xcaddy/builder.go
Aapo Keskimölö 47f9ded5d8
Add XCADDY_GO_BUILD_FLAGS env var (#104)
Add environment variable

 XCADDY_GO_BUILD_FLAGS

to override default build arguments from environment (#102).

To support flags with variable arguments Unix-style quoting is supported.
2022-06-20 13:20:05 -06:00

289 lines
9.2 KiB
Go

// Copyright 2020 Matthew Holt
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package xcaddy
import (
"context"
"fmt"
"io/ioutil"
"log"
"os"
"path"
"path/filepath"
"regexp"
"runtime"
"strconv"
"strings"
"time"
"github.com/Masterminds/semver/v3"
"github.com/caddyserver/xcaddy/internal/utils"
"github.com/google/shlex"
)
// Builder can produce a custom Caddy build with the
// configuration it represents.
type Builder struct {
Compile
CaddyVersion string `json:"caddy_version,omitempty"`
Plugins []Dependency `json:"plugins,omitempty"`
Replacements []Replace `json:"replacements,omitempty"`
TimeoutGet time.Duration `json:"timeout_get,omitempty"`
TimeoutBuild time.Duration `json:"timeout_build,omitempty"`
RaceDetector bool `json:"race_detector,omitempty"`
SkipCleanup bool `json:"skip_cleanup,omitempty"`
SkipBuild bool `json:"skip_build,omitempty"`
Debug bool `json:"debug,omitempty"`
BuildFlags string `json:"build_flags,omitempty"`
}
// Build builds Caddy at the configured version with the
// configured plugins and plops down a binary at outputFile.
func (b Builder) Build(ctx context.Context, outputFile string) error {
if outputFile == "" {
return fmt.Errorf("output file path is required")
}
// the user's specified output file might be relative, and
// because the `go build` command is executed in a different,
// temporary folder, we convert the user's input to an
// absolute path so it goes the expected place
absOutputFile, err := filepath.Abs(outputFile)
if err != nil {
return err
}
// set some defaults from the environment, if applicable
if b.OS == "" {
b.OS = os.Getenv("GOOS")
}
if b.Arch == "" {
b.Arch = os.Getenv("GOARCH")
}
if b.ARM == "" {
b.ARM = os.Getenv("GOARM")
}
// prepare the build environment
buildEnv, err := b.newEnvironment(ctx)
if err != nil {
return err
}
defer buildEnv.Close()
if b.SkipBuild {
log.Printf("[INFO] Skipping build as requested")
return nil
}
// prepare the environment for the go command; for
// the most part we want it to inherit our current
// environment, with a few customizations
env := os.Environ()
env = setEnv(env, "GOOS="+b.OS)
env = setEnv(env, "GOARCH="+b.Arch)
env = setEnv(env, "GOARM="+b.ARM)
if b.RaceDetector && !b.Compile.Cgo {
log.Println("[WARNING] Enabling cgo because it is required by the race detector")
b.Compile.Cgo = true
}
env = setEnv(env, fmt.Sprintf("CGO_ENABLED=%s", b.Compile.CgoEnabled()))
log.Println("[INFO] Building Caddy")
// tidy the module to ensure go.mod and go.sum are consistent with the module prereq
tidyCmd := buildEnv.newCommand(utils.GetGo(), "mod", "tidy")
if err := buildEnv.runCommand(ctx, tidyCmd, b.TimeoutGet); err != nil {
return err
}
// compile
cmd := buildEnv.newCommand(utils.GetGo(), "build",
"-o", absOutputFile,
)
if b.Debug {
// support dlv
cmd.Args = append(cmd.Args, "-gcflags", "all=-N -l")
} else {
if b.BuildFlags != "" {
// override build flags from environment if given
flags, err := shlex.Split(b.BuildFlags)
if err != nil {
log.Fatalf("[FATAL] Splitting arguments failed: %s", b.BuildFlags)
}
cmd.Args = append(cmd.Args, flags...)
} else {
cmd.Args = append(cmd.Args,
"-ldflags", "-w -s", // trim debug symbols
"-trimpath",
)
}
}
if b.RaceDetector {
cmd.Args = append(cmd.Args, "-race")
}
cmd.Env = env
err = buildEnv.runCommand(ctx, cmd, b.TimeoutBuild)
if err != nil {
return err
}
log.Printf("[INFO] Build complete: %s", outputFile)
return nil
}
// setEnv sets an environment variable-value pair in
// env, overriding an existing variable if it already
// exists. The env slice is one such as is returned
// by os.Environ(), and set must also have the form
// of key=value.
func setEnv(env []string, set string) []string {
parts := strings.SplitN(set, "=", 2)
key := parts[0]
for i := 0; i < len(env); i++ {
if strings.HasPrefix(env[i], key+"=") {
env[i] = set
return env
}
}
return append(env, set)
}
// Dependency pairs a Go module path with a version.
type Dependency struct {
// The name (import path) of the Go package. If at a version > 1,
// it should contain semantic import version (i.e. "/v2").
// Used with `go get`.
PackagePath string `json:"module_path,omitempty"`
// The version of the Go module, as used with `go get`.
Version string `json:"version,omitempty"`
}
// ReplacementPath represents an old or new path component
// within a Go module replacement directive.
type ReplacementPath string
// Param reformats a go.mod replace directive to be
// compatible with the `go mod edit` command.
func (r ReplacementPath) Param() string {
return strings.Replace(string(r), " ", "@", 1)
}
func (r ReplacementPath) String() string { return string(r) }
// Replace represents a Go module replacement.
type Replace struct {
// The import path of the module being replaced.
Old ReplacementPath `json:"old,omitempty"`
// The path to the replacement module.
New ReplacementPath `json:"new,omitempty"`
}
// NewReplace creates a new instance of Replace provided old and
// new Go module paths
func NewReplace(old, new string) Replace {
return Replace{
Old: ReplacementPath(old),
New: ReplacementPath(new),
}
}
// newTempFolder creates a new folder in a temporary location.
// It is the caller's responsibility to remove the folder when finished.
func newTempFolder() (string, error) {
var parentDir string
if runtime.GOOS == "darwin" {
// After upgrading to macOS High Sierra, Caddy builds mysteriously
// started missing the embedded version information that -ldflags
// was supposed to produce. But it only happened on macOS after
// upgrading to High Sierra, and it didn't happen with the usual
// `go run build.go` -- only when using a buildenv. Bug in git?
// Nope. Not a bug in Go 1.10 either. Turns out it's a breaking
// change in macOS High Sierra. When the GOPATH of the buildenv
// was set to some other folder, like in the $HOME dir, it worked
// fine. Only within $TMPDIR it broke. The $TMPDIR folder is inside
// /var, which is symlinked to /private/var, which is mounted
// with noexec. I don't understand why, but evidently that
// makes -ldflags of `go build` not work. Bizarre.
// The solution, I guess, is to just use our own "temp" dir
// outside of /var. Sigh... as long as it still gets cleaned up,
// I guess it doesn't matter too much.
// See: https://github.com/caddyserver/caddy/issues/2036
// and https://twitter.com/mholt6/status/978345803365273600 (thread)
// (using an absolute path prevents problems later when removing this
// folder if the CWD changes)
var err error
parentDir, err = filepath.Abs(".")
if err != nil {
return "", err
}
}
ts := time.Now().Format(yearMonthDayHourMin)
return ioutil.TempDir(parentDir, fmt.Sprintf("buildenv_%s.", ts))
}
// versionedModulePath helps enforce Go Module's Semantic Import Versioning (SIV) by
// returning the form of modulePath with the major component of moduleVersion added,
// if > 1. For example, inputs of "foo" and "v1.0.0" will return "foo", but inputs
// of "foo" and "v2.0.0" will return "foo/v2", for use in Go imports and go commands.
// Inputs that conflict, like "foo/v2" and "v3.1.0" are an error. This function
// returns the input if the moduleVersion is not a valid semantic version string.
// If moduleVersion is empty string, the input modulePath is returned without error.
func versionedModulePath(modulePath, moduleVersion string) (string, error) {
if moduleVersion == "" {
return modulePath, nil
}
ver, err := semver.StrictNewVersion(strings.TrimPrefix(moduleVersion, "v"))
if err != nil {
// only return the error if we know they were trying to use a semantic version
// (could have been a commit SHA or something)
if strings.HasPrefix(moduleVersion, "v") {
return "", fmt.Errorf("%s: %v", moduleVersion, err)
}
return modulePath, nil
}
major := ver.Major()
// see if the module path has a major version at the end (SIV)
matches := moduleVersionRegexp.FindStringSubmatch(modulePath)
if len(matches) == 2 {
modPathVer, err := strconv.Atoi(matches[1])
if err != nil {
return "", fmt.Errorf("this error should be impossible, but module path %s has bad version: %v", modulePath, err)
}
if modPathVer != int(major) {
return "", fmt.Errorf("versioned module path (%s) and requested module major version (%d) diverge", modulePath, major)
}
} else if major > 1 {
modulePath += fmt.Sprintf("/v%d", major)
}
return path.Clean(modulePath), nil
}
var moduleVersionRegexp = regexp.MustCompile(`.+/v(\d+)$`)
const (
// yearMonthDayHourMin is the date format
// used for temporary folder paths.
yearMonthDayHourMin = "2006-01-02-1504"
defaultCaddyModulePath = "github.com/caddyserver/caddy"
)