Updating container runtime using standby virtual machines

A computing apparatus comprising:

• a storage system;
• a processing system operatively coupled to the storage system;
• program instructions stored on the storage system that, when executed by the processing system, direct the computing apparatus to:
• identify a request to update a container runtime from a first version to a second version for a first container executing in a first virtual machine, wherein the first container uses a first root filesystem;
• initiate execution of a second container in a second virtual machine with the second version of the container runtime, wherein the second container uses the first root filesystem;
• update a networking configuration to direct communications to the second container in place of the first container;
• and
• stop execution of the first container.

A method comprising:

• identifying a request to update a container runtime from a first version to a second version for a plurality of containers, wherein the plurality of containers each execute on a separate virtual machine;
• for each container in the plurality of containers:
• initiating execution of a standby container in a standby virtual machine with the second version of the container runtime;
• and
• stopping execution of the virtual machine associated with the container.