build fast-runtime helper script

polkadot/scripts/build-fast-rococo-and-update-chain-spec.sh

@@ -0,0 +1,39 @@
+#!/bin/bash -eux
+
+CURRENT_DIR=$(pwd)
+
+#directory were polkadot-sdk is checked out
+POLKADOT_SDK_DIR=/home/miszka/parity/10-genesis-config/polkadot-sdk-rococo
+
+# required epoch duration:
+EPOCH_DURATION_IN_BLOCK=6
+
+# polkadot command:
+DOCKER_IMAGE=paritypr/polkadot-debug:1539-2085d3f0
+POLKADOT_CMD="docker run --rm -v $CURRENT_DIR:/dir -w /dir $DOCKER_IMAGE"
+# POLKADOT_CMD=$POLKADOT_SDK_DIR/target/release/polkadot 
+
+# path to built rococo runtime:
+WASM_RUNTIME_BLOB_PATH=$POLKADOT_SDK_DIR/target/release/wbuild/rococo-runtime/rococo_runtime.compact.compressed.wasm
+
+# build rococo runtime with adjusted epoch diration
+pushd $POLKADOT_SDK_DIR
+ROCOCO_EPOCH_DURATION=$EPOCH_DURATION_IN_BLOCK cargo build --features fast-runtime --release -p rococo-runtime
+popd
+
+# do hexdump of runtime:
+hexdump -v -e '/1 "%02x"' $WASM_RUNTIME_BLOB_PATH > ./runtime.hex
+
+# get westend spec:
+$POLKADOT_CMD build-spec --chain westend-staging  > $CURRENT_DIR/wococo-source.json
+
+# replace runtime in chainspec with newly built runtime with overwritten epoch duration:
+jq --rawfile code runtime.hex  '.genesis.runtime.system.code = "0x" + $code' > $CURRENT_DIR/chainspec-nonraw.json < $CURRENT_DIR/wococo-source.json 
+
+# jq will write numbers in compact way with 1e+18, substrtate json parser dont support it. 
+sed 's/1e+18/1000000000000000000/' -i $CURRENT_DIR/chainspec-nonraw.json
+
+# generate raw
+$POLKADOT_CMD build-spec --chain ./chainspec-nonraw.json --raw > $CURRENT_DIR/chainspec-raw.json
+
+