No network access from console application

[aloneguid]

The latest preview SDK 3.3.617 has some issues with code trying to get access to external network. For instance simple code:

string text = new WebClient().DownloadString("https://microsoft.com");

will fail from console application when running on a local cluster ("no such host is known"). The funny thing is it will succeed when running in API app, therefore the issue is not with docker networking as I thought before. Does anyone have any pointers?

[BigMorty]

@aloneguid - Try adding an EXPOSE statement to the first section of your Dockerfile.

[aloneguid]

Expose works, I posted this as workaround on another thread already but that seems like a bug to me?

[BigMorty]

Glad that worked, sorry I did not see the other thread, which one was it? The SF team is still looking into the root cause of this.

[aloneguid]

I've posted this on Azure advisors originally) found that the only difference between Web and console is expose command, nothing else is happening different, procmon says they fire up identicaly.

[BigMorty]

Gotcha, thanks.

[jsmithtx]

@aloneguid You said the EXPOSE statement worked for you. Could you share your dockerfile or at least the portion that worked? I am trying to get my console Mesh application to talk to my local Cosmos emulator and a local SQL server instance and I can't get it to succeed. Thanks.

[aloneguid]

@jiffypopjr the dockerfile should start like this:

FROM microsoft/dotnet:2.1-runtime AS base
WORKDIR /app
EXPOSE 80 <--- extra line

FROM microsoft/dotnet:2.1-sdk AS build
WORKDIR /src
...

[jsmithtx]

I've exposed both ports, in an attempt to get to the local Cosmos emulator, but this doesn't seem to work. How would I, in a 'worker' Mesh node, get to a local Cosmos instance running on the host system from within the container? I've tried the host name (with also launching Mesh with the -UseComputerName arg), and tried the various IP address that docker inspect provides, but with no success.

The host port for Cosmos is 8081. Thanks!

EXPOSE 80 EXPOSE 8081

[BigMorty]

@sridmad - Any ideas?

[aloneguid]

@jiffypopjr normally you would compose host name as "servicename.applicationname" -this will resolve both in local cluster and Azure well.

Are you trying to access emulator running in a container belonging to the same application, or your host machine?

[sridmad]

Connectivity issue for console project or any image without EXPOSE statement is addressed in the runtime with 3.3.622 SDK.

https://docs.microsoft.com/en-us/azure/service-fabric-mesh/service-fabric-mesh-howto-setup-developer-environment-sdk

[jsmithtx]

@aloneguid I was trying to access the Cosmos emulator that is running in the host machine (https:/localhost:8081). After digging quite a bit, I found that I could use the servicefabric_nat Gateway IP address as the host address and at least was able to access my host instance of Seq logging; however, because the Cosmos emulator uses SSL, the container was unable to establish a trust relationship with the host. Thus far I've attempted to register the Cosmos host local certificate in the container as a CA, Root, and My with no success (RUN certutil -addstore "Root" ./DocumentDBEmulatorCertificate.cer). I may try running the cosmos emulator as a container itself and see if I can do container-to-container communication next. If that fails, I'll try using tcp for communication

[sridmad]

@jiffypopjr , I have opened a different issue for connectivity to ports on machine IP.

[julipur]

@jiffypopjr Hi Josh, wondering if you got this working with Cosmos running in docker (either on the same container as the mesh application or via container to container communication)