Make docker collector threadsafe
Make docker collector threadsafe

mikepea/fullerite,venkey-ariv/fullerite,venkey-ariv/fullerite,baris/fullerite,Yelp/fullerite,mikepea/fullerite,baris/fullerite,mikepea/fullerite,Yelp/fullerite,mikepea/fullerite,baris/fullerite,Yelp/fullerite,Yelp/fullerite,baris/fullerite,venkey-ariv/fullerite,venkey-ariv/fullerite