PHP Fatal error: implode() expects array, string given in fail2ban.inc:161 (OMV8 / Debian 13)

[LeNicoDesBois]

Environment

• OpenMediaVault: 8.0
• Plugin version: openmediavault-fail2ban 8.0
• OS: Debian GNU/Linux 13 Trixie (Raspberry Pi 4)
• Fail2ban: 1.1.0-8

Bug description

When opening Diagnostics → Services → Fail2ban in the OMV web interface,
the following error is displayed:

Invalid RPC response. Please check the syslog for more information.

Error in syslog

PHP Fatal error: Uncaught TypeError: implode(): Argument #2 ($array) must be of type ?array, string given in /usr/share/openmediavault/engined/rpc/fail2ban.inc:161

Root cause

In fail2ban.inc line 161, implode() receives a string instead of an array:

// Buggy code (line 161)
$stats .= implode("\n", "No jail enabled");

// Fix
$stats .= implode("\n", ["No jail enabled"]);

Fix applied

sudo sed -i 's/implode("\\n", "No jail enabled")/implode("\\n", ["No jail enabled"])/' \
  /usr/share/openmediavault/engined/rpc/fail2ban.inc

This one-line fix resolves the issue immediately.

[ryecoaaron]

I will fix it. I think this only really affects people when they have the plugin installed but not using it.

[LeNicoDesBois]

Right! I had the error just after plugin installation and before configuration.

[ryecoaaron]

I will release an update later for this.