Executing commands on a pod fails when only command kwarg is provided

When calling connect_get_namespaced_pod_exec and providing only the required arguments + command, e.g. connect_get_namespaced_pod_exec("mypod", "namespace", command="ls"), I get the following exception:

ApiException: (0)
# Reason: Handshake status 404

After debugging it, I found that the issue lies on how the query string is built for multiple values vs single ones: The resulting url path + query string for the request above is: /api/v1/namespaces/default/pods/mypod/exec&command=ls Note the lack of ? when starting the query string. But when giving another kwarg, e.g. connect_get_namespaced_pod_exec("mypod", "namespace", command="ls", stderr=True), the call works fine.

Note that this issue is specifically when using websockets. Relevant code is on websocket_call

Here’s a full example that reproduces my problem:

from kubernetes.client import configuration
from kubernetes import config
from kubernetes.client.apis import core_v1_api

configuration.assert_hostname = False
config.load_kube_config()
c = core_v1_api.CoreV1Api()
c.connect_get_namespaced_pod_exec("mypod", "namespace", command="ls")
# raises exception "Handshake status 404"

FTR, here’s where I first asked for/got help https://github.com/kubernetes-incubator/client-python/issues/36

[mildebrandt]

Yeah, I’ll create one after my vacation.

[mildebrandt]

It seems my issue was the lack of the “container” parameter since there are two in my pod. However, I needed to run the command through curl to get that message back from the system:

HTTP/1.1 400 Bad Request
Content-Type: application/json
Date: Wed, 30 Aug 2017 02:20:52 GMT
Content-Length: 231

{
  "kind": "Status",
  "apiVersion": "v1",
  "metadata": {},
  "status": "Failure",
  "message": "a container name must be specified for pod mongo-0, choose one of: [mongo mongo-sidecar]",
  "reason": "BadRequest",
  "code": 400
}

It doesn’t seem like the double ampersands cause any issue, but it’s easily fixed by changing:

url += "&command=%s&" % quote_plus(command)

to

url += "&command=%s" % quote_plus(command)

in ws_client.py.