...
2. Create the Network Policy:
kubectl apply -f network_policy.yml
Cross-Node communication
Edge applications must introduce themselves to OpenNESS framework and identify if they would like to activate new edge services or consume an existing service. Edge Application Agent (EAA) component is the handler of all the edge applications hosted by the OpenNESS edge node and acts as their point-of-contact.
OpenNESS-awareness involves (a) authentication, (b) service activation/deactivation, (c) service discovery, (d) service subscription, and (e) Websocket connection establishment. The Websocket connection retains a channel for EAA for notification forwarding to pre-subscribed consumer applications. Notifications are generated by "producer" edge applications and absorbed by "consumer" edge applications.
The sequence of operations for the producer application:
- Authenticate with OpenNESS edge node
- Activate new service and include the list of notifications involved
- Send notifications to OpenNESS edge node according to business logic
The sequence of operations for the consumer application:
- Authenticate with OpenNESS edge node
- Discover the available services on OpenNESS edge platform
- Subscribe to services of interest and listen for notifications
Edge apps will access eaa through eaa.openness (name.namespace) which is a kubernetes service:
https://github.com/open-ness/edgecontroller/blob/master/kube-ovn/openness.yaml#L18
For example: as following links show, openvino consumer will access http://eaa.openness:443/auth for authentication.
https://github.com/open-ness/edgeapps/blob/master/openvino/consumer/cmd/main.go#L24
https://github.com/open-ness/edgeapps/blob/master/openvino/consumer/cmd/main.go#L66
eaa is deployed as a deployment and only 1 eaa will be deployed:
https://github.com/open-ness/edgecontroller/blob/master/kube-ovn/openness.yaml#L41
Because all edge apps will access only 1 eaa, it doesn't matter that eaa is stateful.
For example:
only 1 eaa is deployed on node1. producer1 and producer2 will activate the new service with eaa. consumer1 and consumer2 will consume services stored in eaa. Because all the information are stored in only 1 eaa, there won't be issues.
node1 node2
eaa
producer1 consumer1 producer2 consumer2
Because edge apps on different edge node all can access service eaa, the consumer can consume the service provided by producer which is on a different node.
For example:
producer1 is located in node1 and consumer2 is located on node2. The networking flow will be:
producer1 -> service eaa -> pod eaa
consumer2 -> service eaa -> pod eaa
node1 node2
eaa
producer1 consumer2
OS (Ubuntu)
OpenNESS only supports Centos but ICN is based on Ubuntu 18.04. By changing the ansible scripts of OpenNESS, it is able to deploy OpenNESS on Ubuntu 18.04. The following parts of ansible scripts need to change:
1. Following ansible roles can be removed for OpenNESS master: grub, cnca, multus, nfd. Ansible role grub can be removed for OpenNESS node. Because:
- grub is used to add hugepages to grub and hugepages are not useful for integration OpenNESS with ICN.
- cnca is not required for integration.
- multus has already been integrated with ICN.
- nfd will be integrated directly with ICN.
2. Centos uses yum to install packages and we need to use apt for Ubuntu.
3. Some packages which will be installed by ansible scripts should be removed or replaced. Some Centos packages doesn't exist on Ubuntu and these packages should be removed. For example, yum-utils, device-mapper-persistent-data. Some Centos packages' name are different for Ubuntu. For example, python2-pip should be replaced with python-pip, python-devel should be replaced with python-dev.
4. Selinux is not used on Ubuntu and need to remove the ansible scripts configuring selinux.
5. Epel repository is for Centos and Ubuntu doesn't need this repository.
6. Proxy will be set for yum and need to change the scripts to set proxy for apt.
7. Docker installation for Centos and Ubuntu are different. Need to change the scripts following the installation guide. For example: the docker repository is different for Centos and Ubuntu.
8. Auditd is used for Docker. Auditd is delivered with Centos by default but Ubuntu needs to install auditd.
9. Kubernetes installation for Centos and Ubuntu are different. Need to change the scripts following the installation guide. For example: gpg key is different for Centos and Ubuntu, ubuntu use deb and Centos uses repository.
10. cgroups driver is different for Centos (systemd) and Ubuntu (cgroups). By default, cgroups driver is cgroups and need to remove the ansible scripts which configures cgroups driver to systemd.
11. firewalld is used in Centos and need to change to ufw which is used by Ubuntu.
12. Packages are different for installing openvswitch and ovn. Centos uses RPMs. Ubuntu uses openvswitch-switch, ovn-common, ovn-central and ovn-host.
13. Topology manager and CPU manager is configured for edge node's kubelet. No need to use topology manager and can remove these.