add L2 on L2 demo scripts

demo/challenge_fault.sh

 #!/usr/bin/env bash
 
+# The following variables can be overridden as environment variables:
+# * BLOCK (block whose transition will be challenged)
+# * SKIP_NODE (skip forking a node, useful if you've already forked a node)
+#
+# Example usage:
+# SKIP_NODE=1 BLOCK=13284469 ./demo/challenge_fault.sh
+
 # --- DOC ----------------------------------------------------------------------
 
 # Unlike the simple scenario (cf. challenge_simple.sh), in this
@@ -60,24 +67,31 @@ trap "exit_trap" SIGINT SIGTERM EXIT
 
 # --- BOOT MAINNET FORK --------------------------------------------------------
 
-NODE_LOG="challenge_fault_node.log"
+if [[ ! "$SKIP_NODE" ]]; then
+    NODE_LOG="challenge_fault_node.log"
 
-shout "BOOTING MAINNET FORK NODE IN BACKGROUND (LOG: $NODE_LOG)"
+    shout "BOOTING MAINNET FORK NODE IN BACKGROUND (LOG: $NODE_LOG)"
 
-# get directory containing this file
-SCRIPT_DIR=$(dirname "$(readlink -f "$0")")
+    # get directory containing this file
+    SCRIPT_DIR=$(dirname "$(readlink -f "$0")")
 
-# run a hardhat mainnet fork node
-"$SCRIPT_DIR/forked_node.sh" > "$NODE_LOG" 2>&1 &
+    # run a hardhat mainnet fork node
+    "$SCRIPT_DIR/forked_node.sh" > "$NODE_LOG" 2>&1 &
 
-# give the node some time to boot up
-sleep 10
+    # give the node some time to boot up
+    sleep 10
+fi
 
 # --- CHALLENGE SETUP ----------------------------------------------------------
 
+# hardhat network to use
+NETWORK=${NETWORK:-l1}
+export NETWORK
+
 # block whose transition will be challenged
 # this variable is read by challenge.js, respond.js and assert.js
-export BLOCK=13284491
+BLOCK=${BLOCK:-13284491}
+export BLOCK
 
 # challenge ID, read by respond.js and assert.js
 export ID=0
@@ -90,7 +104,7 @@ shout "GENERATING INITIAL MEMORY STATE CHECKPOINT"
 mipsevm/mipsevm
 
 shout "DEPLOYING CONTRACTS"
-npx hardhat run scripts/deploy.js --network hosthat
+npx hardhat run scripts/deploy.js --network $NETWORK
 
 # challenger will use same initial memory checkpoint and deployed contracts
 cp /tmp/cannon/{golden,deployed}.json /tmp/cannon_fault/
@@ -116,23 +130,23 @@ OUTPUTFAULT=1 BASEDIR=/tmp/cannon_fault mipsevm/mipsevm $BLOCK
 # --- BINARY SEARCH ------------------------------------------------------------
 
 shout "STARTING CHALLENGE"
-BASEDIR=/tmp/cannon_fault npx hardhat run scripts/challenge.js --network hosthat
+BASEDIR=/tmp/cannon_fault npx hardhat run scripts/challenge.js --network $NETWORK
 
 shout "BINARY SEARCH"
 for i in {1..25}; do
     echo ""
     echo "--- STEP $i / 25 --"
     echo ""
-    OUTPUTFAULT=1 BASEDIR=/tmp/cannon_fault CHALLENGER=1 npx hardhat run scripts/respond.js --network hosthat
-    npx hardhat run scripts/respond.js --network hosthat
+    OUTPUTFAULT=1 BASEDIR=/tmp/cannon_fault CHALLENGER=1 npx hardhat run scripts/respond.js --network $NETWORK
+    npx hardhat run scripts/respond.js --network $NETWORK
 done
 
 # --- SINGLE STEP EXECUTION ----------------------------------------------------
 
 shout "ASSERTING AS CHALLENGER (should fail)"
 set +e # this should fail!
-BASEDIR=/tmp/cannon_fault CHALLENGER=1 npx hardhat run scripts/assert.js --network hosthat
+BASEDIR=/tmp/cannon_fault CHALLENGER=1 npx hardhat run scripts/assert.js --network $NETWORK
 set -e
 
 shout "ASSERTING AS DEFENDER (should pass)"
-npx hardhat run scripts/assert.js --network hosthat
+npx hardhat run scripts/assert.js --network $NETWORK

demo/challenge_simple.sh

@@ -77,6 +77,10 @@ fi
 
 # --- CHALLENGE SETUP ----------------------------------------------------------
 
+# hardhat network to use
+NETWORK=${NETWORK:-l1}
+export NETWORK
+
 # challenge ID, read by respond.js and assert.js
 export ID=0
 
@@ -96,7 +100,7 @@ shout "GENERATING INITIAL MEMORY STATE CHECKPOINT"
 mipsevm/mipsevm
 
 shout "DEPLOYING CONTRACTS"
-npx hardhat run scripts/deploy.js --network hosthat
+npx hardhat run scripts/deploy.js --network $NETWORK
 
 # challenger will use same initial memory checkpoint and deployed contracts
 cp /tmp/cannon/{golden,deployed}.json /tmp/cannon_fault/
@@ -119,23 +123,23 @@ ln -s /tmp/cannon_fault/0_$WRONG_BLOCK /tmp/cannon_fault/0_$BLOCK
 # --- BINARY SEARCH ------------------------------------------------------------
 
 shout "STARTING CHALLENGE"
-BASEDIR=/tmp/cannon_fault npx hardhat run scripts/challenge.js --network hosthat
+BASEDIR=/tmp/cannon_fault npx hardhat run scripts/challenge.js --network $NETWORK
 
 shout "BINARY SEARCH"
 for i in {1..23}; do
     echo ""
     echo "--- STEP $i / 23 ---"
     echo ""
-    BASEDIR=/tmp/cannon_fault CHALLENGER=1 npx hardhat run scripts/respond.js --network hosthat
-    npx hardhat run scripts/respond.js --network hosthat
+    BASEDIR=/tmp/cannon_fault CHALLENGER=1 npx hardhat run scripts/respond.js --network $NETWORK
+    npx hardhat run scripts/respond.js --network $NETWORK
 done
 
 # --- SINGLE STEP EXECUTION ----------------------------------------------------
 
 shout "ASSERTING AS CHALLENGER (should fail)"
 set +e # this should fail!
-BASEDIR=/tmp/cannon_fault CHALLENGER=1 npx hardhat run scripts/assert.js --network hosthat
+BASEDIR=/tmp/cannon_fault CHALLENGER=1 npx hardhat run scripts/assert.js --network $NETWORK
 set -e
 
 shout "ASSERTING AS DEFENDER (should pass)"
-npx hardhat run scripts/assert.js --network hosthat
+npx hardhat run scripts/assert.js --network $NETWORK

demo/l2_challenge_fault.sh

+#!/usr/bin/env bash
+
+# Similar to challenge_fault.sh, but runs on L2!
+
+SCRIPT_DIR=$(dirname "$(readlink -f "$0")")
+
+export ETH_RPC_URL=http://127.0.0.1:9545/
+export BLOCK=$(cast block-number)
+
+SKIP_NODE=1 NETWORK=l2 "$SCRIPT_DIR/challenge_fault.sh"

demo/l2_challenge_simple.sh

+#!/usr/bin/env bash
+
+# Similar to challenge_simple.sh, but runs on L2!
+
+SCRIPT_DIR=$(dirname "$(readlink -f "$0")")
+
+export ETH_RPC_URL=http://127.0.0.1:9545/
+export BLOCK=$(cast block-number)
+export WRONG_BLOCK=$(expr $BLOCK - 1)
+
+SKIP_NODE=1 NETWORK=l2 "$SCRIPT_DIR/challenge_simple.sh"

docs/l2-on-l2.md

+# Running Cannon on L2
+
+The original Cannon prototype allows challenging L1 blocks on L1. Normally, the
+challenger should always fail, as L1 blocks are valid by virtue of being
+included on-chain.
+
+The next milestone is to allow challenging L2 blocks on L2. What this proves is
+that the extra logic we added in
+[l2geth](https://github.com/ethereum-optimism/reference-optimistic-geth) (aka
+reference-optimism-geth) does not break anything. It's also a good way to
+exercise our devnet infrastructure.
+
+Running the Cannon demo on a mainnet (L1) fork is a simple as doing:
+
+```bash
+# from repo root
+demo/challenge_simple.sh
+# or
+demo/challenge_fault.sh
+```
+
+For L2, you'll need first to run the devnet locally. For this, clone the
+`develop` branch of the [optimism
+monorepo](https://github.com/ethereum-optimism/optimism), then run:
+
+```bash
+yarn && make build && make devnet-clean && make devnet-up
+```
+
+If you're having trouble building, here's a [full
+transcript](https://github.com/ethereum-optimism/cannon/wiki/Bedrock-Full-Devnet-Setup)
+of all the commands required to run on a fresh cloud linux machine.
+
+Note it's important to run `make devnet-clean` before each invocation of `make
+devnet-up` to work around some issues at the time of writing.
+
+Then you can run the L2 demos:
+
+```bash
+# from repo root
+demo/l2_challenge_simple.sh
+# or
+demo/l2_challenge_fault.sh
+```

hardhat.config.js

@@ -17,14 +17,15 @@ try {
 module.exports = {
   //defaultNetwork: "hosthat",
   networks: {
-    hosthat: {
+    l1: {
       url: "http://127.0.0.1:8545/",
       accounts: ["0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80"],
       timeout: 600_000,
     },
-    cheapeth: {
-      url: "https://rpc.cheapeth.org/rpc",
-      accounts: [private]
+    l2: {
+      url: "http://127.0.0.1:9545/",
+      accounts: ["0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80"],
+      timeout: 600_000,
     },
   },
   solidity: {

scripts/challenge.js

@@ -39,7 +39,10 @@ async function main() {
   for (n of nodes) {
     await mm.AddTrieNode(n)
   }
-  let ret = await c.initiateChallenge(...args)
+// TODO: Setting the gas limit explicitly here shouldn't be necessary, for some
+//    weird reason (to be investigated), it is for L2.
+//  let ret = await c.initiateChallenge(...args)
+  let ret = await c.initiateChallenge(...args, { gasLimit: 10_000_000 })
   let receipt = await ret.wait()
   // ChallengeCreated event
   let challengeId = receipt.events[0].args['challengeId'].toNumber()