Method GetDefaultNetworkConfig

pkg/netutil/netutil.go:371–416

GetDefaultNetworkConfig checks whether the default network exists by first searching for if any network bears the `labels.NerdctlDefaultNetwork` label, or falls back to checking whether any network bears the `DefaultNetworkName` name.

()

// label, or falls back to checking whether any network bears the
// `DefaultNetworkName` name.
func (e *CNIEnv) GetDefaultNetworkConfig() (*NetworkConfig, error) {
	// Search for networks bearing the `labels.NerdctlDefaultNetwork` label.
	defaultLabelFilterF := func(nc *NetworkConfig) bool {
		if nc.NerdctlLabels == nil {
			return false
		} else if _, ok := (*nc.NerdctlLabels)[labels.NerdctlDefaultNetwork]; ok {
			return true
		}
		return false
	}
	labelMatches, err := e.filterNetworks(defaultLabelFilterF)
	if err != nil {
		return nil, err
	}
	if len(labelMatches) >= 1 {
		if len(labelMatches) > 1 {
			log.L.Warnf("returning the first network bearing the %q label out of the multiple found: %#v", labels.NerdctlDefaultNetwork, labelMatches)
		}
		return labelMatches[0], nil
	}

	// Search for networks bearing the DefaultNetworkName.
	defaultNameFilterF := func(nc *NetworkConfig) bool {
		return nc.Name == DefaultNetworkName
	}
	nameMatches, err := e.filterNetworks(defaultNameFilterF)
	if err != nil {
		return nil, err
	}
	if len(nameMatches) >= 1 {
		if len(nameMatches) > 1 {
			log.L.Warnf("returning the first network bearing the %q default network name out of the multiple found: %#v", DefaultNetworkName, nameMatches)
		}

		// Warn the user if the default network was not created by nerdctl.
		match := nameMatches[0]
		exists, statErr := fsExists(e, DefaultNetworkName)
		if match.NerdctlID == nil || statErr != nil || !exists {
			log.L.Warnf("default network named %q does not have an internal nerdctl ID or nerdctl-managed config file, it was most likely NOT created by nerdctl", DefaultNetworkName)
		}

		return nameMatches[0], nil
	}

	return nil, nil
}

func (e *CNIEnv) ensureDefaultNetworkConfig(bridgeIP string) error {
	defaultNet, err := e.GetDefaultNetworkConfig()