Add CI job to verify extrinsic ordering (#1950)

* WIP: add initial check_extrinsics_ordering.sh script

* iterate through runtimes, add gitlab job

* move job to publish

* temp force build-linux-release to run

* update check_extrinsics_ordering.sh

* maybe we have to fetch release

* use node docker image

* revert before opening pr: force bad extrinsic ordering

* revert commits to prepare for PR

* move job to build stage, use bin from test-linux-release

* remove FIXME

* fix PR nags

polkadot/scripts/gitlab/check_extrinsics_ordering.sh

@@ -0,0 +1,59 @@
+#!/bin/bash
+BIN=./target/release/polkadot
+LIVE_WS=wss://rpc.polkadot.io
+LOCAL_WS=ws://localhost:9944
+
+# Kill the polkadot client before exiting
+trap 'kill "$(jobs -p)"' EXIT
+
+runtimes=(
+  "westend"
+  "kusama"
+  "polkadot"
+)
+
+for RUNTIME in "${runtimes[@]}"; do
+  echo "[+] Checking runtime: ${RUNTIME}"
+
+  release_transaction_version=$(
+    git show "origin/release:runtime/${RUNTIME}/src/lib.rs" | \
+      grep 'transaction_version'
+  )
+
+  current_transaction_version=$(
+    grep 'transaction_version' "./runtime/${RUNTIME}/src/lib.rs"
+  )
+
+  echo "[+] Release: ${release_transaction_version}"
+  echo "[+] Ours: ${current_transaction_version}"
+
+  if [ ! "$release_transaction_version" = "$current_transaction_version" ]; then
+    echo "[+] Transaction version for ${RUNTIME} has been bumped since last release."
+    exit 0
+  fi
+
+  if [ "$RUNTIME" = 'polkadot' ]; then
+    LIVE_WS="wss://rpc.polkadot.io"
+  else
+    LIVE_WS="wss://${RUNTIME}-rpc.polkadot.io"
+  fi
+
+  # Start running the local polkadot node in the background
+  $BIN --chain="$RUNTIME-local"  &
+  jobs
+
+  changed_extrinsics=$(
+    polkadot-js-metadata-cmp "$LIVE_WS" "$LOCAL_WS" \
+      | sed 's/^ \+//g' | grep -e 'idx: [0-9]\+ -> [0-9]\+'
+  )
+
+  if [ -n "$changed_extrinsics" ]; then
+    echo "[!] Extrinsics indexing/ordering has changed in the ${RUNTIME} runtime! If this change is intentional, please bump transaction_version in lib.rs. Changed extrinsics:"
+    echo "$changed_extrinsics"
+    exit 1
+  fi
+
+  echo "[+] No change in extrinsics ordering for the ${RUNTIME} runtime"
+  kill "$(jobs -p)"; sleep 5
+done
+