[ZBX-24969] vfs.file.regmatch does not break after match Created: 2024 Aug 05  Updated: 2025 Apr 11  Resolved: 2025 Apr 11

Status: Closed
Project: ZABBIX BUGS AND ISSUES
Component/s: Agent (G)
Affects Version/s: 6.0.32
Fix Version/s: 7.0.12rc1, 7.2.6rc1, 7.4.0rc1 (master)

Type: Problem report Priority: Trivial
Reporter: Sander Linsen Assignee: Armands Arseniuss Skolmeisters
Resolution: Fixed Votes: 0
Labels: None
Remaining Estimate: 0h
Time Spent: 3h
Original Estimate: 3h

Team: Team C
Sprint: S25-W12/13, S25-W14/15
Story Points: 1

 Description   

Steps to reproduce:

  1. Create Item key (for example): vfs.file.regmatch[/var/log/messages, ".", "utf8"]
  2. Get error message: Timeout while processing item.
  3. This is because Zabbix Agent 2 reads the entire file, while we are only searching for one match. When a match is found, Zabbix Agent 2 keeps searching.

Result:

zabbix_agent2 -t 'vfs.file.regmatch[/tmp/messages, ".", "utf8"]' ->

2024/08/02 14:58:13.213737 [MongoDB] plugin "/usr/sbin/zabbix-agent2-plugin/zabbix-agent2-plugin-mongodb" process exited

2024/08/02 14:58:13.218301 [PostgreSQL] plugin "/usr/sbin/zabbix-agent2-plugin/zabbix-agent2-plugin-postgresql" process exited

vfs.file.regmatch[/tmp/messages, ".", "utf8"] [m|ZBX_NOTSUPPORTED] [Timeout while processing item.]

Expected:
The check succeeds and exits with first found match:

./zabbix_agent2 -t 'vfs.file.regmatch[/tmp/messages, ".", "utf8"]'

vfs.file.regmatch[/tmp/messages, ".", "utf8"] [s|1]

Proposed Solution:

We took the source of the Zabbix Agent 2 binary and added a break in the last for loop of:

zabbix-6.0.32/src/go/plugins/vfs/file/regmatch.go

That looks like this:

...
        initial := true
        undecodedBufNumBytes := 0
        var undecodedBuf []byte
        for 0 < undecodedBufNumBytes || initial {
                initial = false
                elapsed := time.Since(start)
                if elapsed.Seconds() > float64(p.options.Timeout) {
                        return nil, errors.New("Timeout while processing item.")
                }                curline++                undecodedBuf, undecodedBufNumBytes, encoding, err = p.readTextLineFromFile(f, encoding)
                if err != nil {
                        return nil, err
                }
                utf8_buf, utf8_bufNumBytes := decodeToUTF8(encoding, undecodedBuf, undecodedBufNumBytes)
                utf8_bufStr := string(utf8_buf[:utf8_bufNumBytes])                if curline >= startline {
                        if match := r.Match([]byte(utf8_bufStr)); match {
                                ret = 1
                                break              <<<<<<<-------- HERE
                        }
                }                if curline >= endline {
                        break
                }
        }        return ret, nil

This will return the expected value and speeds up the processing:

time ./zabbix_agent2 -t 'vfs.file.regmatch[/tmp/messages, ".", "utf8"]'
vfs.file.regmatch[/tmp/messages, ".", "utf8"] [s|1]real    0m0.407s
user    0m0.005s
sys     0m0.006s

 

 Comments   
Comment by Vladislavs Sokurenko [ 2024 Aug 05 ]

This should do the trick:

diff --git a/src/go/plugins/vfs/file/regmatch.go b/src/go/plugins/vfs/file/regmatch.go
index 2addcd79ebe..732ad6a5463 100644
--- a/src/go/plugins/vfs/file/regmatch.go
+++ b/src/go/plugins/vfs/file/regmatch.go
@@ -111,6 +111,7 @@ func (p *Plugin) exportRegmatch(params []string, timeout int) (result interface{
                if curline >= startline {
                        if match := r.Match([]byte(utf8_bufStr)); match {
                                ret = 1
+                               break
                        }
                }
Comment by Sander Linsen [ 2024 Aug 05 ]

Yes, a diff would've been more helpful. Thank you!

Comment by Armands Arseniuss Skolmeisters [ 2025 Apr 08 ]

Available in versions:

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