Replace build.bash with build.go; limit timestamp inclusion

build.go is (should be) cross-platform compatible.

Timestamps are now excluded from all builds on a clean commit,
in an effort to be byte-for-byte reproducible.

README.md

@@ -57,7 +57,7 @@ Caddy binaries have no dependencies and are available for every platform. Get Ca
 customize your build in the browser
 - **[Latest release](https://github.com/mholt/caddy/releases/latest)** for
 pre-built, vanilla binaries
-- **go get** to build from source: `go get github.com/mholt/caddy/caddy` (requires Go 1.8 or newer)
+- **go get** to build from source: `go get github.com/mholt/caddy/caddy` (requires Go 1.8 or newer) - to build with proper version information (required when filing issues), `cd` to the `caddy` folder and use `go run build.go`.
 
 Then make sure the `caddy` binary is in your PATH.
 

caddy/build.bash

-#!/usr/bin/env bash
-#
-# Caddy build script. Automates proper versioning.
-#
-# Usage:
-#
-#     $ ./build.bash [output_filename] [git_repo]
-#
-# Outputs compiled program in current directory.
-# Default git repo is current directory.
-# Builds always take place from current directory.
-
-set -euo pipefail
-
-: ${output_filename:="${1:-}"}
-: ${output_filename:=""}
-
-: ${git_repo:="${2:-}"}
-: ${git_repo:="."}
-
-pkg=github.com/mholt/caddy/caddy/caddymain
-ldflags=()
-
-# Timestamp of build
-name="${pkg}.buildDate"
-value=$(date -u +"%a %b %d %H:%M:%S %Z %Y")
-ldflags+=("-X" "\"${name}=${value}\"")
-
-# Current tag, if HEAD is on a tag
-name="${pkg}.gitTag"
-set +e
-value="$(git -C "${git_repo}" describe --exact-match HEAD 2>/dev/null)"
-set -e
-ldflags+=("-X" "\"${name}=${value}\"")
-
-# Nearest tag on branch
-name="${pkg}.gitNearestTag"
-value="$(git -C "${git_repo}" describe --abbrev=0 --tags HEAD)"
-ldflags+=("-X" "\"${name}=${value}\"")
-
-# Commit SHA
-name="${pkg}.gitCommit"
-value="$(git -C "${git_repo}" rev-parse --short HEAD)"
-ldflags+=("-X" "\"${name}=${value}\"")
-
-# Summary of uncommitted changes
-name="${pkg}.gitShortStat"
-value="$(git -C "${git_repo}" diff-index --shortstat HEAD)"
-ldflags+=("-X" "\"${name}=${value}\"")
-
-# List of modified files
-name="${pkg}.gitFilesModified"
-value="$(git -C "${git_repo}" diff-index --name-only HEAD)"
-ldflags+=("-X" "\"${name}=${value}\"")
-
-go build -ldflags "${ldflags[*]}" -o "${output_filename}"

caddy/build.go

+// +build dev
+
+// build.go automates proper versioning of caddy binaries.
+// Use it like:   go run build.go
+// You can customize the build with the -goos, -goarch, and
+// -goarm CLI options:   go run build.go -goos=windows
+//
+// To get proper version information, this program must be
+// run from the directory of this file, and the source code
+// must be a working git repository, since it needs to know
+// if the source is in a clean state.
+//
+// This program is NOT required to build Caddy from source
+// since it is go-gettable. (You can run plain `go build`
+// in this directory to get a binary.) However, issues filed
+// without version information will likely be closed.
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"os/exec"
+	"path/filepath"
+
+	"github.com/caddyserver/buildworker"
+)
+
+var goos, goarch, goarm string
+
+func init() {
+	flag.StringVar(&goos, "goos", "", "GOOS for which to build")
+	flag.StringVar(&goarch, "goarch", "", "GOARCH for which to build")
+	flag.StringVar(&goarm, "goarm", "", "GOARM for which to build")
+}
+
+func main() {
+	flag.Parse()
+
+	gopath := os.Getenv("GOPATH")
+
+	pwd, err := os.Getwd()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	ldflags, err := buildworker.MakeLdFlags(filepath.Join(pwd, ".."))
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	args := []string{"build", "-ldflags", ldflags}
+	args = append(args, "-asmflags", fmt.Sprintf("-trimpath=%s", gopath))
+	args = append(args, "-gcflags", fmt.Sprintf("-trimpath=%s", gopath))
+	cmd := exec.Command("go", args...)
+	cmd.Stderr = os.Stderr
+	cmd.Stdout = os.Stdout
+	cmd.Env = os.Environ()
+	for _, env := range []string{
+		"CGO_ENABLED=0",
+		"GOOS=" + goos,
+		"GOARCH=" + goarch,
+		"GOARM=" + goarm,
+	} {
+		cmd.Env = append(cmd.Env, env)
+	}
+
+	err = cmd.Run()
+	if err != nil {
+		log.Fatal(err)
+	}
+}

caddy/caddymain/run.go

@@ -186,10 +186,14 @@ func setVersion() {
 	// A development build is one that's not at a tag or has uncommitted changes
 	devBuild = gitTag == "" || gitShortStat != ""
 
+	if buildDate != "" {
+		buildDate = " " + buildDate
+	}
+
 	// Only set the appVersion if -ldflags was used
 	if gitNearestTag != "" || gitTag != "" {
 		if devBuild && gitNearestTag != "" {
-			appVersion = fmt.Sprintf("%s (+%s %s)",
+			appVersion = fmt.Sprintf("%s (+%s%s)",
 				strings.TrimPrefix(gitNearestTag, "v"), gitCommit, buildDate)
 		} else if gitTag != "" {
 			appVersion = strings.TrimPrefix(gitTag, "v")