fix(compose): container locking

Fix container locking which was duplicated and held for the duration of
the concurrent operation so preventing any concurrency.

modules/compose/compose_api.go

@@ -193,8 +193,8 @@ type dockerCompose struct {
 	// only one strategy can be added to a service, to use multiple use wait.ForAll(...)
 	waitStrategies map[string]wait.Strategy
 
-	// used to synchronise writes to the containers map
-	containersLock sync.RWMutex
+	// Used to synchronise writes to the containers.
+	containersLock sync.Mutex
 
 	// cache for containers that are part of the stack
 	// used in ServiceContainer(...) function to avoid calls to the Docker API
@@ -391,10 +391,6 @@ func (d *dockerCompose) Up(ctx context.Context, opts ...StackUpOption) (err erro
 				termSignals = append(termSignals, termSignal)
 			}
 
-			d.containersLock.Lock()
-			defer d.containersLock.Unlock()
-			d.containers[srv.Name] = dc
-
 			return nil
 		})
 	}
@@ -420,11 +416,6 @@ func (d *dockerCompose) Up(ctx context.Context, opts ...StackUpOption) (err erro
 				return err
 			}
 
-			// cache all the containers on compose.up
-			d.containersLock.Lock()
-			defer d.containersLock.Unlock()
-			d.containers[svc] = target
-
 			return strategy.WaitUntilReady(errGrpCtx, target)
 		})
 	}
@@ -511,6 +502,8 @@ func (d *dockerCompose) lookupContainer(ctx context.Context, svcName string) (*t
 
 	ctr.SetProvider(dockerProvider)
 
+	d.containersLock.Lock()
+	defer d.containersLock.Unlock()
 	d.containers[svcName] = ctr
 
 	return ctr, nil
@@ -520,9 +513,6 @@ func (d *dockerCompose) lookupContainer(ctx context.Context, svcName string) (*t
 //
 // Safe for concurrent calls.
 func (d *dockerCompose) lookupNetworks(ctx context.Context) error {
-	d.containersLock.Lock()
-	defer d.containersLock.Unlock()
-
 	networks, err := d.dockerClient.NetworkList(ctx, dockernetwork.ListOptions{
 		Filters: filters.NewArgs(
 			filters.Arg("label", fmt.Sprintf("%s=%s", api.ProjectLabel, d.name)),