This topic describes considerations and strategies for upgrading Consul deployments running on Kubernetes clusters. In addition to upgrading the version of Consul, you may need to update your Helm chart or the release version of the Helm chart.
If you are upgrading from a Consul on Kubernetes release that uses client agents to one using Consul Dataplane, refer to [Upgrading to Consul Dataplane](#upgrading-to-consul-dataplane).
## Version-specific upgrade requirements
As of Consul v1.14.0, Kubernetes deployments use [Consul Dataplane](/consul/docs/connect/dataplane) instead of client agents. If you upgrade Consul from a version that uses client agents to a version that uses dataplanes, you must follow specific steps to update your Helm chart and remove client agents from the existing deployment. Refer to [Upgrading to Consul Dataplane](/consul/docs/k8s/upgrade#upgrading-to-consul-dataplane) for more information.
The v1.0.0 release of the Consul on Kubernetes Helm chart also introduced a change to the [`externalServers[].hosts` parameter](/consul/docs/k8s/helm#v-externalservers-hosts). Previously, you were able to enter a provider lookup as a string in this field. Now, you must include `exec=` at the start of a string containing a provider lookup. Otherwise, the string is treated as a DNS name. Refer to the [`go-netaddrs` library and command line tool](https://github.com/hashicorp/go-netaddrs) for more information.
boruszak
1 year ago