<p>I have existing deployments in k8s, I would like to update container, I updated docker image tag (new unique id) in deployment and run:</p>
<pre><code>kubectl apply -f testdeploy.yml --namespace=myapp
</code></pre>
<p>Output is: <code>deployment.apps/fakename configured</code></p>
<p>But nothing happens.</p>
<p>When I run <code>kubectl get pods --namespace=myapp</code> I can see only one old pod with old age.</p>
<p>Sometimes is working, sometimes not, why?</p>
<p>What is wrong?</p>

<p>try describing the deployment and see the events</p>
<pre><code>kubectl describe &lt;deployment-name&gt; --namespace=myapp
</code></pre>
<p>or</p>
<pre><code>kubectl get events --namespace=myapp
</code></pre>
<p>to understand what is happening.</p>
<p>try checking whether new replicas has been created for changed deployment container image.</p>
<pre><code>kubectl get rs -n myapp
</code></pre>
<p>check the number of replicas expected example when you do <code>kubectl get rs</code>:</p>
<pre><code>NAME                                DESIRED   CURRENT   READY   AGE
&lt;deployment-name&gt;-58ffbb8b76         0         0         0       10s
</code></pre>
<p>maybe few more details would be helpful to understand why was nothing happening when you try to deploy.</p>
<p>kubernetes has nice documentation check this.</p>
<p><a href="https://kubernetes.io/docs/tasks/debug-application-cluster/debug-application-introspection/" rel="nofollow noreferrer">https://kubernetes.io/docs/tasks/debug-application-cluster/debug-application-introspection/</a></p>
