Genesis creation

Horizen initial state is not empty, but reflects the data present in both previous Horizen's chains: ZEND Mainchain and EON.

The pre-calculated initial state, mandatory to start a new collator node, is available for download at this URL: [TODO]

To verify its correctness, anyone can follow the instructions in this tutorial and regenerate the same data.

Prerequisites:

The following software is needed:

1. Fully synched ZEND Mainchain node with dump support enabled:

   • Download latest ZEND release from here: https://github.com/HorizenOfficial/zen/releases
   • Follow the instructions here https://github.com/HorizenLabs/migration-tools/tree/main/snapshot to patch the ZEND node in order to have dump support enabled
   • Compile the node, start and have it fully synched with the old mainchain

2. Fully synched EON Chain node with dump support enabled:

   • Download latest EON release node
   • Add the following fragment in the config file to enable state dump support (important: the fragment must be added BEFORE starting to synch the chain):

   evmStateDump {
       enabled = true
   }
   • Start the node and have it fully synched with the old mainchain

Instructions:

The ZEND Mainchain height that marks the migration will be an input parameter of the process: we will call it MC_MIGRATION_HEIGHT.

1. Execute a dump of ZEND balances at that specified height:

   killall zend
   ./src/dumper -H MC_MIGRATION_HEIGHT > utxos.csv

   Please note the following:

   • killall is needed because ZEND must be stopped while performing the dump
   • If executing a dump of the testnet you must add the flag: -t
   • MC_MIGRATION_HEIGHT must be not too old in the past compared to the latest tip: maximum supported height is tip-100

2. Determination of the EON blockhash to be used for the dump:

   we need to identify the EON block that contains a reference to the mainchain block used for the dump in step 1.

   Execute the following call on the EON node, replacing the MC_MIGRATION_HEIGHT with the correct value:

   curl -sX POST 'http://127.0.0.1:9085/mainchain/blockReferenceInfoBy' -H 'Content-Type: application/json' -H 'accept: application/json' -d '{"height":MC_MIGRATION_HEIGHT, "format": true}' 

   In the response result:

   • hash: corresponds to the mainchain block hash at height MC_MIGRATION_HEIGHT
   • mainchainHeaderSidechainBlockId: it's the EON blockhash of the migration, we'll call it EON_MIGRATION_HASH

3. Dump of EON State:

   Execute the following call on the EON node:
   First parameter of the method must be replaced by EON_MIGRATION_HASH, second one is the local-path of the output dump.

    curl --request POST 'http://127.0.0.1:9085/ethv1' -H 'Content-Type: application/json' -H 'accept: application/json' -d '{ "jsonrpc":"2.0", "method":"zen_dump", "params":["0xbda76ab769c4e158f8e8add81bdf17c9d919fb54cd5e32f1c83cebdfc3dc363c","/zendata/horizen/genesis/TESTNET_1574340/eon_gobi.dump"], "id":1 }'  

4. Execute the dump of the EON stakes:

   Can be executed by calling the script get_all_forger_stakes.py:

   (Replace parameter EON_MIGRATION_HEIGHT with the height of the block EON_MIGRATION_HASH)

   python3 get_all_forger_stakes.py EON_MIGRATION_HEIGHT

5. Convert ZEND csv dump in json format, with the script zend_to_horizen.py:

   Replace the parameter with the path of the file generated at step 1

   python3 zend_to_horizen.py /zendata/horizen/genesis/TESTNET_1574340/utxos.csv

6. Obtain the plain chain spec template:

   This file contains the intial settings of the parachain, excluded any dump of previous states. For the final testnet/mainnet will be provided by HorizenLabs.

7. Merge all the previous artifacts to obtain the final chain spec in plain format with the python script setup_eon2_genesis_json.py:

   python3 setup_eon2_genesis_json.py <step3_file> <step4_file> <step5_file> <step6_file> 

8. Generate the final artifacts starting from the outcome of the previous step:

   In orded to do this you will need a modified docker image able to handle "big size" spec files.
   It is published on DockerHub on every tag, at the docker url: horizen/horizen-spec-builder:< version_number >
   (for example, for Horizen 0.1.0 you can use the image: horizen/horizen-spec-builder:0.1.0
   The artifacts can be generated by interacting with the docker image, as in the following examples:

   1. Raw chain spec:

      docker run --rm -v <step_7_file>:/tmp/para-spec.json --entrypoint horizen-spec-builder $DOCKER_RELEASE build-spec --chain /tmp/para-spec.json  --disable-default-bootnode --raw   > <output_file>
      
      
      

   2. Genesis wasm runtime:

      docker run --rm -v <step_8.1_file>:/tmp/para-spec-raw.json --entrypoint horizen-spec-builder $DOCKER_RELEASE export-genesis-wasm --chain "/tmp/para-spec-raw.json" > <output_wasm>
      
      
      

   3. Genesis state:

      docker run --rm -v <step_8.1_file>:/tmp/para-spec-raw.json --entrypoint horizen-spec-builder $DOCKER_RELEASE export-genesis-state --chain "/tmp/para-spec-raw.json" > <output_genesis_state>

The output of step 8.3 will be a hash of the entire genesis data. By verifying that it matches the one published by Horizen Labs, you can ensure that no data has been tampered with.