remove unused archs

I am not using nor need arm64 and windows. Removing these from the
Makefile. If you see this message and feel like they should be added
back (or different archs), ping me.

.build.yml

@@ -3,6 +3,7 @@ packages:
   - go
   - git
   - make
+  - shellcheck
 sources:
   - https://git.sr.ht/~motiejus/undocker
 tasks:

Makefile

@@ -1,44 +1,36 @@
+SCRIPTS = $(shell awk '/#!\/bin\/(ba)?sh/&&FNR==1{print FILENAME}' $(shell git ls-files))
 GODEPS = $(shell git ls-files '*.go' go.mod go.sum)
 GOBIN = $(shell go env GOPATH)/bin/
-
-GOOSARCHS = $(sort \
-			darwin/amd64 \
-			darwin/arm64 \
-			linux/amd64 \
-			linux/arm64 \
-			windows/amd64/.exe \
-			windows/arm64/.exe)
+GOOSARCHS = $(sort darwin/amd64 linux/amd64)
 
 VSN ?= $(shell git describe --dirty)
 VSNHASH = $(shell git rev-parse --verify HEAD)
 LDFLAGS = -ldflags "-X main.Version=$(VSN) -X main.VersionHash=$(VSNHASH)"
 
+undocker: ## builds binary for the current architecture
+	CGO_ENABLED=0 go build $(LDFLAGS) -o $@
+
 .PHONY: test
 test:
 	go test -race -cover ./...
 
 define undockertarget
-UNDOCKERS += undocker-$(1)-$(2)-$(VSN)$(firstword $(3))
-undocker-$(1)-$(2)-$(VSN)$(firstword $(3)): $(GODEPS)
+UNDOCKERS += undocker-$(1)-$(2)-$(VSN)
+undocker-$(1)-$(2)-$(VSN): $(GODEPS)
 	CGO_ENABLED=0 GOOS=$(1) GOARCH=$(2) go build $(LDFLAGS) -o $$@
 endef
 
 $(foreach goosarch,$(GOOSARCHS),\
-	$(eval $(call undockertarget,$(word 1,$(subst /, ,$(goosarch))),$(word 2,$(subst /, ,$(goosarch))),$(word 3,$(subst /, ,$(goosarch))))))
+	$(eval $(call undockertarget,$(word 1,$(subst /, ,$(goosarch))),$(word 2,$(subst /, ,$(goosarch))))))
 
 .PHONY: all
 all: $(UNDOCKERS)
 
 .PHONY: lint
-lint: vet staticcheck
-
-.PHONY: vet
-vet:
+lint:
 	go vet ./...
-
-.PHONY: staticcheck
-staticcheck:
 	$(GOBIN)staticcheck -f stylish ./...
+	shellcheck $(SCRIPTS)
 
 .INTERMEDIATE: coverage.out
 coverage.out: $(GODEPS)

README.md

@@ -20,6 +20,19 @@ systemd, FreeBSD Jails, and many others.
 
 Undocker has no dependencies outside Golang stdlib.
 
+Installation
+------------
+
+We recommend using [officially released binaries][3]. To build the project
+instead, run:
+
+```
+$ make undocker
+```
+
+The number of officially released binaries is quite limited. If you'd like me
+to expand a list, please contribute a patch to the Makefile.
+
 Usage: convert docker image to rootfs
 -------------------------------------
 
@@ -107,3 +120,4 @@ MIT
 
 [1]: https://www.freedesktop.org/software/systemd/man/systemd.exec.html
 [2]: https://fly.io/blog/docker-without-docker/
+[3]: http://git.sr.ht/~motiejus/undocker

main.go

@@ -53,15 +53,15 @@ type command struct {
 	Stdout    io.Writer
 }
 
-func (c *command) execute(infile string, outfile string) (err error) {
+func (c *command) execute(infile string, outfile string) (_err error) {
 	rd, err := os.Open(infile)
 	if err != nil {
 		return err
 	}
 	defer func() {
-		err1 := rd.Close()
-		if err == nil {
-			err = err1
+		err := rd.Close()
+		if _err == nil {
+			_err = err
 		}
 	}()
 
@@ -74,9 +74,11 @@ func (c *command) execute(infile string, outfile string) (err error) {
 			return fmt.Errorf("create: %w", err)
 		}
 		defer func() {
-			err1 := outf.Close()
-			if err == nil {
-				err = err1
+			err := outf.Close()
+			if _err != nil {
+				os.Remove(outfile)
+			} else {
+				_err = err
 			}
 		}()
 		out = outf

main_test.go

@@ -2,8 +2,10 @@ package main
 
 import (
 	"bytes"
+	"errors"
 	"io"
 	"io/ioutil"
+	"os"
 	"path/filepath"
 	"regexp"
 	"testing"
@@ -13,11 +15,13 @@ func TestExecute(t *testing.T) {
 	var _foo = []byte("foo foo")
 
 	tests := []struct {
-		name    string
-		fixture func(*testing.T, string)
-		infile  string
-		outfile string
-		wantErr string
+		name      string
+		fixture   func(*testing.T, string)
+		flattener func(io.ReadSeeker, io.Writer) error
+		infile    string
+		outfile   string
+		wantErr   string
+		assertion func(*testing.T, string)
 	}{
 		{
 			name:   "ok passthrough via stdout",
@@ -41,6 +45,31 @@ func TestExecute(t *testing.T) {
 			},
 			outfile: "t20-out.txt",
 		},
+		{
+			name:   "bad flattener should remove the file",
+			infile: "t30-in.txt",
+			fixture: func(t *testing.T, dir string) {
+				fname := filepath.Join(dir, "t30-in.txt")
+				if err := ioutil.WriteFile(fname, _foo, 0644); err != nil {
+					t.Fatalf("unexpected error: %v", err)
+				}
+			},
+			flattener: flattenBad,
+			outfile:   "t30-out.txt",
+			wantErr:   "some error",
+			assertion: func(t *testing.T, dir string) {
+				d, err := os.ReadDir(dir)
+				if err != nil {
+					t.Fatalf("unexpected error: %v", err)
+				}
+				if len(d) != 1 {
+					t.Fatalf("expected 1 entry, got %d", len(d))
+				}
+				if d[0].Name() != "t30-in.txt" {
+					t.Fatalf("expected to find only t30-in.txt, got %s", d[0].Name())
+				}
+			},
+		},
 		{
 			name:    "infile does not exist",
 			infile:  "t3-does-not-exist.txt",
@@ -57,7 +86,10 @@ func TestExecute(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			dir := t.TempDir()
 			var stdout bytes.Buffer
-			c := &command{Stdout: &stdout}
+			if tt.flattener == nil {
+				tt.flattener = flattenPassthrough
+			}
+
 			if tt.fixture != nil {
 				tt.fixture(t, dir)
 			}
@@ -65,9 +97,14 @@ func TestExecute(t *testing.T) {
 				tt.outfile = filepath.Join(dir, tt.outfile)
 			}
 			inf := filepath.Join(dir, tt.infile)
-			c.flattener = flattenPassthrough
 
+			c := &command{Stdout: &stdout, flattener: tt.flattener}
 			err := c.execute(inf, tt.outfile)
+
+			if tt.assertion != nil {
+				tt.assertion(t, dir)
+			}
+
 			if tt.wantErr != "" {
 				if err == nil {
 					t.Fatal("expected error, got nil")
@@ -78,10 +115,10 @@ func TestExecute(t *testing.T) {
 				}
 				return
 			}
-			var out []byte
 			if err != nil {
 				t.Fatalf("unexpected error: %v", err)
 			}
+			var out []byte
 			if tt.outfile == "-" {
 				out = stdout.Bytes()
 			} else {
@@ -91,8 +128,9 @@ func TestExecute(t *testing.T) {
 				}
 			}
 			if !bytes.Equal([]byte("foo foo"), out) {
-				t.Errorf("out != foo foo: %s", string(out))
+				t.Errorf("out != foo foo: %q", string(out))
 			}
+
 		})
 	}
 }
@@ -101,3 +139,7 @@ func flattenPassthrough(r io.ReadSeeker, w io.Writer) error {
 	_, err := io.Copy(w, r)
 	return err
 }
+
+func flattenBad(_ io.ReadSeeker, _ io.Writer) error {
+	return errors.New("some error")
+}

release

@@ -6,24 +6,24 @@ err() {
     exit 1
 }
 
-[[ -n "$(git status --porcelain)" ]] && \
+git status --porcelain | grep -q "" &&
     err "working tree is dirty, commit your changes first."
 
 [[ ! "$1" =~ ^v([0-9]+)\.([0-9]+)(\.([0-9]+))?$ ]] && \
     err "arg1 accepts the following formats: v1.0 v1.0.0"
 
-[[ -n "$(git tag | grep "^$1$")" ]] && \
+git tag | grep -q "^$1$" &&
     err "tag $1 already exists"
 
 last_tag=$(git tag | tail -1)
 
-make -B -j$(nproc) VSN=$1 sha256sum.txt.asc
+make -B -j"$(nproc)" VSN="$1" sha256sum.txt.asc
 
 {
-    echo undocker $1
+    echo undocker "$1"
     echo
-    echo Changelog since $last_tag:
-    git log --pretty=format:"- [%cn] %s" $last_tag..HEAD
+    echo Changelog since "$last_tag":
+    git log --pretty=format:"- [%cn] %s" "$last_tag"..HEAD
     echo
     echo
     echo sha256sums of released binaries: