/blob/master/docker-compose.yml) file and add image to your abci application. ``` abci0: container_name: abci0 image: "abci-image" build: context: . dockerfile: abci.Dockerfile command: networks: localnet: ipv4_address: 192.167.10.6 abci1: container_name: abci1 image: "abci-image" build: context: . dockerfile: abci.Dockerfile command: networks: localnet: ipv4_address: 192.167.10.7 abci2: container_name: abci2 image: "abci-image" build: context: . dockerfile: abci.Dockerfile command: networks: localnet: ipv4_address: 192.167.10.8 abci3: container_name: abci3 image: "abci-image" build: context: . dockerfile: abci.Dockerfile command: networks: localnet: ipv4_address: 192.167.10.9 ``` Override the [command](https://github.com/tendermint/tendermint/blob/master/networks/local/localnode/Dockerfile#L12) in each node to connect to it's abci. ``` 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](https://github.com/tendermint/tendermint/blob/master/docs/networks/docker-compose.md#run-a-testnet) ## 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.