I was following this blog post and at this command,

helm upgrade --install airflow airflow/ \ --namespace airflow \ --values values.yaml

I got this error. in airflow: chart metadata (Chart.yaml) missing but I actually have the Chart.yaml file under airflow/.

$ ls
Chart.yaml      charts          requirements.yaml   tiller.yaml
Icon?           requirements.lock   templates       values.yaml

helm version & kubectl pod below

$ helm version
Client: &version.Version{SemVer:"v2.13.1", GitCommit:"618447cbf203d147601b4b9bd7f8c37a5d39fbb4", GitTreeState:"clean"}
Server: &version.Version{SemVer:"v2.13.1", GitCommit:"618447cbf203d147601b4b9bd7f8c37a5d39fbb4", GitTreeState:"clean"}

$ kubectl get pods --namespace kube-system
NAME                                    READY     STATUS    RESTARTS   AGE
coredns-fb8b8dccf-9z8v5                 1/1       Running   3          6h
coredns-fb8b8dccf-wdtpl                 1/1       Running   3          6h
etcd-minikube                           1/1       Running   1          6h
kube-addon-manager-minikube             1/1       Running   1          6h
kube-apiserver-minikube                 1/1       Running   1          6h
kube-controller-manager-minikube        1/1       Running   1          6h
kube-proxy-m4whq                        1/1       Running   0          2h
kube-scheduler-minikube                 1/1       Running   1          6h
kubernetes-dashboard-79dd6bfc48-5z9cx   1/1       Running   3          6h
storage-provisioner                     1/1       Running   3          6h
tiller-deploy-8458f6c667-wmv62          1/1       Running   1          4h

Could someone help to fix it?