PostStarthook exited with 126 - shell

Question

I need to copy some configuration files already present in a location B to a location A where I have mounted a persistent volume, in the same container.
for that I tried to configure a post start hook as follows
lifecycle:
postStart:
exec:
command:
- "sh"
- "-c"
- >
if [! -d "/opt/A/data" ] ; then
cp -rp /opt/B/. /opt/A;
fi;
rm -rf /opt/B
but it exited with 126
Any tips please

Answer 1

You should give a space after the first bracket [. The following Deployment works:
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx
labels:
app: nginx
spec:
replicas: 1
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx
ports:
- containerPort: 80
lifecycle:
postStart:
exec:
command:
- "sh"
- "-c"
- >
if [ ! -d "/suren" ] ; then
cp -rp /docker-entrypoint.sh /home/;
fi;
rm -rf /docker-entrypoint.sh
So, this nginx container starts with a docker-entrypoint.sh script by default. After the container has started, is won't find the directory suren, that will give true to the if statement, it will copy the script into /home directory and remove the script from the root.
# kubectl exec nginx-8d7cc6747-5nvwk 2> /dev/null -- ls /home/
docker-entrypoint.sh

Answer 2

Here is the yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: oracledb
labels:
app: oracledb
spec:
selector:
matchLabels:
app: oracledb
strategy:
type: Recreate
template:
metadata:
labels:
app: oracledb
spec:
containers:
- env:
- name: DB_SID
value: ORCLCDB
- name: DB_PDB
value: pdb
- name: DB_PASSWD
value: pwd
image: oracledb
imagePullPolicy: IfNotPresent
name: oracledb
lifecycle:
postStart:
exec:
command:
- "sh"
- "-c"
- >
if [ ! -d "/opt/oracle/oradata/ORCLCDB" ] ; then
cp -rp /opt/oracle/files/* /opt/oracle/oradata;
fi;
rm -rf /opt/oracle/files/
volumeMounts:
- mountPath: /opt/oracle/oradata
name: oradata
securityContext:
fsGroup: 54321
terminationGracePeriodSeconds: 30
volumes:
- name: oradata
persistentVolumeClaim:
claimName: oradata