I'm using this spec that contains one init container and two containers.
Init container creates a file on /etc/secrets/secrets.env that the first container has to source: source /etc/secrets/secrets.env.
I'm trying to do that using this spec:
spec:
containers:
- name: source-envs
image: ????
command: ["/bin/sh", "-c", "source /etc/secrets/secrets.env"]
volumes:
- name: sidekick-backend-volume
emptyDir: {}
I don't quite figure out how to do that.
Any ideas?
It should work by sharing a volume between the init container and the first container, mounted on /etc/secrets:
spec:
initContainers:
- name: create-envs
image: ????
command: ["/bin/sh", "-c", "touch /etc/secrets/secrets.env"]
volumeMounts:
- mountPath: /etc/secrets/
name: sidekick-backend-volume
containers:
- name: source-envs
image: ????
command: ["/bin/sh", "-c", "source /etc/secrets/secrets.env"]
volumeMounts:
- mountPath: /etc/secrets/
name: sidekick-backend-volume
volumes:
- name: sidekick-backend-volume
emptyDir: {}
Related
I want to display the pod IP address in an nginx pod. Currently I am using an init container to initialize the pod by writing to a volume.
apiVersion: v1
kind: Pod
metadata:
name: init-demo
spec:
containers:
- name: nginx
image: nginx
volumeMounts:
- name: workdir
mountPath: /usr/share/nginx/html
# These containers are run during pod initialization
initContainers:
- name: install
image: busybox:1.28
env:
- name: POD_IP
valueFrom:
fieldRef:
fieldPath: status.podIP
command:
- echo
- $(POD_IP) >> /work-dir/index.html
volumeMounts:
- name: workdir
mountPath: "/work-dir"
dnsPolicy: Default
volumes:
- name: workdir
emptyDir: {}
This should work in theory, but the file redirect doesn't work and the mounted file in the nginx container is blank. There's probably an easier way to do this, but I'm curious why this doesn't work.
Nothing is changed, except how command is passed in the init container. See this for an explanation.
apiVersion: v1
kind: Pod
metadata:
name: init-demo
spec:
containers:
- name: nginx
image: nginx
volumeMounts:
- name: workdir
mountPath: /usr/share/nginx/html
# These containers are run during pod initialization
initContainers:
- name: install
image: busybox:1.28
env:
- name: POD_IP
valueFrom:
fieldRef:
fieldPath: status.podIP
command:
- 'sh'
- '-c'
- 'echo $(POD_IP) > /work-dir/index.html'
volumeMounts:
- name: workdir
mountPath: "/work-dir"
dnsPolicy: Default
volumes:
- name: workdir
emptyDir: {}
We had build a docker image that contains an existing file inside. /opt/app/agent/oneagent. When I test the docker image individually, i can see the file inside the directory.
However, when I use it as an initcontainer to mount that directory to the main container, it does not see the directory.
apiVersion: v1
kind: Pod
metadata:
name: test
spec:
containers:
- name: nginx
image: nginx
ports:
- containerPort: 80
volumeMounts:
- name: workdir
mountPath: /data
# These containers are run during pod initialization
initContainers:
- name: dynainit
image: localhost:5000/dyna1
imagePullPolicy: IfNotPresent
command: ["/bin/sh"]
args: ["ls -la /opt/app/agent/oneagent"]
volumeMounts:
- name: workdir
mountPath: "/data"
dnsPolicy: Default
volumes:
- name: workdir
emptyDir: {}
the init container logs it shows
/bin/sh: can't open 'ls -la /opt/app/agent/oneagent': No such file or directory
What i really want to do is mount /opt/app/agent/oneagent from the init container to the main container.
Is that possible to mount existing files or init containers can only work by downloading the file in the beginning?
You can copy files from your init container /opt/app/agent/oneagent to workdir volume. When your main container mount workdir it will see the files copied. The error in your question is not volume related, just add -c to your command will do.
...
command: ["/bin/sh","-c"]
args: ["ls -la /opt/app/agent/oneagent"]
...
I got it working using "-c" inside the command key.
apiVersion: v1
kind: Pod
metadata:
name: test
spec:
initContainers:
- name: dynainit
image: localhost:5000/dyna1
imagePullPolicy: IfNotPresent
command: ["/bin/sh", "-c"]
args: ["cp -R /opt/app/agent /data"]
volumeMounts:
- name: workdir
mountPath: "/data"
dnsPolicy: Default
volumes:
- name: workdir
emptyDir: {}
containers:
- name: nginx
image: nginx
ports:
- containerPort: 80
volumeMounts:
- name: workdir
mountPath: /opt/app
I have created a deployment and I wanted to mount the host path to the container, and when I check the container I see only empty folder.
Why am I getting this error? What can be the cause?
EDIT: I am using Windows OS.
apiVersion: apps/v1
kind: Deployment
metadata:
name: myservicepod6
labels:
app: servicepod
spec:
replicas: 1
selector:
matchLabels:
app: servicepod
template:
metadata:
labels:
app: servicepod
spec:
containers:
- name: php
image: php:7.2-apache
command: ["/bin/sh", "-c"]
args: ["service apache2 start; sleep infinity"]
ports:
- name: serviceport
containerPort: 80
volumeMounts:
- mountPath: /var/www/html/
name: hostvolume
volumes:
- name: hostvolume
hostPath:
path: /C/Users/utkarsh/pentesting/learnings/kubernetes/app/objectmanagement/deployments/src/*
EDIT FOR THE ANSWER -
I start the minkube - minikube start --mount-string="$HOME/test/src/code/file:/data"
Then I changed the deployment file like below
Showing only volume part
spec:
volumes:
- name: hostvolume
hostPath:
path: /C/Users/utkarsh/pentesting/learnings/kubernetes/app/deployments/src
containers:
- name: php
image: php:7.2-apache
command: ["/bin/sh", "-c"]
args: ["service apache2 start; sleep infinity"]
ports:
- name: serviceport
containerPort: 80
volumeMounts:
- name: hostvolume
mountPath: /test/src/code/file
When I log into the pod and went to the directory (/test/src/code/file) I found the directory empty
let me know what am I missing?
After a detailed search and hit and trial method - Found the way
Only for minikube:-
First we need to mount the host folder into the directory name:
minikube mount src/:/var/www/html
Then we need to define hostPath and mountPath as
/var/www/html
Because now we have mount the folder to html folder.
volumes:
- name: hostvolume
hostPath:
path: /var/www/html
containers:
- name: php
image: php:7.2-apache
command: ["/bin/sh", "-c"]
args: ["service apache2 start; sleep infinity"]
workingDir: /var/www/html
ports:
- name: serviceport
containerPort: 80
volumeMounts:
- name: hostvolume
mountPath: /var/www/html
I'm testing out whether I can mount data from S3 using initContainer. What I intended and expected was same volume being mounted to both initContainer and Container. Data from S3 gets downloaded using InitContainer to mountPath called /s3-data, and as the Container is run after the initContainer, it can read from the path the volume was mounted to.
However, the Container doesn't show me any logs, and just says 'stream closed'. The initContainer shows logs that data were successfully downloaded from S3.
What am I doing wrong? Thanks in advance.
apiVersion: batch/v1
kind: Job
metadata:
name: train-job
spec:
template:
spec:
initContainers:
- name: data-download
image: <My AWS-CLI Image>
command: ["/bin/sh", "-c"]
args:
- aws s3 cp s3://<Kubeflow Bucket>/kubeflowdata.tar.gz /s3-data
volumeMounts:
- mountPath: /s3-data
name: s3-data
env:
- name: AWS_ACCESS_KEY_ID
valueFrom:
secretKeyRef: {key: AWS_ACCESS_KEY_ID, name: aws-secret}
- name: AWS_SECRET_ACCESS_KEY
valueFrom:
secretKeyRef: {key: AWS_SECRET_ACCESS_KEY, name: aws-secret}
containers:
- name: check-proper-data-mount
image: <My Image>
command: ["/bin/sh", "-c"]
args:
- cd /s3-data
- echo "Just s3-data dir"
- ls
- echo "After making a sample file"
- touch sample.txt
- ls
volumeMounts:
- mountPath: /s3-data
name: s3-data
volumes:
- name: s3-data
emptyDir: {}
restartPolicy: OnFailure
backoffLimit: 6
You can try like the below mentioned the argument part
---
apiVersion: v1
kind: Pod
metadata:
labels:
purpose: demonstrate-command
name: command-demo
spec:
containers:
-
args:
- cd /s3-data;
echo "Just s3-data dir";
ls;
echo "After making a sample file";
touch sample.txt;
ls;
command:
- /bin/sh
- -c
image: "<My Image>"
name: containername
for reference:
How to set multiple commands in one yaml file with Kubernetes?
I´m trying to retrieve some code from gitlab in my yaml.
Unfortunatly the job fails to initalize the pod. I have checked all the logs and it fails with the following message:
0 container "filter-human-genome-and-create-mapping-stats" in pod "create-git-container-5lhp2" is waiting to start: PodInitializing
Here is the yaml file:
apiVersion: batch/v1
kind: Job
metadata:
name: create-git-container
namespace: diag
spec:
template:
spec:
initContainers:
- name: bash-script-git-downloader
image: alpine/git
volumeMounts:
- mountPath: /bash_scripts
name: bash-script-source
command: ["/bin/sh","-c"]
args: ["git", "clone", "https://.......#gitlab.com/scripts.git" ]
containers:
- name: filter-human-genome-and-create-mapping-stats
image: myimage
env:
- name: OUTPUT
value: "/output"
command: ["ls"]
volumeMounts:
- mountPath: /bash_scripts
name: bash-script-source
- mountPath: /output
name: output
volumes:
- name: bash-script-source
emptyDir: {}
- name: output
persistentVolumeClaim:
claimName: output
restartPolicy: Never
If you use bash -c, it expects only one argument. So you have to pass your args[] as one argument. There are ways to do it:
command: ["/bin/sh","-c"]
args: ["git clone https://.......#gitlab.com/scripts.git"]
or
command: ["/bin/sh","-c", "git clone https://.......#gitlab.com/scripts.git"]
or
args: ["/bin/sh","-c", "git clone https://.......#gitlab.com/scripts.git"]
or
command:
- /bin/sh
- -c
- |
git clone https://.......#gitlab.com/scripts.git
or
args:
- /bin/sh
- -c
- |
git clone https://.......#gitlab.com/scripts.git