async def main():
# Load default kubeconfig file and create an aiohttp client instance.
config = k8s.utils.load_config(warn=False)
client = k8s.clients.get_aiohttp(config)
proxy = k8s.api_proxy.Proxy(config)
# Namespaces and Pods are in the K8s Core API, Deployments in an extension.
corev1 = k8s.CoreV1Api(proxy)
extv1beta = k8s.ExtensionsV1beta1Api(proxy)
# Compile the necessary request parameters (headers, body, parameters, ...)
# for the API calls we want to make. We also specify watch=True because we
# want to listen to changes.
cargs_ns = corev1.list_namespace(timeout_seconds=5, watch=True)
cargs_pods = corev1.list_pod_for_all_namespaces(timeout_seconds=5,
watch=True)
cargs_deploy = extv1beta.list_deployment_for_all_namespaces(
timeout_seconds=5, watch=True) # noqa
# Define and dispatch the tasks.
tasks = [
watch_resource(client, cargs_ns),
watch_resource(client, cargs_pods),
watch_resource(client, cargs_deploy),
]
await asyncio.gather(*tasks)
# Close all pending connections.
await client.close()
async def main():
# Create a client instance and load the credentials from ~/.kube/kubeconfig
api_client = k8s.config.new_client_from_config()
# Namespaces and Pods are part of the K8s Core API.
corev1 = k8s.CoreV1Api(api_client)
# Deployments are part of the Extension API (still in beta).
extv1beta = k8s.ExtensionsV1beta1Api(api_client)
# Specify and dispatch the tasks.
tasks = [
watch_resource(corev1.list_namespace, timeout_seconds=5),
watch_resource(corev1.list_pod_for_all_namespaces, timeout_seconds=5),
watch_resource(extv1beta.list_deployment_for_all_namespaces,
timeout_seconds=5),
]
await asyncio.gather(*tasks)
# Close all pending connections.
await api_client.close()
async def create_deployment(api_client):
img_alpine_34, img_alpine_35 = 'alpine:3.4', 'alpine:3.5'
time_between_steps = 3
# Create deployment.
base_path = os.path.dirname(os.path.abspath(__file__))
fname = os.path.join(base_path, 'manifests/create-deployment.yaml')
body = yaml.safe_load(open(fname, 'r'))
name, namespace = body['metadata']['name'], body['metadata']['namespace']
img_orig = body['spec']['template']['spec']['containers'][0]['image']
del fname
body['spec']['template']['spec']['containers'][0]['image'] = img_alpine_34
img_new = body['spec']['template']['spec']['containers'][0]['image']
print(f'Replaced <{img_orig}> with <{img_new}>')
# -------------------------------------------------------------------------
# Create Deployment
# -------------------------------------------------------------------------
k8s_v1beta = k8s.ExtensionsV1beta1Api(api_client)
print(f'Creating deployment {name}...')
resp = await k8s_v1beta.create_namespaced_deployment(body=body,
namespace=namespace)
assert isinstance(resp.http, aiohttp.client_reqrep.ClientResponse)
print(' ->', resp.http.method, resp.http.status, resp.http.url)
# -------------------------------------------------------------------------
# Path Deployment
# -------------------------------------------------------------------------
# print(f'Patching deployment {name}...')
# fname = os.path.join(base_path, 'manifests/patch-deployment.yaml')
# body_patch = yaml.safe_load(open(fname, 'r'))
# resp = await k8s_v1beta.patch_namespaced_deployment(
# name=name, namespace=namespace, body=body_patch)
# await asyncio.sleep(time_between_steps)
# -------------------------------------------------------------------------
# Execute Command in Pod
# -------------------------------------------------------------------------
print(f'\nConnecting to a login pod: ', end='', flush=True)
# Try several times to connect to the pod. We have to do this because we
# only just created the pod and it takes a few seconds until it is ready.
for i in range(300):
# Get a list of all pods.
resp = await k8s.CoreV1Api(api_client).list_namespaced_pod(namespace)
assert isinstance(resp.http, aiohttp.client_reqrep.ClientResponse)
# Find all running pods whose name starts with 'login'.
pods = resp.obj.items
pods = [_ for _ in pods if _.metadata.name.lower().startswith('login')]
pods = [_ for _ in pods if _.status.phase.lower() == 'running']
# Wait, rinse and repeat if Kubernetes returned an error or we found no
# running login Pod.
if resp.http.status != 200 or len(pods) == 0:
print('.', end='', flush=True)
await asyncio.sleep(0.1)
continue
print('\n ->', resp.http.method, resp.http.status, resp.http.url, '\n')
# Could be a stale deployment - not a problem, but let user know.
if len(pods) > 1:
print('Found multiple login pods')
# Extract the pod name that we will connect to.
pod_name = pods[0].metadata.name
print(f'Connecting to Pod <{pod_name}>')
# Connect to the pod and run a few shell commands. This will return a
# Websocket connection that we will consume afterwards.
v1_ws = k8s.CoreV1Api(api_client=api_client)
exec_command = [
'/bin/sh', '-c',
'echo This is stderr >&2; sleep 0s; echo This is stdout'
]
websocket = await v1_ws.connect_get_namespaced_pod_exec(
pod_name,
namespace,
command=exec_command,
stderr=True,
stdin=False,
stdout=True,
tty=False)
assert isinstance(websocket.http,
aiohttp.client._WSRequestContextManager)
# Consume the Websocket until all commands have finished and Kubernetes
# closes the connection.
async with websocket.http as ws:
async for msg in ws:
print(f' Websocket received: {msg.data}')
break
else:
print('No login has entered "running" state yet: skip connection test')
# -------------------------------------------------------------------------
# Replace Deployment
# -------------------------------------------------------------------------
img_orig = body['spec']['template']['spec']['containers'][0]['image']
body['spec']['template']['spec']['containers'][0]['image'] = img_alpine_35
img_new = body['spec']['template']['spec']['containers'][0]['image']
print(f'Replaced <{img_orig}> with <{img_new}>')
print(f'\nReplacing deployment {name}...')
resp = await k8s_v1beta.replace_namespaced_deployment(name=name,
namespace=namespace,
body=body)
assert isinstance(resp.http, aiohttp.client_reqrep.ClientResponse)
print(' ->', resp.http.method, resp.http.status, resp.http.url)
# -------------------------------------------------------------------------
# Delete Deployment
# -------------------------------------------------------------------------
await asyncio.sleep(time_between_steps)
print(f'\nDeleting deployment {name}...')
del_opts = k8s.V1DeleteOptions(
api_version='v1',
kind='DeleteOptions',
grace_period_seconds=0,
propagation_policy='Foreground',
)
resp = await k8s_v1beta.delete_namespaced_deployment(name=name,
namespace=namespace,
body=del_opts)
assert isinstance(resp.http, aiohttp.client_reqrep.ClientResponse)
print(' ->', resp.http.method, resp.http.status, resp.http.url)
print('------------ End of Demo ------------')
async def create_deployment(proxy, client):
img_alpine_34, img_alpine_35 = 'alpine:3.4', 'alpine:3.5'
time_between_steps = 3
# Load the manifest with a valid Python/Alpine container deployment.
base_path = os.path.dirname(os.path.abspath(__file__))
fname = os.path.join(base_path, 'manifests/create-deployment.yaml')
body = yaml.safe_load(open(fname, 'r'))
name, namespace = body['metadata']['name'], body['metadata']['namespace']
img_orig = body['spec']['template']['spec']['containers'][0]['image']
del fname
# Assign a specific container image (we will later replace that container
# and re-deploy to illustrate the workflow).
body['spec']['template']['spec']['containers'][0]['image'] = img_alpine_34
img_new = body['spec']['template']['spec']['containers'][0]['image']
print(f'Replaced <{img_orig}> with <{img_new}>')
# ----------------------------------------------------------------------
# Create the namespace <aiokubernet>.
# ----------------------------------------------------------------------
manifest = {
'apiVersion': 'v1',
'kind': 'Namespace',
'metadata': {
'name': namespace
},
}
cargs = k8s.api.CoreV1Api(proxy).create_namespace(body=manifest)
ret = await client.request(**cargs)
if ret.status == 201:
print(f'Namespace <{namespace}> created')
elif ret.status == 409:
print(f'Namespace <{namespace}> already exists')
else:
print(f'Error {ret.status}')
print(await ret.text())
# -------------------------------------------------------------------------
# Create Deployment
# -------------------------------------------------------------------------
k8s_v1beta = k8s.ExtensionsV1beta1Api(proxy)
print(f'Creating deployment {name}...')
cargs = k8s_v1beta.create_namespaced_deployment(body=body,
namespace=namespace)
http = await client.request(**cargs)
print(' ->', http.method, http.status, http.url)
del cargs, http
# -------------------------------------------------------------------------
# Patch Deployment
# -------------------------------------------------------------------------
# print(f'Patching deployment {name}...')
# fname = os.path.join(base_path, 'manifests/patch-deployment.yaml')
# body_patch = yaml.safe_load(open(fname, 'r'))
# resp = await k8s_v1beta.patch_namespaced_deployment(
# name=name, namespace=namespace, body=body_patch)
# await asyncio.sleep(time_between_steps)
# -------------------------------------------------------------------------
# Search For The Login Pod
# -------------------------------------------------------------------------
print(f'\nConnecting to a login pod: ', end='', flush=True)
# Try several times to connect to the pod. We have to do this because we
# only just created the pod and it takes a few seconds until it is ready.
for i in range(300):
# Get a list of all pods.
cargs = k8s.CoreV1Api(proxy).list_namespaced_pod(namespace)
http = await client.request(**cargs)
pods = k8s.swagger.unpack(await http.read())
# Find all running pods whose name starts with 'login'.
pods = [
_ for _ in pods.items
if _.metadata.name.lower().startswith('login')
]
pods = [_ for _ in pods if _.status.phase.lower() == 'running']
# Briefly wait before looking for a suitable pod, unless we already found one.
if http.status != 200 or len(pods) == 0:
print('.', end='', flush=True)
await asyncio.sleep(0.1)
continue
print('\n ->', http.method, http.status, http.url, '\n')
del cargs, http
# Could be a stale deployment - not a problem, but let user know.
if len(pods) > 1:
print('Found multiple login pods')
# Extract the pod name that we will connect to.
login_pod_name = pods[0].metadata.name
print(f'Connecting to Pod <{login_pod_name}>')
break
else:
login_pod_name = None
print('No login has entered "running" state yet: skip connection test')
# -------------------------------------------------------------------------
# Execute Command in Login Pod via GET request.
# -------------------------------------------------------------------------
if login_pod_name is not None:
print('\nNon-interactive Websocket')
# Connect to the pod and print something to the terminal.
cargs = k8s.CoreV1Api(
api_client=proxy).connect_get_namespaced_pod_exec(
login_pod_name,
namespace,
command=['/bin/sh', '-c', 'echo Hello World'],
stderr=True,
stdin=True,
stdout=True,
tty=True)
# Tell K8s that this is a Websocket, not a GET.
cargs['headers']['sec-websocket-protocol'] = 'v4.channel.k8s.io'
url = k8s.api_client.get_websocket_url(cargs['url'])
# Connect the Websocket and consume the Websocket until Kubernetes closes it.
ws_session = client.ws_connect(url, headers=cargs['headers'])
async with ws_session as ws:
async for msg in ws:
chan, msg = msg.data[0], msg.data[1:]
print(f' Websocket Channel {chan}: {msg}')
del cargs, url, ws_session
# -------------------------------------------------------------------------
# Use interactive Websocket to execute commands in Login Pod
# -------------------------------------------------------------------------
if login_pod_name is not None:
print('\nInteractive Websocket')
# Connect to the pod and issue a single command to spawn a shell. We
# will then use a websocket to send commands to that shell.
wargs = k8s.CoreV1Api(
api_client=proxy).connect_get_namespaced_pod_exec(
login_pod_name,
namespace,
command=['/bin/sh'],
stderr=True,
stdin=True,
stdout=True,
tty=True)
# Tell K8s that this is a Websocket, not a GET.
wargs['headers']['sec-websocket-protocol'] = 'v4.channel.k8s.io'
url = k8s.api_client.get_websocket_url(wargs['url'])
# Connect the Websocket and consume the Websocket until Kubernetes closes it.
ws_session = client.ws_connect(url, headers=wargs['headers'])
async with ws_session as ws:
# The \x00 prefix denotes `stdin`, which is where we need to send
# the command to. The rest is just a sequence of two shell commands.
await ws.send_bytes(b'\x00' + b'ls --color=never /\nexit\n')
# Read until we receive something on channel 3 to tell us that this was it.
async for msg in ws:
chan, msg = msg.data[0], msg.data[1:]
print(f' Websocket Channel {chan}: {msg}')
# -------------------------------------------------------------------------
# Replace Deployment
# -------------------------------------------------------------------------
img_orig = body['spec']['template']['spec']['containers'][0]['image']
body['spec']['template']['spec']['containers'][0]['image'] = img_alpine_35
img_new = body['spec']['template']['spec']['containers'][0]['image']
print(f'Replaced <{img_orig}> with <{img_new}>')
print(f'\nReplacing deployment {name}...')
cargs = k8s_v1beta.replace_namespaced_deployment(name,
namespace,
body=body)
http = await client.request(**cargs)
assert isinstance(http, aiohttp.client_reqrep.ClientResponse)
print(' ->', http.method, http.status, http.url)
del cargs, http
# -------------------------------------------------------------------------
# Delete Deployment
# -------------------------------------------------------------------------
await asyncio.sleep(time_between_steps)
print(f'\nDeleting deployment {name}...')
del_opts = k8s.V1DeleteOptions(
api_version='v1',
kind='DeleteOptions',
grace_period_seconds=0,
propagation_policy='Foreground',
)
cargs = k8s_v1beta.delete_namespaced_deployment(name,
namespace,
body=del_opts)
http = await client.request(**cargs)
assert isinstance(http, aiohttp.client_reqrep.ClientResponse)
print(' ->', http.method, http.status, http.url)
del cargs, http
print('------------ End of Demo ------------')