Kubeless - Revision history

Christoph: /* Sample function */

2021-09-12T06:12:40Z

‎Sample function

Christoph: /* Sample function */

2020-02-29T11:18:55Z

‎Sample function

Christoph: /* Sample function */

2020-02-29T11:17:23Z

‎Sample function

Christoph: /* Installation */

2020-02-29T11:16:45Z

‎Installation

Christoph at 21:45, 31 October 2019

2019-10-31T21:45:04Z

Christoph: Created page with "'''Kubeless''' "is a Kubernetes-native serverless framework that lets you deploy small bits of code (functions) without having to worry about the underlying infrastructure. It..."

2019-10-31T21:28:43Z

Created page with "'''Kubeless''' "is a Kubernetes-native serverless framework that lets you deploy small bits of code (functions) without having to worry about the underlying infrastructure. It..."

New page

'''Kubeless''' "is a Kubernetes-native serverless framework that lets you deploy small bits of code (functions) without having to worry about the underlying infrastructure. It is designed to be deployed on top of a Kubernetes cluster and take advantage of all the great Kubernetes primitives". ~ [https://kubeless.io/ source]

==Installation==

Installation is made of three steps:

* Download the kubeless CLI from the [https://github.com/kubeless/kubeless/releases release page].
* Create a kubeless namespace (used by default)
* Then use one of the YAML manifests found in the release page to deploy kubeless. It will create a _functions_ Custom Resource Definition and launch a controller.

There are several kubeless manifests being shipped for multiple k8s environments (non-rbac, rbac and openshift), pick the one that corresponds to your environment:

* <code>kubeless-$RELEASE.yaml</code> is used for RBAC Kubernetes cluster.
* <code>kubeless-non-rbac-$RELEASE.yaml</code> is used for non-RBAC Kubernetes cluster.
* <code>kubeless-openshift-$RELEASE.yaml</code> is used to deploy Kubeless to OpenShift (1.5+).

For example, this below is a show case of deploying kubeless to a Kubernetes cluster (with RBAC available).
<pre>
$ export RELEASE=$(curl -s https://api.github.com/repos/kubeless/kubeless/releases/latest | grep tag_name | cut -d '"' -f 4)
$ kubectl create ns kubeless
$ kubectl create -f https://github.com/kubeless/kubeless/releases/download/$RELEASE/kubeless-$RELEASE.yaml

$ kubectl get pods -n kubeless
NAME READY STATUS RESTARTS AGE
kubeless-controller-manager-567dcb6c48-ssx8x 1/1 Running 0 1h

$ kubectl get deployment -n kubeless
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
kubeless-controller-manager 1 1 1 1 1h

$ kubectl get customresourcedefinition
NAME AGE
cronjobtriggers.kubeless.io 1h
functions.kubeless.io 1h
httptriggers.kubeless.io 1h
</pre>

Details on [https://kubeless.io/docs/function-controller-configuration#install-kubeless-in-different-namespace installing kubeless in a different namespace] can be found here.

* Install the kubeless CLI:
<pre>
export OS=$(uname -s| tr '[:upper:]' '[:lower:]')
curl -OL https://github.com/kubeless/kubeless/releases/download/$RELEASE/kubeless_$OS-amd64.zip && \
unzip kubeless_$OS-amd64.zip && \
sudo mv bundles/kubeless_$OS-amd64/kubeless /usr/local/bin/
</pre>
Binaries for x86 architectures can be found as well in the [https://github.com/kubeless/kubeless/releases releases page].

==Sample function==

You can use the CLI to create a function. Here is a toy:
<pre>
def hello(event, context):
print event
return event['data']
</pre>

Functions in Kubeless have the same format regardless of the language of the function or the event source. In general, every function:

* Receives an object event as their first parameter. This parameter includes all the information regarding the event source. In particular, the key 'data' should contain the body of the function request.
* Receives a second object context with general information about the function.
* Returns a string/object that will be used as response for the caller.

You can find more details about the function interface [https://kubeless.io/docs/kubeless-functions#functions-interface here].

You create it with:
<pre>
$ kubeless function deploy hello --runtime python2.7 \
--from-file test.py \
--handler test.hello
INFO[0000] Deploying function...
INFO[0000] Function hello submitted for deployment
INFO[0000] Check the deployment status executing 'kubeless function ls hello'
</pre>

Let's dissect the command:

* <code>hello</code>: This is the name of the function we want to deploy.
* <code>--runtime python2.7</code>: This is the runtime we want to use to run our function. Available runtimes can be found executing <code>kubeless get-server-config</code>.
* <code>--from-file test.py</code>: This is the file containing the function code. It is supported to specify a zip file as far as it does not exceed the maximum size for an etcd entry (1 MB).
* <code>--handler test.foobar</code>: This specifies the file and the exposed function that will be used when receiving requests. In this example, we are using the function <code>foobar</code> from the file <code>test.py</code>.

You can find the rest of options available when deploying a function executing <code>kubeless function deploy --help</code>

You will see the function custom resource created:
<pre>
$ kubectl get functions
NAME AGE
hello 1h

$ kubeless function ls
NAME NAMESPACE HANDLER RUNTIME DEPENDENCIES STATUS
hello default helloget.foo python2.7 1/1 READY
</pre>
* You can then call the function with:
<pre>
$ kubeless function call hello --data 'Hello world!'
Hello world!
</pre>

Or you can curl directly with <code>kubectl</code> proxy using an [https://kubernetes.io/docs/tasks/access-application-cluster/access-cluster/#manually-constructing-apiserver-proxy-urls apiserver proxy URL].

* For example:
<pre>
$ kubectl proxy -p 8080 &

$ curl -L --data '{"Another": "Echo"}' \
--header "Content-Type:application/json" \
localhost:8080/api/v1/namespaces/default/services/hello:http-function-port/proxy/
{"Another": "Echo"}
</pre>

Kubeless also supports [https://kubernetes.io/docs/concepts/services-networking/ingress/ ingress] which means you can provide your custom URL to the function. Please refer to [https://kubeless.io/docs/http-triggers this doc] for more details.

; Clean up

* You can delete the function and uninstall Kubeless:
<pre>
$ kubeless function delete hello

$ kubeless function ls
NAME NAMESPACE HANDLER RUNTIME DEPENDENCIES STATUS

$ kubectl delete -f https://github.com/kubeless/kubeless/releases/download/$RELEASE/kubeless-$RELEASE.yaml
</pre>

==See also==
* [[Kubernetes]]

==External links==
* [https://kubeless.io/ Official website]
* [https://kubeless.io/docs/quick-start/ Quick Start]

[[Category:Technical and Specialized Skills]]
[[Category:DevOps]]

@@ Line 74: / Line 74: @@
 </pre>
-Let's dissect the command:
+Let us dissect the command:
 * <code>hello</code>: This is the name of the function we want to deploy.

@@ Line 49: / Line 49: @@
 ==Sample function==
-You can use the CLI to create a function. Here is a toy:
+You can use the CLI to create a function. Here is a toy example:
 <pre>
 def hello(event, context):
-  print event
+    print event
-  return event['data']
+    return event['data']
 </pre>
 Functions in Kubeless have the same format regardless of the language of the function or the event source. In general, every function:
-* Receives an object event as their first parameter. This parameter includes all the information regarding the event source. In particular, the key 'data' should contain the body of the function request.
+* Receives an object event as their first parameter. This parameter includes all the information regarding the event source. In particular, the key "data" should contain the body of the function request.
 * Receives a second object context with general information about the function.
-* Returns a string/object that will be used as response for the caller.
+* Returns a string/object that will be used as a response for the caller.
 You can find more details about the function interface [https://kubeless.io/docs/kubeless-functions#functions-interface here].
@@ Line 99: / Line 99: @@
 </pre>
-Or you can curl directly with <code>kubectl</code> proxy using an [https://kubernetes.io/docs/tasks/access-application-cluster/access-cluster/#manually-constructing-apiserver-proxy-urls apiserver proxy URL].
+Or you can [[curl]] directly with <code>kubectl</code> proxy using an [https://kubernetes.io/docs/tasks/access-application-cluster/access-cluster/#manually-constructing-apiserver-proxy-urls apiserver proxy URL].
 * For example:
@@ Line 111: / Line 111: @@
 </pre>
-Kubeless also supports [https://kubernetes.io/docs/concepts/services-networking/ingress/ ingress] which means you can provide your custom URL to the function. Please refer to [https://kubeless.io/docs/http-triggers this doc] for more details.
+Kubeless also supports [https://kubernetes.io/docs/concepts/services-networking/ingress/ ingress] which means you can provide your custom URL to the function. Refer to [https://kubeless.io/docs/http-triggers this doc] for more details.
 ; Clean up

@@ Line 67: / Line 67: @@
 <pre>
 $ kubeless function deploy hello --runtime python2.7 \
-                                --from-file test.py \
+                                 --from-file test.py \
-                                --handler test.hello
+                                 --handler test.hello
 INFO[0000] Deploying function...
 INFO[0000] Function hello submitted for deployment

@@ Line 5: / Line 5: @@
 Installation is made of three steps:
-* Download the kubeless CLI from the [https://github.com/kubeless/kubeless/releases release page].
+* Download the kubeless CLI from the [https://github.com/kubeless/kubeless/releases release page];
-* Create a kubeless namespace (used by default)
+* create a kubeless namespace (used by default); and
-* Then use one of the YAML manifests found in the release page to deploy kubeless. It will create a _functions_ Custom Resource Definition and launch a controller.
+* then use one of the YAML manifests found in the release page to deploy kubeless. It will create a ''functions'' Custom Resource Definition and launch a controller.
 There are several kubeless manifests being shipped for multiple k8s environments (non-rbac, rbac and openshift), pick the one that corresponds to your environment:
-* <code>kubeless-$RELEASE.yaml</code> is used for RBAC Kubernetes cluster.
+* <code>kubeless-${RELEASE}.yaml</code> is used for RBAC Kubernetes cluster.
-* <code>kubeless-non-rbac-$RELEASE.yaml</code> is used for non-RBAC Kubernetes cluster.
+* <code>kubeless-non-rbac-${RELEASE}.yaml</code> is used for non-RBAC Kubernetes cluster.
-* <code>kubeless-openshift-$RELEASE.yaml</code> is used to deploy Kubeless to OpenShift (1.5+).
+* <code>kubeless-openshift-${RELEASE}.yaml</code> is used to deploy Kubeless to OpenShift (1.5+).
 For example, this below is a show case of deploying kubeless to a Kubernetes cluster (with RBAC available).
@@ Line 19: / Line 19: @@
 $ export RELEASE=$(curl -s https://api.github.com/repos/kubeless/kubeless/releases/latest | grep tag_name | cut -d '"' -f 4)
 $ kubectl create ns kubeless
-$ kubectl create -f https://github.com/kubeless/kubeless/releases/download/$RELEASE/kubeless-$RELEASE.yaml
+$ kubectl create -f https://github.com/kubeless/kubeless/releases/download/${RELEASE}/kubeless-${RELEASE}.yaml
 $ kubectl get pods -n kubeless
@@ Line 40: / Line 40: @@
 * Install the kubeless CLI:
 <pre>
-export OS=$(uname -s| tr '[:upper:]' '[:lower:]')
+$ export OS=$(uname -s| tr '[:upper:]' '[:lower:]')
-curl -OL https://github.com/kubeless/kubeless/releases/download/$RELEASE/kubeless_$OS-amd64.zip && \
+$ curl -OL https://github.com/kubeless/kubeless/releases/download/${RELEASE}/kubeless_${OS}-amd64.zip && \
-  unzip kubeless_$OS-amd64.zip && \
+    unzip kubeless_${OS}-amd64.zip && \
-  sudo mv bundles/kubeless_$OS-amd64/kubeless /usr/local/bin/
+    sudo mv bundles/kubeless_${OS}-amd64/kubeless /usr/local/bin/
 </pre>
 Binaries for x86 architectures can be found as well in the [https://github.com/kubeless/kubeless/releases releases page].

@@ Line 127: / Line 127: @@
 ==See also==
 * [[Kubernetes]]
 ==External links==