I have a configMap that stores a json file:
apiVersion: v1
data:
config.json: |
{{- toPrettyJson $.Values.serviceConfig | nindent 4 }}
kind: ConfigMap
metadata:
name: service-config
namespace: {{ .Release.Namespace }}
In my deployment.yaml, I use volume and envFrom
spec:
... ...
volumes:
- name: config-vol
configMap:
name: service-config
containers:
- name: {{ .Chart.Name }}
envFrom:
- configMapRef:
name: service-config
... ...
volumeMounts:
- mountPath: /src/config
name: config-vol
After I deployed the helm and run kubectl describe pods, I god this:
Environment Variables from:
service-config ConfigMap Optional: false
I wonder how can I get/use this service-config in my code? My values.yaml can extract the value under env but I don't know how to extract the value of configMap. Is there a way I can move this service-config or the json file stored in it as the variable of env in values.yaml? Thank you in advance!
Related
I have a list of docker images which I want to pass as an environment variable to deployment.yaml
values.yaml
contributions_list:
- image: flogo-aws
tag: 36
- image: flogo-awsec2
tag: 37
- image: flogo-awskinesis
tag: 18
- image: flogo-chargify
tag: 19
deployment.yaml
apiVersion: batch/v1
kind: Job
metadata:
name: container-image-extractor
namespace: local-tibco-tci
labels:
app.cloud.tibco.com/name: container-image-extractor
spec:
backoffLimit: 0
template:
metadata:
labels:
app.cloud.tibco.com/name: container-image-extractor
spec:
nodeSelector:
kubernetes.io/os: linux
restartPolicy: Never
containers:
- name: container-image-extractor
image: reldocker.tibco.com/stratosphere/container-image-extractor
imagePullPolicy: IfNotPresent
env:
- name: SOURCE_DOCKER_IMAGE
value: "<docker_image>:<docker_tag>" # docker image from which contents to be copied
My questions are as follows.
Is this the correct way to pass an array of docker image and tags as an argument to deployment.yaml
How would I replace <docker_image> and <docker_tag> in deployment.yaml from values.yaml and incrementally job should be triggered for each docker image and tag.
This is how I would do it, creating a job for every image in your list
{{- range .Values.contributions_list }}
apiVersion: batch/v1
kind: Job
metadata:
name: "container-image-extractor-{{ .image }}-{{ .tag }}"
namespace: local-tibco-tci
labels:
app.cloud.tibco.com/name: container-image-extractor
spec:
backoffLimit: 0
template:
metadata:
labels:
app.cloud.tibco.com/name: container-image-extractor
spec:
nodeSelector:
kubernetes.io/os: linux
restartPolicy: Never
containers:
- name: container-image-extractor
image: reldocker.tibco.com/stratosphere/container-image-extractor
imagePullPolicy: IfNotPresent
env:
- name: SOURCE_DOCKER_IMAGE
value: "{{ .image }}:{{ .tag }}" # docker image from which contents to be copied
{{ end }}
If you use a value outside of this contribution list (release name, env, whatever), do not forget to change the scope such {{ $.Values.myjob.limits.cpu | quote }}. The $. is important :)
Edit: If you don't change the name at each iteration of the loop, it will override the configuration every time. With different names, you will have multiple jobs created.
You need to fix a deployment.yaml as below:
{{- range $contribution := .Values.contributions_list }}
apiVersion: batch/v1
kind: Job
metadata:
name: container-image-extractor
namespace: local-tibco-tci
labels:
app.cloud.tibco.com/name: container-image-extractor
spec:
backoffLimit: 0
template:
metadata:
labels:
app.cloud.tibco.com/name: container-image-extractor
spec:
nodeSelector:
kubernetes.io/os: linux
restartPolicy: Never
containers:
- name: container-image-extractor
image: reldocker.tibco.com/stratosphere/container-image-extractor
imagePullPolicy: IfNotPresent
env:
- name: SOURCE_DOCKER_IMAGE
value: "{{ $contribution.image }}:{{ $contribution.tag }}"
{{- end }}
If you want to know helm template syntax, you can see this document
In my deployment, I would like to use a Persistent Volume Claim in combination with a config map mount. For example, I'd like the following:
volumeMounts:
- name: py-js-storage
mountPath: /home/python
- name: my-config
mountPath: /home/python/my-config.properties
subPath: my-config.properties
readOnly: true
...
volumes:
- name: py-storage
{{- if .Values.py.persistence.enabled }}
persistentVolumeClaim:
claimName: python-storage
{{- else }}
emptyDir: {}
{{- end }}
Is this a possible and viable way to go? Is there any better way to approach such situation?
Since you didn't give your use case, my answer will be based on if it is possible or not. In fact: Yes, it is.
I'm supposing you wish mount file from a configMap in a mount point that already contains other files, and your approach to use subPath is correct!
When you need to mount different volumes on the same path, you need specify subPath or the content of the original dir will be hidden.
In other words, if you want to keep both files (from the mount point and from configMap) you must use subPath.
To illustrate this, I've tested with the deployment code below. There I mount the hostPath /mnt that contains a file called filesystem-file.txt in my pod and the file /mnt/configmap-file.txt from my configmap test-pd-plus-cfgmap:
Note: I'm using Kubernetes 1.18.1
Configmap:
apiVersion: v1
kind: ConfigMap
metadata:
name: test-pd-plus-cfgmap
data:
file-from-cfgmap: file data
Deployment:
apiVersion: apps/v1
kind: Deployment
metadata:
name: test-pv
spec:
replicas: 3
selector:
matchLabels:
app: test-pv
template:
metadata:
labels:
app: test-pv
spec:
containers:
- image: nginx
name: nginx
volumeMounts:
- mountPath: /mnt
name: task-pv-storage
- mountPath: /mnt/configmap-file.txt
subPath: configmap-file.txt
name: task-cm-file
volumes:
- name: task-pv-storage
persistentVolumeClaim:
claimName: task-pv-claim
- name: task-cm-file
configMap:
name: test-pd-plus-cfgmap
As a result of the deployment, you can see the follow content in /mnt of the pod:
$ kubectl exec test-pv-5bcb54bd46-q2xwm -- ls /mnt
configmap-file.txt
filesystem-file.txt
You could check this github issue with the same discussion.
Here you could read a little more about volumes subPath.
You can go with the following approach.
In your deployment.yaml template file you can configure:
...
{{- if .Values.volumeMounts }}
volumeMounts:
{{- range .Values.volumeMounts }}
- name: {{ .name }}
mountPath: {{ .mountPath }}
{{- end }}
{{- end }}
...
{{- if .Values.volumeMounts }}
volumes:
{{- range .Values.volumeMounts }}
- name: {{ .name }}
{{ toYaml .volumeSource | indent 8 }}
{{- end }}
{{- end }}
And your values.yaml file you can define any volume sources:
volumeMounts:
- name: volume-mount-1
mountPath: /var/data
volumeSource:
persistentVolumeClaim:
claimName: pvc-name
- name: volume-mount-2
mountPath: /var/config
volumeSource:
configMap:
name: config-map-name
In this way, you don't have to worry about the source of the volume. You can add any kind of sources in your values.yaml file and you don't have to update the deployment.yaml template.
Hope this helps!
so for example i have
database:
name: x-a2d9f4
replicaCount: 1
repository: mysql
tag: 5.7
pullPolicy: IfNotPresent
tier: database
app:
name: x-576a77
replicaCount: 1
repository: wordpress
tag: 5.2-php7.3
pullPolicy: IfNotPresent
tier: frontend
global:
namespace: x-c0ecdb9f
env:
name: WORDPRESS_DB_HOST
value:
and I want to do something like this
env:
name: WORDPRESS_DB_HOST
value: {{ .Values.database.name | lower }}
All these are examples from the same values.yaml
is this possible in Helm?
Yes, you can achieve this using the 'tpl' function
The tpl function allows developers to evaluate strings as templates inside a template. This is useful to pass a template string as a value to a chart or render external configuration files. Syntax: {{ tpl TEMPLATE_STRING VALUES }}
values.yaml
database:
name: x-a2d9f4
env:
name: WORDPRESS_DB_HOST
value: "{{ .Values.database.name | upper }}"
configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
name: {{ .Release.Name }}-configmap
data:
some: {{ tpl .Values.env.value . }}
output:
> helm template .
# Source: mychart/templates/configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
name: release-name-configmap
data:
some: X-A2D9F4
I'm using a kubernetes ConfigMap that contains database configurations for an app and there is a secret that has the database password.
I need to use this secret in the ConfigMap so when I try to add environment variable in the ConfigMap and specify the value in the pod deployment from the secret I'm not able to connect to mysql with password as the values in the ConfigMap took the exact string of the variable.
apiVersion: v1
kind: ConfigMap
metadata:
name: config
data:
APP_CONFIG: |
port: 8080
databases:
default:
connector: mysql
host: "mysql"
port: "3306"
user: "root"
password: "$DB_PASSWORD"
and the deployment.yaml
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: app
labels:
app: backend
spec:
replicas: 1
template:
metadata:
labels:
app: backend
spec:
containers:
- name: app
image: simple-app-image
ports:
- name: "8080"
containerPort: 8080
env:
- name: APP_CONFIG
valueFrom:
configMapKeyRef:
name: config
key: APP_CONFIG
- name: DB_PASSWORD
valueFrom:
secretKeyRef:
name: "mysql-secret"
key: "mysql-root-password"
Note: the secret exist and I'm able to get "mysql-root-password" value and use to login to the database
Kubernetes can't make that substitution for you, you should do it with shell in the entrypoint of the container.
This is a working example. I modify the default entrypoint to create a new variable with that substitution. After this command you should add the desired entrypoint.
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: app
labels:
app: backend
spec:
replicas: 1
template:
metadata:
labels:
app: backend
spec:
containers:
- name: app
image: simple-app-image
command:
- /bin/bash
- -c
args:
- "NEW_APP_CONFIG=$(echo $APP_CONFIG | envsubst) && echo $NEW_APP_CONFIG && <INSERT IMAGE ENTRYPOINT HERE>"
ports:
- name: "app"
containerPort: 8080
env:
- name: APP_CONFIG
valueFrom:
configMapKeyRef:
name: config
key: APP_CONFIG
- name: DB_PASSWORD
valueFrom:
secretKeyRef:
name: "mysql-secret"
key: "mysql-root-password"
You could do something like this in HELM:
{{- define "getValueFromSecret" }}
{{- $len := (default 16 .Length) | int -}}
{{- $obj := (lookup "v1" "Secret" .Namespace .Name).data -}}
{{- if $obj }}
{{- index $obj .Key | b64dec -}}
{{- else -}}
{{- randAlphaNum $len -}}
{{- end -}}
{{- end }}
Then you could do something like this in configmap:
{{- include "getValueFromSecret" (dict "Namespace" .Release.Namespace "Name" "<secret_name>" "Length" 10 "Key" "<key>") -}}
The secret should be already present while deploying; or you can control the order of deployment using https://github.com/vmware-tanzu/carvel-kapp-controller
I would transform the whole configMap into a secret and deploy the database password directly in there.
Then you can mount the secret as a file to a volume and use it like a regular config file in the container.
I have created a kubernetes configmap which contains multiple key value pairs. I want to mount each value in a different path. Im using helm to create charts.
apiVersion: v1
kind: ConfigMap
metadata:
name: {{ .Values.name }}-configmap
namespace: {{ .Values.namespace }}
labels:
name: {{ .Values.name }}-configmap
data:
test1.yml: |-
{{ .Files.Get .Values.test1_filename }}
test2.yml: |-
{{ .Files.Get .Values.test2_filename }}
I want test1.yml and test2.yml to be mounted in different directories.How can i do it?
You can use subPath field to pickup specific file from configMap:
volumeMounts:
- mountPath: /my/first/path/test.yaml
name: configmap
subPath: test1.yaml
- mountPath: /my/second/path/test.yaml
name: configmap
subPath: test2.yaml