Currently there is no official release of Docker available for Ubuntu 18.10. Therefore you’ll run into errors like this one:  
		
		
			
			
			
			
				
					
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						$ sudo apt-get install docker-ce Reading package lists... Done Building dependency tree        Reading state information... Done Package docker-ce is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source   E: Package 'docker-ce' has no installation candidate  | 
					
				
			 
		 
 But there is already a way to utilize the test repo to have Docker for Ubuntu 18.10: 
		
		
			
			
			
			
				
					
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						sudo apt install apt-transport-https ca-certificates curl software-properties-common curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add - sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu bionic test" sudo apt install docker-ce    | 
					
				
			 
		 
 Before you apply this fix, please check if the official resources have been updated at: https://docs.docker.com/install/linux/docker-ce/ubuntu/