fix(driver): bypass Istio ambient inbound capture for sandbox pods#13
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On OpenShift with Istio ambient mesh (HBONE mode), ztunnel intercepts inbound TCP to the pod and re-originates connections from the pod's main IP instead of preserving the sandbox veth source address. This breaks the proxy's /proc/net/tcp-based identity resolution because peer_addr() returns ztunnel's address, not the sandbox's 10.200.0.2. Always annotate sandbox pods with: ambient.istio.io/bypass-inbound-capture: "true" This tells Istio ambient to skip inbound interception, preserving the original source address on the veth pair so identity resolution can correlate sockets to sandbox processes. The sidecar-mode annotation (traffic.sidecar.istio.io/excludeInboundPorts) has no effect in ambient mode. Fixes: kagenti/kagenti#1855 Assisted-By: Claude (Anthropic AI) <noreply@anthropic.com> Signed-off-by: Paolo Dettori <dettori@us.ibm.com>
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Jun 8, 2026
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Self-review (automated)
Clean, minimal fix that adds a single Istio ambient annotation to bypass inbound capture on sandbox pods. The root cause explanation is excellent — documents the ztunnel HBONE source-address rewriting behavior and why the sidecar-mode annotation doesn't help.
Areas reviewed: Go, Tests, Commit conventions, PR format, Security
Commits: 1 commit, signed-off ✓
CI status: all passing (Build, DCO, Lint, Test)
No issues found. LGTM.
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Summary
ambient.istio.io/bypass-inbound-capture: "true"so Istio ambient mode does not intercept inbound traffic to the pod's internal proxy portRoot Cause
On OpenShift with Istio ambient mesh (HBONE mode), ztunnel intercepts inbound TCP and re-originates connections from the pod's main IP (
10.128.x.x) instead of preserving the sandbox veth source address (10.200.0.2). This breaks the proxy's/proc/net/tcp-based identity resolution —peer_addr()returns ztunnel's address, and the port lookup in the sandbox network namespace's TCP table finds nothing.The sidecar-mode annotation (
traffic.sidecar.istio.io/excludeInboundPorts) has no effect in ambient mode — onlyambient.istio.io/bypass-inbound-captureworks.On Kind (upstream Istio 1.28), ztunnel already preserves source IPs through the REDIRECT, so this annotation is a harmless no-op there.
Test plan
go test ./internal/driver/passes (updated existing annotation test)Fixes: kagenti/kagenti#1855
Assisted-By: Claude Code