Debug containerized apps

With version 0.9.0 and later, the Docker extension provides more support for debugging applications within Docker containers, such as scaffolding launch.json configurations for attaching a debugger to applications running within a container.

The Docker extension provides a docker debug configuration provider that manages how VS Code will launch an application and/or attach a debugger to the application in a running Docker container. This provider is configured via entries within launch.json, with configuration being specific to each application platform supported by the provider.

The Docker extension currently supports debugging Node.js and .NET Core applications within Docker containers.

Node.js

More information about debugging Node.js applications within Docker containers can be found at Debug Node.js within a container.

Example launch.json configuration for debugging a Node.js application:

{
  "version": "0.2.0",
  "configurations": [
    {
      "name": "Launch Node.js in Docker",
      "type": "docker",
      "request": "launch",
      "preLaunchTask": "Run Docker Container",
      "platform": "node"
    }
  ]
}

.NET Core

More information about debugging .NET Core applications within Docker containers can be found in Debug .NET Core within Docker containers.

The previous (Preview) .NET Core Docker debugging support is being deprecated. You can still find documentation on that support at Debug .NET Core - Deprecated.

Example launch.json configuration for debugging a .NET Core application:

{
  "version": "0.2.0",
  "configurations": [
    {
      "name": "Launch .NET Core in Docker",
      "type": "docker",
      "request": "launch",
      "preLaunchTask": "Run Docker Container",
      "netCore": {
        "appProject": "${workspaceFolder}/project.csproj"
      }
    }
  ]
}

Configuration reference

Property Description
containerName Name of the container used for debugging.
dockerServerReadyAction Options for launching a browser to the Docker container. Similar to serverReadyAction, but replaces container ports with host ports.
removeContainerAfterDebug Whether to remove the debug container after debugging.
platform The target plaform for the application. Can be netCore or node.
netCore Options for debugging .NET Core projects in Docker.
node Options for debugging Node.js projects in Docker.

dockerServerReadyAction object properties

Property Description
action The action to take when the pattern is found. Can be debugWithChrome or openExternally.
containerName The container name to match the host port.
pattern The regex pattern to look for in Debug console output.
uriFormat The URI format to launch.
webRoot The root folder from which web pages are served. Used only when action is set to debugWithChrome.

netCore object properties

Properties passed in the netCore object are generally passed on to the .NET Core debug adaptor, even if not specifically listed below. The complete list of debugger properties is in the OmniSharp VS Code extension documentation.

Property Description
appProject The .NET Core project (.csproj, .fsproj, etc.) to debug.

node object properties

These properties are the same as those described in the VS Code documentation for attaching a debugger to Node.js applications. All properties passed in the node object will be passed on to the Node.js debug adaptor, even if not specifically listed below.

Property Description Default
port Optional. The debug port to use. 9229
address Optional. TCP/IP address of the debug port.
sourceMaps Optional. Enable source maps by setting this to true.
outFiles Optional. Array of glob patterns for locating generated JavaScript files.
autoAttachChildProcesses Optional. Track all subprocesses of debuggee and automatically attach to those that are launched in debug mode.
timeout Optional. When restarting a session, give up after this number of milliseconds.
stopOnEntry Optional. Break immediately when the program launches.
localRoot Optional. VS Code's root directory. The root workspace folder.
remoteRoot Optional. Node's root directory within the Docker container. /usr/src/app
smartStep Optional. Try to automatically step over code that doesn't map to source files.
skipFiles Optional. Automatically skip files covered by these glob patterns.
trace Optional. Enable diagnostic output.

Next steps

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