Function removeConfigs

cli/command/service/update.go:859–891

removeConfigs figures out which configs in the existing spec should be kept after the update.

(flags *pflag.FlagSet, spec *swarm.ContainerSpec, credSpecName, credSpecID string)

// removeConfigs figures out which configs in the existing spec should be kept
// after the update.
func removeConfigs(flags *pflag.FlagSet, spec *swarm.ContainerSpec, credSpecName, credSpecID string) []*swarm.ConfigReference {
	keepConfigs := []*swarm.ConfigReference{}

	toRemove := buildToRemoveSet(flags, flagConfigRemove)
	// all configs in spec.Configs should have both a Name and ID, because
	// they come from an already-accepted spec.
	for _, config := range spec.Configs {
		// if the config is a Runtime target, make sure it's still in use right
		// now, the only use for Runtime target is credential specs.  if, in
		// the future, more uses are added, then this check will need to be
		// made more intelligent.
		if config.Runtime != nil {
			// if we're carrying over a credential spec explicitly (because the
			// user passed --credential-spec with the same config name) then we
			// should match on credSpecName. if we're carrying over a
			// credential spec implicitly (because the user did not pass any
			// --credential-spec flag) then we should match on credSpecID. in
			// either case, we're keeping the config that already exists.
			if config.ConfigName == credSpecName || config.ConfigID == credSpecID {
				keepConfigs = append(keepConfigs, config)
			}
			// continue the loop, to skip the part where we check if the config
			// is in toRemove.
			continue
		}

		if _, exists := toRemove[config.ConfigName]; !exists {
			keepConfigs = append(keepConfigs, config)
		}
	}

	return keepConfigs
}

func envKey(value string) string {
	k, _, _ := strings.Cut(value, "=")