tendermint-kvstore

Tendermint tutorial

Get latest Tendermint source

mkdir -p ~/work/tendermint
cd ~/work/tendermint
git clone https://github.com/tendermint/tendermint.git

Build Tendermint and install executable in $GOPATH/bin/tendermint

cd tendermint
go mod tidy
make tools
make install

Create Tendermint default configurations

Create default node config in a sample folder. Note that if TMHOME is not specified, the config will be created in $HOME/.tendermint.

mkdir -p ~/work/tendermint/node
cd ~/work/tendermint/node
TMHOME="." tendermint init

Build sample kvstore app

Assume that this repo is cloned in ~/work/tendermint/kvstore.

cd ~/work/tendermint/kvstore
# go mod init github.com/yxuco/tendermint-kvstore
go mod tidy
go build

Start kvstore app

start the kvstore app, which will wait for tendermint node to connect.

cd ~/work/tendermint/node
rm example.sock
../kvstore/kvstore

Start full Tendermint node

In another terminal, start a full tendermint node, and connect it to kvstore app.

cd ~/work/tendermint/node
TMHOME="." tendermint node --proxy_app=unix://example.sock

Send test transaction and query

From another terminal, send a transaction

curl -s 'localhost:26657/broadcast_tx_commit?tx="tendermint=rocks"'

Send a query

curl -s 'localhost:26657/abci_query?data="tendermint"'

Check base64 encoded key-values in query result

echo -n "dGVuZGVybWludA==" | base64 --decode
echo -n "cm9ja3M=" | base64 --decode

Test kvstore app as built-in app

Shutdown Tendermint node and kvstore app from the previous testing. Restart the kvstore app as a built-in app.

../kvstore/kvstore -config "./config/config.toml" -built-in true

The built-in app itself is a full Tendermint node. From another terminal, send new transaction and query similar the previous tests.

Send transaction and query using JSON-RPC

When sending transaction and queries using JSON-RPC, instead of OpenAPI in the previous steps, you need to encode the data carefully as required by the app.

Transaction parameters must use base64 encoding, e.g.,

tx=$(echo -n "tendermint=jsonrpc" | base64)
curl --header "Content-Type: application/json" --request POST --data '{"method": "broadcast_tx_commit", "params": {"tx": "'${tx}'"}, "id": 1}' localhost:26657

Query parameters must use HEX dump, e.g.,

data=$(echo -n "tendermint" | xxd -pu)
curl --header "Content-Type: application/json" --request POST --data '{"method": "abci_query", "params": {"data": "'${data}'"}, "id": 2}' localhost:26657

Subscribe block events using websocket

Install wscat

npm install -g wscat

Start wscat and connect to a full tendermint node, then subscribe NewBlock events

wscat --connect ws://localhost:26657/websocket
{ "jsonrpc": "2.0", "method": "subscribe", "params": ["tm.event='NewBlock'"], "id": 1 }