Flannel is a Container Network Interface (CNI) plug-in that you can use to create a virtual network for containers based on Virtual Private Cloud (VPC). You can use Flannel to enable internal communication in a Kubernetes cluster. This topic describes the release notes for Flannel.

Introduction

The Flannel network plug-in provided by Container Service for Kubernetes (ACK) allocates the pod CIDR block, which is independent of the VPC CIDR block. In an ACK cluster, the Flannel network plug-in works with the VPC in which the cluster is deployed. Packets are forwarded based on the VPC route table. This improves communication efficiency because no tunneling technologies such as Virtual Extensible Local Area Network (VXLAN) are required to encapsulate the packets. For more information about the group identity feature, see Overview.

Precautions

Flannel is an open source CNI plug-in, which is simple and stable. You can use Flannel with VPC. This allows your clusters and containers to run in high-performance and stable networks. For more information, see Flannel.

Release notes

October 2022

Version Image address Release date Description Impact
v0.15.1.19-d460293f-aliyun registry.cn-hangzhou.aliyuncs.com/acs/flannel:v0.15.1.19-d460293f-aliyun 2022-10-27
  • Compatibility with scenarios where the CNIVersion field is missing is supported.
  • CVE-2021-45079 is patched.
No impact on workloads

September 2022

Version Image address Release date Description Impact
v0.15.1.18-6f371e73-aliyun registry.cn-hangzhou.aliyuncs.com/acs/flannel:v0.15.1.18-6f371e73-aliyun 2022-09-26 By default, Node Informer is disabled to improve performance. No impact on workloads

August 2022

Version Image address Release date Description Impact
v0.15.1.13-941db231-aliyun registry.cn-hangzhou.aliyuncs.com/acs/flannel:v0.15.1.13-941db231-aliyun 2022-08-29 CVE-2022-37434 is fixed. No impact on workloads

July 2022

Version Image address Release date Description Impact
v0.15.1.11-7e95fe23-aliyun registry.cn-hangzhou.aliyuncs.com/acs/flannel:v0.15.1.11-7e95fe23-aliyun 2022-07-28 /var/run is used as the default directory to cache IP addresses. This prevents IP leaks that are caused by server restarts. No impact on workloads

May 2022

Version Image address Release date Description Impact
v0.15.1.8-1634a106-aliyun registry.cn-hangzhou.aliyuncs.com/acs/flannel:v0.15.1.8-1634a106-aliyun 2022-05-10 The CVE-2022-28391 vulnerability is fixed. No impact on workloads

April 2022

Version Image address Release date Description Impact
v0.15.1.6-a320565c-aliyun registry.cn-hangzhou.aliyuncs.com/acs/flannel:v0.15.1.6-a320565c-aliyun 2022-04-08 An init container that is used to install the Flannel plug-in is added. No impact on workloads

January 2022

Version Image address Release date Description Impact
v0.15.1.5-11d1c700-aliyun registry.cn-hangzhou.aliyuncs.com/acs/flannel:v0.15.1.5-11d1c700-aliyun 2022-01-25 Instances that use the ARM64 architecture are supported. No impact on workloads

December 2021

Version Image address Release date Description Impact
v0.15.1.4-e02c8f12-aliyun registry.cn-hangzhou.aliyuncs.com/acs/flannel:v0.15.1.4-e02c8f12-aliyun 2021-12-01
  • The API version of resources such as Authorization is updated to support Kubernetes 1.22.
  • Services can be exposed by using the HostPort method.
  • By default, the hairpin mode is enabled. By default, the hairpin mode is disabled for Flannel of earlier versions. For more information about how to manually enable the hairpin mode, see How do I enable a pod to access a Service that is used to expose the pod? .
No impact on workloads

May 2021

Version Image address Release date Description Impact
v0.13.0.1-466064b-aliyun registry.cn-hangzhou.aliyuncs.com/acs/flannel:v0.13.0.1-466064b-aliyun 2021-05-24
  • Iptables is supported to enable compatibility with CentOS 8 and Alibaba Cloud Linux 3 and later versions.
  • Proactive checks and corrections of IP forwarding configurations are supported.
No impact on workloads

August 2019

Version Image address Release date Description Impact
v0.11.0.2-g6e46593e-aliyun registry.cn-hangzhou.aliyuncs.com/acs/flannel:v0.11.0.2-g6e46593e-aliyun 2019-08-02 The issue that source IP addresses are not retained after Flannel is updated is fixed. No impact on workloads