I want to apt-get install sysstat command in kubernetes yaml file - kubernetes

Question

Cluster information:
Kubernetes version: 1.8
Cloud being used: (put bare-metal if not on a public cloud) AWS EKS
Host OS: debian linux
When I deploy pods,I want to my pod to install and start sysstat automatically
this is my two yaml flies below but it doesn’t work CrashLoopBackoff when I put the command: ["/bin/sh", “-c”]、args: [“apt-get install sysstat”]」 below 「image:」
cat deploy/db/statefulset.yaml
apiVersion: apps/v1
kind: StatefulSet
metadata:
name:
sbdemo-postgres-sfs
spec:
serviceName: sbdemo-postgres-service
replicas: 1
selector:
matchLabels:
app: sbdemo-postgres-sfs
template:
metadata:
labels:
app: sbdemo-postgres-sfs
spec:
containers:
- name: postgres
image: dayan888/springdemo:postgres9.6
ports:
- containerPort: 5432
**command: ["/bin/bash", "-c"]**
**args: ["apt-get install sysstat"]**
volumeMounts:
- name: pvc-db-volume
mountPath: /var/lib/postgresql
volumeClaimTemplates:
- metadata:
name: pvc-db-volume
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1G
cat deploy/web/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: sbdemo-nginx
spec:
replicas: 3
selector:
matchLabels:
app: sbdemo-nginx
template:
metadata:
labels:
app: sbdemo-nginx
spec:
containers:
- name: nginx
image: gobawoo21/springdemo:nginx
**command: ["/bin/bash", "-c"]**
**args: ["apt-get install sysstat"]**
ports:
- containerPort: 80
volumeMounts:
- name: nginx-conf
mountPath: /etc/nginx/nginx.conf
subPath: nginx.conf
- name: server-conf
mountPath: /etc/nginx/conf.d/server.conf
subPath: server.conf
volumes:
- name: nginx-conf
configMap:
name: nginx-conf
items:
- key: nginx.conf
path: nginx.conf
- name: server-conf
configMap:
name: server-conf
items:
- key: server.conf
path: server.conf
Does anyone know about how to set the repository automatically when deploy pods?
Regards

Answer 1

The best practice is to install packages at image build stage. You can simply add this step to your Dockerfile.
FROM postgres:9.6
RUN apt-get update &&\
apt-get install sysstat -y &&\
rm -rf /var/lib/apt/lists/*
COPY deploy/db/init_ddl.sh /docker-entrypoint-initdb.d/
RUN chmod +x /docker-entrypoint-initdb.d/init_ddl.sh
Kube Manifest
spec:
containers:
- name: postgres
image: harik8/sof:62298191
imagePullPolicy: Always
ports:
- containerPort: 5432
env:
- name: POSTGRES_PASSWORD
value: password
volumeMounts:
- name: pvc-db-volume
mountPath: /var/lib/postgresql
It should run (Please ignore POSTGRES_PASSWORD env variable)
$ kubectl get po
NAME READY STATUS RESTARTS AGE
sbdemo-postgres-sfs-0 1/1 Running 0 8m46s
Validation
$ kubectl exec -it sbdemo-postgres-sfs-0 bash
root#sbdemo-postgres-sfs-0:/# iostat
Linux 4.19.107 (sbdemo-postgres-sfs-0) 06/10/2020 _x86_64_ (4 CPU)
avg-cpu: %user %nice %system %iowait %steal %idle
10.38 0.01 6.28 0.24 0.00 83.09
Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn
vda 115.53 1144.72 1320.48 1837135 2119208
scd0 0.02 0.65 0.00 1048 0

Answer 2

If this is possible, something is wrong. Your container should not be running as root and so even if you fixed this approach, it shouldn’t work. What you need to do is put this in your container build instead (I.e. in the Dockerfile).