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<title>135.&nbsp;Kubernetes PropertySource implementations</title><link rel="stylesheet" type="text/css" href="css/manual-multipage.css"><meta name="generator" content="DocBook XSL Stylesheets V1.79.1"><link rel="home" href="multi_spring-cloud.html" title="Spring Cloud"><link rel="up" href="multi__spring_cloud_kubernetes.html" title="Part&nbsp;XVII.&nbsp;Spring Cloud Kubernetes"><link rel="prev" href="multi__discoveryclient_for_kubernetes.html" title="134.&nbsp;DiscoveryClient for Kubernetes"><link rel="next" href="multi__ribbon_discovery_in_kubernetes.html" title="136.&nbsp;Ribbon discovery in Kubernetes"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">135.&nbsp;Kubernetes PropertySource implementations</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="multi__discoveryclient_for_kubernetes.html">Prev</a>&nbsp;</td><th width="60%" align="center">Part&nbsp;XVII.&nbsp;Spring Cloud Kubernetes</th><td width="20%" align="right">&nbsp;<a accesskey="n" href="multi__ribbon_discovery_in_kubernetes.html">Next</a></td></tr></table><hr></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a name="_kubernetes_propertysource_implementations" href="#_kubernetes_propertysource_implementations"></a>135.&nbsp;Kubernetes PropertySource implementations</h2></div></div></div><p>The most common approach to configure your Spring Boot application is to create an <code class="literal">application.properties|yaml</code> or
an <code class="literal">application-profile.properties|yaml</code> file containing key-value pairs providing customization values to your
application or Spring Boot starters. Users may override these properties by specifying system properties or environment
variables.</p><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_configmap_propertysource" href="#_configmap_propertysource"></a>135.1&nbsp;ConfigMap PropertySource</h2></div></div></div><p>Kubernetes provides a resource named <a class="link" href="http://kubernetes.io/docs/user-guide/configmap/" target="_top">ConfigMap</a> to externalize the
parameters to pass to your application in the form of key-value pairs or embedded <code class="literal">application.properties|yaml</code> files.
The <a class="link" href="./spring-cloud-kubernetes-config" target="_top">Spring Cloud Kubernetes Config</a> project makes Kubernetes `ConfigMap`s available
during application bootstrapping and triggers hot reloading of beans or Spring context when changes are detected on
observed `ConfigMap`s.</p><p>The default behavior is to create a <code class="literal">ConfigMapPropertySource</code> based on a Kubernetes <code class="literal">ConfigMap</code> which has <code class="literal">metadata.name</code> of either the name of
your Spring application (as defined by its <code class="literal">spring.application.name</code> property) or a custom name defined within the
<code class="literal">bootstrap.properties</code> file under the following key <code class="literal">spring.cloud.kubernetes.config.name</code>.</p><p>However, more advanced configuration are possible where multiple ConfigMaps can be used
This is made possible by the <code class="literal">spring.cloud.kubernetes.config.sources</code> list.
For example one could define the following ConfigMaps</p><pre class="programlisting"><span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">spring</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> application</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> name</span>: cloud-k8s-app
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> cloud</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> kubernetes</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> config</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> name</span>: default-name
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> namespace</span>: default-namespace
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> sources</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-comment"># Spring Cloud Kubernetes will lookup a ConfigMap named c1 in namespace default-namespace</span>
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> - name</span>: c1
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-comment"># Spring Cloud Kubernetes will lookup a ConfigMap named default-name in whatever namespace n2</span>
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> - namespace</span>: n2
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-comment"># Spring Cloud Kubernetes will lookup a ConfigMap named c3 in namespace n3</span>
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> - namespace</span>: n3
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> name</span>: c3</pre><p>In the example above, it <code class="literal">spring.cloud.kubernetes.config.namespace</code> had not been set,
then the ConfigMap named <code class="literal">c1</code> would be looked up in the namespace that the application runs</p><p>Any matching <code class="literal">ConfigMap</code> that is found, will be processed as follows:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">apply individual configuration properties.</li><li class="listitem">apply as <code class="literal">yaml</code> the content of any property named <code class="literal">application.yaml</code></li><li class="listitem">apply as properties file the content of any property named <code class="literal">application.properties</code></li></ul></div><p>The single exception to the aforementioned flow is when the <code class="literal">ConfigMap</code> contains a <span class="strong"><strong>single</strong></span> key that indicates
the file is a YAML or Properties file. In that case the name of the key does NOT have to be <code class="literal">application.yaml</code> or
<code class="literal">application.properties</code> (it can be anything) and the value of the property will be treated correctly.
This features facilitates the use case where the <code class="literal">ConfigMap</code> was created using something like:</p><p><code class="literal">kubectl create configmap game-config --from-file=/path/to/app-config.yaml</code></p><p>Example:</p><p>Let&#8217;s assume that we have a Spring Boot application named <code class="literal">demo</code> that uses properties to read its thread pool
configuration.</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><code class="literal">pool.size.core</code></li><li class="listitem"><code class="literal">pool.size.maximum</code></li></ul></div><p>This can be externalized to config map in <code class="literal">yaml</code> format:</p><pre class="programlisting"><span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">kind</span>: ConfigMap
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">apiVersion</span>: v1
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">metadata</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> name</span>: demo
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">data</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> pool.size.core</span>: <span class="hl-number">1</span>
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> pool.size.max</span>: <span class="hl-number">16</span></pre><p>Individual properties work fine for most cases but sometimes embedded <code class="literal">yaml</code> is more convenient. In this case we will
use a single property named <code class="literal">application.yaml</code> to embed our <code class="literal">yaml</code>:</p><pre class="literallayout"> ```yaml
kind: ConfigMap
apiVersion: v1
metadata:
name: demo
data:
application.yaml: |-
pool:
size:
core: 1
max:16</pre><pre class="screen">The following also works:
```yaml
kind: ConfigMap
apiVersion: v1
metadata:
name: demo
data:
custom-name.yaml: |-
pool:
size:
core: 1
max:16</pre><p>Spring Boot applications can also be configured differently depending on active profiles which will be merged together
when the ConfigMap is read. It is possible to provide different property values for different profiles using an
<code class="literal">application.properties|yaml</code> property, specifying profile-specific values each in their own document
(indicated by the <code class="literal">---</code> sequence) as follows:</p><pre class="programlisting"><span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">kind</span>: ConfigMap
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">apiVersion</span>: v1
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">metadata</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> name</span>: demo
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">data</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> application.yml</span>: |-
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> greeting</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> message</span>: Say Hello to the World
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> farewell</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> message</span>: Say Goodbye
---
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> spring</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> profiles</span>: development
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> greeting</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> message</span>: Say Hello to the Developers
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> farewell</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> message</span>: Say Goodbye to the Developers
---
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> spring</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> profiles</span>: production
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> greeting</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> message</span>: Say Hello to the Ops</pre><p>In the above case, the configuration loaded into your Spring Application with the <code class="literal">development</code> profile will be:</p><pre class="programlisting"><span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> greeting</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> message</span>: Say Hello to the Developers
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> farewell</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> message</span>: Say Goodbye to the Developers</pre><p>whereas if the <code class="literal">production</code> profile is active, the configuration will be:</p><pre class="programlisting"><span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> greeting</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> message</span>: Say Hello to the Ops
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> farewell</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> message</span>: Say Goodbye</pre><p>If both profiles are active, the property which appears last within the configmap will overwrite preceding values.</p><p>To tell to Spring Boot which <code class="literal">profile</code> should be enabled at bootstrap, a system property can be passed to the Java
command launching your Spring Boot application using an env variable that you will define with the OpenShift
<code class="literal">DeploymentConfig</code> or Kubernetes <code class="literal">ReplicationConfig</code> resource file as follows:</p><pre class="programlisting"><span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">apiVersion</span>: v1
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">kind</span>: DeploymentConfig
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">spec</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> replicas</span>: <span class="hl-number">1</span>
...
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> spec</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> containers</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> - env</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> - name</span>: JAVA_APP_DIR
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> value</span>: /deployments
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> - name</span>: JAVA_OPTIONS
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> value</span>: -Dspring.profiles.active=developer</pre><p><span class="strong"><strong>Notes:</strong></span>
- check the security configuration section, to access config maps from inside a pod you need to have the correct
Kubernetes service accounts, roles and role bindings.</p><div class="table"><a name="d0e35173" href="#d0e35173"></a><p class="title"><b>Table&nbsp;135.1.&nbsp;Properties:</b></p><div class="table-contents"><table class="table" summary="Properties:" style="border-collapse: collapse;border-top: 1px solid ; border-bottom: 1px solid ; "><colgroup><col class="col_1"><col class="col_2"><col class="col_3"><col class="col_4"></colgroup><thead><tr><th style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top">Name</th><th style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top">Type</th><th style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top">Default</th><th style="border-bottom: 1px solid ; " align="left" valign="top">Description</th></tr></thead><tfoot><tr><th style="border-right: 1px solid ; " align="left" valign="top"><p>spring.cloud.kubernetes.config.enableApi</p></th><th style="border-right: 1px solid ; " align="left" valign="top"><p>Boolean</p></th><th style="border-right: 1px solid ; " align="left" valign="top"><p>true</p></th><th style="" align="left" valign="top"><p>Enable/Disable consuming ConfigMaps via APIs</p></th></tr></tfoot><tbody><tr><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>spring.cloud.kubernetes.config.enabled</p></td><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>Boolean</p></td><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>true</p></td><td style="border-bottom: 1px solid ; " align="left" valign="top"><p>Enable Secrets PropertySource</p></td></tr><tr><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>spring.cloud.kubernetes.config.name</p></td><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>String</p></td><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>${spring.application.name}</p></td><td style="border-bottom: 1px solid ; " align="left" valign="top"><p>Sets the name of ConfigMap to lookup</p></td></tr><tr><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>spring.cloud.kubernetes.config.namespace</p></td><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>String</p></td><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>Client namespace</p></td><td style="border-bottom: 1px solid ; " align="left" valign="top"><p>Sets the Kubernetes namespace where to lookup</p></td></tr><tr><td style="border-right: 1px solid ; " align="left" valign="top"><p>spring.cloud.kubernetes.config.paths</p></td><td style="border-right: 1px solid ; " align="left" valign="top"><p>List</p></td><td style="border-right: 1px solid ; " align="left" valign="top"><p>null</p></td><td style="" align="left" valign="top"><p>Sets the paths where ConfigMaps are mounted</p></td></tr></tbody></table></div></div><br class="table-break"></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_secrets_propertysource" href="#_secrets_propertysource"></a>135.2&nbsp;Secrets PropertySource</h2></div></div></div><p>Kubernetes has the notion of [Secrets](<a class="link" href="https://kubernetes.io/docs/concepts/configuration/secret/" target="_top">https://kubernetes.io/docs/concepts/configuration/secret/</a>) for storing
sensitive data such as password, OAuth tokens, etc. This project provides integration with <code class="literal">Secrets</code> to make secrets
accessible by Spring Boot applications. This feature can be explicitly enabled/disabled using the <code class="literal">spring.cloud.kubernetes.secrets.enabled</code> property.</p><p>The <code class="literal">SecretsPropertySource</code> when enabled will lookup Kubernetes for <code class="literal">Secrets</code> from the following sources:
1. reading recursively from secrets mounts
2. named after the application (as defined by <code class="literal">spring.application.name</code>)
3. matching some labels</p><p>Please note that by default, consuming Secrets via API (points 2 and 3 above) <span class="strong"><strong>is not enabled</strong></span> for security reasons
and it is recommend that containers share secrets via mounted volumes. Otherwise proper RBAC security configurations must be provided
to make sure that unauthorized access to Secrets occurs.</p><p>If the secrets are found their data is made available to the application.</p><p><span class="strong"><strong>Example:</strong></span></p><p>Let&#8217;s assume that we have a spring boot application named <code class="literal">demo</code> that uses properties to read its database
configuration. We can create a Kubernetes secret using the following command:</p><pre class="screen">oc create secret generic db-secret --from-literal=username=user --from-literal=password=p455w0rd</pre><p>This would create the following secret (shown using <code class="literal">oc get secrets db-secret -o yaml</code>):</p><pre class="programlisting"><span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">apiVersion</span>: v1
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">data</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> password</span>: cDQ1NXcwcmQ=
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> username</span>: dXNlcg==
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">kind</span>: Secret
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">metadata</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> creationTimestamp</span>: <span class="hl-number">2017</span>-<span class="hl-number">07</span>-<span class="hl-number">04</span>T09:<span class="hl-number">15</span>:<span class="hl-number">57</span>Z
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> name</span>: db-secret
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> namespace</span>: default
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> resourceVersion</span>: <span xmlns:d="http://docbook.org/ns/docbook" class="hl-string">"357496"</span>
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> selfLink</span>: /api/v1/namespaces/default/secrets/db-secret
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> uid</span>: <span class="hl-number">63</span>c89263-<span class="hl-number">6099</span>-<span class="hl-number">11e7</span>-b3da-<span class="hl-number">76d</span>6186905a8
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">type</span>: Opaque</pre><p>Note that the data contains Base64-encoded versions of the literal provided by the create command.</p><p>This secret can then be used by your application for example by exporting the secret&#8217;s value as environment variables:</p><pre class="programlisting"><span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">apiVersion</span>: v1
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">kind</span>: Deployment
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">metadata</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> name</span>: ${project.artifactId<span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">}</span>
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">spec</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> template</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> spec</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> containers</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> - env</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> - name</span>: DB_USERNAME
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> valueFrom</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> secretKeyRef</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> name</span>: db-secret
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> key</span>: username
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> - name</span>: DB_PASSWORD
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> valueFrom</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> secretKeyRef</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> name</span>: db-secret
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> key</span>: password</pre><p>You can select the Secrets to consume in a number of ways:</p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p class="simpara">By listing the directories where secrets are mapped:
<code class="literal">`
-Dspring.cloud.kubernetes.secrets.paths=/etc/secrets/db-secret,etc/secrets/postgresql
</code>`</p><pre class="literallayout">If you have all the secrets mapped to a common root, you can set them like:</pre><pre class="literallayout">```
-Dspring.cloud.kubernetes.secrets.paths=/etc/secrets
```</pre></li><li class="listitem">By setting a named secret:
<code class="literal">`
-Dspring.cloud.kubernetes.secrets.name=db-secret
</code>`</li><li class="listitem">By defining a list of labels:
<code class="literal">`
-Dspring.cloud.kubernetes.secrets.labels.broker=activemq
-Dspring.cloud.kubernetes.secrets.labels.db=postgresql
</code>`</li></ol></div><div class="table"><a name="d0e35338" href="#d0e35338"></a><p class="title"><b>Table&nbsp;135.2.&nbsp;Properties:</b></p><div class="table-contents"><table class="table" summary="Properties:" style="border-collapse: collapse;border-top: 1px solid ; border-bottom: 1px solid ; "><colgroup><col class="col_1"><col class="col_2"><col class="col_3"><col class="col_4"></colgroup><thead><tr><th style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top">Name</th><th style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top">Type</th><th style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top">Default</th><th style="border-bottom: 1px solid ; " align="left" valign="top">Description</th></tr></thead><tfoot><tr><th style="border-right: 1px solid ; " align="left" valign="top"><p>spring.cloud.kubernetes.secrets.enableApi</p></th><th style="border-right: 1px solid ; " align="left" valign="top"><p>Boolean</p></th><th style="border-right: 1px solid ; " align="left" valign="top"><p>false</p></th><th style="" align="left" valign="top"><p>Enable/Disable consuming secrets via APIs (examples 2 and 3)</p></th></tr></tfoot><tbody><tr><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>spring.cloud.kubernetes.secrets.enabled</p></td><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>Boolean</p></td><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>true</p></td><td style="border-bottom: 1px solid ; " align="left" valign="top"><p>Enable Secrets PropertySource</p></td></tr><tr><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>spring.cloud.kubernetes.secrets.name</p></td><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>String</p></td><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>${spring.application.name}</p></td><td style="border-bottom: 1px solid ; " align="left" valign="top"><p>Sets the name of the secret to lookup</p></td></tr><tr><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>spring.cloud.kubernetes.secrets.namespace</p></td><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>String</p></td><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>Client namespace</p></td><td style="border-bottom: 1px solid ; " align="left" valign="top"><p>Sets the Kubernetes namespace where to lookup</p></td></tr><tr><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>spring.cloud.kubernetes.secrets.labels</p></td><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>Map</p></td><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>null</p></td><td style="border-bottom: 1px solid ; " align="left" valign="top"><p>Sets the labels used to lookup secrets</p></td></tr><tr><td style="border-right: 1px solid ; " align="left" valign="top"><p>spring.cloud.kubernetes.secrets.paths</p></td><td style="border-right: 1px solid ; " align="left" valign="top"><p>List</p></td><td style="border-right: 1px solid ; " align="left" valign="top"><p>null</p></td><td style="" align="left" valign="top"><p>Sets the paths where secrets are mounted (example 1)</p></td></tr></tbody></table></div></div><br class="table-break"><p><span class="strong"><strong>Notes:</strong></span>
- The property <code class="literal">spring.cloud.kubernetes.secrets.labels</code> behaves as defined by
<a class="link" href="https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-Configuration-Binding#map-based-binding" target="_top">Map-based binding</a>.
- The property <code class="literal">spring.cloud.kubernetes.secrets.paths</code> behaves as defined by
<a class="link" href="https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-Configuration-Binding#collection-based-binding" target="_top">Collection-based binding</a>.
- Access to secrets via API may be restricted for security reasons, the preferred way is to mount secret to the POD.</p><p>Example of application using secrets (though it hasn&#8217;t been updated to use the new <code class="literal">spring-cloud-kubernetes</code> project):
<a class="link" href="https://github.com/fabric8-quickstarts/spring-boot-camel-config" target="_top">spring-boot-camel-config</a></p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_propertysource_reload" href="#_propertysource_reload"></a>135.3&nbsp;PropertySource Reload</h2></div></div></div><p>Some applications may need to detect changes on external property sources and update their internal status to reflect the new configuration.
The reload feature of Spring Cloud Kubernetes is able to trigger an application reload when a related <code class="literal">ConfigMap</code> or
<code class="literal">Secret</code> changes.</p><p>This feature is disabled by default and can be enabled using the configuration property <code class="literal">spring.cloud.kubernetes.reload.enabled=true</code>
(eg. in the <span class="strong"><strong>application.properties</strong></span> file).</p><p>The following levels of reload are supported (property <code class="literal">spring.cloud.kubernetes.reload.strategy</code>):
- <span class="strong"><strong><code class="literal">refresh</code> (default)</strong></span>: only configuration beans annotated with <code class="literal">@ConfigurationProperties</code> or <code class="literal">@RefreshScope</code> are reloaded.
This reload level leverages the refresh feature of Spring Cloud Context.
- <span class="strong"><strong><code class="literal">restart_context</code></strong></span>: the whole Spring <span class="emphasis"><em>ApplicationContext</em></span> is gracefully restarted. Beans are recreated with the new configuration.
- <span class="strong"><strong><code class="literal">shutdown</code></strong></span>: the Spring <span class="emphasis"><em>ApplicationContext</em></span> is shut down to activate a restart of the container.
When using this level, make sure that the lifecycle of all non-daemon threads is bound to the ApplicationContext
and that a replication controller or replica set is configured to restart the pod.</p><p>Example:</p><p>Assuming that the reload feature is enabled with default settings (<span class="strong"><strong><code class="literal">refresh</code></strong></span> mode), the following bean will be refreshed when the config map changes:</p><pre class="programlisting"><em><span class="hl-annotation" style="color: gray">@Configuration</span></em>
<em><span class="hl-annotation" style="color: gray">@ConfigurationProperties(prefix = "bean")</span></em>
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">public</span> <span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">class</span> MyConfig {
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">private</span> String message = <span xmlns:d="http://docbook.org/ns/docbook" class="hl-string">"a message that can be changed live"</span>;
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-comment">// getter and setters</span>
}</pre><p>A way to see that changes effectively happen is creating another bean that prints the message periodically.</p><pre class="programlisting"><em><span class="hl-annotation" style="color: gray">@Component</span></em>
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">public</span> <span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">class</span> MyBean {
<em><span class="hl-annotation" style="color: gray">@Autowired</span></em>
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">private</span> MyConfig config;
<em><span class="hl-annotation" style="color: gray">@Scheduled(fixedDelay = 5000)</span></em>
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">public</span> <span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">void</span> hello() {
System.out.println(<span xmlns:d="http://docbook.org/ns/docbook" class="hl-string">"The message is: "</span> + config.getMessage());
}
}</pre><p>The message printed by the application can be changed using a <code class="literal">ConfigMap</code> as follows:</p><pre class="programlisting"><span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">apiVersion</span>: v1
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">kind</span>: ConfigMap
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">metadata</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> name</span>: reload-example
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">data</span>:
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> application.properties</span>: |-
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute"> bean.message</span>=Hello World!</pre><p>Any change to the property named <code class="literal">bean.message</code> in the <code class="literal">ConfigMap</code> associated to the pod will be reflected in the
output. More generally speaking, changes associated to properties prefixed with the value defined by the <code class="literal">prefix</code>
field of the <code class="literal">@ConfigurationProperties</code> annotation will be detected and reflected in the application.
[Associating a <code class="literal">ConfigMap</code> to a pod](#configmap-propertysource) is explained above.</p><p>The full example is available in [spring-cloud-kubernetes-reload-example](spring-cloud-kubernetes-examples/kubernetes-reload-example).</p><p>The reload feature supports two operating modes:
- <span class="strong"><strong>event (default)</strong></span>: watches for changes in config maps or secrets using the Kubernetes API (web socket).
Any event will produce a re-check on the configuration and a reload in case of changes.
The <code class="literal">view</code> role on the service account is required in order to listen for config map changes. A higher level role (eg. <code class="literal">edit</code>) is required for secrets
(secrets are not monitored by default).
- <span class="strong"><strong>polling</strong></span>: re-creates the configuration periodically from config maps and secrets to see if it has changed.
The polling period can be configured using the property <code class="literal">spring.cloud.kubernetes.reload.period</code> and defaults to <span class="strong"><strong>15 seconds</strong></span>.
It requires the same role as the monitored property source.
This means, for example, that using polling on file mounted secret sources does not require particular privileges.</p><div class="table"><a name="d0e35568" href="#d0e35568"></a><p class="title"><b>Table&nbsp;135.3.&nbsp;Properties:</b></p><div class="table-contents"><table class="table" summary="Properties:" style="border-collapse: collapse;border-top: 1px solid ; border-bottom: 1px solid ; "><colgroup><col class="col_1"><col class="col_2"><col class="col_3"><col class="col_4"></colgroup><thead><tr><th style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top">Name</th><th style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top">Type</th><th style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top">Default</th><th style="border-bottom: 1px solid ; " align="left" valign="top">Description</th></tr></thead><tfoot><tr><th style="border-right: 1px solid ; " align="left" valign="top"><p>spring.cloud.kubernetes.reload.period</p></th><th style="border-right: 1px solid ; " align="left" valign="top"><p>Long</p></th><th style="border-right: 1px solid ; " align="left" valign="top"><p>15000</p></th><th style="" align="left" valign="top"><p>The period in milliseconds for verifying changes when using the <span class="strong"><strong>polling</strong></span> strategy</p></th></tr></tfoot><tbody><tr><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>spring.cloud.kubernetes.reload.enabled</p></td><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>Boolean</p></td><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>false</p></td><td style="border-bottom: 1px solid ; " align="left" valign="top"><p>Enables monitoring of property sources and configuration reload</p></td></tr><tr><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>spring.cloud.kubernetes.reload.monitoring-config-maps</p></td><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>Boolean</p></td><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>true</p></td><td style="border-bottom: 1px solid ; " align="left" valign="top"><p>Allow monitoring changes in config maps</p></td></tr><tr><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>spring.cloud.kubernetes.reload.monitoring-secrets</p></td><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>Boolean</p></td><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>false</p></td><td style="border-bottom: 1px solid ; " align="left" valign="top"><p>Allow monitoring changes in secrets</p></td></tr><tr><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>spring.cloud.kubernetes.reload.strategy</p></td><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>Enum</p></td><td style="border-right: 1px solid ; border-bottom: 1px solid ; " align="left" valign="top"><p>refresh</p></td><td style="border-bottom: 1px solid ; " align="left" valign="top"><p>The strategy to use when firing a reload (<span class="strong"><strong>refresh</strong></span>, <span class="strong"><strong>restart_context</strong></span>, <span class="strong"><strong>shutdown</strong></span>)</p></td></tr><tr><td style="border-right: 1px solid ; " align="left" valign="top"><p>spring.cloud.kubernetes.reload.mode</p></td><td style="border-right: 1px solid ; " align="left" valign="top"><p>Enum</p></td><td style="border-right: 1px solid ; " align="left" valign="top"><p>event</p></td><td style="" align="left" valign="top"><p>Specifies how to listen for changes in property sources (<span class="strong"><strong>event</strong></span>, <span class="strong"><strong>polling</strong></span>)</p></td></tr></tbody></table></div></div><br class="table-break"><p><span class="strong"><strong>Notes</strong></span>:
- Properties under <span class="strong"><strong>spring.cloud.kubernetes.reload.</strong></span> should not be used in config maps or secrets: changing such properties at runtime may lead to unexpected results;
- Deleting a property or the whole config map does not restore the original state of the beans when using the <span class="strong"><strong>refresh</strong></span> level.</p></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="multi__discoveryclient_for_kubernetes.html">Prev</a>&nbsp;</td><td width="20%" align="center"><a accesskey="u" href="multi__spring_cloud_kubernetes.html">Up</a></td><td width="40%" align="right">&nbsp;<a accesskey="n" href="multi__ribbon_discovery_in_kubernetes.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">134.&nbsp;DiscoveryClient for Kubernetes&nbsp;</td><td width="20%" align="center"><a accesskey="h" href="multi_spring-cloud.html">Home</a></td><td width="40%" align="right" valign="top">&nbsp;136.&nbsp;Ribbon discovery in Kubernetes</td></tr></table></div></body></html>
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