Cisco APIC Container Plug-in Release 5.1(1), Release Notes

Cisco APIC Container Plug-in Release 5.1(1), Release Notes

This document describes the features, bugs, and limitations for the Cisco Application Policy Infrastructure Controller (APIC) Container Plug-in.

The Cisco Application Centric Infrastructure (ACI) Container Network Interface (CNI) Plug-in provides network services to Kubernetes, Red Hat OpenShift, and Docker EE clusters on a Cisco ACI fabric. It allows the cluster pods to be treated as fabric end points in the fabric integrated overlay, as well as providing IP Address Management (IPAM), security, and load balancing services.

Release Notes are sometimes updated with new information about restrictions and bugs. See the following website for the most recent version of this document:

https://www.cisco.com/c/en/us/support/cloud-systems-management/application-policy-infrastructure-controller-apic/tsd-products-support-series-home.html

Note: The documentation set for this product strives to use bias-free language. For the purposes of this documentation set, bias-free is defined as language that does not imply discrimination based on age, disability, gender, racial identity, ethnic identity, sexual orientation, socioeconomic status, and intersectionality. Exceptions may be present in the documentation due to language that is hardcoded in the user interfaces of the product software, language used based on RFP documentation, or language that is used by a referenced third-party product.

 

 

 

Contents

This document includes the following sections:

Cisco ACI Virtualization Compatibility Matrix

New and Changed Information

New Software Features

Changes In Behavior

Known Limitations

Usage Guidelines

Supported Scale

Bugs

Related Documentation

Cisco ACI Virtualization Compatibility Matrix

For information about Cisco ACI supported Container Products, see the Cisco ACI Virtualization Compatibility Matrix at the following URL:

https://www.cisco.com/c/dam/en/us/td/docs/Website/datacenter/aci/virtualization/matrix/virtmatrix.html

New and Changed Information

This section lists the new and changed features in this release.

New Software Features

Changes In Behavior

■      The acc-provision Debian and RPM packages are now only built for Python 3.

■      To perform ACI CNI upgrade, acc-provision has a new “--upgrade” option.

Known Limitations

■      Istio 1.6.5 deployment is a preview feature and is expected to rapidly evolve in the next release in response to upstream community changes. This may create issues with backward compatibility and as such this feature should only be used in experimental or pilot deployments.

■      The Cisco ACI CNI Plug-in is not integrated with the Multi-Site Orchestrator. When deploying to a Multi-Site deployment, the Cisco ACI configurations implemented by the plug-in must not be affected by the Multi-Site Orchestrator.

■      SNAT is not supported for services inside the same fabric.

Usage Guidelines

■      If you are upgrading a Kubernetes cluster that was provisioned with ACI CNI version 4.2(2), or you are deploying a new cluster with kubernetes-1.15 or kubernetes-1.16 flavors, you need to add the following configuration to the original acc-provision input file:

Also note that upgrading a Cisco ACI CNI cluster requires running acc-provision with the “--upgrade” option.

■      Istio installation can be disabled by setting the config parameter “install-istio” to False in the acc-provision-input file and generate/apply the deployment file.

■      The scope of the SNAT service graph contract can be configured by the user in the acc-provision input file as follows:

Valid values (as allowed by Cisco APIC) are "global", "tenant" and "context". The default is set to "global".

■      The aci-containers-controller pod subscribes for notifications on certain objects to the Cisco APIC. There is a timeout associated with this subscription. A shorter timeout requires more frequent subscription renewals. The timeout is set to 900 seconds for Cisco APIC 4.x and can be changed by configuring the acc-provision input file:

Note: The subscription timeout is configurable only in Cisco APIC 4.x or later.

■      The memory limit for the Open vSwitch container is set to 1GB. It can be changed by configuring the acc-provision input file as follows:

■      The Multus CNI deployment can enabled in the OpenShift installation by performing the following configuration in the acc-provision input file:

■      Policy Based Routing (PBR) tracking can be enabled for the Cisco APIC service graph created for supporting the SNAT feature. More details on PBR tracking can be found in the chapter “Configuring Policy-Based Redirect” In the Cisco APIC Layer 4 to Layer 7 Services Deployment Guide, Release 4.2(x).

One HealthGroup for each node is created, and it is associated with the redirect policy of the SNAT service graph with the internet protocol service level agreement (IP SLA) interval set to 5 seconds. This interval is configurable through the acc- provision input file:

If the service_monitor_interval is set to zero, PBR tracking is disabled.

PBR tracking can be also be enabled for other Cisco APIC service graphs created for each Kubernetes external service, setting the following configuration in the acc-provision input file:

If enabled, the service_monitoring_interval described earlier applies here as well.

Note that in a Cisco ACI CNI-based cluster, the same worker node is used to provide both the external Layer 4 load balancer and SNAT services. So if PBR tracking is enabled, and if the worker node reports unhealthy status for SNAT, a fault appears in the redirect policies associated with all other (non-SNAT) service graphs that have this node. However, this fault does not actually affect those other services and traffic from those services is still distributed to that node. The fault manifests for those other services only in the Cisco APIC GUI.

Note: The following are general usage guidelines that also apply to this release:

■      You should be familiar with installing and using Kubernetes or OpenShift. Cisco ACI does not provide the Kubernetes or OpenShift installer. Refer to the following documents on Cisco.com for details:

—     Cisco ACI and Kubernetes Integration

—     Installing OpenShift 4.5 on OpenStack 13

—     Installing OpenShift 4.5 on VMware vSphere

—     Cisco ACI CNI Plugin for Red Hat OpenShift Container Platform Architecture and Design Guide

—     Upgrading the Cisco ACI CNI Plug-in

■      The Cisco ACI CNI plug-in implements various functions running as containers inside pods. The released images for those containers for a given version are available on the Docker Hub website under user noiro. A copy of those container images and the RPM/DEB packages for support tools (acc-provision and acikubectl) are also published on the Software Download page on Cisco.com.

■      OpenShift has a tighter security model by default, and many off-the-shelf Kubernetes applications, such as guestbook, may not run on OpenShift (if, for example, they run as root or open privileged ports like 80).

■      Refer to the article “Getting any Docker image running in your own OpenShift cluster” on the Red Hat OpenShift website for details. The Cisco ACI CNI Plug-in is not aware of any configuration on OpenShift cluster or pods when it comes to working behind a proxy. Running OpenShift "oc new-app," for instance, may require access to Git Hub, and if the proxy settings on the OpenShift cluster are not correctly set, this access may fail. Ensure your proxy settings are correctly set.

■      In this release, the maximum supported number of PBR based external services is 250 virtual IP addresses (VIPs). Scalability is expected to increase in upcoming releases.

Note: With OpenShift, master nodes and router nodes are tainted by default, and you might see lower scale than an upstream Kubernetes installation on the same hardware.

■      Some deployments require installation of an “allow” entry in IP Tables for IGMP. This must be added to all hosts running an OpFlex agent and using VXLAN encapsulation to the leaf. The rule must be added using the following command:

 

In order to make this change persistent across reboots, add the command either to /etc/rc.d/rc.local or to a cron job that runs after reboot.

■      Both RHEL and Ubuntu distributions set net.ipv4.igmp_max_memberships set to 20 by default. This limits the number of end point groups (EPGs) that can be used in addition to the kube-default EPG for pod networking. If you anticipate using more than 20 EPGs, set the value to the desired number of EPGs on each node as follows:

■      For the VMware VDS integration, you can refer to the Enhanced Link Aggregation Group (eLAG) configured through the Cisco APIC by using the following configuration in the acc-provision input file:

Supported Scale

For the verified scalability limits (except for CLI limits), see the Verified Scalability Guide for this release. For Kubernetes-based Integrations (including Docker, OpenShift, and Rancher), and OpenStack Platform Scale Limits, see the following  table.

Note: The scalability information in the following table applies to Kubernetes or OpenStack resources integrated with OpFlex into the Cisco ACI fabric. It does not apply to Microsoft SCVMM hosts or Cisco ACI Virtual Edge instances.

 

1-    The indicated scale value is for Cisco ACI version 5.0(1) and later. If the ACI version is less than 5.0(1), the number of supported OpFlex hosts are 40.

Notes:

■      For containers, an endpoint corresponds to a pod’s network interface.

■      For OpenStack, an endpoint corresponds to any of the following:

—   A virtual machine (VM) interface (also known as vnic)

—     A DHCP agent’s port in OpenStack (if in DHCP namespace on the network controller)

—   A floating IP address

■      Total virtual endpoints on a leaf can be calculated as virtual endpoints / leaf = VPCs x EPGs, where:

—   VPCs is the number of VPC links on the switch in the attachment profile used by the OpenStack Virtual Machine Manager (VMM).

—     EPGs is the number of EPGs provisioned for the OpenStack VMM.

■      For the CLI verified scalability limits, see the Cisco NX-OS Style Command-Line Interface Configuration Guide for this release.

■      For OpFlex hosts per port — a port is either a physical port or a vPC. One vPC equals one port.The number of member ports in a vPC is inconsequential.

Issues

This section contains lists of bugs and known behaviors.

Open Issues

Resolved Issues

Known Behaviors

This section lists known behaviors. Click the Bug ID to access the Bug Search Tool and see additional information about the bug.

Related Documentation

The Cisco Application Policy Infrastructure Controller (APIC) documentation can be accessed from the following website:

https://www.cisco.com/c/en/us/support/cloud-systems-management/application-policy-infrastructure-controller-apic/tsd-products- support-series-home.html

The documentation includes installation, upgrade, configuration, programming, and troubleshooting guides, technical references, release notes, and knowledge base (KB) articles, as well as other documentation. KB articles provide information about a specific use case or a specific topic.

By using the "Choose a topic" and "Choose a document type" fields of the Cisco APIC documentation website, you can narrow down the displayed documentation list to make it easier to find the desired document.

 

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