Debugging within Docker Containers

With version 0.9.0, 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.

Platform Support

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

.NET Core

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

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

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"
            }
        }
    ]
}

Node.js

More information about debugging Node.js applications within Docker containers can be found here.

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"
        }
    ]
}

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.