Add custom linter to enforce config version import chain

.github/workflows/ci.yml

@@ -25,7 +25,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@7a3fe6cf4cb3a834922a1244abfce67bcef6a0c5 # v6.2.0
         with:
-          go-version: "1.26.0"
+          go-version: "1.26.1"
           cache: true
 
       - name: Lint
@@ -48,7 +48,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@7a3fe6cf4cb3a834922a1244abfce67bcef6a0c5 # v6.2.0
         with:
-          go-version: "1.26.0"
+          go-version: "1.26.1"
           cache: true
 
       - name: Install Task
@@ -76,7 +76,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@7a3fe6cf4cb3a834922a1244abfce67bcef6a0c5 # v6.2.0
         with:
-          go-version: "1.26.0"
+          go-version: "1.26.1"
           cache: true
 
       - name: Install go-licences

.gitignore

@@ -8,6 +8,7 @@ evals
 .vscode
 .idea/
 *.debug
+/lint/lint
 
 # agents
 agent.yaml

Dockerfile

@@ -1,6 +1,6 @@
 # syntax=docker/dockerfile:1
 
-ARG GO_VERSION="1.26.0"
+ARG GO_VERSION="1.26.1"
 ARG ALPINE_VERSION="3.22"
 ARG XX_VERSION="1.9.0"
 

Taskfile.yml

@@ -46,6 +46,7 @@ tasks:
     desc: Run golangci-lint
     cmds:
       - golangci-lint run
+      - go run ./lint .
       - go mod tidy --diff >/dev/null || (echo "go.mod/go.sum files are not tidy" && exit 1)
     sources:
       - "{{.GO_SOURCES}}"

go.mod

@@ -1,6 +1,6 @@
 module github.com/docker/docker-agent
 
-go 1.26.0
+go 1.26.1
 
 require (
 	charm.land/bubbles/v2 v2.0.0
@@ -128,6 +128,7 @@ require (
 	github.com/containerd/stargz-snapshotter/estargz v0.18.2 // indirect
 	github.com/cyphar/filepath-securejoin v0.4.1 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/dgageot/rubocop-go v0.0.0-20260323134452-aecdd6345645
 	github.com/distribution/reference v0.6.0 // indirect
 	github.com/dlclark/regexp2 v1.11.5 // indirect
 	github.com/docker/distribution v2.8.3+incompatible // indirect

go.sum

@@ -178,6 +178,8 @@ github.com/cyphar/filepath-securejoin v0.4.1/go.mod h1:Sdj7gXlvMcPZsbhwhQ33GguGL
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/dgageot/rubocop-go v0.0.0-20260323134452-aecdd6345645 h1:7UgEWAo69Dgbtii1j1FLWE88+Rem9Qly4LLrrQhAN0s=
+github.com/dgageot/rubocop-go v0.0.0-20260323134452-aecdd6345645/go.mod h1:r8YOJV5+/30NZ8HW/2NbWUObBGDXGvfHrjgury5YlFI=
 github.com/dgageot/ultraviolet v0.0.0-20260313154905-9451997d56b6 h1:88fWkkjwzuI4tRTqadbJIbA9O+gO67oyu+2OpHHuuT8=
 github.com/dgageot/ultraviolet v0.0.0-20260313154905-9451997d56b6/go.mod h1:SQpCTRNBtzJkwku5ye4S3HEuthAlGy2n9VXZnWkEW98=
 github.com/distribution/reference v0.6.0 h1:0IXCQ5g4/QMHHkarYzh5l+u8T3t73zM5QvfrDyIgxBk=

lint/config_version_import.go

@@ -0,0 +1,123 @@
+package main
+
+import (
+	"fmt"
+	"go/ast"
+	"go/token"
+	"path/filepath"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"github.com/dgageot/rubocop-go/cop"
+)
+
+// ConfigVersionImport enforces that config version packages (pkg/config/vN)
+// only import their immediate predecessor (pkg/config/v{N-1}) and the shared
+// types package (pkg/config/types). This preserves the strict migration chain:
+// v0 → v1 → v2 → … → latest.
+type ConfigVersionImport struct{}
+
+func (*ConfigVersionImport) Name() string { return "Lint/ConfigVersionImport" }
+func (*ConfigVersionImport) Description() string {
+	return "Config version packages must only import their immediate predecessor"
+}
+func (*ConfigVersionImport) Severity() cop.Severity { return cop.Error }
+
+// configVersionRe matches "pkg/config/vN" at the end of an import path.
+var configVersionRe = regexp.MustCompile(`pkg/config/v(\d+)$`)
+
+// Check inspects import declarations in config version packages.
+func (c *ConfigVersionImport) Check(fset *token.FileSet, file *ast.File) []cop.Offense {
+	if len(file.Imports) == 0 {
+		return nil
+	}
+
+	// Determine which config version package this file belongs to.
+	filename := fset.Position(file.Package).Filename
+	dirVersion, isVersioned := extractDirVersion(filename)
+	dirIsLatest := isLatestDir(filename)
+
+	if !isVersioned && !dirIsLatest {
+		return nil
+	}
+
+	var offenses []cop.Offense
+
+	for _, imp := range file.Imports {
+		importPath := strings.Trim(imp.Path.Value, `"`)
+
+		if !strings.Contains(importPath, "pkg/config/") {
+			continue
+		}
+
+		if strings.HasSuffix(importPath, "pkg/config/types") {
+			continue
+		}
+
+		if isVersioned {
+			offenses = append(offenses, c.checkVersionedImport(fset, imp, importPath, dirVersion)...)
+		} else if dirIsLatest {
+			offenses = append(offenses, c.checkLatestImport(fset, imp, importPath)...)
+		}
+	}
+
+	return offenses
+}
+
+func (c *ConfigVersionImport) checkVersionedImport(fset *token.FileSet, imp *ast.ImportSpec, importPath string, dirVersion int) []cop.Offense {
+	if strings.HasSuffix(importPath, "pkg/config/latest") {
+		return []cop.Offense{cop.NewOffense(c, fset, imp.Path.Pos(), imp.Path.End(),
+			fmt.Sprintf("config v%d must not import pkg/config/latest", dirVersion))}
+	}
+
+	m := configVersionRe.FindStringSubmatch(importPath)
+	if m == nil {
+		return nil
+	}
+
+	importedVersion, _ := strconv.Atoi(m[1])
+	expected := dirVersion - 1
+
+	if expected < 0 {
+		return []cop.Offense{cop.NewOffense(c, fset, imp.Path.Pos(), imp.Path.End(),
+			"config v0 must not import other config version packages")}
+	}
+
+	if importedVersion != expected {
+		return []cop.Offense{cop.NewOffense(c, fset, imp.Path.Pos(), imp.Path.End(),
+			fmt.Sprintf("config v%d must import v%d (its predecessor), not v%d", dirVersion, expected, importedVersion))}
+	}
+
+	return nil
+}
+
+func (c *ConfigVersionImport) checkLatestImport(fset *token.FileSet, imp *ast.ImportSpec, importPath string) []cop.Offense {
+	if configVersionRe.MatchString(importPath) {
+		return nil
+	}
+
+	return []cop.Offense{cop.NewOffense(c, fset, imp.Path.Pos(), imp.Path.End(),
+		"pkg/config/latest should only import config version or types packages, not "+importPath)}
+}
+
+func extractDirVersion(filename string) (int, bool) {
+	normalized := filepath.ToSlash(filename)
+
+	re := regexp.MustCompile(`/pkg/config/v(\d+)/`)
+	m := re.FindStringSubmatch(normalized)
+	if m == nil {
+		return 0, false
+	}
+
+	v, err := strconv.Atoi(m[1])
+	if err != nil {
+		return 0, false
+	}
+	return v, true
+}
+
+func isLatestDir(filename string) bool {
+	normalized := filepath.ToSlash(filename)
+	return strings.Contains(normalized, "/pkg/config/latest/")
+}

lint/main.go

@@ -0,0 +1,37 @@
+// Package main runs project-specific linting cops using rubocop-go.
+//
+// Usage: go run ./lint ./...
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/dgageot/rubocop-go/config"
+	"github.com/dgageot/rubocop-go/cop"
+	"github.com/dgageot/rubocop-go/runner"
+)
+
+func main() {
+	cop.Register(&ConfigVersionImport{})
+	cops := cop.All()
+	fmt.Printf("Inspecting Go files with %d cop(s)\n", len(cops))
+
+	cfg := config.DefaultConfig()
+	r := runner.New(cops, cfg, os.Stdout)
+
+	paths := os.Args[1:]
+	if len(paths) == 0 {
+		paths = []string{"."}
+	}
+
+	offenseCount, err := r.Run(paths)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+
+	if offenseCount > 0 {
+		os.Exit(1)
+	}
+}