Repository: istio/istio
File: tools/istio-iptables/pkg/capture/helper.go (Go)

Code before:
							}
						}
					}
				}
				if !deltaFound {
					for _, cmd := range ipCfg.checkRules {
						if _, err := ext.Run(log, true, constants.IPTables, ipCfg.ver, nil, cmd...); err != nil {
							deltaFound = true
							log.Debugf("[%s] iptables check rules failed", ipCfg.versionName)
							break
						}
					}
				}
				curDeltaExists = deltaFound
			}
		}
		results = append(results, ipFamilyResult{curResidueExists, curDeltaExists, !emptyExpectedState, ipCfg.versionName})
	}
	log.Debugf("iptables state verification summary: %+v", results)
	var globalResidueExists, globalDeltaExists bool
	for _, res := range results {
		globalDeltaExists = globalDeltaExists || res.deltaExists
		if res.residueExists && res.plannedIstioRules {
			log.Infof("Ignoring residues because no rules are planned for %s", res.versionName)
			globalResidueExists = true
		}
	}

	if !globalResidueExists {
		log.Info("Clean-state detected, new iptables are needed")
		return false, true
	}

	if globalDeltaExists {
		log.Info("Found residues of old iptables rules/chains, reconciliation is recommended")
	} else {
		log.Info("Found compatible residues of old iptables rules/chains, reconciliation not needed")
	}

	return globalResidueExists, globalDeltaExists
}

// HasIstioLeftovers checks the given iptables state for any chains or rules related to Istio.
// It scans the provided map of tables, chains, and rules to identify any chains that start with the "ISTIO_" prefix,
// as well as any rules that involve Istio-specific jumps.
// The function returns a map where the keys are the tables, and the values are structs containing the leftover
// "ISTIO_" chains and jump rules for each table. Only tables with Istio-related leftovers are included in the result.
func HasIstioLeftovers(state map[string]map[string][]string) map[string]struct{ Chains, Rules []string } {
	output := make(map[string]struct{ Chains, Rules []string })
	for table, chains := range state {
		istioChains := []string{}

Review comment (suggestion):
I think, the statement should be as follows.

```suggestion
    // If any of the families have residues, it implies that globalResidueExists
    globalResidueExists = globalResidueExists || res.residueExists
```

Code after:
							}
						}
					}
				}
				if !deltaFound {
					for _, cmd := range ipCfg.checkRules {
						if _, err := ext.Run(log, true, constants.IPTables, ipCfg.ver, nil, cmd...); err != nil {
							deltaFound = true
							log.Debugf("[%s] iptables check rules failed", ipCfg.versionName)
							break
						}
					}
				}
				curDeltaExists = deltaFound
			}
		}
		results = append(results, ipFamilyResult{curResidueExists, curDeltaExists, !emptyExpectedState, ipCfg.versionName})
	}
	log.Debugf("iptables state verification summary: %+v", results)
	var globalResidueExists, globalDeltaExists bool
	for _, res := range results {
		globalDeltaExists = globalDeltaExists || res.deltaExists
		if res.residueExists && res.plannedIstioRules {
			globalResidueExists = true
		} else if res.residueExists {
			log.Infof("Ignoring residues because no rules are planned for %s", res.versionName)
		}
	}

	if !globalResidueExists {
		log.Info("Clean-state detected, new iptables are needed")
		return false, true
	}

	if globalDeltaExists {
		log.Info("Found residues of old iptables rules/chains, reconciliation is recommended")
	} else {
		log.Info("Found compatible residues of old iptables rules/chains, reconciliation not needed")
	}

	return globalResidueExists, globalDeltaExists
}

// HasIstioLeftovers checks the given iptables state for any chains or rules related to Istio.
// It scans the provided map of tables, chains, and rules to identify any chains that start with the "ISTIO_" prefix,
// as well as any rules that involve Istio-specific jumps.
// The function returns a map where the keys are the tables, and the values are structs containing the leftover
// "ISTIO_" chains and jump rules for each table. Only tables with Istio-related leftovers are included in the result.
func HasIstioLeftovers(state map[string]map[string][]string) map[string]struct{ Chains, Rules []string } {
	output := make(map[string]struct{ Chains, Rules []string })
	for table, chains := range state {