From 4bb09063fcfcb8a58984ad6c478012f8d5f17d0f Mon Sep 17 00:00:00 2001
From: Jack Robertson <jack.robertson@nexusmods.com>
Date: Tue, 11 Jul 2023 17:03:33 +0100
Subject: [PATCH] refactor: move slog package to root, add configuration
options and tests
---
options.go | 25 ++++++++++++++++++++++++
slog.go | 51 ++++++++++++++++++++++++++++++++++++++++++++++++
slog_test.go | 34 ++++++++++++++++++++++++++++++++
src/main/main.go | 10 ----------
src/slog/slog.go | 41 --------------------------------------
5 files changed, 110 insertions(+), 51 deletions(-)
create mode 100644 options.go
create mode 100644 slog.go
create mode 100644 slog_test.go
delete mode 100644 src/main/main.go
delete mode 100644 src/slog/slog.go
diff --git a/options.go b/options.go
new file mode 100644
index 0000000..fd76bee
--- /dev/null
+++ b/options.go
@@ -0,0 +1,25 @@
+package slog
+
+import (
+ "golang.org/x/exp/slog"
+ "io"
+)
+
+type Options struct {
+ Leveler slog.Leveler
+ Writer io.Writer
+}
+
+type Option func(*Options)
+
+func WithLeveler(leveler slog.Leveler) Option {
+ return func(o *Options) {
+ o.Leveler = leveler
+ }
+}
+
+func WithWriter(writer io.Writer) Option {
+ return func(o *Options) {
+ o.Writer = writer
+ }
+}
diff --git a/slog.go b/slog.go
new file mode 100644
index 0000000..603449a
--- /dev/null
+++ b/slog.go
@@ -0,0 +1,51 @@
+package slog
+
+import (
+ "golang.org/x/exp/slog"
+ "os"
+ "strings"
+)
+
+func New(opts ...Option) *slog.Logger {
+ options := &Options{
+ Leveler: slog.LevelDebug,
+ Writer: os.Stdout,
+ }
+ for _, opt := range opts {
+ opt(options)
+ }
+
+ // Attributes modified for datadog schema via HandlerOptions.ReplaceAttr
+ // Per recommendation at https://pkg.go.dev/golang.org/x/exp/slog#JSONHandler
+ // See datadog: https://docs.datadoghq.com/logs/log_configuration/attributes_naming_convention/#reserved-attributes
+ replaceAttr := func(groups []string, attr slog.Attr) slog.Attr {
+ if attr.Key == "msg" {
+ attr.Key = "message"
+ }
+ if attr.Key == "time" {
+ attr.Key = "date"
+ }
+ if attr.Key == "level" {
+ attr.Key = "status"
+ attr.Value = slog.StringValue(strings.ToLower(attr.Value.String()))
+ }
+ return attr
+ }
+
+ handlerOptions := &slog.HandlerOptions{
+ Level: options.Leveler,
+ AddSource: true,
+ ReplaceAttr: replaceAttr,
+ }
+ logHandler := slog.NewJSONHandler(options.Writer, handlerOptions)
+ logger := slog.New(logHandler)
+
+ hostname, err := os.Hostname()
+ if err != nil {
+ logger.Error("Failed to get hostname.", slog.String("error", err.Error()))
+ } else {
+ logger = logger.With("host", hostname)
+ }
+
+ return logger
+}
diff --git a/slog_test.go b/slog_test.go
new file mode 100644
index 0000000..f1007b4
--- /dev/null
+++ b/slog_test.go
@@ -0,0 +1,34 @@
+package slog
+
+import (
+ "bufio"
+ "bytes"
+ "encoding/json"
+ "golang.org/x/exp/slog"
+ "testing"
+)
+
+func TestNew(t *testing.T) {
+ var buf bytes.Buffer
+
+ logger := New(WithWriter(&buf))
+ logger.Info("Foo", slog.String("bar", "baz"))
+ logger.Error("Bar", slog.String("baz", "qux"))
+
+ scanner := bufio.NewScanner(&buf)
+
+ // Scan the first log.
+ scanner.Scan()
+ infoLog := scanner.Bytes()
+ var infoLogMap map[string]any
+ if err := json.Unmarshal(infoLog, &infoLogMap); err != nil {
+ t.Errorf("Failed to unmarshal info log: %s", err.Error())
+ }
+ t.Log(infoLogMap)
+ if infoLogMap["status"] != "info" {
+ t.Errorf("Expected info log level, got %s", infoLogMap["level"])
+ }
+ if infoLogMap["bar"] != "baz" {
+ t.Errorf("Expected bar=baz, got %s", infoLogMap["bar"])
+ }
+}
diff --git a/src/main/main.go b/src/main/main.go
deleted file mode 100644
index c2e8c45..0000000
--- a/src/main/main.go
+++ /dev/null
@@ -1,10 +0,0 @@
-package main
-
-import (
- "gitlab.nexdev.uk/pub/go-slog/src/slog"
-)
-
-func main() {
- logger := slog.InitLogger()
- logger.Info("Logger test.")
-}
diff --git a/src/slog/slog.go b/src/slog/slog.go
deleted file mode 100644
index 8c58241..0000000
--- a/src/slog/slog.go
+++ /dev/null
@@ -1,41 +0,0 @@
-package slog
-
-import (
- "golang.org/x/exp/slog"
- "os"
- "strings"
-)
-
-func InitLogger() *slog.Logger {
- // Could set logger level via ENV vars in future.
- programLevel := new(slog.LevelVar)
- programLevel.Set(slog.LevelDebug)
-
- // Attributes modified for datadog schema via HandlerOptions.ReplaceAttr
- // Per recommendation at https://pkg.go.dev/golang.org/x/exp/slog#JSONHandler
- // See datadog: https://docs.datadoghq.com/logs/log_configuration/attributes_naming_convention/#reserved-attributes
- loggerReplace := func(groups []string, a slog.Attr) slog.Attr {
- if a.Key == "msg" {
- a.Key = "message"
- }
- if a.Key == "time" {
- a.Key = "date"
- }
- if a.Key == "level" {
- a.Key = "status"
- a.Value = slog.StringValue(strings.ToLower(a.Value.String()))
- }
- return a
- }
- logger := slog.New(slog.NewJSONHandler(os.Stdout,
- &slog.HandlerOptions{Level: programLevel, AddSource: true, ReplaceAttr: loggerReplace}))
- hostname, hostnameErr := os.Hostname()
- if hostnameErr == nil {
- logger = logger.With("host", hostname)
- } else {
- logger.Error("Failed to get hostname.", slog.String("error", hostnameErr.Error()))
- }
-
- logger.Info("Initialised.")
- return logger
-}
--
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