DEV_CHAIN.md

Steps to setup and run Erigon dev chain. This tutorial is made for macOS.

1. Clone and Build Erigon

Open terminal 1 and type the following command

git clone --recurse-submodules -j8 https://github.com/ledgerwatch/erigon.git
cd erigon
make erigon

2. Build RPCdeamon

On the same terminal folder you can build the RPC daemon.

make rpcdaemon

3. Start Node 1

If evereything is fine, by changing directory to erigon/build/bin you will see the two exec for erigon and rpc daemon. On the terminal you can type the following command to start node1.

./erigon --datadir=dev --chain dev --private.api.addr=localhost:9090 --mine

Argument notes:

• datadir : Tells where the data is stored, default level is dev folder.
• chain : Tells that we want to run Erigon in the dev chain.
• private.api.addr=localhost:9090 : Tells where Eigon is going to listen for connections.
• mine : Add this if you want the node to mine.
• dev.period : Add this to specify the timing interval amongst blocks. Number of seconds MUST be > 0 (if you want empty blocks) otherwise the default value 0 does not allow mining of empty blocks.

The result will be somenthing like this:

Now save the enode information generated in the logs, we will use this in a minute. Here there is an example.

enode://d30d079163d7b69fcb261c0538c0c3faba4fb4429652970e60fa25deb02a789b4811e98b468726ba0be63b9dc925a019f433177eb6b45c23bb78892f786d8f7a@127.0.0.1:53171 

4. Start RPC deamon

Open terminal 2 and navigate to erigon/build/bin folder. Here type the following command

./rpcdaemon --datadir=dev  --private.api.addr=localhost:9090 --http.api=eth,erigon,web3,net,debug,trace,txpool,parity

The result will look like this:

5. Start Node 2

Node 2 has to connect to Node 1 in order to sync. As such, we will use the argument --staticpeers. To tell Node 2 where Node 1 is we will use the Enode info of Node 1 we saved before.

Open terminal 3 and navigate to erigon/build/bin folder. Paste in the following command the Enode info and run it, be careful to remove the last part ?discport=0.

./erigon --datadir=dev2  --chain dev --private.api.addr=localhost:9091 \
    --staticpeers "enode://d30d079163d7b69fcb261c0538c0c3faba4fb4429652970e60fa25deb02a789b4811e98b468726ba0be63b9dc925a019f433177eb6b45c23bb78892f786d8f7a@127.0.0.1:53171" \
    --nodiscover

To check if the nodes are connected, you can go to the log of both the nodes and look for the line

[p2p] GoodPeers eth66=1

Note: this might take a while it is not istantaneus, also if you see a 1 on either one of the two the node is fine.

6. Interact with the node using RPC

Open a terminal 4 and type

  curl -X POST -H "Content-Type: application/json" --data '{"jsonrpc": "2.0", "method": "eth_chainId", "params": [], "id":1}' localhost:8545

The result should look like this:

{"jsonrpc":"2.0","id":1,"result":"0x539"}

Other commands you can try:

curl -X POST -H "Content-Type: application/json" --data '{"jsonrpc": "2.0", "method": "eth_gasPrice", "params": [], "id":1}' localhost:8545

curl -X POST -H "Content-Type: application/json" --data '{"jsonrpc": "2.0", "method": "eth_mining", "params": [], "id":1}' localhost:8545

 curl -X POST -H "Content-Type: application/json" --data '{"jsonrpc": "2.0", "method": "eth_syncing", "params": [], "id":1}' localhost:8545

 curl -X POST -H "Content-Type: application/json" --data '{"jsonrpc": "2.0", "method": "net_peerCount", "params": [], "id":74}' localhost:8545

 curl -X POST -H "Content-Type: application/json" --data '{"jsonrpc": "2.0", "method": "eth_blockNumber", "params": [], "id":83}' localhost:8545

7. Send a transaction with metamask

Finally, we want to try sending a transaction between two accounts. For this example we will use dev accounts retrived from Erigon code:

• Account with balance (Dev 1)

  • address = 0x67b1d87101671b127f5f8714789C7192f7ad340e
  • privateKey = 26e86e45f6fc45ec6e2ecd128cec80fa1d1505e5507dcd2ae58c3130a7a97b48

• Empty account (Dev 2)

  • address = 0xa94f5374Fce5edBC8E2a8697C15331677e6EbF0B
  • privateKey = 45a915e4d060149eb4365960e6a7a45f334393093061116b197e3240065ff2d8

Now from metamask, you can import Dev 1 , and then send a transaction to pass some ethers from Dev 1 to Dev 2. From the RPC daemon terminal, you will see something like this

Finally you will see the ethers in the Dev 2 account balance.

7. Check a mined block

Now we want to check the creation of a new block and that all the nodes sync.

Below we can see that block 1 is created (blocn_num=1) and that the next block to be proposed increments from 1 to 2 ( block=2). The other nodes will see the same update.