openstack
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kuryr-kubernetes
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Howto document for UDP services 

This patch includes instructions for creating and
verifying Kubernetes UDP services.

Implements: blueprint services-udp-support
Change-Id: I7dc1065f11d6ade872125ea565865da0038d2bf9
This commit is contained in:
Yossi Boaron 2018-10-09 08:21:22 +03:00
parent be53aae4c2
commit 381e3ca73f
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doc/source/installation/index.rst
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@ -45,3 +45,4 @@ This section describes how you can install and configure kuryr-kubernetes
ocp_route
multi_vif_with_npwg_spec
sriov
testing_udp_services

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Testing UDP Services
====================
In this example, we will use the `kuryr-udp-demo`_ image.
This image implements a simple UDP server that listens on port 9090,
and replies towards client when a packet is received.
We first create a deployment named demo::
$ kubectl run --image=yboaron/kuryr-udp-demo demo
deployment "demo" created
As the next step, we will scale the deployment to 2 pods::
$ kubectl scale deploy/demo --replicas=2
deployment "demo" scaled
At this point we should have two pods running the `kuryr-udp-demo`_ image::
$ kubectl get pods
NAME READY STATUS RESTARTS AGE
demo-fbb89f54c-92ttl 1/1 Running 0 31s
demo-fbb89f54c-q9fq7 1/1 Running 0 1m
Next, we expose the deployment as a service, setting UDP port to 90::
$ kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.0.0.129 <none> 443/TCP 17m
$ kubectl expose deploy/demo --protocol UDP --port 90 --target-port 9090
service "demo" exposed
$ kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
demo ClusterIP 10.0.0.150 <none> 90/UDP 16s
kubernetes ClusterIP 10.0.0.129 <none> 443/TCP 17m
Now, let's check the OpenStack load balancer created by Kuryr for **demo** service::
$ openstack loadbalancer list
+--------------------------------------+--------------------+----------------------------------+-------------+---------------------+----------+
| id | name | project_id | vip_address | provisioning_status | provider |
+--------------------------------------+--------------------+----------------------------------+-------------+---------------------+----------+
| eb5123e8-6bb5-4680-ac64-dcf25c57ced3 | default/kubernetes | fdc9ac3b36474fbf8c7ab77f4f783ec5 | 10.0.0.129 | ACTIVE | amphora |
| 67f19a39-dfb9-4a7a-bafe-7d6789982d91 | default/demo | fdc9ac3b36474fbf8c7ab77f4f783ec5 | 10.0.0.150 | ACTIVE | amphora |
+--------------------------------------+--------------------+----------------------------------+-------------+---------------------+----------+
$ openstack loadbalancer show default/demo
+---------------------+--------------------------------------+
| Field | Value |
+---------------------+--------------------------------------+
| admin_state_up | True |
| created_at | 2018-10-09T06:06:14 |
| description | |
| flavor | |
| id | 67f19a39-dfb9-4a7a-bafe-7d6789982d91 |
| listeners | 7b374ecf-80c4-44be-a725-9b0c3fa2d0fa |
| name | default/demo |
| operating_status | ONLINE |
| pools | d549df5b-e008-49a6-8695-b6578441553e |
| project_id | fdc9ac3b36474fbf8c7ab77f4f783ec5 |
| provider | amphora |
| provisioning_status | ACTIVE |
| updated_at | 2018-10-09T06:07:53 |
| vip_address | 10.0.0.150 |
| vip_network_id | eee6af72-9fbb-48b5-8e52-9f8bdf61cbab |
| vip_port_id | ccd8be94-c65e-4bb2-afe7-44aa3d0617ea |
| vip_qos_policy_id | None |
| vip_subnet_id | 3376291d-6c23-48cb-b6c6-37cefd57f914 |
+---------------------+--------------------------------------+
Checking the load balancer's details, we can see that the load balancer is
listening on UDP port 90::
$ openstack loadbalancer listener show 7b374ecf-80c4-44be-a725-9b0c3fa2d0fa
+---------------------------+--------------------------------------+
| Field | Value |
+---------------------------+--------------------------------------+
| admin_state_up | True |
| connection_limit | -1 |
| created_at | 2018-10-09T06:07:37 |
| default_pool_id | d549df5b-e008-49a6-8695-b6578441553e |
| default_tls_container_ref | None |
| description | |
| id | 7b374ecf-80c4-44be-a725-9b0c3fa2d0fa |
| insert_headers | None |
| l7policies | |
| loadbalancers | 67f19a39-dfb9-4a7a-bafe-7d6789982d91 |
| name | default/demo:UDP:90 |
| operating_status | ONLINE |
| project_id | fdc9ac3b36474fbf8c7ab77f4f783ec5 |
| protocol | UDP |
| protocol_port | 90 |
| provisioning_status | ACTIVE |
| sni_container_refs | [] |
| timeout_client_data | 50000 |
| timeout_member_connect | 5000 |
| timeout_member_data | 50000 |
| timeout_tcp_inspect | 0 |
| updated_at | 2018-10-09T06:07:53 |
+---------------------------+--------------------------------------+
And the load balancer has two members listening on UDP port 9090::
$ openstack loadbalancer member list d549df5b-e008-49a6-8695-b6578441553e
+--------------------------------------+-----------------------------------+----------------------------------+---------------------+-----------+---------------+------------------+--------+
| id | name | project_id | provisioning_status | address | protocol_port | operating_status | weight |
+--------------------------------------+-----------------------------------+----------------------------------+---------------------+-----------+---------------+------------------+--------+
| b2c63e7b-47ed-4a6f-b8bb-acaa6742a0ad | default/demo-fbb89f54c-q9fq7:9090 | fdc9ac3b36474fbf8c7ab77f4f783ec5 | ACTIVE | 10.0.0.74 | 9090 | ONLINE | 1 |
| 7fa773b1-cf76-4a0b-8004-153423e59ef6 | default/demo-fbb89f54c-92ttl:9090 | fdc9ac3b36474fbf8c7ab77f4f783ec5 | ACTIVE | 10.0.0.88 | 9090 | ONLINE | 1 |
+--------------------------------------+-----------------------------------+----------------------------------+---------------------+-----------+---------------+------------------+--------+
At this point, we have both the kubernetes **demo** service and corresponding
openstack load balancer running, and we are ready to run the
client application.
For the client application we will use the `udp-client`_ python script.
The UDP client script sends UDP message towards specific IP and port, and
waits for a response from the server.
The way that the client application can communicate with the server is by
leveraging the Kubernetes service functionality.
First we clone the client script::
$ git clone https://github.com/yboaron/udp-client-script.git
Cloning into 'udp-client-script'...
remote: Enumerating objects: 15, done.
remote: Counting objects: 100% (15/15), done.
remote: Compressing objects: 100% (13/13), done.
remote: Total 15 (delta 4), reused 3 (delta 1), pack-reused 0
Unpacking objects: 100% (15/15), done.
$
And we need the UDP server service IP and port::
$ kubectl get svc demo
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
demo ClusterIP 10.0.0.150 <none> 90/UDP 20m
$
Last step will be to ping the UDP server service::
$ python udp-client-script/client.py 10.0.0.150 90
demo-fbb89f54c-92ttl: HELLO, I AM ALIVE!!!
$ python udp-client-script/client.py 10.0.0.150 90
demo-fbb89f54c-q9fq7: HELLO, I AM ALIVE!!!
Since the `kuryr-udp-demo`_ application concatenates the pod's name to the
replyed message, it is plain to see that both service's pods are
replying to the requests from the client.
.. _kuryr-udp-demo: https://hub.docker.com/r/yboaron/kuryr-udp-demo/
.. _udp-client: https://github.com/yboaron/udp-client-script