Access environment variables set by configMapRef in kubernetes pod - node.js

Question

I have a set of environment variables in my deployment using EnvFrom and configMapRef. The environment variables held in these configMaps were set by kustomize originally from json files.
spec.template.spec.containers[0].
envFrom:
- secretRef:
name: eventstore-login
- configMapRef:
name: environment
- configMapRef:
name: eventstore-connection
- configMapRef:
name: graylog-connection
- configMapRef:
name: keycloak
- configMapRef:
name: database
The issue is that it's not possible for me to access the specific environment variables directly.
Here is the result of running printenv in the pod:
...
eventstore-login={
"EVENT_STORE_LOGIN": "admin",
"EVENT_STORE_PASS": "changeit"
}
evironment={
"LOTUS_ENV":"dev",
"DEV_ENV":"dev"
}
eventstore={
"EVENT_STORE_HOST": "eventstore-cluster",
"EVENT_STORE_PORT": "1113"
}
graylog={
"GRAYLOG_HOST":"",
"GRAYLOG_SERVICE_PORT_GELF_TCP":""
}
...
This means that from my nodejs app I need to do something like this
> process.env.graylog
'{\n "GRAYLOG_HOST":"",\n "GRAYLOG_SERVICE_PORT_GELF_TCP":""\n}\n'
This only returns the json string that corresponds to my original json file. But I want to be able to do something like this:
process.env.GRAYLOG_HOST
To retrieve my environment variables. But I don't want to have to modify my deployment to look something like this:
env:
- name: NODE_ENV
value: dev
- name: EVENT_STORE_HOST
valueFrom:
secretKeyRef:
name: eventstore-secret
key: EVENT_STORE_HOST
- name: EVENT_STORE_PORT
valueFrom:
secretKeyRef:
name: eventstore-secret
key: EVENT_STORE_PORT
- name: KEYCLOAK_REALM_PUBLIC_KEY
valueFrom:
configMapKeyRef:
name: keycloak-local
key: KEYCLOAK_REALM_PUBLIC_KEY
Where every variable is explicitly declared. I could do this but this is more of a pain to maintain.

Answer 1

Short answer:
You will need to define variables explicitly or change configmaps so they have 1 environment variable = 1 value structure, this way you will be able to refer to them using envFrom. E.g.:
"apiVersion": "v1",
"data": {
"EVENT_STORE_LOGIN": "admin",
"EVENT_STORE_PASS": "changeit"
},
"kind": "ConfigMap",
More details
Configmaps are key-value pairs that means for one key there's only one value, configmaps can get string as data, but they can't work with map.
I tried edited manually the configmap to confirm the above and got following:
invalid type for io.k8s.api.core.v1.ConfigMap.data: got "map", expected "string"
This is the reason why environment comes up as one string instead of structure.
For example this is how configmap.json looks:
$ kubectl describe cm test2
Name: test2
Namespace: default
Labels: <none>
Annotations: <none>
Data
====
test.json:
----
environment={
"LOTUS_ENV":"dev",
"DEV_ENV":"dev"
}
And this is how it's stored in kubernetes:
$ kubectl get cm test2 -o json
{
"apiVersion": "v1",
"data": {
"test.json": "evironment={\n \"LOTUS_ENV\":\"dev\",\n \"DEV_ENV\":\"dev\"\n}\n"
},
In other words observed behaviour is expected.
Useful links:
ConfigMaps
Configure a Pod to Use a ConfigMap