Sending .Net Core application settings to kubernetes pods as environment variables

I believe you are referring to the env in the container definition for a Pod. From the YAML/JSON perspective, I don't see a problem with specifying a : in a key for an environment variable. You can also put it within quotes and should be valid JSON/YAML:

# convert.yamlapiVersion: v1kind: Podmetadata:  name: envar-demo  labels:    purpose: demonstrate-envarsspec:  containers:  - name: envar-demo-container    image: dotnetapp    env:    - name: ConnectionString:Mydb      value: ConnectionString

Same in JSON:

$ kubectl convert -f convert.yaml -o=json{    "kind": "Pod",    "apiVersion": "v1",    "metadata": {        "name": "envar-demo",        "creationTimestamp": null,        "labels": {            "purpose": "demonstrate-envars"        }    },    "spec": {        "containers": [            {                "name": "envar-demo-container",                "image": "dotnetapp",                "env": [                    {                        "name": "ConnectionString:Mydb",                        "value": "ConnectionString"                    }                ],                "resources": {},                "terminationMessagePath": "/dev/termination-log",                "terminationMessagePolicy": "File",                "imagePullPolicy": "Always"            }        ],        "restartPolicy": "Always",        "terminationGracePeriodSeconds": 30,        "dnsPolicy": "ClusterFirst",        "securityContext": {},        "schedulerName": "default-scheduler"    },    "status": {}}

However, looks like this was a known issue with Windows/.NET applications. An attempt to fix it has been tried and ditched due to the fact the this is not valid in Bash. But looks like they settled to use the __ instead of : workaround

Yes, example

In the Appsettings.json

 "ConnectionStrings": {    "Azure": "Server=tcp:uw2qdisa

In the manifest.yml

    env:    - name:  ConnectionStrings__Azure      valueFrom:        configMapKeyRef:          name: config-disa          key: ConnectionStrings

Explanation on Kubernetes

• Some .Net Core applications expect environment variables with a colon (:) in the name. Kubernetes currently does not allow this. Replace colon (:) with double underscore (__) as documented here.