[start] Start command does not connect to web or api server on Node 18

[sinedied]

Before filing this issue, please ensure you're using the latest CLI by running swa --version and comparing to the latest version on npm.

Are you accessing the CLI from the default port :4280 ?

• No, I am using a different port number (--port) and accessing the CLI from that port
• Yes, I am accessing the CLI from port :4280

Make sure you are accessing the URL printed in the console when running swa start!

ℹ️ NOTE: Make sure to enable debug logs when running any swa commands using --verbose=silly

Describe the bug
On Node 18, npm start never connects to a web or api server, it's stuck until timeout. On Node 16, no issue.

This is related to this issue jeffbski/wait-on#137 of the wait-on package.

[sgollapudi77]

Hi @sinedied , is there any alternative that we can use instead of "wait-on" package?

[rodyvansambeek]

As a temporary workaround you can use 127.0.0.1 in stead of localhost for the API and/or for the frontend, use it like this:

swa start --host=127.0.0.1 --app-devserver-url=http://127.0.0.1:3010

Mind that the port number 3010 can be different on your side of course, and you should add your own extra parameters.

[sinedied]

Hi @sinedied , is there any alternative that we can use instead of "wait-on" package?

None that I know of. This is problematic in the whole Node.js ecosystem as they made the changed the priority order from ipv4 to ipv6.
We could work around that on our side but it would be a bit convoluted (trying both localhost and 127.0.0.1, and connecting to the first one that succeed.

As a temporary workaround you can use 127.0.0.1 in stead of localhost for the API and/or for the frontend, use it like this:

swa start --host=127.0.0.1 --app-devserver-url=http://127.0.0.1:3010

Mind that the port number 3010 can be different on your side of course, and you should add your own extra parameters.

You're right, but the --host isn't needed, only --app-devserver-url=http://127.0.0.1:<PORT> or --api-devserver-url=http://127.0.0.1:<PORT>.

One issue is that once the --api-devserver-url option is set, the Function API emulator doesn't start automatically anymore and need to be run manually.

[rodyvansambeek]

One issue is that once the --api-devserver-url option is set, the Function API emulator doesn't start automatically anymore and need to be run manually.

You are right, but that's why you include the --host in combination with the --api-location option (and not the --api-devserver-url option), in my example I omitted the api-location option, but it should look something like:

swa start --host=127.0.0.1 --app-devserver-url=http://127.0.0.1:<DEVSERVER-PORT> --run "<RUN COMMAND>" --api-location ./api --port <SWA-PORT> --api-port <API-PORT>

[sgollapudi77]

One issue is that once the --api-devserver-url option is set, the Function API emulator doesn't start automatically anymore and need to be run manually.

You are right, but that's why you include the --host in combination with the --api-location option (and not the --api-devserver-url option), in my example I omitted the api-location option, but it should look something like:

swa start --host=127.0.0.1 --app-devserver-url=http://127.0.0.1:<DEVSERVER-PORT> --run "<RUN COMMAND>" --api-location ./api --port <SWA-PORT> --api-port <API-PORT>

This is so painful from user perspective, may be we should try giving these params internally while starting the swa if the node version is 18.

[rodyvansambeek]

One issue is that once the --api-devserver-url option is set, the Function API emulator doesn't start automatically anymore and need to be run manually.

You are right, but that's why you include the --host in combination with the --api-location option (and not the --api-devserver-url option), in my example I omitted the api-location option, but it should look something like:

swa start --host=127.0.0.1 --app-devserver-url=http://127.0.0.1:<DEVSERVER-PORT> --run "<RUN COMMAND>" --api-location ./api --port <SWA-PORT> --api-port <API-PORT>

This is so painful from user perspective, may be we should try giving these params internally while starting the swa if the node version is 18.

Agreed that it's painful from a user perspective, but the problem is in the related package wait-on which resolves to the ::1 IPv6 address. I don't think it's a SWA-CLI specific issue.

[sinedied]

This is so painful from user perspective, may be we should try giving these params internally while starting the swa if the node version is 18.

We can't do that, as some servers listen on ipv6 by default and works fine with http://localhost, but would break with http://127.0.0.1 (Node.js server running on Node 18 for example).

[Psvensso]

Another workaround to get people going with node 18.

Using swa 1.1.1 and Node 18.12.1 i was able to get everything to work as expected with

swa start --host=127.0.0.1 --port=3010 --app-devserver-url=http://127.0.0.1:3000

My react apps runs on 3000 (Vite React)
And my public facing endpoint (swa) i now accessible on 3010

[jamesclancy]

I was getting this issue on Win 11. I switched to running the swa start in WSL and it is working for me again with node 18.

[johnnyreilly]

Thought I'd share my own workaround. I installed concurrently:

npm i concurrently

Then I separated out my front end / back end scripts like so:

    "debug": "concurrently -n \"staticwebapp,functionapp\" -c \"bgBlue.bold,bgMagenta.bold\" \"npm run debug:staticwebapp\" \"npm run debug:functionapp\"",
    "debug:staticwebapp": "cd src/StaticWebApp && npm run debug",
    "debug:functionapp": "cd src/FunctionApp && func start",

Where the npm run debug in src/StaticWebApp is:

        "debug": "swa start http://localhost:5173 --run \"npm run dev\" --api-location http://127.0.0.1:7071",

This allows me to work around the issue.

https://johnnyreilly.com/static-web-apps-cli-node-18-could-not-connect-to-api