package ctr import ( "context" "github.com/containers/podman/v2/libpod" "github.com/containers/podman/v2/pkg/parallel" "github.com/sirupsen/logrus" ) // ContainerOp performs the given function on the given set of // containers, using a number of parallel threads. // If no error is returned, each container specified in ctrs will have an entry // in the resulting map; containers with no error will be set to nil. func ContainerOp(ctx context.Context, ctrs []*libpod.Container, applyFunc func(*libpod.Container) error) (map[*libpod.Container]error, error) { // We could use a sync.Map but given Go's lack of generic I'd rather // just use a lock on a normal map... // The expectation is that most of the time is spent in applyFunc // anyways. var ( errMap = make(map[*libpod.Container]<-chan error) ) for _, ctr := range ctrs { c := ctr logrus.Debugf("Starting parallel job on container %s", c.ID()) errChan := parallel.Enqueue(ctx, func() error { return applyFunc(c) }) errMap[c] = errChan } finalErr := make(map[*libpod.Container]error) for ctr, errChan := range errMap { err := <-errChan finalErr[ctr] = err } return finalErr, nil }