按Corda V3.1文档部署Ubuntu服务启动Cordapp时遇Permission denied错误

Hey there, let's work through this permission denied error you're facing when launching your Corda example node (Party B) as a systemd service on Ubuntu. This is a common issue tied to file system permissions or service configuration, so here are the key steps to diagnose and fix it:

1. Verify Node Directory Permissions #

First, make sure the user running your Corda service has full read/write access to the node's root directory and all its contents.

• Find your node's directory (e.g., /opt/corda/nodes/partyB), then check its current ownership and permissions with:

  ls -ld /opt/corda/nodes/partyB
  

• If the owner isn't the user your systemd service runs as (let's assume you're using a dedicated corda user), fix the ownership recursively:

  sudo chown -R corda:corda /opt/corda/nodes/partyB
  

• Ensure the user has read, write, and directory execution permissions:

  sudo chmod -R u+rwX /opt/corda/nodes/partyB
  

  (The X flag adds execution rights only to directories, not files—this is safer than full 777 permissions.)

2. Configure Systemd Service to Run as the Correct User #

If your systemd service is running as root (the default if not specified), it might clash with permissions set for a regular corda user. Update your service file (typically at /etc/systemd/system/corda-partyB.service):

• Add these lines under the [Service] section:

  User=corda
  Group=corda
  

• Reload systemd to pick up the changes, then restart the service:

  sudo systemctl daemon-reload
  sudo systemctl restart corda-partyB
  

3. Check Temporary Directory Permissions #

Java relies on the /tmp directory for temporary files, and incorrect permissions here can cause the error.

• Verify /tmp has the correct sticky-bit permissions:

  ls -ld /tmp
  

  You should see output like drwxrwxrwt—the t at the end is critical.
• If not, fix it with:

  sudo chmod 1777 /tmp
  

4. Validate Node Configuration Paths #

Double-check your node.conf file for paths that might point to restricted directories:

• Look for settings like baseDirectory, logPath, or database persistence paths. For example, if logs are configured to write to /var/log/corda, ensure the corda user owns that directory:

  sudo mkdir -p /var/log/corda
  sudo chown corda:corda /var/log/corda
  

5. Test Manual Node Execution #

To confirm the issue is permission-related, switch to the corda user and run the node manually:

su - corda
java -jar /opt/corda/corda.jar --config-file /opt/corda/nodes/partyB/node.conf

If you get the same permission error here, it confirms the problem is with the user's access rights rather than systemd-specific configuration.

Most of the time, the root cause is a mismatch between the systemd service's running user and the node directory's ownership. Following these steps should resolve the "Permission denied" error and get your Party B node up and running.

内容的提问来源于stack exchange，提问作者Austin Moothart