Mounting a volume with kubectl

TL;DR I don't know what the issue was but I ended up solving this by making the build request very verbose.

I ended up solving this by setting debug to very verbose (v=0) and noticing that my volume mount was completely ignored by kubectl and not present in the request to the API:

I0929 13:31:22.429307   14616 request.go:897] Request Body: {"kind":"Pod","apiVersion":"v1","metadata":{"name":"alpine","creationTimestamp":null,"labels":{"run":"alpine"}},"spec":{"volumes":[{"name":"store","emptyDir":{}}],"containers":[{"name":"alpine","image":"alpine:latest","args":["sh"],"resources":{},"terminationMessagePath":"/dev/termination-log","terminationMessagePolicy":"File","imagePullPolicy":"IfNotPresent","stdin":true,"stdinOnce":true,"tty":true}],"restartPolicy":"Never","terminationGracePeriodSeconds":30,"dnsPolicy":"ClusterFirst","securityContext":{},"schedulerName":"default-scheduler"},"status":{}}

I copy pasted that request, and edited it to add the same volume mount as above, and it worked:

kubectl run -i --rm --tty alpine --overrides='{    "kind": "Pod",    "apiVersion": "v1",    "metadata": {        "name": "alpine",        "creationTimestamp": null,        "labels": {            "run": "alpine"        }    },    "spec": {        "containers": [{            "name": "alpine",            "image": "alpine:latest",            "args": ["sh"],            "resources": {},            "terminationMessagePath": "/dev/termination-log",            "terminationMessagePolicy": "File",            "imagePullPolicy": "IfNotPresent",            "stdin": true,            "stdinOnce": true,            "tty": true,            "volumeMounts": [{              "mountPath": "/home/store",              "name": "store"            }]        }],        "volumes": [{          "name":"store",          "emptyDir":{}        }],        "restartPolicy": "Never",        "terminationGracePeriodSeconds": 30,        "dnsPolicy": "ClusterFirst",        "securityContext": {},        "schedulerName": "default-scheduler"    },    "status": {}}'  --image=alpine:latest -v=9 --restart=Never -- sh