Mac users guide¶

This guide runs a node on macOS, on Ethereum Classic or on the Mordor test network, from an installed geth to a launchd agent that starts it when you log in. Running a node covers what every platform shares.

Commands are shown for both networks. Use the lines for the network you chose, and keep its flag on every command.

1. Install¶

Install geth as Installation, macOS shows, including clearing the quarantine attribute if a browser downloaded it. Then check it:

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geth version        # Core-Geth 1.13.0-stable

2. Choose the network¶

With no flag, the node runs Ethereum Classic. This guide passes --classic anyway, so that every command says which network it is for.

3. Start the node¶

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geth --classic      # Ethereum Classic
geth --mordor       # Mordor

The node runs in the foreground and logs to the terminal. Its first line names the network: Starting Core-Geth on Ethereum Classic... or Starting Core-Geth on Mordor testnet.... What a healthy first sync looks like explains the lines that follow. Other nodes reach yours on port 30303, over TCP and UDP (Ports and listeners).

For a configuration, add its flags after the network flag, such as geth --classic --http --http.api eth,net,web3. Step 6 shows how the agent takes them.

To keep the chain on another disk, add --datadir, such as --datadir /Volumes/Data/core-geth/mordor. Then give attach the socket inside that directory: geth --mordor attach /Volumes/Data/core-geth/mordor/geth.ipc.

4. Check that it syncs¶

In a second terminal window:

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# Ethereum Classic
geth --classic attach --exec 'eth.syncing'       # an object while it syncs, false once synced
geth --classic attach --exec 'net.peerCount'     # above 0 within minutes
geth --classic attach --exec 'eth.blockNumber'   # once synced, compare with a block explorer

# Mordor
geth --mordor attach --exec 'eth.syncing'
geth --mordor attach --exec 'net.peerCount'
geth --mordor attach --exec 'eth.blockNumber'

attach looks for the node’s socket in the data directory of the network you name, so a Mordor node needs --mordor here too. How to tell it is done lists every sign of a finished sync.

5. Use it¶

attach without --exec opens an interactive console on the node. Type exit to leave it; the node keeps running.

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geth --mordor attach

For wallets and programs, start the node with --http, such as geth --mordor --http. It serves JSON-RPC on 127.0.0.1:8545. From a second terminal window:

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curl -s -X POST -H 'Content-Type: application/json' \
  --data '{"jsonrpc":"2.0","id":1,"method":"eth_chainId","params":[]}' http://127.0.0.1:8545

The result is 0x3d on Ethereum Classic and 0x3f on Mordor. Read RPC exposure before you serve it beyond 127.0.0.1.

6. Keep it running: a launchd agent¶

A launchd agent starts the node when you log in, restarts it if it fails, and gives it five minutes to stop. It runs while you are logged in, and a Mac that sleeps pauses the node until it wakes.

Create the agent. Set NETWORK to classic or mordor, then run the rest as it is. The file it writes names the network in the agent’s label, the flag and the log file:

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NETWORK=classic      # or: NETWORK=mordor
mkdir -p ~/Library/LaunchAgents ~/Library/Logs
cat > ~/Library/LaunchAgents/com.coregeth.$NETWORK.plist <<EOF
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
  <key>Label</key>
  <string>com.coregeth.$NETWORK</string>
  <key>ProgramArguments</key>
  <array>
    <string>/usr/local/bin/geth</string>
    <string>--$NETWORK</string>
  </array>
  <key>RunAtLoad</key>
  <true/>
  <key>KeepAlive</key>
  <dict>
    <key>SuccessfulExit</key>
    <false/>
  </dict>
  <key>ExitTimeOut</key>
  <integer>300</integer>
  <key>StandardErrorPath</key>
  <string>$HOME/Library/Logs/core-geth-$NETWORK.log</string>
</dict>
</plist>
EOF

For a configuration, add each of its flags to ProgramArguments as its own <string> line after <string>--$NETWORK</string>, joining a flag to its value with =: <string>--http.api=eth,net,web3</string>.

Start it now, then follow its log. It starts again each time you log in:

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launchctl bootstrap gui/$(id -u) ~/Library/LaunchAgents/com.coregeth.$NETWORK.plist
tail -f ~/Library/Logs/core-geth-$NETWORK.log

What the agent’s settings do:

• RunAtLoad starts the node when the agent loads: now, and at each login.
• KeepAlive, with SuccessfulExit set to false, restarts the node after it exits with an error. A node that stops cleanly exits without one, and launchd leaves it stopped.
• ExitTimeOut is how long launchd waits after its SIGTERM before it kills the node. The system default is shorter than a stop during the first sync can take (stop times).
• StandardErrorPath is where the log goes, because the node logs to standard error.

The agent runs the node as you, with the default data directory, so the commands in steps 4 and 5 reach it unchanged. To run a node with no one logged in, install the same file as a launch daemon in /Library/LaunchDaemons instead, with a UserName key naming the account to run it as; man launchd.plist documents both.

7. Stop it cleanly¶

• In the foreground: press Ctrl-C once, then wait for Blockchain stopped and the prompt.
• As an agent: with NETWORK set as in step 6, unload it. launchd sends the node SIGTERM, and the log then ends with Blockchain stopped. The agent loads again at your next login; delete its file to keep it from starting.

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launchctl bootout gui/$(id -u)/com.coregeth.$NETWORK
rm ~/Library/LaunchAgents/com.coregeth.$NETWORK.plist      # only to keep it from starting at login

Pressing Ctrl-C again does not speed up a stop. Stop it safely shows what a clean stop logs, and why a stop during the first sync takes longer.

8. Update it¶

Stop the node, install the new release’s geth the same way as in step 1, and start the node again. Upgrading within v1.13.x lists what to read and check. A node on a v1.12.x release follows the Mac migration guide instead.