gas-oracle

gas-oracle

This service is responsible for sending transactions to the Sequencer to update the L2 gas price over time. It consists of a set of functions found in the gasprices package that define the parameters of how the gas prices are updated and then the oracle package is responsible for observing the Sequencer over time and send transactions that actually do update the gas prices.

Generating the Bindings

Note: this only needs to happen if the ABI of the OVM_GasPriceOracle is updated.

This project uses abigen to automatically create smart contract bindings in Go. To generate the bindings, be sure that the latest ABI and bytecode are committed into the repository in the abis directory.

Use the following command to generate the bindings:

$ make binding

Be sure to use abigen built with the same version of go-ethereum as what is in the go.mod file.

Building the service

The service can be built with the Makefile. A binary will be produced called the gas-oracle.

$ make gas-oracle

Running the service

Use the --help flag when running the gas-oracle to see it's configuration options.

NAME:
   gas-oracle - Remotely Control the Optimism Gas Price

USAGE:
   gas-oracle [global options] command [command options] [arguments...]

VERSION:
   0.0.0-1.10.4-stable

DESCRIPTION:
   Configure with a private key and an Optimism HTTP endpoint to send transactions that update the L2 gas price.

COMMANDS:
     help, h  Shows a list of commands or help for one command

GLOBAL OPTIONS:
   --ethereum-http-url value                  Sequencer HTTP Endpoint (default: "http://127.0.0.1:8545") [$GAS_PRICE_ORACLE_ETHEREUM_HTTP_URL]
   --chain-id value                           L2 Chain ID (default: 0) [$GAS_PRICE_ORACLE_CHAIN_ID]
   --gas-price-oracle-address value           Address of OVM_GasPriceOracle (default: "0x420000000000000000000000000000000000000F") [$GAS_PRICE_ORACLE_GAS_PRICE_ORACLE_ADDRESS]
   --private-key value                        Private Key corresponding to OVM_GasPriceOracle Owner [$GAS_PRICE_ORACLE_PRIVATE_KEY]
   --transaction-gas-price value              Hardcoded tx.gasPrice, not setting it uses gas estimation (default: 0) [$GAS_PRICE_ORACLE_TRANSACTION_GAS_PRICE]
   --loglevel value                           log level to emit to the screen (default: 3) [$GAS_PRICE_ORACLE_LOG_LEVEL]
   --floor-price value                        gas price floor (default: 1) [$GAS_PRICE_ORACLE_FLOOR_PRICE]
   --target-gas-per-second value              target gas per second (default: 11000000) [$GAS_PRICE_ORACLE_TARGET_GAS_PER_SECOND]
   --max-percent-change-per-epoch value       max percent change of gas price per second (default: 0.1) [$GAS_PRICE_ORACLE_MAX_PERCENT_CHANGE_PER_EPOCH]
   --average-block-gas-limit-per-epoch value  average block gas limit per epoch (default: 1.1e+07) [$GAS_PRICE_ORACLE_AVERAGE_BLOCK_GAS_LIMIT_PER_EPOCH]
   --epoch-length-seconds value               length of epochs in seconds (default: 10) [$GAS_PRICE_ORACLE_EPOCH_LENGTH_SECONDS]
   --significant-factor value                 only update when the gas price changes by more than this factor (default: 0.05) [$GAS_PRICE_ORACLE_SIGNIFICANT_FACTOR]
   --wait-for-receipt                         wait for receipts when sending transactions [$GAS_PRICE_ORACLE_WAIT_FOR_RECEIPT]
   --metrics                                  Enable metrics collection and reporting [$GAS_PRICE_ORACLE_METRICS_ENABLE]
   --metrics.addr value                       Enable stand-alone metrics HTTP server listening interface (default: "127.0.0.1") [$GAS_PRICE_ORACLE_METRICS_HTTP]
   --metrics.port value                       Metrics HTTP server listening port (default: 6060) [$GAS_PRICE_ORACLE_METRICS_PORT]
   --metrics.influxdb                         Enable metrics export/push to an external InfluxDB database [$GAS_PRICE_ORACLE_METRICS_ENABLE_INFLUX_DB]
   --metrics.influxdb.endpoint value          InfluxDB API endpoint to report metrics to (default: "http://localhost:8086") [$GAS_PRICE_ORACLE_METRICS_INFLUX_DB_ENDPOINT]
   --metrics.influxdb.database value          InfluxDB database name to push reported metrics to (default: "gas-oracle") [$GAS_PRICE_ORACLE_METRICS_INFLUX_DB_DATABASE]
   --metrics.influxdb.username value          Username to authorize access to the database (default: "test") [$GAS_PRICE_ORACLE_METRICS_INFLUX_DB_USERNAME]
   --metrics.influxdb.password value          Password to authorize access to the database (default: "test") [$GAS_PRICE_ORACLE_METRICS_INFLUX_DB_PASSWORD]
   --help, -h                                 show help
   --version, -v                              print the version

Testing the service

The service can be tested with the Makefile

$ make test