I have an Azure SQL Database with a private end point setup and my Azure function can connect to it in one environment. Public Access is set to Deny for the SQL instance.
I have another function in another vnet that doesn't connect to the SQL instance. The function is on a vnet with Route All enabled. How can I diagnose this?
I have tried using the Console using the following commands:
tcpping FQDN:1433
^ the above works and says it can connect.
nameresolver FQDN
^ the above resolves to a public IP address.
SET WEBSITE_DNS_
^ returns 168.63.129.16
This issue was due to missing DNS entries in the second environments vnet DNS Server section.
Related
We have created the Vnet with virtual network gateway for point to site VPN, PostgresDB, Azure function APP.
We are able to establish connections with a point-to-site VPN.
Configuration:
Resources configuration in Azure functions:- Private endpoint and
vnet integration.
Resources configuration in PostgresDB:- Private endpoint and in
connection security set Deny public network access to "Yes"
If in PostgresDB we configured Deny public network to "No" then azure function communicating to Postgres DB and works find.
Issue :
when we are trying to access Azure DB from Private function with hostname its failed to establish the connection but it works if we replace Azure DB hostname with private IP.
Same with VPN connection when we try to connect Postgress DB with server name it doesn't work but works with private endpoint IP.
Error:-
Result: Failure Exception: OperationalError: FATAL: The public network access on this server is disabled. To connect to this server, use the Private Endpoint from inside your virtual network.
we need a solution to create a connection between the azure function to private Postgres DB.
In order to solve the above issue, please check the below points.
Enable private endpoint at Azure Function & DB
If you are denying the public network access to 'Yes' then you need to make allow Azure Service to 'Yes' and add Vnet Rule with function subnet.
Go to the private DNS zones and check vnet(Vnet in which DB & Function created) are added into the private DNS zone.
I have an Azure logical SQL server to which I added a Private Link, the NIC is attached to an existing vnet\subnet. Our company's VPN is linked to that vnet and I can see other devices on the private link's subnet but not the SQL Server.
The SQL Server is reachable on the public URL (temporarily for testing) but trying to ping or tracert the server with the private IP fails, I can ping and tracert to other VMs on the same subnet.
I'm not using a custom DNS zone because it's imperative that we configure it with the IP and I haven't made any changes to our company DNS (I'm expecting not to have to).
Other than creating the private link and attaching it to the SQL Server, what else needs to be done? What am I missing?
I'am working on the same Issue. It's still not solved yet but there are some steps you need to do.
For the Connectivity it's required to add a DNS, especially if you want to connect from the On-Prem. Azure has a default DNS-Solution for Azure-Resources. The Problem is: From On-Prem you can't access the default Azure-DNS-Service.
So you have to configure a DNS-Zone (in Azure or On-Prem).
I try to connect a application who is in a subnet sub_A to a postgresql database that have a private endpoint in the subnet sub_B and still fail to do it.
I do a lot of try and i am able to connect in the database from a VM in sub_B so i expect that the issue comes from sub_A but here is ma configuration i configure on the database server the vmnet rules for sub_A and sub_B.
I configure the both subnet with the service endpoints "Microsoft.Sql"
and when i try to connect in the database throught the private endpoint i still get the error
error: FATAL: Client from Azure Virtual Networks is not allowed to access the server using Private IP. Please make sure your Virtual Network is correctly configured.
can you help me and tell me what i missed?
In this case, make sure the DNS record is set correctly.
If you have an application hosting on the app services, you could enable VNet Integration and you need to add the following app settings to work with Azure DNS Private Zones.
WEBSITE_DNS_SERVER with value 168.63.129.16
WEBSITE_VNET_ROUTE_ALL with value 1
If you have an application hosting on Azure VM or VMs, you could compare the DNS records of VMs in subnet A with subnet B. From subnet A, you need to make sure you can resolve to the private IP address from PostgreSQL database FQDN. Between Subnet A and Subnet B should not be network blocked.
For example, From SubnetA, verify that the private link points to the PostgreSQL resource and the necessary resolution is happening.
C:\Users\azureadmin>nslookup demoprivatelinkserver.postgres.database.azure.com.
Server: UnKnown
Address: 168.63.129.16
Non-authoritative answer:
Name: demoprivatelinkserver.postgres.database.azure.com
Address: 10.1.3.4
For more information, you could read this blog or let me know if you need further help.
I'm trying to set up elastic jobs to run a procedure on another database.
I set up code to run as below:
EXEC jobs.sp_add_target_group 'DatabaseGroup'
GO
EXEC jobs.sp_add_target_group_member
'DatabaseGroup',
#target_type = N'SqlDatabase',
#server_name='test-db01.database.windows.net',
#database_name =N'TEST'
GO
EXEC jobs.sp_add_job #job_name='Hourly Update', #description='Runs Hourly Update',
#schedule_interval_type='Hours',#schedule_interval_count=1
EXEC jobs.sp_add_jobstep #job_name='Hourly Update',
#command=N'exec [TT].[HOURLY_UPDATE]',
#credential_name='JobRun',
#target_group_name='DatabaseGroup'
EXEC jobs.sp_start_job 'Hourly Update'
So when i submit my job to run
I got the following error:
Failed to connect to the target database: Reason: An instance-specific error occurred while establishing a connection to SQL Server. Connection was denied since Deny Public Network Access is set to Yes
To connect to this server, use the Private Endpoint from inside your virtual network
(Msg 47073, Level 14, State 1, Line 65536)
So my private end point name is called db01.test.****.com <- confidential name used
So I recreate the group_member & resubmit job again
EXEC jobs.sp_add_target_group_member
'DatabaseGroup',
#target_type = N'SqlDatabase',
#server_name='db01.test.****.com',
#database_name =N'TEST'
GO
The new error below is:
The server 'db01.test.****.com' cannot be used as a job target because it is not an Azure SQL Database server in the same Azure cloud as this job agent.
The server's fully qualified host name must end with '.database.windows.net'.
So any ideas how i can get around this scenario & get my job to submit
Your private endpoint should still be registered in Azure DNS using the 'database.windows.net' domain suffix. If you've created your own internal A records on your own managed DNS servers this would be the expected behavior.
A quick workaround on this is to put modify your HOSTS file on your source system using the Private Endpoint IP and the FQDN and it should work. Managing HOSTS files is not something you want to do for any period of time.
If you're running this all from within Azure, you should be able to leverage Azure DNS. - - Create a zone called 'privatelink.database.windows.net'
Create an A record with your Db01 & Private IP Address in this zone
On your VNET - check to see if your using Azure DNS or Custom DNS.
If Custom DNS - you will need to setup your DNS servers to do DNS forwarding and send requests for 'privatelink.windows.net' to Azure DNS. Only IPs that are registered with Azure will be authorized to query Azure DNS. If you're using Azure DNS it will start working.
If it doesn't resolve for you right away then you will have to check to see if the Private DNS Zone has a virtual network link that connects your VNETs.
Azure Private DNS
https://learn.microsoft.com/en-us/azure/private-link/private-endpoint-dns
Private DNS Documentation:
https://learn.microsoft.com/en-us/azure/dns/private-dns-privatednszone
DNS Links Documentation:
https://learn.microsoft.com/en-us/azure/dns/private-dns-virtual-network-links#resolution-virtual-network
Unfortunately Private Endpoints are not supported with Elastic Jobs. You must enable "Allow Azure Services and resources to access this server" for Elastic Jobs to work.
I've created a SQL Server and then created a private link with my TESTVNET/SUBNET1 with private IP 10.1.1.4. I've now disabled Public access for the SQL server.
I have an Azure function running on App Service which I've VNET Integrated with VNET/SUBNET2.
Subnet 2 shows it's delegated to server farms. (also if someone can explain what does delegate to means, I found I cannot create any VM in that subnet as well, probably it's just can't be useful for any other purpose)
Now when my azure function tries to connect to DB. it fails with below error:
2020-08-30T15:25:45.216 [Error] Unhandled rejection SequelizeAccessDeniedError: Cannot open server "10.1.1.4" requested by the login. The login failed.
However, if I give the public FQDN it gives me below error.
2020-08-30T15:29:43.654 [Error] Unhandled rejection SequelizeAccessDeniedError: Reason: An instance-specific error occurred while establishing a connection to SQL Server. The public network interface on this server is not accessible. To connect to this server, use the Private Endpoint from inside your virtual network.
Here the Private DNS created by Private endpoint should have been ideally used to get the private IP of the SQL database, but it seems the function is not using the private DNS probably because not running in an isolated environment.
Now in my Azure function Application settings, I've added WEBSITE_VNET_ROUTE_ALL =1 which should mean that all the requests should be routed to VNET. So now If I enable public access internet, and allow Azure services to access DB (I think azure added the public IP by default). The function gets connected to the DB.
Now I want to understand where I'm going wrong and why is the private endpoint connection not working. Any help is appreciated.
In the DB firewall settings, I've allowed traffic from below to subnets:
Network Configuration
TESTVNET: 10.1.0.0/16
SUBNET 1: 10.1.1.0/24
SUBNET 2: 10.1.2.0/24
I've disabled Service endpoint for SQL in both SUBNET 1 and SUBNET 2. My NSG has default settings i.e.
AllowVnetInBound, AllowAzureLoadBalancerInBound, DenyAllInBound
AllowVnetOutBound, AllowInternetOutBound, DenyAllOutBound.
Since my private link has a private IP present in the same VNET I don't think NSG should have any impact.
New to Azure, testing things out. Thank you for your patience.
To make Azure Function connect to a private endpoint you will need to use VNET integration.
After your app integrates with your VNet, it uses the same DNS server that your VNet is configured with. By default, your app won't work with Azure DNS Private Zones. To work with Azure DNS Private Zones you need to add the following app settings:
WEBSITE_DNS_SERVER with value 168.63.129.16
WEBSITE_VNET_ROUTE_ALL with value 1
These settings will send all of your outbound calls from your app into your VNet in addition to enabling your app to use Azure DNS private zones. Reference here.
Then you could set up Private Link for Azure SQL Database. You can create an Azure VM from a new subnet in the same VNet to check connectivity using SQL Server Management Studio (SSMS). If you enable the private endpoint, you should get a client private IP from that Azure VM to connect the Azure SQL database with its FQDN.
For more information, you could read private endpoint VS service endpoint in this blog.