Calico version 3 has been released with several new features, including storing data in etcd version 3, running Felix on Windows in policy-only mode, supporting migration from Calico v2.6.5, and enhancements to the calicoctl command line utility. It also includes changes such as assigning host veth pairs a standard MAC address, offering an environment variable to clean up old CNI configuration data, and removing support for deprecated etcd configuration variables. However, it has some limitations including only being offered for Kubernetes, OpenShift, and host endpoints integrations currently, and not supporting GoBGP or route reflector clustering.

1. Anirban Sen Chowdhary

2. “Project Calico is the world's simplest, most scalable, open networking
solution for OpenStack”.
Calico, a pure layer3 approach to Virtual Networking for highly scalable &
flexible Data centers. It is a open-source technology, that implements
large, standards-based cloud data center infrastructures
Calico supports rich and flexible network policy that enforces on every
node in a cluster, to provide tenant isolation, security groups, and external
reachability constraints.

3. Recently, Calico 3 has been lunched with a bang!
We will now check what’s there in new Calico version 3.

4. What’s in Calico 3 ?

5. Calico has now following features:
• Calico now stores its data in etcd version 3

6. Calico has now following features:
• Calico now stores its data in etcd version 3
• Felix now compiles and runs on Windows in
policy-only mode.

7. Calico has now following features:
• Calico now stores its data in etcd version 3
• Felix now compiles and runs on Windows in
policy-only mode.
• This version of Calico easily supports
migration and upgrade from Calico v2.6.5

8. Calico has now following features:
• Calico now stores its data in etcd version 3
• Felix now compiles and runs on Windows in
policy-only mode.
• This version of Calico easily supports
migration and upgrade from Calico v2.6.5
• calicoctl enhancements with new features.

9. Calico other changes:
• Calico now assigns the host side of veth pairs a MAC address
of ee:ee:ee:ee:ee:ee. If this fails, it uses a kernel-generated MAC
address as before. For more information, refer to the
Troubleshooting FAQ. cni-plugin #436 (@tmjd)
•The CNI plugin now offers an optional environment variable
called CNI_OLD_CONF_NAME. If set, the CNI plug-in cleans up
old configuration data during an upgrade, making it easier to
migrate to a new CNI_CONF_NAME value. cni-plugin
#392(@weikinhuang)
•The CNI plugin no longer throws a file exists message when
programming routes. cni-plugin #406 (@gunjan5)

10. Calico other changes:
• After a period of deprecation, this release removes support for
the ETCD_AUTHORITY and ETCD_SCHEME environment
variables. Calico no longer reads these values. If you have not
transitioned to ETCD_ENDPOINTS, you must do so as of v3.0.
Refer to Configuring calicoctl - etcdv3 datastore for more
information.
•A new node controller for Kubernetes deployments clears data
associated with deleted nodes from the Calico datastore,
preventing conflicts that can lead to crash loops.

11. Calico other changes:
• Calico now works with Kubernetes network services proxy
with IPVS/LVS. Calico enforces network policies with kube-
proxy running in IPVS mode for Kubernetes clusters. Currently
only workload ingress policy is supported.
•Rolling update is now enabled by default in the Kubernetes self-
hosted manifests. calico
• The CNI plugin now offers an optional environment variable
called CNI_OLD_CONF_NAME.

12. Unfortunately there are few limitations found as follows:
• Currently it is offered only for Kubernetes, OpenShift, and host
endpoint integrations.
•GoBGP is currently not supported.
•Route reflectors cannot be clustered.

13. For more information visit
https://www.projectcalico.org/
https://docs.projectcalico.org/v2.6/introduction/
https://blog.tigera.io/tagged/calico