[YanLongDai]

This PR is for:

• Agent

Fixes controller_ips[0] index out of bounds panic in remaining locations

Steps to reproduce the bug

This PR fixes the same controller_ips[0] index out of bounds issue in the remaining 3 locations in agent/src/trident.rs, following the same approach as PR #11929.

1. Deploy DeepFlow Agent v7.2.2 on KylinOS V10 (aarch64)
2. Create config file without controller-ips field:

   controller-port: 30035
   log-file: /var/log/deepflow-agent/deepflow-agent.log
   log-level: info
   agent-mode: standalone

3. Start agent: systemctl start deepflow-agent
4. Agent crashes immediately with signal 6 (SIGABRT)

When the agent starts without controller-ips configured, it may panic at different locations depending on the execution path:

• Line 720: Trident::run() function (eBPF initialization path)
• Line 848: Synchronizer::new() call (config sync path)
• Line 971: SidecarPoller::new() call (sidecar mode path)

Stack trace example (Line 720):

Stack trace of thread:
#0  raise (libc.so.6)
#1  abort (libc.so.6)
#2-#10 Rust panic chain
#11 deepflow_agent::trident::Trident::run (deepflow-agent)  ← PANIC HERE
#12 deepflow_agent::main (deepflow-agent)

Test environment:

OS: KylinOS V10 (aarch64)
Kernel: 4.19.90-89.37.v2401.ky10.aarch64
Architecture: ARM64 (aarch64)
DeepFlow Agent: v7.2.2 (native community version)

Verification:

Program Version	Config	Result
Native (70M)	Minimal (no controller-ips)	❌ Crash
Native (70M)	With controller-ips	✅ Normal

Conclusion: This is a bug in the native DeepFlow code, verified on community version v7.2.2.

Changes to fix the bug

Location 1: Trident::run() - Line 720

Before:

let controller_ip: IpAddr = config_handler.static_config.controller_ips[0].parse()?;

After:

let controller_ip: IpAddr = config_handler
    .static_config
    .controller_ips
    .first()
    .ok_or_else(|| {
        anyhow::anyhow!(
            "controller_ips is empty, please configure controller-ips in standalone mode"
        )
    })?
    .parse()?;

Location 2: Synchronizer::new() - Line 848

Before:

config_handler.static_config.controller_ips[0].clone(),

After:

config_handler
    .static_config
    .controller_ips
    .first()
    .ok_or_else(|| {
        anyhow::anyhow!(
            "controller_ips is empty, please configure controller-ips in standalone mode"
        )
    })?
    .clone(),

Location 3: SidecarPoller::new() - Line 971

Before:

config_handler.static_config.controller_ips[0].parse()?,

After:

config_handler
    .static_config
    .controller_ips
    .first()
    .ok_or_else(|| {
        anyhow::anyhow!(
            "controller_ips is empty, please configure controller-ips in standalone mode"
        )
    })?
    .parse()?,

Affected branches

• main

Related PR

• PR fix(agent): prevent panic when controller_ips is empty in Trident::start #11929: fix(agent): prevent panic when controller_ips is empty in Trident::start

Checklist

• Verified the fix on KylinOS V10 (aarch64) with DeepFlow Agent v7.2.2
• Tested with both minimal and full config formats
• No breaking changes - maintains backward compatibility
• Same fix pattern as PR fix(agent): prevent panic when controller_ips is empty in Trident::start #11929
• Added unit test to verify the fix.
• Verified eBPF program runs successfully on linux 4.14.x.
• Verified eBPF program runs successfully on linux 4.19.x.
• Verified eBPF program runs successfully on linux 5.2.x.

Note: The eBPF verification items are not applicable for this fix as it only modifies configuration parsing logic, not eBPF programs.

---

Signed-off-by: Dai Yanlong daiyanlong@kylinos.cn

cc @lzf575 @rvql Please review this fix. Thanks!