Restoring container connectivity for containerized routers

1 . A computing device comprising:

memory;

processing circuitry communicably coupled to the memory;

a containerized router configured to execute on the processing circuitry, wherein the containerized router includes a containerized virtual router configured to implement a data plane for the containerized router and a containerized routing protocol process configured to implement a control plane for the containerized router,

wherein the containerized router is configured to, as part of a containerized router initialization process:

read container attachment information from the memory, the container attachment information persisted to the memory by a prior instance of the containerized router; and

configure the containerized router with the container attachment information to enable network communications by a logically-related group of one or more containers via the containerized router.

2 . The computing device of claim 1 , wherein the container attachment information comprise interface information for one or more virtual network interfaces in the containerized virtual router that connect to the logically-related group of one or more containers and configuration information for configuring the one or more virtual network interfaces that connects to the logically-related group of one or more containers.

3 . The computing device of claim 2 , wherein the interface information include one or more of a virtual network address associated with each of the one or more virtual network interfaces or a virtual network identifier for each of the one or more virtual network interfaces, and wherein the configuration information include one or more of information for configuring the one or more virtual network interfaces or route information for the one or more virtual network interfaces.

4 . The computing device of claim 2 , wherein to configure the containerized router with the container attachment information, the containerized router is further configured to:

add, based on the interface information, the one or more virtual network interfaces that connects to the logically-related group of one or more containers to the containerized virtual router; and

configure, based on the configuration information, the one or more virtual network interfaces.

5 . The computing device of claim 2 ,

wherein the containerized virtual router of the prior instance of the containerized router is configured to store the interface information for the one or more virtual network interfaces that connect to the logically-related group of one or more containers; and

wherein the containerized routing protocol process of the prior instance of the containerized router is configured to store the configuration information for configuring the one or more virtual network interfaces that connects to the logically-related group of one or more containers.

6 . The computing device of claim 1 , wherein to configure the containerized router to enable the network communications by the logically-related group of one or more containers via the containerized router, the containerized router is further configured to:

re-attach the logically-related group of one or more containers to the containerized router, without receiving, after installation of the containerized router, a request from a container network interface (CNI) plugin to attach the logically-related group of one or more containers executing on the processing circuitry to the containerized router and without re-starting the logically-related group of one or more containers.

7 . The computing device of claim 1 , wherein the container attachment information includes information for attaching each of a plurality of logically-related groups of one or more containers to the containerized router, including, for each of the plurality of logically-related groups of one or more containers, a corresponding unique identifier, wherein the processing circuitry is further configured to:

determine, based on the corresponding, unique identifier for each of the plurality of logically-related groups of one or more containers, that one or more of the plurality of logically-related groups of one or more containers specified in the container attachment information are no longer running on the processing circuitry; and

remove information for the one or more of the plurality of logically-related groups of one or more containers from the container attachment information,

wherein to configure the containerized router with the container attachment information to enable the network communications by the logically-related group of one or more containers, the containerized router is further configured to configure the containerized router with the container attachment information to enable the network communications by each of a remaining one or more logically-related groups of one or more containers specified in the container attachment information via the containerized router based on the container attachment information.

8 . The computing device of claim 1 , wherein the logically-related group of one or more containers comprises a Kubernetes pod.

9 . The computing device of claim 1 , further comprising a container network interface (CNI) plugin configured to execute on the processing circuitry and to send, to the prior instance of the containerized router, a request to attach the logically-related group of one or more containers to the containerized router;

wherein the prior instance of the containerized router is further configured to:

in response to receiving the request from the CNI plugin, determine, based on the request, the container attachment information for attaching the logically-related group of one or more containers to the prior instance of the containerized router;

attach the logically-related group of one or more containers to the prior instance of the containerized router based on the container attachment information; and

store, based on the request and in the memory, the container attachment information.

10 . A method comprising:

reading, by a containerized router executing on processing circuitry as part of an initialization process, container attachment information from memory, the container attachment information persisted to the memory by a prior instance of the containerized router, wherein the containerized router includes a containerized virtual router configured to implement a data plane for the containerized router and a containerized routing protocol process configured to implement a control plane for the containerized router; and

configuring, by the containerized router executing on the processing circuitry as part of the initialization process, the containerized router with the container attachment information to enable network communications by a logically-related group of one or more containers via the containerized router.

11 . The method of claim 10 , wherein the container attachment information comprise interface information for one or more virtual network interfaces in the containerized virtual router that connect to the logically-related group of one or more containers and configuration information for configuring the one or more virtual network interfaces that connects to the logically-related group of one or more containers.

12 . The method of claim 11 , wherein the interface information include one or more of a virtual network address associated with each of the one or more virtual network interfaces or a virtual network identifier for each of the one or more virtual network interfaces, and wherein the configuration information include one or more of information for configuring the one or more virtual network interfaces or route information for the one or more virtual network interfaces.

13 . The method of claim 11 , wherein configuring the containerized router with the container attachment information comprises:

adding, by the containerized router executing on the processing circuitry and based on the interface information, the one or more virtual network interfaces that connects to the logically-related group of one or more containers to the containerized virtual router; and

configuring, by the containerized router executing on the processing circuitry and based on the configuration information, the one or more virtual network interfaces.

14 . The method of claim 11 , further comprising:

storing, by the containerized virtual router of the prior instance of the containerized router, the interface information for the one or more virtual network interfaces that connect to the logically-related group of one or more containers; and

storing, by the containerized routing protocol process of the prior instance of the containerized router, the configuration information for configuring the one or more virtual network interfaces that connects to the logically-related group of one or more containers.

15 . The method of claim 10 , wherein configuring, by the containerized router, the containerized router to enable the network communications by the logically-related group of one or more containers further comprises:

re-attaching, by the containerized router executing on the processing circuitry, the logically-related group of one or more containers to the containerized router, without receiving, after re-installation of the containerized router, a second request from a container network interface (CNI) plugin to attach the logically-related group of one or more containers executing on the processing circuitry to the containerized router and without re-starting the logically-related group of one or more containers.

16 . The method of claim 10 , wherein the container attachment information includes information for attaching each of a plurality of logically-related groups of one or more containers to the containerized router, including, for each of the plurality of logically-related groups of one or more containers, a corresponding unique identifier, further comprising:

determining, by the processing circuitry and based on the corresponding, unique identifier for each of the plurality of logically-related groups of one or more containers, that one or more of the plurality of logically-related groups of one or more containers specified in the container attachment information are no longer running on the processing circuitry; and

removing, by the one or more processing circuitry, information for the one or more of the plurality of logically-related groups of one or more containers from the container attachment information;

wherein configuring, by the containerized router executing on the processing circuitry, the containerized router with the container attachment information to enable the network communications by the logically-related group of one or more containers further comprises configuring, by the containerized router executing on the processing circuitry, the containerized router to enable the network communications by each of a remaining one or more logically-related groups of one or more containers specified in the container attachment information via the containerized router based on the container attachment information.

17 . The method of claim 10 , wherein the logically-related group of one or more containers comprise a Kubernetes pod.

18 . The method of claim 10 , further comprising:

sending, by a container network interface (CNI) plugin executing on the processing circuitry, to the prior instance of the containerized router, a request to attach the logically-related group of one or more containers to the containerized router;

in response to receiving the request from the CNI plugin, determining, by the prior instance of the containerized router executing on the processing circuitry and based on the request, the container attachment information for attaching the logically-related group of one or more containers to the prior instance of the containerized router;

attaching, by the prior instance of the containerized router executing on the processing circuitry, the logically-related group of one or more containers to the prior instance of the containerized router based on the container attachment information; and

storing, by the prior instance of the containerized router executing on the processing circuitry, and based on the request and in the memory, the container attachment information.

19 . Non-transitory computer-readable storage media, storing instructions, which when executed by processing circuitry of a computing device, cause the processing circuitry to:

reading, by a containerized router executing on the processing circuitry, container attachment information from memory, the container attachment information persisted to the memory by a prior instance of the containerized router, wherein the containerized router includes a containerized virtual router configured to implement a data plane for the containerized router and a containerized routing protocol process configured to implement a control plane for the containerized router; and

configuring, by the containerized router executing on the processing circuitry, the containerized router with the container attachment information to enable network communications by a logically-related group of one or more containers via the containerized router.

20 . The non-transitory computer-readable storage media of claim 19 , wherein the container attachment information comprise interface information for one or more virtual network interfaces in the containerized virtual router that connect to the logically-related group of one or more containers and configuration information for configuring the one or more virtual network interfaces that connects to the logically-related group of one or more containers.