dap

Visual and Interactive Debugging of Dockerfile on editors via DAP (Debug Adapter Protocol)

Buildg allows visual and interactive debugging of Dockerfile on editors like VS Code, emacs and Neovim.

This is provided throgh DAP(Debug Adapter Protocol) supported by editors (official list).

Getting Started

• VS Code: https://github.com/ktock/vscode-buildg
• Emacs: ./emacs
• Neovim: ./nvim

Refer to the VS Code documentation for UI usage: https://code.visualstudio.com/docs/editor/debugging

Repl commands

exec

Execute command in the step.

Alias: e

Usage: exec [OPTIONS] [ARGS...]

If ARGS isn't provided, /bin/sh is used by default.

Flags:

• --image: Execute command in the debuger image specified by image property in the lauch configuration. If not specified, the command is executed on the rootfs of the current step.
• --mountroot value: Mountpoint to mount the rootfs of the step. ignored if --image isn't specified. (default: /debugroot)
• --init-state: Execute commands in an initial state of that step (experimental)
• --tty, -t: Allocate tty (enabled by default)
• -i: Enable stdin. (FIXME: must be set with tty) (enabled by default)
• --env value, -e value: Set environment variables
• --workdir value, -w value: Working directory inside the container

help

Shows a list of commands or help for one command

Alias: h

Usage: help [COMMAND]

Launch Configuration

In the launch configuration (e.g. launch.json on VS Code), the following properties are provided.

• program string REQUIRED : Absolute path to Dockerfile.
• stopOnEntry boolean : Automatically stop after launch. (default: true)
• target string : Target build stage to build.
• image string : Image to use for debugging stage.
• build-args array : Build-time variables.
• ssh array : Allow forwarding SSH agent to the build. Format: default|<id>[=<socket>|<key>[,<key>]]
• secrets array : Expose secret value to the build. Format: id=secretname,src=filepath

Common and mandatory properties are the following (see VS Code documentation for details).

• type : Type of debugger to use. Must be dockerfile.
• request : The request type. launch is only supported in buildg as of now.
• name : The reader-friendly name of this configuration.

Known Limitations

Following lists the current known limitations that should be eliminated in the futural version.

• Step Into and Step Out in Debug toolbar is unsupported in buildg. To inspect instructions deeper, you can use exec REPL command instead.
• Logpoint, conditional, function and data breakpoints aren't supported.
• Setting value to a variable isn't supported.
• attach request type in launch configuration isn't supported.