CI: automatically update the fastcrypto pointer

This is a sibling PR to MystenLabs#4393 which allowed logic that would automatically update the NW pointer.

.github/workflows/fastcrypto_pull.yml

@@ -0,0 +1,41 @@
+name: Update the Fastcrypto pointer Sui
+on:
+  ## Allow triggering this workflow manually via GitHub CLI/web
+  workflow_dispatch:
+  schedule:
+    # Update on every hour at 10 past the hour
+    - cron:  '10 * * * *'
+
+jobs:
+  update-dep:
+    runs-on: ubuntu-latest
+    # Important settings as we don't want to open a PR when the update fails
+    continue-on-error: false
+    strategy:
+      fail-fast: true
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions-rs/toolchain@v1
+      - uses: bmwill/rust-cache@v1 # Fork of 'Swatinem/rust-cache' which allows caching additional paths
+      - name: Install cargo-hakari, and cache the binary
+        uses: baptiste0928/cargo-install@v1
+        with:
+          crate: cargo-hakari
+          locked: true
+      - name: Update the Narwhal pointer
+        run: |
+          scripts/update_fastcrypto.sh
+      - name: Create Pull Request
+        uses: peter-evans/create-pull-request@v4
+        with:
+            # TODO: change the token to something FC-specific?
+            token: ${{ secrets.NW_AUTO_UPDATE }}
+            commit-message: chore(deps) Update the Fastcrypto pointer
+            title: chore(deps) Update the Fastcrypto pointer
+            body: |
+              - Update Fastcrypto
+  
+              Auto-generated by [create-pull-request][1] and the scripts/update_fastcrypto.sh script
+
+              [1]: https://github.com/peter-evans/create-pull-request
+            branch: update-fastcrypto

scripts/update_fastcrypto.sh

@@ -0,0 +1,85 @@
+#!/bin/bash
+# Copyright (c) Mysten Labs, Inc.
+# SPDX-License-Identifier: Apache-2.0
+
+# shellcheck disable=SC2181
+# This script attempts to update the Fastcrypto pointer in Sui
+# It is expected to fail in some cases, notably when those updates require code changes 
+set -e
+set -eo pipefail
+
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+TOPLEVEL="${DIR}/../"
+GREP=${GREP:=grep}
+
+# Crutch for old bash versions
+# Very minimal readarray implementation using read. Does NOT work with lines that contain double-quotes due to eval()
+readarray() {
+	while IFS= read -r var; do
+        MAPFILE+=("$var")
+	done
+}
+
+
+# check for the presence of needed executables:
+# - we use GNU grep in perl re mode
+# - we use cargo-hakari
+function check_gnu_grep() {
+	GNUSTRING=$($GREP --version|head -n1| grep 'GNU grep')
+	if [[ -z $GNUSTRING ]];
+	then 
+		echo "Could not find GNU grep. This requires GNU grep 3.7 with PCRE expressions"; exit 1
+	else 
+		return 0
+	fi
+}
+
+function check_cargo_hakari() {
+	cargo hakari --version > /dev/null 2>&1
+	if [[ $? -ne 0 ]]; then
+		echo "Could not find cargo hakari. Please install"; exit 1		
+	else
+		return 0
+	fi
+}
+
+
+function latest_fc_revision() {
+	FC_CHECKOUT=$(mktemp -d)
+	cd "$FC_CHECKOUT"
+	git clone --depth 1 https://github.com/mystenlabs/fastcrypto
+	cd fastcrypto
+	git rev-parse HEAD
+}
+
+function current_fc_revision() {
+	cd "$TOPLEVEL"
+	readarray -t <<< "$(find ./ -iname '*.toml' -exec $GREP -oPe 'git = "https://github.com/MystenLabs/fastcrypto", *rev *= *\"\K[0-9a-fA-F]+' '{}' \;)"
+	watermark=${MAPFILE[0]}
+	for i in "${MAPFILE[@]}"; do
+	    if [[ "$watermark" != "$i" ]]; then
+        	not_equal=true
+	        break
+	    fi
+	done
+
+	[[ -n "$not_equal" ]] && echo "Different values found for the current Fastcrypto revision in Sui, aborting" && exit 1
+	echo "$watermark"
+}
+
+# Check for tooling
+check_gnu_grep
+check_cargo_hakari
+
+# Debug prints
+CURRENT_FC=$(current_fc_revision)
+LATEST_FC=$(latest_fc_revision)
+if [[ "$CURRENT_FC" != "$LATEST_FC" ]]; then
+	echo "About to replace $CURRENT_FC with $LATEST_FC as the Narwhal pointer in Sui"
+else
+	exit 0
+fi
+
+# Edit the source & run hakari
+find ./ -iname "*.toml"  -execdir sed -i '' -re "s/$CURRENT_FC/$LATEST_FC/" '{}' \;
+cargo hakari generate