<p>created a very simple nginx pod and run into status <code>ImagePullBackoff</code></p>
<pre><code>Events:
  Type     Reason     Age                   From               Message
  ----     ------     ----                  ----               -------
  Normal   Scheduled  32m                   default-scheduler  Successfully assigned reloader/nginx to aks-appnodepool1-22779252-vmss000000
  Warning  Failed     29m                   kubelet            Failed to pull image &quot;nginx&quot;: rpc error: code = Unknown desc = failed to pull and unpack image &quot;docker.io/library/nginx:latest&quot;: failed to resolve reference &quot;docker.io/library/nginx:latest&quot;: failed to do request: Head &quot;https://registry-1.docker.io/v2/library/nginx/manifests/latest&quot;: dial tcp 52.200.78.26:443: i/o timeout
  Warning  Failed     27m                   kubelet            Failed to pull image &quot;nginx&quot;: rpc error: code = Unknown desc = failed to pull and unpack image &quot;docker.io/library/nginx:latest&quot;: failed to resolve reference &quot;docker.io/library/nginx:latest&quot;: failed to do request: Head &quot;https://registry-1.docker.io/v2/library/nginx/manifests/latest&quot;: dial tcp 52.21.28.242:443: i/o timeout
  Warning  Failed     23m                   kubelet            Failed to pull image &quot;nginx&quot;: rpc error: code = Unknown desc = failed to pull and unpack image &quot;docker.io/library/nginx:latest&quot;: failed to resolve reference &quot;docker.io/library/nginx:latest&quot;: failed to do request: Head &quot;https://registry-1.docker.io/v2/library/nginx/manifests/latest&quot;: dial tcp 3.223.210.206:443: i/o timeout
  Normal   Pulling    22m (x4 over 32m)     kubelet            Pulling image &quot;nginx&quot;
  Warning  Failed     20m (x4 over 29m)     kubelet            Error: ErrImagePull
  Warning  Failed     20m                   kubelet            Failed to pull image &quot;nginx&quot;: rpc error: code = Unknown desc = failed to pull and unpack image &quot;docker.io/library/nginx:latest&quot;: failed to resolve reference &quot;docker.io/library/nginx:latest&quot;: failed to do request: Head &quot;https://registry-1.docker.io/v2/library/nginx/manifests/latest&quot;: dial tcp 3.228.155.36:443: i/o timeout
  Warning  Failed     20m (x7 over 29m)     kubelet            Error: ImagePullBackOff
  Warning  Failed     6m41s                 kubelet            Failed to pull image &quot;nginx&quot;: rpc error: code = Unknown desc = failed to pull and unpack image &quot;docker.io/library/nginx:latest&quot;: failed to resolve reference &quot;docker.io/library/nginx:latest&quot;: failed to do request: Head &quot;https://registry-1.docker.io/v2/library/nginx/manifests/latest&quot;: dial tcp 52.5.157.114:443: i/o timeout
  Normal   BackOff    2m17s (x65 over 29m)  kubelet            Back-off pulling image &quot;nginx&quot;
</code></pre>
<p>Checked network status:</p>
<ul>
<li>A VM in the same subnet can access &quot;https://registry-1.docker.io/v2/library/nginx/manifests/latest&quot; and <code>telnet 52.5.157.114 443</code> successful.</li>
<li><code>docker pull nginx</code> successfully on the VM in the same subnet.</li>
<li><code>kubectl exec</code> into a running pod in the same cluster can <code>wget https://registry-1.docker.io/v2/library/nginx/manifests/latest</code> successfully.
.
What is the possible problem?</li>
</ul>

Dongkai Yu
<p>When I wget/curl or anything you want to access</p>
<pre><code>https://registry-1.docker.io/v2/library/nginx/manifests/latest
</code></pre>
<p>It says</p>
<pre><code>{&quot;errors&quot;:[{&quot;code&quot;:&quot;UNAUTHORIZED&quot;,&quot;message&quot;:&quot;authentication required&quot;,&quot;detail&quot;:[{&quot;Type&quot;:&quot;repository&quot;,&quot;Class&quot;:&quot;&quot;,&quot;Name&quot;:&quot;library/nginx&quot;,&quot;Action&quot;:&quot;pull&quot;}]}]}
</code></pre>
<p>However this is because you need to be logged in to pull this image from this repository.</p>
<p>2 solutions:</p>
<p>The first is simple, in the image field just replace this url by <code>nginx:latest</code> and it should work</p>
<p>The second: create a <a href="https://kubernetes.io/docs/tasks/configure-pod-container/pull-image-private-registry/" rel="nofollow noreferrer">regcred</a></p>
