Add XCADDY_SKIP_BUILD option (#41)

* feat: add XCADDY_NO_BUILD to not run go build

* Rename XCADDY_NO_BUILD to XCADDY_SKIP_BUILD

* fix rebase

README.md

@@ -124,8 +124,9 @@ Because the subcommands and flags are constrained to benefit rapid plugin protot
 
 - `CADDY_VERSION` sets the version of Caddy to build.
 - `XCADDY_RACE_DETECTOR=1` enables the Go race detector in the build.
-- `XCADDY_SKIP_CLEANUP=1` causes xcaddy to leave build artifacts on disk after exiting.
 - `XCADDY_SETCAP=1` will run `sudo setcap cap_net_bind_service=+ep` on the temporary binary before running it when in dev mode.
+- `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.
 
 ---
 

builder.go

@@ -42,6 +42,7 @@ type Builder struct {
 	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"`
 }
 
 // Build builds Caddy at the configured version with the
@@ -77,6 +78,12 @@ func (b Builder) Build(ctx context.Context, outputFile string) error {
 	}
 	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

cmd/xcaddy/main.go

@@ -32,6 +32,7 @@ import (
 var (
 	caddyVersion = os.Getenv("CADDY_VERSION")
 	raceDetector = os.Getenv("XCADDY_RACE_DETECTOR") == "1"
+	skipBuild    = os.Getenv("XCADDY_SKIP_BUILD") == "1"
 	skipCleanup  = os.Getenv("XCADDY_SKIP_CLEANUP") == "1"
 )
 
@@ -111,6 +112,7 @@ func runBuild(ctx context.Context, args []string) error {
 		Plugins:      plugins,
 		Replacements: replacements,
 		RaceDetector: raceDetector,
+		SkipBuild:    skipBuild,
 		SkipCleanup:  skipCleanup,
 	}
 	err := builder.Build(ctx, output)
@@ -216,6 +218,7 @@ func runDev(ctx context.Context, args []string) error {
 		},
 		Replacements: replacements,
 		RaceDetector: raceDetector,
+		SkipBuild:    skipBuild,
 		SkipCleanup:  skipCleanup,
 	}
 	err = builder.Build(ctx, binOutput)