Using ExternalName with Azure SQL DB connectionstring Kubernetes - sql-server

Question

Recently, I have been facing lots of issues with Environmental Variables, More details in this topic here
I have 3 different kubernetes clusters with different SQL hosted on Azure SQL. I want to deploy from one repo into all 3 clusters
Since i could not overwrite values using environmental variables i resulted in using Kubernetes ExternalName and Service Endpoint. However this does not seem to work for Azure SQL DB. Below are the codes working for me
kind: "Service"
apiVersion: "v1"
metadata:
name: "mssql"
namespace: dev
spec:
ports:
-
name: "mssql"
protocol: "TCP"
port: 1433
targetPort: 1433
nodePort: 0
---
kind: "Endpoints"
apiVersion: "v1"
metadata:
name: "mssql"
namespace: dev
subsets:
-
addresses:
-
ip: "192.168.24.10"
ports:
-
port: 1433
name: "mssql"
Here is my connectionstring
{
"ConnectionStrings": {
"DefaultConnection": "Server= mssql; database=TransactionLogs;Persist Security Info=False;user id=sa;password=exTened;MultipleActiveResultSets=True;Encrypt=True;TrustServerCertificate=True;Connection Timeout=30;"
},
"Logging": {
"LogLevel": {
"Default": "Information",
"Microsoft.AspNetCore": "Warning"
}
},
"AllowedHosts": "*",
"TransferPay": "input value",
"TransferPayConn": "input value"
}
I'm able to reach my local hosted databse like this. However since Azure SQL use DNS instead so i resulted in using ExternalName, See code below
apiVersion: v1
kind: Service
metadata:
name: mssqlnew
namespace: app-prod
spec:
externalName: dbinstance.database.windows.net
ports:
- port: 1433
protocol: TCP
targetPort: 1433
sessionAffinity: None
type: ExternalName
I ran nslookup from the DNS util Pod and got this response
root#dnsutils:/# nslookup mssql
Server: 10.0.0.10
Address: 10.0.0.10#53
mssql.a-prod.svc.cluster.local canonical name = dbinstance.database.windows.net.
dbinstance.database.windows.net canonical name = dbinstance.privatelink.database.windows.net.
dbinstance.privatelink.database.windows.net canonical name = dataslice6.eastus.database.windows.net.
dataslice6.eastus.database.windows.net canonical name = dataslice6eastus.trafficmanager.net.
dataslice6eastus.trafficmanager.net canonical name = cr3.eastus1-a.control.database.windows.net.
Name: cr3.eastus1-a.control.database.windows.net
Address: 40.79.153.12
However when i spin up my application i get this error
Cannot open server "mssql" requested by the login. The login failed.
Another Failed Attempt
I tried using Secrets for this also
apiVersion: v1
kind: Secret
metadata:
name: sql-db
namespace: a-prod
data:
server: **
username: **
password: **
database: **
type: Opaque
Deployment.Yaml
env:
- name: Logging__LogLevel__Default
value: Debug
- name: Logging__LogLevel__Microsoft.AspNetCore
value: Debug
- name: username
valueFrom:
secretKeyRef:
name: sql-db
key: username
- name: server
valueFrom:
secretKeyRef:
name: sql-db
key: server
- name: password
valueFrom:
secretKeyRef:
name: sql-db
key: password
- name: database
valueFrom:
secretKeyRef:
name: sql-db
key: database
connection string (appsetting.json)
{
"ConnectionStrings": {
"DefaultConnection": "Server= $server; database=$database;Persist Security Info=False;user id=$username;password=$password;MultipleActiveResultSets=True;Encrypt=True;TrustServerCertificate=True;Connection Timeout=30;"
},
"Logging": {
"LogLevel": {
"Default": "Information",
"Microsoft.AspNetCore": "Warning"
}
},
"AllowedHosts": "*",
"TransferPay": "input value",
"TransferPayConn": "input value"
}
After doing all these, connection to azure db is not active
PS: I need not write the application. However i can share info with the Developer, This was Built on .Net 6
After reading this article https://thewindowsupdate.com/2020/03/09/how-to-use-different-domain-name-to-connect-to-azure-sql-server/ i found out that i need to pass servername into connection string as
Server= mssql; database=TransactionLogs;Persist Security Info=False;user id=servername#sa(username);password=exTened;MultipleActiveResultSets=True;Encrypt=True;TrustServerCertificate=True;Connection Timeout=30;"
This works, However i still don't know how to replace this for the multiple Database.