NodeId validator fails if no file exists

[bernd]

Expected Behavior

The server should start and create a node-id file if none exists.

Current Behavior

If there is no existing node-id file, the NodeId validator fails with the following message:

2017-12-20 09:41:20,337 ERROR: org.graylog2.bootstrap.CmdLineTool - Invalid configuration
com.github.joschi.jadconfig.ValidationException: Node ID file at path /usr/share/graylog/data/config/node-id isn't a file, readable. Please specify the correct path or change the permissions
	at org.graylog2.Configuration$NodeIdFileValidator.validate(Configuration.java:375) ~[graylog.jar:?]
	at org.graylog2.Configuration$NodeIdFileValidator.validate(Configuration.java:345) ~[graylog.jar:?]
	at com.github.joschi.jadconfig.JadConfig.validateParameter(JadConfig.java:215) ~[graylog.jar:?]
	at com.github.joschi.jadconfig.JadConfig.processClassFields(JadConfig.java:148) ~[graylog.jar:?]
	at com.github.joschi.jadconfig.JadConfig.process(JadConfig.java:99) ~[graylog.jar:?]
	at org.graylog2.bootstrap.CmdLineTool.processConfiguration(CmdLineTool.java:351) [graylog.jar:?]
	at org.graylog2.bootstrap.CmdLineTool.readConfiguration(CmdLineTool.java:344) [graylog.jar:?]
	at org.graylog2.bootstrap.CmdLineTool.run(CmdLineTool.java:177) [graylog.jar:?]
	at org.graylog2.bootstrap.Main.main(Main.java:44) [graylog.jar:?]

Steps to Reproduce (for bugs)

1. Download and extract the Graylog server artifact
2. Create graylog.conf file
3. Start server via ./bin/graylogctl run
4. Check out error message

Context

Related issues and PRs:

• Permission issues on node-id file lead to not very helpful error messages and exit #4410 - Initial issue report
• check node id file permissions as part of parameter validation #4417 - First attempt for a fix
• fix node id file permission checks #4428 - Second attempt for a fix
• Revert node-id file validations #4433 - Revert PR for 2.4

We reverted the changes in 2.4 to avoid more risk and delays for the release.

Your Environment

• Graylog Version: 2.4.0-rc.1