feat: follower node sync from DA

[NazariiDenha]

1. Purpose or design rationale of this PR

This PR implements a follower node from DA/L1 mode which reproduces the L2 state solely from L1 events and loading data from DA (calldata is retrieved from L1 RPC directly, historical blobs are loaded via beacon node or blob APIs and verified via versionedHash).

On a high level, it works as follows: the L2 functionality of the node is disabled and instead it connects only to the configured L1 RPC, retrieves all rollup events (commit batch, revert, finalize), L1 messages and batch data (i.e. calldata or blobs since Bernoulli). Once an event is finalized on L1 the resulting state (meaning L2 state and blocks) are derived and verified from this data.

The derivation process works by implementing a pipeline with following steps:
- DAQueue: uses DataSource to retrieve events and corresponding data (calldata or blob).
- BatchQueue: sorts different DATypes and returns committed, finalized batches in order.
- BlockQueue: converts batches to PartialBlocks that can be used to create the L2 state
- DASyncer: executes PartialBlock and inserts into chain

How to run?

Run l2geth with the --da.sync flag and provide blob APIs with e.g. --da.blob.blobscan=https://api.blobscan.com/blobs/ --da.blob.blocknative=https://api.ethernow.xyz/v1/blob/ for mainnet and --da.blob.blobscan=https://api.sepolia.blobscan.com/blobs/ for Sepolia.

./build/bin/geth --scroll \
  --datadir "tmp/mainnet-l2geth-datadir" \
  --gcmode archive --cache.noprefetch \
  --http --http.addr "0.0.0.0" --http.port 8545 --http.api "eth,net,web3,debug,scroll" \
  --l1.endpoint "<L1 RPC node>" \
  --da.sync=true \
  --da.blob.blobscan=https://api.blobscan.com/blobs/ --da.blob.blocknative=https://api.ethernow.xyz/v1/blob/ \
  --verbosity 3

A full sync will take about ~2 days depending on the speed of the RPC node and the local machine. Progess is reported as follows for every 1000 blocks applied:

INFO [08-01|16:44:42.173] L1 sync progress                         blockhain height=87000 block hash=608eec..880ebd root=218215..9a58a2

Limitations

The state root of a block can be reproduced when using this mode of syncing but currently not the block hash. This is due to the fact that currently the header fields difficulty and extraData are not stored on DA but these fields are utilized by Clique consensus which is used by the Scroll protocol. This will be fixed in a future upgrade where the main implementation on l2geth is already done: #903 #913.

To verify the locally created state root against mainnet, we can do the following:

# query local block info
curl localhost:8545 -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","method":"eth_getHeaderByNumber","params":["0x2AF8"],"id":0}' | jq

# query mainnet block info
curl https://rpc.scroll.io -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","method":"eth_getHeaderByNumber","params":["0x2AF8"],"id":0}' | jq

By comparing the headers we can most importantly see that state root , receiptsRoot and everything that has to do with the state matches. However, the following fields will be different:

• difficulty and therefore totalDifficulty
• extraData
• size due to differences in header size
• hash and therefore parentHash

Example local output for block 11000:

{
  "jsonrpc": "2.0",
  "id": 0,
  "result": {
    "difficulty": "0xa",
    "extraData": "0x0102030405060708",
    "gasLimit": "0x989680",
    "gasUsed": "0xa410",
    "hash": "0xf3cdafbe35d5e7c18d8274bddad9dd12c94b83a81cefeb82ebb73fa799ff9fcc",
    "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
    "miner": "0x0000000000000000000000000000000000000000",
    "mixHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
    "nonce": "0x0000000000000000",
    "number": "0x2af8",
    "parentHash": "0xde244f7e8bc54c8809e6c2ce65c439b58e90baf11f6cf9aaf8df33a827bd01ab",
    "receiptsRoot": "0xd95b673818fa493deec414e01e610d97ee287c9421c8eff4102b1647c1a184e4",
    "sha3Uncles": "0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347",
    "size": "0x252",
    "stateRoot": "0x0f387e78e4a7457a318c7bce7cde0b05c3609347190144a7e105ef05194ae218",
    "timestamp": "0x6526db8e",
    "totalDifficulty": "0x1adb1",
    "transactionsRoot": "0x6a81c9342456693d57963883983bba024916f4d277392c9c1dc497e3518a78e3"
  }
}

Example remote output:

{
  "id": 0,
  "jsonrpc": "2.0",
  "result": {
    "difficulty": "0x2",
    "extraData": "0xd883050000846765746888676f312e31392e31856c696e7578000000000000009920319c246ec8ae4d4f73f07d79f68b2890e9c2033966efe5a81aedddae12875c3170f0552f48b7e5d8e92ac828a6008b2ba7c5b9c4a0af1692337bbdc792be01",
    "gasLimit": "0x989680",
    "gasUsed": "0xa410",
    "hash": "0xb7848d5b300247d7c33aeba0f1b33375e1cb3113b950dffc140945e9d3d88d58",
    "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
    "miner": "0x0000000000000000000000000000000000000000",
    "mixHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
    "nonce": "0x0000000000000000",
    "number": "0x2af8",
    "parentHash": "0xa93e6143ab213a044eb834cdd391a6ef2c818de25b04a3839ee44a75bd28a2c7",
    "receiptsRoot": "0xd95b673818fa493deec414e01e610d97ee287c9421c8eff4102b1647c1a184e4",
    "sha3Uncles": "0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347",
    "size": "0x2ab",
    "stateRoot": "0x0f387e78e4a7457a318c7bce7cde0b05c3609347190144a7e105ef05194ae218",
    "timestamp": "0x6526db8e",
    "totalDifficulty": "0x55f1",
    "transactionsRoot": "0x6a81c9342456693d57963883983bba024916f4d277392c9c1dc497e3518a78e3"
  }
}

2. PR title

Your PR title must follow conventional commits (as we are doing squash merge for each PR), so it must start with one of the following types:

• build: Changes that affect the build system or external dependencies (example scopes: yarn, eslint, typescript)
• ci: Changes to our CI configuration files and scripts (example scopes: vercel, github, cypress)
• docs: Documentation-only changes
• feat: A new feature
• fix: A bug fix
• perf: A code change that improves performance
• refactor: A code change that doesn't fix a bug, or add a feature, or improves performance
• style: Changes that do not affect the meaning of the code (white-space, formatting, missing semi-colons, etc)
• test: Adding missing tests or correcting existing tests

3. Deployment tag versioning

Has the version in params/version.go been updated?

• This PR doesn't involve a new deployment, git tag, docker image tag, and it doesn't affect traces
• Yes

4. Breaking change label

Does this PR have the breaking-change label?

• This PR is not a breaking change
• Yes

---

• To see the specific tasks where the Asana app for GitHub is being used, see below:
  • https://app.asana.com/0/0/1206426155875158

[vyzo]

first pass generally looks ok, left some comments.

I will do another pass later.

[jonastheis]

Closing this PR as it is superseded by #1013 which is based on the new base branch syncupstream/active.