Enable overriding build flags from environment

README.md

@@ -157,6 +157,7 @@ Because the subcommands and flags are constrained to benefit rapid plugin protot
 - `XCADDY_SKIP_BUILD=1` causes xcaddy to not compile the program, it is used in conjunction with build tools such as [GoReleaser](https://goreleaser.com). Implies `XCADDY_SKIP_CLEANUP=1`.
 - `XCADDY_SKIP_CLEANUP=1` causes xcaddy to leave build artifacts on disk after exiting.
 - `XCADDY_WHICH_GO` sets the go command to use when for example more then 1 version of go is installed.
+- `XCADDY_GO_BUILD_FLAGS` overrides default build arguments. Supports Unix-style shell quoting, for example: XCADDY_GO_BUILD_FLAGS="-ldflags '-w s'".
 ---
 
 © 2020 Matthew Holt

builder.go

@@ -30,6 +30,7 @@ import (
 
  "github.com/Masterminds/semver/v3"
  "github.com/caddyserver/xcaddy/internal/utils"
+ "github.com/google/shlex"
 )
 
 // Builder can produce a custom Caddy build with the
@@ -45,6 +46,7 @@ type Builder struct {
  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
@@ -115,10 +117,19 @@ func (b Builder) Build(ctx context.Context, outputFile string) error {
  // support dlv
  cmd.Args = append(cmd.Args, "-gcflags", "all=-N -l")
  } else {
- cmd.Args = append(cmd.Args,
- "-ldflags", "-w -s", // trim debug symbols
- "-trimpath",
- )
+ 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/main.go

@@ -40,6 +40,7 @@ var (
  skipBuild = os.Getenv("XCADDY_SKIP_BUILD") == "1"
  skipCleanup = os.Getenv("XCADDY_SKIP_CLEANUP") == "1" || skipBuild
  buildDebugOutput = os.Getenv("XCADDY_DEBUG") == "1"
+ buildFlags = os.Getenv("XCADDY_GO_BUILD_FLAGS")
 )
 
 func Main() {
@@ -134,6 +135,7 @@ func runBuild(ctx context.Context, args []string) error {
  SkipBuild: skipBuild,
  SkipCleanup: skipCleanup,
  Debug: buildDebugOutput,
+ BuildFlags: buildFlags,
  }
  err := builder.Build(ctx, output)
  if err != nil {

environment.go

@@ -98,6 +98,7 @@ func (b Builder) newEnvironment(ctx context.Context) (*environment, error) {
  tempFolder: tempFolder,
  timeoutGoGet: b.TimeoutGet,
  skipCleanup: b.SkipCleanup,
+ buildFlags: b.BuildFlags,
  }
 
  // initialize the go module
@@ -177,6 +178,7 @@ type environment struct {
  tempFolder string
  timeoutGoGet time.Duration
  skipCleanup bool
+ buildFlags string
 }
 
 // Close cleans up the build environment, including deleting

go.mod

@@ -2,4 +2,7 @@ module github.com/caddyserver/xcaddy
 
 go 1.14
 
-require github.com/Masterminds/semver/v3 v3.1.1
+require (
+ github.com/Masterminds/semver/v3 v3.1.1
+ github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510
+)

go.sum

@@ -1,2 +1,4 @@
 github.com/Masterminds/semver/v3 v3.1.1 h1:hLg3sBzpNErnxhQtUy/mmLR2I9foDujNK030IGemrRc=
 github.com/Masterminds/semver/v3 v3.1.1/go.mod h1:VPu/7SZ7ePZ3QOrcuXROw5FAcLl4a0cBrbBpGY/8hQs=
+github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510 h1:El6M4kTTCOh6aBiKaUGG7oYTSPP8MxqL4YI3kZKwcP4=
+github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510/go.mod h1:pupxD2MaaD3pAXIBCelhxNneeOaAeabZDe5s4K6zSpQ=