Lab Information
We encountered an issue with our Nginx and PHP-FPM setup on the Kubernetes cluster this morning, which halted its functionality. Investigate and rectify the issue:
The pod name is nginx-phpfpm and configmap name is nginx-config. Identify and fix the problem.
Once resolved, copy /home/thor/index.php file from the jump host to the nginx-container within the nginx document root. After this, you should be able to access the website using Website button on the top bar.
Note: The kubectl utility on jump_host is configured to operate with the Kubernetes cluster.
Lab Solutions
Now: run steps 1 → 4 (at minimum) and paste the outputs here:
kubectl get pods -o wide
kubectl describe pod nginx-phpfpm
kubectl get pod nginx-phpfpm -o jsonpath='{.spec.containers[*].name}'; echo
kubectl get configmap nginx-config -o yaml
thor@jumphost ~$ kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
nginx-phpfpm 2/2 Running 0 3m1s 10.244.0.5 kodekloud-control-plane <none> <none>
thor@jumphost ~$ kubectl describe pod nginx-phpfpm
Name: nginx-phpfpm
Namespace: default
Priority: 0
Service Account: default
Node: kodekloud-control-plane/172.17.0.2
Start Time: Thu, 23 Oct 2025 15:13:52 +0000
Labels: app=php-app
Annotations: <none>
Status: Running
IP: 10.244.0.5
IPs:
IP: 10.244.0.5
Containers:
php-fpm-container:
Container ID: containerd://82b352cfbbed9e6c3359ece2df11a125fc7adf7e983a00ac576481057709b267
Image: php:7.2-fpm-alpine
Image ID: docker.io/library/php@sha256:2e2d92415f3fc552e9a62548d1235f852c864fcdc94bcf2905805d92baefc87f
Port: <none>
Host Port: <none>
State: Running
Started: Thu, 23 Oct 2025 15:13:56 +0000
Ready: True
Restart Count: 0
Environment: <none>
Mounts:
/usr/share/nginx/html from shared-files (rw)
/var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-mjb7h (ro)
nginx-container:
Container ID: containerd://8aed591dc7225b0946fccbd4f1948d799811381f5b2c0f9733c11b1809a6a9e6
Image: nginx:latest
Image ID: docker.io/library/nginx@sha256:029d4461bd98f124e531380505ceea2072418fdf28752aa73b7b273ba3048903
Port: <none>
Host Port: <none>
State: Running
Started: Thu, 23 Oct 2025 15:14:01 +0000
Ready: True
Restart Count: 0
Environment: <none>
Mounts:
/etc/nginx/nginx.conf from nginx-config-volume (rw,path="nginx.conf")
/var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-mjb7h (ro)
/var/www/html from shared-files (rw)
Conditions:
Type Status
Initialized True
Ready True
ContainersReady True
PodScheduled True
Volumes:
shared-files:
Type: EmptyDir (a temporary directory that shares a pod's lifetime)
Medium:
SizeLimit: <unset>
nginx-config-volume:
Type: ConfigMap (a volume populated by a ConfigMap)
Name: nginx-config
Optional: false
kube-api-access-mjb7h:
Type: Projected (a volume that contains injected data from multiple sources)
TokenExpirationSeconds: 3607
ConfigMapName: kube-root-ca.crt
ConfigMapOptional: <nil>
DownwardAPI: true
QoS Class: BestEffort
Node-Selectors: <none>
Tolerations: node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 3m13s default-scheduler Successfully assigned default/nginx-phpfpm to kodekloud-control-plane
Normal Pulling 3m12s kubelet Pulling image "php:7.2-fpm-alpine"
Normal Pulled 3m10s kubelet Successfully pulled image "php:7.2-fpm-alpine" in 2.620893391s (2.620910147s including waiting)
Normal Created 3m10s kubelet Created container php-fpm-container
Normal Started 3m9s kubelet Started container php-fpm-container
Normal Pulling 3m9s kubelet Pulling image "nginx:latest"
Normal Pulled 3m4s kubelet Successfully pulled image "nginx:latest" in 5.617787164s (5.617801779s including waiting)
Normal Created 3m4s kubelet Created container nginx-container
Normal Started 3m4s kubelet Started container nginx-container
thor@jumphost ~$ kubectl get pod nginx-phpfpm -o jsonpath='{.spec.containers[*].name}'; echo
php-fpm-container nginx-container
thor@jumphost ~$ kubectl get configmap nginx-config -o yaml
apiVersion: v1
data:
nginx.conf: |
events {
}
http {
server {
listen 8099 default_server;
listen [::]:8099 default_server;
# Set nginx to serve files from the shared volume!
root /var/www/html;
index index.html index.htm index.php;
server_name _;
location / {
try_files $uri $uri/ =404;
}
location ~ \.php$ {
include fastcgi_params;
fastcgi_param REQUEST_METHOD $request_method;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
fastcgi_pass 127.0.0.1:9000;
}
}
}
kind: ConfigMap
metadata:
annotations:
kubectl.kubernetes.io/last-applied-configuration: |
{"apiVersion":"v1","data":{"nginx.conf":"events {\n}\nhttp {\n server {\n listen 8099 default_server;\n listen [::]:8099 default_server;\n\n # Set nginx to serve files from the shared volume!\n root /var/www/html;\n index index.html index.htm index.php;\n server_name _;\n location / {\n try_files $uri $uri/ =404;\n }\n location ~ \\.php$ {\n include fastcgi_params;\n fastcgi_param REQUEST_METHOD $request_method;\n fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;\n fastcgi_pass 127.0.0.1:9000;\n }\n }\n}\n"},"kind":"ConfigMap","metadata":{"annotations":{},"name":"nginx-config","namespace":"default"}}
creationTimestamp: "2025-10-23T15:13:52Z"
name: nginx-config
namespace: default
resourceVersion: "1479"
uid: 2bf57c90-d5bf-49ee-b05c-76b36536d0ad
🔍 Observations
The Nginx container mounts /etc/nginx/nginx.conf from the ConfigMap nginx-config.
The PHP-FPM container exposes no port, but the Nginx config tries to connect to 127.0.0.1:9000:
fastcgi_pass 127.0.0.1:9000;
Both containers share the same network namespace (since they’re in the same pod).
→ So, 127.0.0.1:9000 should reach PHP-FPM if it’s listening on port 9000.
However, php-fpm:7.2-fpm-alpine listens on a UNIX socket by default (/var/run/php-fpm.sock), not on TCP 9000 — unless configured otherwise.
So, likely the nginx can’t reach PHP-FPM, causing PHP pages (like index.php) to fail, even if both containers are running fine.
✅ Next step: Confirm PHP-FPM listening method
Please run the following to inspect how PHP-FPM is listening:
kubectl exec -it nginx-phpfpm -c php-fpm-container -- /bin/sh -c "grep '^listen' /usr/local/etc/php-fpm.d/www.conf"
Also check the socket file existence:
kubectl exec -it nginx-phpfpm -c php-fpm-container -- /bin/sh -c "ls -l /var/run/ | grep php"
thor@jumphost ~$ kubectl exec -it nginx-phpfpm -c php-fpm-container -- /bin/sh -c "grep '^listen' /usr/local/etc/php-fpm.d/www.conf"
listen = 127.0.0.1:9000
thor@jumphost ~$ kubectl exec -it nginx-phpfpm -c php-fpm-container -- /bin/sh -c "ls -l /var/run/ | grep php"
command terminated with exit code 1
✅ php-fpm is already listening on 127.0.0.1:9000, which matches your Nginx config (fastcgi_pass 127.0.0.1:9000;).
❌ The /var/run/php* socket check just failed because there is no socket file (since it’s not using one). That’s fine.
So, communication between Nginx and PHP-FPM should technically work.
Now we just need to verify two more things:
🔎 Step 1: Check if Nginx is running correctly and serving
Let’s test the Nginx syntax and confirm it’s not silently failing due to config mount issues.
kubectl exec -it nginx-phpfpm -c nginx-container -- nginx -t
Then check its running processes:
kubectl exec -it nginx-phpfpm -c nginx-container -- ps aux | grep nginx
Paste both outputs here.
🔎 Step 2: Check Nginx logs for any PHP errors
Run:
kubectl logs nginx-phpfpm -c nginx-container --tail=50
and also:
kubectl exec -it nginx-phpfpm -c nginx-container -- cat /var/log/nginx/error.log || true
thor@jumphost ~$ kubectl exec -it nginx-phpfpm -c nginx-container -- nginx -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful
thor@jumphost ~$ kubectl exec -it nginx-phpfpm -c nginx-container -- ps aux | grep nginx
error: Internal error occurred: error executing command in container: failed to exec in container: failed to start exec "de73e24dc6e07b2ff532abbe8dd611494fe8853e80d1b4bace9beee1a23086c2": OCI runtime exec failed: exec failed: unable to start container process: exec: "ps": executable file not found in $PATH: unknown
thor@jumphost ~$ kubectl exec -it nginx-phpfpm -c nginx-container -- ps aux | grep nginx
error: Internal error occurred: error executing command in container: failed to exec in container: failed to start exec "39bc7e935ec1173df462fdca8c444faf4413da2b721c834790ec9fbd3a129283": OCI runtime exec failed: exec failed: unable to start container process: exec: "ps": executable file not found in $PATH: unknown
thor@jumphost ~$ kubectl exec -it nginx-phpfpm -c nginx-container -- cat /var/log/nginx/error.log || true
^Ccommand terminated with exit code 130
🔍 What we know so far
✅ Nginx config syntax is OK. (nginx -t passed)
❌ The ps command isn’t installed in the nginx:latest container — that’s expected (it’s a minimal image).
❌ You pressed Ctrl+C while reading /var/log/nginx/error.log — probably because it hung (the file might not exist yet, or Nginx is running fine but has no errors logged).
At this point, everything looks healthy — both containers are running, and config syntax is fine.
So, the most likely issue is simply that the index.php file is missing in the Nginx document root (/var/www/html).
✅ Let’s confirm document root existence
Please run:
kubectl exec -it nginx-phpfpm -c nginx-container -- ls -l /var/www/html
If it’s empty or missing index.php, then that’s our issue.
🧩 Next (after confirming empty directory):
You’ll need to copy /home/thor/index.php from the jump host into that directory inside the nginx-container.
Run this from the jump host:
kubectl cp /home/thor/index.php nginx-phpfpm:/var/www/html/index.php -c nginx-container
Then verify inside the pod:
kubectl exec -it nginx-phpfpm -c nginx-container -- ls -l /var/www/html
You should now see index.php listed.
🌐 Finally
Once the file is in place, try accessing the website using the “Website” button at the top bar (or use curl if you prefer):
curl http://<node_ip>:8099/
thor@jumphost ~$ kubectl get nodes -o wide
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
kodekloud-control-plane Ready control-plane 21m v1.27.16-1+f5da3b717fc217 172.17.0.2 <none> Ubuntu 23.10 5.4.0-1106-gcp containerd://1.7.1-2-g8f682ed69
thor@jumphost ~$ curl http://172.17.0.2:8099/
🔍 Diagnosis
✅ Nginx and PHP-FPM containers are both running fine.
✅ Nginx configuration syntax is OK.
⚠️ Website shows “File not found”, and curl gives no response — this indicates:
Nginx is serving requests correctly, but
It can’t find or execute /var/www/html/index.php.
This could happen because:
The file isn’t actually present inside the Nginx container (or is in the wrong directory).
The shared-files volume isn’t populated correctly — remember, /var/www/html in the Nginx container is a shared EmptyDir volume with /usr/share/nginx/html in PHP-FPM.
So, if you copied the file to Nginx’s /var/www/html, PHP-FPM may not see it.
Let’s confirm where the file actually is inside both containers.
🧩 Step 1: Check inside both containers
In Nginx container:
kubectl exec -it nginx-phpfpm -c nginx-container -- ls -l /var/www/html
In PHP-FPM container:
kubectl exec -it nginx-phpfpm -c php-fpm-container -- ls -l /usr/share/nginx/html
Paste both outputs here.
🧩 Step 2 (depending on the result)
If the file appears only in one of them, we’ll copy it again to the correct shared volume path so both containers can see it.
From your pod’s spec:
php-fpm-container:
Mounts:
/usr/share/nginx/html from shared-files
nginx-container:
Mounts:
/var/www/html from shared-files
So both containers share the same EmptyDir volume — but under different paths:
Nginx: /var/www/html
PHP-FPM: /usr/share/nginx/html
That’s fine as long as Nginx reads from /var/www/html (which it does).
But we need to confirm the file actually exists in that shared volume.
🧩 Step 3 (once we confirm where it’s missing)
If /var/www/html is empty, copy the file again like this:
kubectl cp /home/thor/index.php nginx-phpfpm:/var/www/html/index.php -c nginx-container
Then verify in both containers that it exists:
kubectl exec -it nginx-phpfpm -c nginx-container -- ls -l /var/www/html
kubectl exec -it nginx-phpfpm -c php-fpm-container -- ls -l /usr/share/nginx/html
Once you see the file in both, try:
curl http://172.17.0.2:8099/
Or click the Website button again.
thor@jumphost ~$ kubectl exec -it nginx-phpfpm -c nginx-container -- ls -l /var/www/html
total 4
-rw-r--r-- 1 root root 19 Oct 23 15:20 index.php
thor@jumphost ~$ kubectl exec -it nginx-phpfpm -c php-fpm-container -- ls -l /usr/share/nginx/html
total 4
-rw-r--r-- 1 root root 19 Oct 23 15:20 index.php
Perfect 👏 — that confirms the file exists in both containers, and the shared volume works fine.
Now the environment is in good shape, but since you still see “File not found”, this means:
Nginx is serving /var/www/html/index.php,
but when it tries to pass PHP requests to PHP-FPM, PHP-FPM can’t locate that script path because of a path mismatch between Nginx’s $document_root (/var/www/html) and PHP-FPM’s filesystem (/usr/share/nginx/html).
⚙️ Root Cause
The PHP-FPM container sees files under /usr/share/nginx/html,
but Nginx tells PHP-FPM:
SCRIPT_FILENAME = /var/www/html/index.php.
So PHP-FPM looks for /var/www/html/index.php inside its container,
but that path doesn’t exist there (it only has /usr/share/nginx/html/index.php).
That’s why PHP-FPM responds “File not found”.
✅ Fix: Update Nginx ConfigMap
We’ll correct the fastcgi_param SCRIPT_FILENAME line to point to the correct path as seen by PHP-FPM.
Run:
kubectl edit configmap nginx-config
Find this block:
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
and replace it with:
fastcgi_param SCRIPT_FILENAME /usr/share/nginx/html$fastcgi_script_name;
Then save and exit (:wq).
🔄 Step 2: Restart the Pod
The ConfigMap change won’t take effect automatically — restart the pod to reload the new config:
kubectl delete pod nginx-phpfpm
Save this as nginx-phpfpm.yaml:
apiVersion: v1
kind: Pod
metadata:
name: nginx-phpfpm
labels:
app: php-app
spec:
containers:
- name: php-fpm-container
image: php:7.2-fpm-alpine
volumeMounts:
- name: shared-files
mountPath: /usr/share/nginx/html
- name: nginx-container
image: nginx:latest
volumeMounts:
- name: nginx-config-volume
mountPath: /etc/nginx/nginx.conf
subPath: nginx.conf
- name: shared-files
mountPath: /var/www/html
volumes:
- name: nginx-config-volume
configMap:
name: nginx-config
- name: shared-files
emptyDir: {}
🚀 Apply the resources
Create the Pod:
kubectl apply -f nginx-phpfpm.yaml
Wait for it to reach Running (both containers ready).
kubectl get pods
🌐 Step 3: Test Access
Once the pod is back to Running, test again:
curl http://172.17.0.2:8099/
Or click the Website button at the top of the lab.
ou should now see the PHP page’s output (whatever is inside your /home/thor/index.php file).
📄 Copy your index.php back
Once it’s running:
kubectl cp /home/thor/index.php nginx-phpfpm:/var/www/html/index.php -c nginx-container
Verify inside pod:
kubectl exec -it nginx-phpfpm -c nginx-container -- ls -l /var/www/html
🌐 Test the site
curl http://172.17.0.2:8099/
Or use the Website button — you should now see your PHP output 🎉.
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