Docker in WSL - Can't connect to SQL server on 'localhost' but with '127.0.0.1' SQL Server 2017-latest

Question

Docker in WSL - Can't connect to SQL server on 'localhost' but with '127.0.0.1' SQL Server 2017-latest

Anonymous

Trying to spin up an mssql server with a docker-compose file:

version: "3.7"
services:
  sqlserver:
    image: mcr.microsoft.com/mssql/server:2017-latest
    container_name: sqlserver
    user: root
    ports:
      - "1433:1433"
    environment:
      SA_USERNAME: sa
      SA_PASSWORD: Dev1234!
      ACCEPT_EULA: Y
      MSSQL_AGENT_ENABLED: 'true'
    volumes:
      - ./volumes/data2:/var/opt/mssql/data
      - ./volumes/backup:/var/opt/mssql/Backup

The server is up and running successfully, But when tried to connect with PowerShell script code:

$connectionString = "Data Source=localhost,1433;User ID=sa;Password=Dev1234!;"
$connection = New-Object System.Data.SqlClient.SqlConnection($connectionString)
$connection.Open();

It throws error like:

"A network-related or instance-specific error occurred while
establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name
is correct and that SQL Server is configured to allow remote connections. (provider: TCP Provider, error: 0 - The
remote computer refused the network connection.)"

That is, it fails when trying to connect with 'localhost' as host, it is successfully connecting when "127.0.0.1" is specified as host.

The same happens when I tried to connect with SQL server management studio.

enter image description here

I could able to connect with 'localhost' to db with udl file also:

User's image

My docker engine is running in wsl, an ubuntu distro specifically. There is MySQL and different other servers already spun up which I can access with localhost.

Is there anything I need to specify in docker-compose to make this work? When checking documentation, there are no params aligned to it as I see.

Seeya Xi-MSFT 16,586 Reputation points

2023-02-17T05:46:31.3633333+00:00

Hi @Vishnu Prasad-FT ,

We have not received a response from you. Did the reply could help you? If the response helped, do "Accept Answer". If it doesn't work, please let us know the progress. By doing so, it will benefit all community members who are having this similar issue. Your contribution is highly appreciated.

Best regards,

Seeya
Seeya Xi-MSFT 16,586 Reputation points

2023-02-20T09:15:19.19+00:00

Hi @Vishnu Prasad-FT ,

In order to benefit all community members who are having this similar issue, please choose an answer to accept or vote for the answer you think is useful to you. Your contribution is highly appreciated.

Best regards,

Seeya

NWiddup-msft 1 Microsoft Employee

Hi @Anonymous ,

I've done a similar thing to you and am able to get this working for both localhost and 127.0.0.1.

$guid = New-Guid
$containerName = 'Sql2017-Local'

docker pull mcr.microsoft.com/mssql/server:2019-latest

docker run -p 51433:1433 -e "MSSQL_SA_PASSWORD=SecurePassword1!" -e "ACCEPT_EULA=Y" -e "MSSQL_PID=Developer" --label source="$containerName" -d --name "$containerName-$guid" -v sql2017volume:/var/opt/mssql mcr.microsoft.com/mssql/server:2017-latest

As you can see, I am able to connect (using SSMS) to both endpoints on the specified port.

User's image

Additionally, I was able to connect using the below code through PowerShell.

$sqlConn = New-Object System.Data.SqlClient.SqlConnection
$sqlConn.ConnectionString = "Server=localhost,51433;Integrated Security=false;Initial Catalog=master;User ID=sa;Password='SecurePassword1!'"
$sqlConn.Open()

$sqlConn

And you can see the connection is open:

User's image

And with 127.0.0.1, again you can see the connection working with PowerShell.

$sqlConn = New-Object System.Data.SqlClient.SqlConnection
$sqlConn.ConnectionString = "Server='127.0.0.1,51433';Integrated Security=false;Initial Catalog=master;User ID=sa;Password='SecurePassword1!'"
$sqlConn.Open()

$sqlConn

User's image

As was said in a previous answer, maybe check if you have a firewall blocking connections. Alternatively, try changing "Data Source" to "Server" and maybe try surrounding your password with quotes?

Anonymous

2023-02-23T06:13:20.1766667+00:00

Sorry for the late reply @NWiddup-msft the exact steps I followed, but still no hope, which means I'm in some network-related error. I hope your docker is in WSL itself.
NWiddup-msft 1 Reputation point Microsoft Employee

2023-02-23T07:44:33.5066667+00:00

Interesting you would call that out - I've just checked and yes it looks like I'm using WLS2 backend (not WSL - I wonder if this makes a difference?). I'm also using Docker v20.10.22 & docker desktop 4.16.3 (96739) - maybe an update for docker might help?

Otherwise, could you try either redownloading the 2017 image, and/or also try the MCR/SQLServer:2019-latest? I wonder if the image could somehow be corrupted (I don't know that this can even happen - but something to try)?

If connections are working via 127.0.0.1 but not via localhost, can you check the SQL Errorlogs? There may be something more helpful in there?

HTH

1 answer

Your answer

Seeya Xi-MSFT 16,586 Reputation points

2023-02-17T05:46:31.3633333+00:00

Hi @Vishnu Prasad-FT ,

We have not received a response from you. Did the reply could help you? If the response helped, do "Accept Answer". If it doesn't work, please let us know the progress. By doing so, it will benefit all community members who are having this similar issue. Your contribution is highly appreciated.

Best regards,

Seeya
Seeya Xi-MSFT 16,586 Reputation points

2023-02-20T09:15:19.19+00:00

Hi @Vishnu Prasad-FT ,

In order to benefit all community members who are having this similar issue, please choose an answer to accept or vote for the answer you think is useful to you. Your contribution is highly appreciated.

Best regards,

Seeya
NWiddup-msft 1 Reputation point Microsoft Employee

2023-02-23T04:24:44.0833333+00:00

Hi @Anonymous ,

I've done a similar thing to you and am able to get this working for both localhost and 127.0.0.1.

$guid = New-Guid $containerName = 'Sql2017-Local' docker pull mcr.microsoft.com/mssql/server:2019-latest docker run -p 51433:1433 -e "MSSQL_SA_PASSWORD=SecurePassword1!" -e "ACCEPT_EULA=Y" -e "MSSQL_PID=Developer" --label source="$containerName" -d --name "$containerName-$guid" -v sql2017volume:/var/opt/mssql mcr.microsoft.com/mssql/server:2017-latest

As you can see, I am able to connect (using SSMS) to both endpoints on the specified port.

Additionally, I was able to connect using the below code through PowerShell.

$sqlConn = New-Object System.Data.SqlClient.SqlConnection $sqlConn.ConnectionString = "Server=localhost,51433;Integrated Security=false;Initial Catalog=master;User ID=sa;Password='SecurePassword1!'" $sqlConn.Open() $sqlConn

And you can see the connection is open:

And with 127.0.0.1, again you can see the connection working with PowerShell.

$sqlConn = New-Object System.Data.SqlClient.SqlConnection $sqlConn.ConnectionString = "Server='127.0.0.1,51433';Integrated Security=false;Initial Catalog=master;User ID=sa;Password='SecurePassword1!'" $sqlConn.Open() $sqlConn

As was said in a previous answer, maybe check if you have a firewall blocking connections. Alternatively, try changing "Data Source" to "Server" and maybe try surrounding your password with quotes?
Anonymous

2023-02-23T06:13:20.1766667+00:00

Sorry for the late reply @NWiddup-msft the exact steps I followed, but still no hope, which means I'm in some network-related error. I hope your docker is in WSL itself.
NWiddup-msft 1 Reputation point Microsoft Employee

2023-02-23T07:44:33.5066667+00:00

Interesting you would call that out - I've just checked and yes it looks like I'm using WLS2 backend (not WSL - I wonder if this makes a difference?). I'm also using Docker v20.10.22 & docker desktop 4.16.3 (96739) - maybe an update for docker might help?

Otherwise, could you try either redownloading the 2017 image, and/or also try the MCR/SQLServer:2019-latest? I wonder if the image could somehow be corrupted (I don't know that this can even happen - but something to try)?

If connections are working via 127.0.0.1 but not via localhost, can you check the SQL Errorlogs? There may be something more helpful in there?

HTH

Answer 1

Seeya Xi-MSFT 16,586

Hi @Anonymous ,

Please check if all the network protocols of SQL Server Configuration Manager are turned on. If they are, please go to properties again and check if the port number is 1433.

Also, go to your firewall and check if this port is blocked.

Best regards,

Seeya

If the answer is the right solution, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

Anonymous

2023-02-23T06:17:15.7933333+00:00

Hi, @Seeya Xi-MSFT sorry for the late reply,

My sql-server is in docker wsl, so still I need SQL Server Configuration Manager to configure network ?
Anonymous

2023-02-23T06:18:54.63+00:00

Also, the port is not blocked anyway, I could able to access different services when running in the same port. Anyways thanks for the time

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Docker in WSL - Can't connect to SQL server on 'localhost' but with '127.0.0.1' SQL Server 2017-latest

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