Currently, the only place you can specify the namespace is on the Kubernetes deployment targets. This namespace from the target is written into the kubectl context, and as long as you’re using a version of Helm >= 2.6.1 then Helm will use this.
We have an open issue to allow this namespace to be overriden by the Helm Upgrade step, which we plan on implementing soon.
In the meantime, if setting the namespace on the deployment target is not suitable, you can always fallback to using a
Run a kubectl CLI script step and scripting the
helm upgrade ... command yourself.
I hope that helps.