14458: Avoid panic by removing defer close()

Channels will be garbage collected when they go unreferenced.

Make the errors channel buffered to avoid lingering goroutines trying
to send on an unbuffered error channel with no reciever.

Arvados-DCO-1.1-Signed-off-by: Peter Amstutz <pamstutz@veritasgenetics.com>

diff --git a/lib/controller/fed_collections.go b/lib/controller/fed_collections.go
index b9cd20582951505fe7b43c07c490be9507535720..38cf409e6efc8cd4800eaccf244df7eb0e42adc2 100644 (file)
--- a/lib/controller/fed_collections.go
+++ b/lib/controller/fed_collections.go
@@ -209,15 +209,12 @@ func (h *collectionFederatedRequestHandler) ServeHTTP(w http.ResponseWriter, req
        wg := sync.WaitGroup{}
        pdh := m[1]
        success := make(chan *http.Response)
-       errorChan := make(chan error)
+       errorChan := make(chan error, h.handler.Cluster.RequestLimits.GetMultiClusterRequestConcurrency())
 
        // use channel as a semaphore to limit the number of concurrent
        // requests at a time
        sem := make(chan bool, h.handler.Cluster.RequestLimits.GetMultiClusterRequestConcurrency())
 
-       defer close(errorChan)
-       defer close(success)
-       defer close(sem)
        defer cancelFunc()
 
        for remoteID := range h.handler.Cluster.RemoteClusters {