Connection Issues with Linux Custom-Container Apps

“az webapp exec rejects Linux custom-container web apps whose kind is "linux,container" ### Describe the bug TLDR; I'm unable to connect to my linux container running on Azure App Service because I get the following error: `Site is not a Linux web app. 'az webapp exec' is only supported for Linux web apps.` **Details:** `az webapp exec` fails with "Site is not a Linux web app" for a Linux custom-container web app whose `kind` is `linux,container`. The site is a Linux web app by every other measure: it runs on a Linux App Service plan, `reserved` is `true`, `siteConfig.linuxFxVersion` is `DOCKER|...`, and the portal shows its operating system as Linux. The check in `webapp_exec.py` calls `is_linux_webapp`, which first calls `is_webapp`. `is_webapp` requires the substring `app` in `kind`. Because `linux,container` doesn't contain `app`, the site is rejected before the `linux` check is reached. - [webapp_exec.py#L66-L67](https://github.com/Azure/azure-cli/blob/5f64a805d897437f4d10e35e829968d274277386/src/azure-cli/azure/cli/command_modules/appservice/webapp_exec.py#L66-L67) - [utils.py#L424-L433](https://github.com/Azure/azure-cli/blob/5f64a805d897437f4d10e35e829968d274277386/src/azure-cli/azure/cli/command_modules/appservice/utils.py#L424-L433) For comparison, `az webapp ssh` decides with `webapp.reserved`, which is `true` for this site: - [custom.py#L13079-L13082](https://github.com/Azure/azure-cli/blob/5f64a805d897437f4d10e35e829968d274277386/src/azure-cli/azure/cli/command_modules/appservice/custom.py#L13079-L13082) Users can't work around this by correcting the kind. A PATCH that sets `kind` to `app,linux,container` succeeds, and the activity log records `Microsoft.Web/sites/write` as Succeeded, but a later GET still returns `linux,container`. All six web apps in our resource group have this kind, so this likely affects other sites created the same way. Site properties: ``` az webapp show -g <rg> -n <app> --query "{kind:kind, reserved:reserved, linuxFxVersion:siteConfig.linuxFxVersion}" { "kind": "linux,container", "linuxFxVersion": "DOCKER|<registry>.azurecr.io/<image>:latest", "reserved": true } ``` Failing command, debug output trimmed to the relevant lines: ``` az webapp exec --subscription <subscription-id> -g <rg> -n <app> --debug DEBUG: cli.knack.cli: Command arguments: ['webapp', 'exec', '--subscription', '<subscription-id>', '--resource-group', '<rg>', '--name', '<app>', '--debug'] DEBUG: cli.azure.cli.core.sdk.policies: Request URL: 'https://management.azure.com/subscriptions/<subscription-id>/resourceGroups/<rg>/providers/Microsoft.Web/sites/<app>?api-version=2025-05-01' DEBUG: cli.azure.cli.core.sdk.policies: Response status: 200 azure.cli.core.azclierror.ValidationError: Site is not a Linux web app. 'az webapp exec' is only supported for Linux web apps. ERROR: cli.azure.cli.core.azclierror: Site is not a Linux web app. 'az webapp exec' is only supported for Linux web apps. ``` Attempt to correct the kind, which is accepted but not applied: ``` az rest --method patch --url "https://management.azure.com/subscriptions/<subscription-id>/resourceGroups/<rg>/providers/Microsoft.Web/sites/<app>?api-version=2024-04-01" --body '{\"kind\":\"app,linux,container\"}' az webapp show -g <rg> -n <app> --query kind "linux,container" ``` ### Related command az webapp exec ### Errors Site is not a Linux web app. 'az webapp exec' is only supported for Linux web apps. ### Issue script & Debug output Site properties: ``` az webapp show -g <rg> -n <app> --query "{kind:kind, reserved:reserved, linuxFxVersion:siteConfig.linuxFxVersion}" { "kind": "linux,container", "linuxFxVersion": "DOCKER|<registry>.azurecr.io/<image>:latest", "reserved": true } ``` Failing command, debug output trimmed to the relevant lines: ``` az webapp exec --subscription <subscription-id> -g <rg> -n <app> --debug DEBUG: cli.knack.cli: Command arguments: ['webapp', 'exec', '--subscription', '<subscription-id>', '--resource-g”