65 lines
2.3 KiB
Markdown
65 lines
2.3 KiB
Markdown
---
|
|
title: Dev mode
|
|
sort_key: B
|
|
---
|
|
|
|
Geth has a development mode that sets up a single node Ethereum test network with options optimized for developing on local machines. You enable it with the `--dev` argument.
|
|
|
|
Starting geth in dev mode does the following:
|
|
|
|
- Initializes the data directory with a testing genesis block
|
|
- Sets max peers to 0
|
|
- Turns off discovery by other nodes
|
|
- Sets the gas price to 0
|
|
- Uses the Clique PoA consensus engine with which allows blocks to be mined as-needed without excessive CPU and memory consumption
|
|
- Uses on-demand block generation, producing blocks when transactions are waiting to be mined
|
|
|
|
## Start Geth in Dev Mode
|
|
|
|
You can specify a data directory to maintain state between runs using the `--datadir` option, otherwise, databases are ephemeral and in-memory:
|
|
|
|
```shell
|
|
mkdir test-chain-dir
|
|
```
|
|
|
|
For this guide, start geth in dev mode, and enable [RPC](../../_rpc/server.md) so you can connect other applications to geth. For this guide, we use Remix, the web-based Ethereum IDE, so also allow its domains to accept cross-origin requests.
|
|
|
|
```shell
|
|
geth --datadir test-chain-dir --rpc --dev --rpccorsdomain "https://remix.ethereum.org,http://remix.ethereum.org"
|
|
```
|
|
|
|
Connect to the IPC console on the node from another terminal window:
|
|
|
|
```shell
|
|
geth attach <IPC_LOCATION>
|
|
```
|
|
|
|
Once geth is running in dev mode, you can interact with it in the same way as when geth is running in other ways.
|
|
|
|
For example, create a test account:
|
|
|
|
```shell
|
|
> personal.newAccount()
|
|
```
|
|
|
|
And transfer ether from the coinbase to the new account:
|
|
|
|
```shell
|
|
> eth.sendTransaction({from:eth.coinbase, to:eth.accounts[1], value: web3.toWei(0.05, "ether")})
|
|
```
|
|
|
|
And check the balance of the account:
|
|
|
|
```shell
|
|
> eth.getBalance(eth.accounts[1])
|
|
```
|
|
|
|
If you want to test your dapps with a realistic block time use the `--dev.period` option when you start dev mode with the `--dev.period 14` argument.
|
|
|
|
## Connect Remix to Geth
|
|
|
|
With geth now running, open <https://remix.ethereum.org>. Compile the contract as normal,
|
|
but when you deploy and run a contract, select _Web3 Provider_ from the _Environment_
|
|
dropdown, and add "http://127.0.0.1:8545" to the popup box. Click _Deploy_, and interact
|
|
with the contract. You should see contract creation, mining, and transaction activity.
|