Aspire in windows Not connecting to Docker Desktop on Mac M1

Question

Aspire in windows Not connecting to Docker Desktop on Mac M1

Ali AL Hoshaimy 0

I have docker desktop running on Mac M1, and trying to connect to it from Visual Studio in Windows 11 inside Parallels. I am able to browse apps running in Docker from edge in windows with no issues.
Aspire app out project is able to run the docker containers, however, it is connecting to them using the localhost connection string. I want to force Aspire to use "host" instead of "localhost".
any idea?

2 answers

Your answer

Answer 1

Hope you are doing good! Thank you for reaching out. Please find the answer below.

1.Check Environment Variables: You can try setting the ASPIRE_HOST environment variable in your Windows environment to the appropriate host IP address. Sometimes, using host.docker.internal can help bridge the network between Docker containers and the host machine.

2.Modify Connection String: If you can, modify the connection string in your Aspire app configuration to point to the host address. Here's a possible format:

{
"ConnectionStrings": {
"DefaultConnection": "Server=host;Database=yourDatabase;User Id=yourUser;Password=yourPassword;"
}
}

3.Inspect Docker Settings: Ensure Docker is set up properly in Parallels. Sometimes, adjusting the network settings might help establish a better connection.

4.Firewall/Network Policies: Ensure there are no firewall rules on your Windows system or network policies in your Docker settings that could be blocking the connection.

5.Ensure Docker on the Mac is configured to expose the daemon over TCP:

Open Docker Desktop → Settings → General → Enable “Expose daemon on tcp://localhost:2375 without TLS”.

6.Restart Aspire or Visual Studio after setting the environment variable.

If the issue still persists, we'll happy to assist further needed. "Kindly mark the response as answered if the issue resolved".

Ali AL Hoshaimy 0 Reputation points

2025-09-16T15:39:20.75+00:00

It is still not working. Although, the Visual Studio run did create the containers in Docker on Mac as below:

When it comes to Aspire dashboard from Windows, it is still connecting to local host:

the Aspire variable is set as needed and docker ps command works fine

Answer 2

Susmitha T (INFOSYS LIMITED) 755 Microsoft External Staff

Hope you are doing good! Thank you for reaching out. Please find the answer below.

Aspire is still defaulting to localhost. Here's how to force it to use the correct host:

Verify Aspire Configuration

Ensure Aspire is actually reading the ASPIRE_HOST environment variable. You might need to:

Set it in the Visual Studio launch settings (launchSettings.json).
Or set it globally in Windows Environment Variables and restart Visual Studio.

Update Connection Strings Explicitly

In your Aspire app’s configuration (e.g., appsettings.json or Program.cs), replace localhost with 10.211.55.2 or host.docker.internal:

"ConnectionStrings": {

"DefaultConnection": "Server=10.211.55.2;Database=yourDatabase;User Id=yourUser;Password=yourPassword;"

}

Use host.docker.internal

This alias works well across Docker Desktop setups and is often more reliable than raw IPs.

Check Docker Health Probes

The "unhealthy" status might be due to missing or misconfigured health checks in your Dockerfiles or Compose setup. Add proper HEALTHCHECK instructions if needed.

Expose Docker Daemon Properly

Make sure Docker Desktop on Mac has:

“Expose daemon on tcp://localhost:2375 without TLS” enabled.
Firewall rules allow traffic from Parallels VM to port 2375.

Let me know if you need any further help with this. We'll be happy to assist.

If you find this helpful, please mark this as answered.

Ali AL Hoshaimy 0 Reputation points

2025-09-17T16:02:32.0233333+00:00

Thank you for your answers,
if I use docker compose file and start from the mac machine, I can update the connection strings in the projects and connect fine.

Still, I am trying the Aspire project as a whole solution, and like to run all together; however, the aspire keeps targeting the "localhost" even if the ASPIRE_HOST variable is set in the project or windows variables.

This is kind of strange and not sure how to get this resolved.
Susmitha T (INFOSYS LIMITED) 755 Reputation points Microsoft External Staff

2025-09-18T10:28:08.97+00:00
Thanks for reaching out.

On research, Aspire is designed primarily for local development, and its internal proxy system is hardcoded to use localhost for resource endpoints. Even if you set ASPIRE_HOST, Aspire may override it silently due to how it recalculates endpoint URLs from annotations during runtime.

This behavior is confirmed in GitHub issue. where developers noted that Aspire ignores custom hostnames and reverts to localhost without warning.

kindly refer the given links:

Support for Non Localhost Hosts of Resources · Issue #9272 · dotnet/aspire

Workaround:

Use Wildcard Hosts in launchSettings.json

Modify your launchSettings.json to use a wildcard host like * or +: "applicationUrl": "http://*:8080"

This allows Aspire to bind to all interfaces and may help it respect external hostnames.

Use host.docker.internal in Connection Strings

Update your connection strings explicitly in appsettings.json or Program.cs:

"ConnectionStrings": {

"DefaultConnection": "Server=host.docker.internal;Database=yourDatabase;User Id=yourUser;Password=yourPassword;"

}

This alias bridges the VM-to-host networking and is more reliable than raw IPs.

3. Disable Proxying in Aspire: This forces Aspire to expose the container directly without routing through its internal proxy.

Use Reverse Proxy Endpoint Workaround:

You can implement a custom extension method like WithReverseProxyEndpoint to manually inject non-localhost URLs into Aspire’s dashboard.

Expose Docker Daemon on Mac:

Ensure Docker Desktop on Mac has: “Expose daemon on tcp://localhost:2375 without TLS” enabled

Also verify that firewall rules allow traffic from the Parallels VM to port 2375.

Let me know if you need any further help with this. We'll be happy to assist.

If you find this helpful, please mark this as answered.
Susmitha T (INFOSYS LIMITED) 755 Reputation points Microsoft External Staff

2025-09-23T05:26:55.21+00:00

"Hope you're doing well. We're following up on the thread. Please let us know whether the issue persists or has been resolved. If the issue has been resolved, kindly mark the response as answered. We'll close this thread by 9th October, so we are hoping for your reply before that"
Susmitha T (INFOSYS LIMITED) 755 Reputation points Microsoft External Staff

2025-09-29T05:05:02.0233333+00:00

"Hope you're doing well. We're following up on the thread. Please let us know whether the issue persists or has been resolved. If the issue has been resolved, kindly mark the response as answered. We'll close this thread by 9th October, so we are hoping for your reply before that".
Susmitha T (INFOSYS LIMITED) 755 Reputation points Microsoft External Staff

2025-10-03T05:03:19.6433333+00:00

"Hope you're doing well. We're following up on the thread. Please let us know whether the issue persists or has been resolved. If the issue has been resolved, kindly mark the response as answered. We'll close this thread by 9th October, so we are hoping for your reply before that".
Susmitha T (INFOSYS LIMITED) 755 Reputation points Microsoft External Staff

2025-10-09T03:50:54.2633333+00:00

Since the thread has been open for a considerable time, we will be proceeding to close the thread. If the issue persists or reoccurs, please feel free to raise a new thread. We’ll be happy to assist you further.

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Aspire in windows Not connecting to Docker Desktop on Mac M1

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