Sync test script

You can inspect whether the branch contains breaking changes from master using this script. It simply tries to sync from scratch on both branches and tries to continue to sync on the other branch. Although it doesn't automagically detect state root mismatches, you might inspect easily by seeing the progress stalls or spurious logs.

#/bin/bash

## USAGE
## ./cross-sync.sh master feature/blah ./db-synctest 192.168.100.123:3485 192.168.100.123:8080

BASE=$1
REMOTE=$2
DB_PATH=$3
BOOTSTRAP=$4
JSON_RPC=$5

# sccache makes 'error reading compile response from server' error
unset RUSTC_WRAPPER
# clear log
echo "" > ./cross-sync.log

function best_block_number() {
	local HOST=$1

	local RESP=`curl --retry 5 --retry-connrefused --retry-delay 1 \
		-s -H 'Content-Type: application/json' \
		-d '{"jsonrpc": "2.0", "method": "chain_getBestBlockNumber", "params": [], "id": null}' \
		$HOST`
	echo $RESP | sed -n 's/.*"result":\([0-9]*\).*/\1/p'
}

function upstream_block_number() { best_block_number "$JSON_RPC"; }

function current_block_number() { best_block_number "http://localhost:8080"; }

function sync_to() {
	local TARGET_BN=$1
	local DB_PATH=$2
	local BRANCH=$3
	local WAIT_MORE=$4
	
	git checkout $BRANCH
	cargo build --release

	ENABLE_DELEGATIONS=true \
	ENABLE_ORDER=true \
	RUST_LOG=info,mio=warn,tokio=warn,hyper=warn,rpc=info \
	./target/release/codechain -c corgi --jsonrpc-port 8080 --port 3485 \
		--no-tx-relay --enable-devel-api --no-miner --no-discovery \
		--bootstrap-addresses $BOOTSTRAP \
		--db-path "$DB_PATH" &
	CODECHAIN=$!
	trap "kill -INT $CODECHAIN; wait $CODECHAIN; exit" SIGINT
	sleep 2
	while true; do
		BN=`current_block_number`
		if [ -z "$BN" ]; then
			echo "Node doesn't responds" 1>&2
			exit -1
		fi
		if [ "$BN" -ge "$TARGET_BN" ]; then 
			break
		fi
		echo "$BRANCH-$DB_PATH $BN/$TARGET_BN" >> ./cross-sync.log
		sleep 1
	done
	sleep $WAIT_MORE
	kill -INT $CODECHAIN
	wait $CODECHAIN
	trap 'exit -1' SIGINT
}

function run(){
	local DB_PATH=$1
	local SCRATCH=$2
	local CONTINUE=$3

	# Sync from scratch with branch SCRATCH. This will test sync compatibility.
	sync_to `upstream_block_number` "$DB_PATH" "$SCRATCH" 0
	# Continue to sync with branch CONTINUE. This will test it can boot and further sync with existing db.
	sync_to `upstream_block_number` "$DB_PATH" "$CONTINUE" 60
}

set -ex
run "$DB_PATH-base-remote" "$BASE" "$REMOTE"
run "$DB_PATH-remote-base" "$REMOTE" "$BASE"

If your JSONRPC is behind the ssh, you can try forwarding

ssh ssh -o 'ControlPath ./jsonrpc.ctrl' -fNTM -L 9000:localhost:8080 $SSH_JSON_RPC
bash cross-sync.sh master feature/blah ./db-synctest 192.168.100.123:3485 localhost:9000
ssh -o 'ControlPath ./jsonrpc.ctrl' -TO exit $SSH_JSON_RPC