Build tags for smaller binaries that don't need net/http or encoding/json

.gitignore

@@ -1 +1,6 @@
+.DS_Store
 .golangci.yml
+fullsize
+smallsize
+coverage.out
+coverage?.out

.vscode/launch.json

@@ -0,0 +1,14 @@
+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Launch test function with tags",
+            "type": "go",
+            "request": "launch",
+            "mode": "test",
+            "program": "${workspaceFolder}",
+            "buildFlags": "-tags=no_json"
+        }
+
+    ]
+}

Makefile

@@ -2,7 +2,22 @@
 all: test example
 
 test:
-	go test . -race ./...
+	go test -race ./...
+	go test -tags no_json ./...
+	go test -tags no_http ./...
+
+local-coverage: coverage
+	go test -coverprofile=coverage.out ./...
+	go tool cover -html=coverage.out
+
+coverage:
+	go test -coverprofile=coverage1.out ./...
+	go test -tags no_net -coverprofile=coverage2.out ./...
+	go test -tags no_json -coverprofile=coverage3.out ./...
+	go test -tags no_http,no_json -coverprofile=coverage4.out ./...
+	# cat coverage*.out > coverage.out
+	go install github.com/wadey/gocovmerge@b5bfa59ec0adc420475f97f89b58045c721d761c
+	gocovmerge coverage?.out > coverage.out
 
 example:
 	@echo "### Colorized (default) ###"
@@ -17,9 +32,20 @@ line:
 screenshot: line example
 	@echo
 
+size-check:
+	@echo "### Size of the binary:"
+	CGO_ENABLED=0 go build -ldflags="-w -s" -trimpath -o ./fullsize ./levelsDemo
+	ls -lh ./fullsize
+	CGO_ENABLED=0 go build -tags no_net -ldflags="-w -s" -trimpath -o ./smallsize ./levelsDemo
+	ls -lh ./smallsize
+	CGO_ENABLED=0 go build -tags no_http,no_json -ldflags="-w -s" -trimpath -o ./smallsize ./levelsDemo
+	ls -lh ./smallsize
+	gsa ./smallsize # go install github.com/Zxilly/go-size-analyzer/cmd/gsa@master
+
 
 lint: .golangci.yml
 	golangci-lint run
+	golangci-lint run --build-tags no_json
 
 .golangci.yml: Makefile
 	curl -fsS -o .golangci.yml https://raw.githubusercontent.com/fortio/workflows/main/golangci.yml

README.md

@@ -34,7 +34,7 @@ log.S(log.Info, "msg", log.Attr("key1", value1)...)
 
 See the `Config` object for options like whether to include line number and file name of caller or not etc
 
-New since 1.4 server logging (as used in [fortio.org/scli](https://pkg.go.dev/fortio.org/scli#ServerMain) for instance) is now structured (json), client logging (as setup by [fortio.org/cli](https://pkg.go.dev/fortio.org/scli#ServerMain) remains as before.
+New since 1.4 server logging (as used in [fortio.org/scli](https://pkg.go.dev/fortio.org/scli#ServerMain) for instance) is now structured (JSON), client logging (as setup by [fortio.org/cli](https://pkg.go.dev/fortio.org/scli#ServerMain) remains as before.
 
 One can also revert server to not be JSON through config.
 
@@ -46,7 +46,7 @@ Which can be converted to JSONEntry but is also a fixed, optimized format (ie ts
 
 The timestamp `ts` is in seconds.microseconds since epoch (golang UnixMicro() split into seconds part before decimal and microseconds after)
 
-Since 1.8 the Go Routine ID is present in json (`r` field) or colorized log output (for multi threaded server types).
+Since 1.8 the Go Routine ID is present in JSON (`r` field) or colorized log output (for multi threaded server types).
 
 Optional additional `KeyValue` pairs can be added to the base structure using the new `log.S` or passed to `log.LogRequest` using `log.Any` and `log.Str`. Note that numbers, as well as arrays of any type and maps of string keys to any type are supported (but more expensive to serialize recursively).
 
@@ -63,7 +63,7 @@ When output is redirected, JSON output:
 {"ts":1689986143.4634,"level":"err","r":1,"file":"levels.go","line":23,"msg":"This is an error message"}
 {"ts":1689986143.463403,"level":"crit","r":1,"file":"levels.go","line":24,"msg":"This is a critical message"}
 {"ts":1689986143.463406,"level":"fatal","r":1,"file":"levels.go","line":25,"msg":"This is a fatal message"}
-This is a non json output, will get prefixed with a exclamation point with logc
+This is a non JSON output, will get prefixed with a exclamation point with logc
 ```
 
 When on console:
@@ -100,3 +100,11 @@ LOGGER_GOROUTINE_ID=false
 LOGGER_COMBINE_REQUEST_AND_RESPONSE=true
 LOGGER_LEVEL='Info'
 ```
+
+# Small binaries
+
+If you're never logging http requests/responses, use `-tags no_http` (or `-tags no_net`) to exclude the http/https logging utilities (which pulls in a lot of dependencies because of `net/http` init).
+
+If you never need to JSON log complex structures/types that have a special `json.Marshaler` then you can use `-tags no_net,no_json` for the smallest executables
+
+(see `make size-check`)

codecov.yml

@@ -0,0 +1,6 @@
+coverage:
+  ignore:
+    - "levelsDemo"
+# not used (is nothing at all used?)
+#  files:
+#    - "coverage*.out"

http_logging.go

@@ -12,6 +12,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+//go:build !no_http && !no_net
+// +build !no_http,!no_net
+
 package log
 
 import (

http_logging_test.go

@@ -1,3 +1,6 @@
+//go:build !no_http && !no_net
+// +build !no_http,!no_net
+
 package log // import "fortio.org/fortio/log"
 
 import (

json_logging.go

@@ -0,0 +1,67 @@
+// Copyright 2017-2024 Fortio Authors
+//
+// 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.
+
+// Moved json logging out so it can be skipped for smallest binaries based on build tags.
+// only difference is with nested struct/array logging or logging of types with json Marchaller interface.
+
+//go:build !no_json
+
+package log // import "fortio.org/log"
+
+import (
+	"encoding/json"
+	"fmt"
+	"strconv"
+)
+
+var fullJSON = true
+
+func toJSON(v any) string {
+	bytes, err := json.Marshal(v)
+	if err != nil {
+		return strconv.Quote(fmt.Sprintf("ERR marshaling %v: %v", v, err))
+	}
+	str := string(bytes)
+	// We now handle errors before calling toJSON: if there is a marshaller we use it
+	// otherwise we use the string from .Error()
+	return str
+}
+
+func (v ValueType[T]) String() string {
+	// if the type is numeric, use Sprint(v.val) otherwise use Sprintf("%q", v.Val) to quote it.
+	switch s := any(v.Val).(type) {
+	case bool, int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64,
+		float32, float64:
+		return fmt.Sprint(s)
+	case string:
+		return fmt.Sprintf("%q", s)
+	case error:
+		// Sadly structured errors like nettwork error don't have the reason in
+		// the exposed struct/JSON - ie on gets
+		// {"Op":"read","Net":"tcp","Source":{"IP":"127.0.0.1","Port":60067,"Zone":""},
+		// "Addr":{"IP":"127.0.0.1","Port":3000,"Zone":""},"Err":{}}
+		// instead of
+		// read tcp 127.0.0.1:60067->127.0.0.1:3000: i/o timeout
+		// Noticed in https://github.com/fortio/fortio/issues/913
+		_, hasMarshaller := s.(json.Marshaler)
+		if hasMarshaller {
+			return toJSON(v.Val)
+		} else {
+			return fmt.Sprintf("%q", s.Error())
+		}
+	/* It's all handled by json fallback now even though slightly more expensive at runtime, it's a lot simpler */
+	default:
+		return toJSON(v.Val) // was fmt.Sprintf("%q", fmt.Sprint(v.Val))
+	}
+}

json_logging_test.go

@@ -0,0 +1,20 @@
+//go:build !no_json
+// +build !no_json
+
+package log // import "fortio.org/fortio/log"
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestToJSON_MarshalError(t *testing.T) {
+	badValue := make(chan int)
+
+	expected := fmt.Sprintf("\"ERR marshaling %v: %v\"", badValue, "json: unsupported type: chan int")
+	actual := toJSON(badValue)
+
+	if actual != expected {
+		t.Errorf("Expected %q, got %q", expected, actual)
+	}
+}

levelsDemo/levels.go

@@ -14,10 +14,10 @@ func main() {
 	log.Config.GoroutineID = false
 	log.Debugf("This is a debug message without goroutine id, file:line nor prefix (cli style)")
 	log.Config = log.DefaultConfig()
-	// So log fatal doesn't panic nor exit (so we can print the non json last line).
+	// So log fatal doesn't panic nor exit (so we can print the non JSON last line).
 	log.Config.FatalPanics = false
 	log.Config.FatalExit = func(int) {}
-	// Meat of the example: (some of these are reproducing fixed issues in `logc` json->console attributes detection)
+	// Meat of the example: (some of these are reproducing fixed issues in `logc` JSON->console attributes detection)
 	log.Debugf("Back to default (server) logging style with a debug message ending with backslash \\")
 	log.LogVf("This is a verbose message")
 	log.Printf("This an always printed, file:line omitted message (and no level in console)")
@@ -28,5 +28,5 @@ func main() {
 	log.Errf("This is an error message")
 	log.Critf("This is a critical message")
 	log.Fatalf("This is a fatal message") //nolint:revive // we disabled exit for this demo
-	fmt.Println("This is a non json output, will get prefixed with a exclamation point with logc")
+	fmt.Println("This is a non JSON output, will get prefixed with a exclamation point with logc")
 }

logger.go

@@ -25,7 +25,6 @@ package log // import "fortio.org/log"
 
 import (
 	"bytes"
-	"encoding/json"
 	"flag"
 	"fmt"
 	"io"
@@ -349,7 +348,7 @@ func Logf(lvl Level, format string, rest ...interface{}) {
 	logPrintf(lvl, format, rest...)
 }
 
-// Used when doing our own logging writing, in JSON/structured mode.
+// Used when doing our own logging writing, in JSON/structured mode (and some color variants as well, misnomer).
 var (
 	jWriter = jsonWriter{w: os.Stderr, tsBuf: make([]byte, 0, 32)}
 )
@@ -617,6 +616,11 @@ func Bool(key string, value bool) KeyVal {
 	return Any(key, value)
 }
 
+func Rune(key string, value rune) KeyVal {
+	// Special case otherwise rune is printed as int32 number
+	return Any(key, string(value)) // similar to "%c".
+}
+
 func (v *KeyVal) StringValue() string {
 	if !v.Cached {
 		v.StrValue = v.Value.String()
@@ -631,45 +635,6 @@ type ValueType[T ValueTypes] struct {
 	Val T
 }
 
-func toJSON(v any) string {
-	bytes, err := json.Marshal(v)
-	if err != nil {
-		return strconv.Quote(fmt.Sprintf("ERR marshaling %v: %v", v, err))
-	}
-	str := string(bytes)
-	// We now handle errors before calling toJSON: if there is a marshaller we use it
-	// otherwise we use the string from .Error()
-	return str
-}
-
-func (v ValueType[T]) String() string {
-	// if the type is numeric, use Sprint(v.val) otherwise use Sprintf("%q", v.Val) to quote it.
-	switch s := any(v.Val).(type) {
-	case bool, int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64,
-		float32, float64:
-		return fmt.Sprint(s)
-	case string:
-		return fmt.Sprintf("%q", s)
-	case error:
-		// Sadly structured errors like nettwork error don't have the reason in
-		// the exposed struct/JSON - ie on gets
-		// {"Op":"read","Net":"tcp","Source":{"IP":"127.0.0.1","Port":60067,"Zone":""},
-		// "Addr":{"IP":"127.0.0.1","Port":3000,"Zone":""},"Err":{}}
-		// instead of
-		// read tcp 127.0.0.1:60067->127.0.0.1:3000: i/o timeout
-		// Noticed in https://github.com/fortio/fortio/issues/913
-		_, hasMarshaller := s.(json.Marshaler)
-		if hasMarshaller {
-			return toJSON(v.Val)
-		} else {
-			return fmt.Sprintf("%q", s.Error())
-		}
-	/* It's all handled by json fallback now even though slightly more expensive at runtime, it's a lot simpler */
-	default:
-		return toJSON(v.Val) // was fmt.Sprintf("%q", fmt.Sprint(v.Val))
-	}
-}
-
 // Our original name, now switched to slog style Any.
 func Attr[T ValueTypes](key string, value T) KeyVal {
 	return Any(key, value)