Initial support of DAP (Debug Adapter Protocol)

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>

README.md

@@ -27,7 +27,7 @@ buildg debug --image=debugging-tools /path/to/build/context
 
 For the detailed command refenrece, refer to [Command reference](#command-reference) in the following
 
-### Exmaple
+### Exmaple with terminal
 
 Debug the following Dockerfile:
 
@@ -109,6 +109,15 @@ hi
 (buildg) quit
 ```
 
+## Use on IDEs
+
+Buildg allows visual and interactive debugging of Dockerfile on editors like VS Code, emacs and Neovim.
+This is provided throgh [DAP(Debug Adapter Protocol)](https://microsoft.github.io/debug-adapter-protocol/) supported by editors [(official list)](https://microsoft.github.io/debug-adapter-protocol/implementors/tools/).
+
+See [`./examples/dap/README.md`](./examples/dap/README.md) for usage of DAP.
+
+![Buildg on VS Code](./docs/images/vscode-dap.png)
+
 ## Install
 
 - Requirements
@@ -173,6 +182,9 @@ Leveraging the generic features added through the work, this project implements
 - [buildg debug](#buildg-debug)
 - [buildg prune](#buildg-prune)
 - [buildg du](#buildg-du)
+- [buildg dap serve](#buildg-dap-serve)
+- [buildg dap prune](#buildg-dap-prune)
+- [buildg dap du](#buildg-dap-du)
 - [Debug shell commands](#debug-shell-commands)
   - [break](#break)
   - [breakpoints](#breakpoints)
@@ -221,6 +233,35 @@ Show disk usage information
 
 Usage: `buildg du`
 
+## buildg dap serve
+
+Serve Debug Adapter Protocol (DAP) via stdio.
+Should be called from editors. 
+See [`./examples/dap/README.md`](./examples/dap/README.md) for usage of DAP.
+
+Usage: `buildg dap serve [OPTIONS] [ARGS...]`
+
+Flags:
+- `--log-file value`: Path to the file to output logs
+
+## buildg dap prune
+
+Prune DAP cache.
+See [`./examples/dap/README.md`](./examples/dap/README.md) for usage of DAP.
+
+Usage: `buildg dap prune [OPTIONS]`
+
+Flags:
+
+- `--all`: Prune including internal/frontend references
+
+## buildg dap du
+
+Show disk usage of DAP cache
+See [`./examples/dap/README.md`](./examples/dap/README.md) for usage of DAP.
+
+Usage: `buildg dap du`
+
 ## Debug shell commands
 
 ### break

break.go

@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"strconv"
 
-	"github.com/moby/buildkit/solver/pb"
+	"github.com/ktock/buildg/pkg/buildkit"
 	"github.com/urfave/cli"
 )
 
@@ -28,17 +28,18 @@ on-fail  breaks on step that returns an error
 			}
 			h := hCtx.handler
 			var key string
-			var b breakpoint
+			var b buildkit.Breakpoint
 			if bp == "on-fail" {
 				key = "on-fail"
-				b = newOnFailBreakpoint()
+				b = buildkit.NewOnFailBreakpoint()
 			} else if l, err := strconv.ParseInt(bp, 10, 64); err == nil {
-				b = newLineBreakpoint(hCtx.locs[0].source.Filename, l)
+				b = buildkit.NewLineBreakpoint(hCtx.locs[0].Source.Filename, l)
 			}
 			if b == nil {
 				return fmt.Errorf("cannot parse breakpoint %q", bp)
 			}
-			return h.breakpoints.add(key, b)
+			_, err := h.Breakpoints().Add(key, b)
+			return err
 		},
 	}
 }
@@ -50,8 +51,8 @@ func breakpointsCommand(ctx context.Context, hCtx *handlerContext) cli.Command {
 		Usage:     "Show breakpoints key-value pairs",
 		UsageText: "breakpoints",
 		Action: func(clicontext *cli.Context) error {
-			hCtx.handler.breakpoints.forEach(func(key string, b breakpoint) bool {
-				fmt.Printf("[%s]: %v\n", key, b)
+			hCtx.handler.Breakpoints().ForEach(func(key string, b buildkit.Breakpoint) bool {
+				fmt.Fprintf(hCtx.stdout, "[%s]: %v\n", key, b)
 				return true
 			})
 			return nil
@@ -72,10 +73,10 @@ BREAKPOINT_KEY is the key of a breakpoint which is printed when executing "break
 			if bpKey == "" {
 				return fmt.Errorf("breakpoint key must be set")
 			}
-			if _, ok := hCtx.handler.breakpoints.get(bpKey); !ok {
+			if _, ok := hCtx.handler.Breakpoints().Get(bpKey); !ok {
 				return fmt.Errorf("breakpoint %q not found", bpKey)
 			}
-			hCtx.handler.breakpoints.clear(bpKey)
+			hCtx.handler.Breakpoints().Clear(bpKey)
 			return nil
 		},
 	}
@@ -87,7 +88,7 @@ func clearAllCommand(ctx context.Context, hCtx *handlerContext) cli.Command {
 		Usage:     "Clear all breakpoints",
 		UsageText: "clearall",
 		Action: func(clicontext *cli.Context) error {
-			hCtx.handler.breakpoints.clearAll()
+			hCtx.handler.Breakpoints().ClearAll()
 			return nil
 		},
 	}
@@ -100,7 +101,7 @@ func nextCommand(ctx context.Context, hCtx *handlerContext) cli.Command {
 		Usage:     "Proceed to the next line",
 		UsageText: "next",
 		Action: func(clicontext *cli.Context) error {
-			hCtx.handler.breakEachVertex = true
+			hCtx.handler.BreakEachVertex(true)
 			hCtx.continueRead = false
 			return nil
 		},
@@ -114,58 +115,9 @@ func continueCommand(ctx context.Context, hCtx *handlerContext) cli.Command {
 		Usage:     "Proceed to the next breakpoint",
 		UsageText: "continue",
 		Action: func(clicontext *cli.Context) error {
-			hCtx.handler.breakEachVertex = false
+			hCtx.handler.BreakEachVertex(false)
 			hCtx.continueRead = false
 			return nil
 		},
 	}
 }
-
-func newLineBreakpoint(filename string, line int64) breakpoint {
-	return &lineBreakpoint{filename, line}
-}
-
-type lineBreakpoint struct {
-	filename string
-	line     int64
-}
-
-func (b *lineBreakpoint) isTarget(ctx context.Context, info breakpointContext) (bool, string, error) {
-	for _, loc := range info.locs {
-		if loc.source.Filename != b.filename {
-			continue
-		}
-		for _, r := range loc.ranges {
-			if int64(r.Start.Line) <= b.line && b.line <= int64(r.End.Line) {
-				return true, "reached " + b.String(), nil
-			}
-		}
-	}
-	return false, "", nil
-}
-
-func (b *lineBreakpoint) String() string {
-	return fmt.Sprintf("line: %s:%d", b.filename, b.line)
-}
-
-func (b *lineBreakpoint) addMark(source *pb.SourceInfo, line int64) bool {
-	return source.Filename == b.filename && line == b.line
-}
-
-func newOnFailBreakpoint() breakpoint {
-	return &onFailBreakpoint{}
-}
-
-type onFailBreakpoint struct{}
-
-func (b *onFailBreakpoint) isTarget(ctx context.Context, info breakpointContext) (bool, string, error) {
-	return info.status.err != nil, fmt.Sprintf("caught error %v", info.status.err), nil
-}
-
-func (b *onFailBreakpoint) String() string {
-	return "breaks on fail"
-}
-
-func (b *onFailBreakpoint) addMark(source *pb.SourceInfo, line int64) bool {
-	return false
-}