feat: initial shared logging module

slog SetupLogger (text/json/otel), context logger helpers, MockLogger test
helper, and a request-logger HTTP middleware sub-package. Replaces the logging
package + middleware request-logger copied across the backend services.

.gitea/workflows/ci.yaml

@@ -0,0 +1,35 @@
+name: logging
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  test:
+    if: gitea.event_name == 'pull_request'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - uses: actions/setup-go@v6
+        with:
+          go-version: 'stable'
+      - name: Format check
+        run: |
+          go install mvdan.cc/gofumpt@latest
+          test -z "$(gofumpt -l .)"
+      - name: Run tests
+        run: go test -race ./...
+  vulnerabilities:
+    if: gitea.event_name == 'pull_request'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - uses: actions/setup-go@v6
+        with:
+          go-version: 'stable'
+      - name: Check vulnerabilities
+        run: |
+          go install golang.org/x/vuln/cmd/govulncheck@latest
+          govulncheck ./...

.gitignore

@@ -0,0 +1,4 @@
+.idea
+.claude
+/release
+coverage.txt

README.md

@@ -0,0 +1,13 @@
+# logging
+
+Shared logging primitives for Shiny backend services.
+
+- `SetupLogger(level, format, service, version)` — configures the slog default
+  logger (text / json / otel) and returns it.
+- `ContextWithLogger` / `LoggerFromContext` — carry a logger on the context.
+- `NewMockLogger()` — test helper for asserting log output.
+- `logging/middleware.RequestLogger(logger)` — HTTP middleware that debug-logs
+  request/response bodies.
+
+Replaces the `logging` package (and the `middleware` request-logger) copied
+into the backend services.

go.mod

@@ -0,0 +1,22 @@
+module gitea.unbound.se/shiny/logging
+
+go 1.25.0
+
+require (
+	github.com/stretchr/testify v1.11.1
+	go.opentelemetry.io/contrib/bridges/otelslog v0.19.0
+)
+
+require (
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/go-logr/logr v1.4.3 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
+	go.opentelemetry.io/otel v1.44.0 // indirect
+	go.opentelemetry.io/otel/log v0.20.0 // indirect
+	go.opentelemetry.io/otel/metric v1.44.0 // indirect
+	go.opentelemetry.io/otel/trace v1.44.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

go.sum

@@ -0,0 +1,38 @@
+github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
+github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/logr v1.4.3 h1:CjnDlHq8ikf6E492q6eKboGOC0T8CDaOvkHCIg8idEI=
+github.com/go-logr/logr v1.4.3/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
+github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
+github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
+github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
+github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
+github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
+github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/rogpeppe/go-internal v1.14.1 h1:UQB4HGPB6osV0SQTLymcB4TgvyWu6ZyliaW0tI/otEQ=
+github.com/rogpeppe/go-internal v1.14.1/go.mod h1:MaRKkUm5W0goXpeCfT7UZI6fk/L7L7so1lCWt35ZSgc=
+github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
+github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
+go.opentelemetry.io/auto/sdk v1.2.1 h1:jXsnJ4Lmnqd11kwkBV2LgLoFMZKizbCi5fNZ/ipaZ64=
+go.opentelemetry.io/auto/sdk v1.2.1/go.mod h1:KRTj+aOaElaLi+wW1kO/DZRXwkF4C5xPbEe3ZiIhN7Y=
+go.opentelemetry.io/contrib/bridges/otelslog v0.19.0 h1:5RgvxieNq9tS3ewrV1vnODvbHPfKUIJcYtF9Cvz+6aQ=
+go.opentelemetry.io/contrib/bridges/otelslog v0.19.0/go.mod h1:iTBIdNwx/xmUhfgJs6+84S4dIK059811cO1eUBjKcHY=
+go.opentelemetry.io/otel v1.44.0 h1:JjwHmHpA4iZ3wBxluu2fbbE7j4kqlE8jXyAyPXH7HqU=
+go.opentelemetry.io/otel v1.44.0/go.mod h1:BMgjTHL9WPRlRjL2oZCBTL4whCGtXch2H4BhOPIAyYc=
+go.opentelemetry.io/otel/log v0.20.0 h1:/5i0vuHxCLWUfChWG41K9wkM0jafruPw9NU1/RCJirs=
+go.opentelemetry.io/otel/log v0.20.0/go.mod h1:wOcMcjsZpG8x7Bak7IhSi/lg8wscV2C1VdrKCLPlt0E=
+go.opentelemetry.io/otel/metric v1.44.0 h1:1w0gILTcHdr3YI+ixLyjemwrVnsMURbTZFrSYCdDdmc=
+go.opentelemetry.io/otel/metric v1.44.0/go.mod h1:8O7hanEPBNgEMmybD3s2VBKcgWOCsA6tzHBPODAiquo=
+go.opentelemetry.io/otel/trace v1.44.0 h1:jxF5CsGYCe74MCRx2X4g7WsY/VBKRqqpNvXlX/6gtIk=
+go.opentelemetry.io/otel/trace v1.44.0/go.mod h1:oLl1jrMQAVo6v3GAggN+1VH9VIz9iUSvW53sW1Q8PIE=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

log.go

@@ -0,0 +1,63 @@
+package logging
+
+import (
+	"context"
+	"log/slog"
+	"os"
+
+	"go.opentelemetry.io/contrib/bridges/otelslog"
+)
+
+type Logger interface {
+	Info(msg string, args ...any)
+	Warn(msg string, args ...any)
+	Error(msg string, args ...any)
+}
+
+var defaultLogger *slog.Logger
+
+type contextKey string
+
+const loggerKey = contextKey("logger")
+
+func SetupLogger(logLevel, logFormat, serviceName, buildVersion string) *slog.Logger {
+	var leveler slog.LevelVar
+
+	err := leveler.UnmarshalText([]byte(logLevel))
+	handlerOpts := &slog.HandlerOptions{
+		AddSource:   false,
+		Level:       leveler.Level(),
+		ReplaceAttr: nil,
+	}
+	var handler slog.Handler
+	switch logFormat {
+	case "json":
+		handler = slog.NewJSONHandler(os.Stdout, handlerOpts)
+	case "text":
+		handler = slog.NewTextHandler(os.Stdout, handlerOpts)
+	case "otel":
+		handler = otelslog.NewHandler(serviceName,
+			otelslog.WithVersion(buildVersion))
+	}
+	defaultLogger = slog.New(handler).With("service", serviceName).With("version", buildVersion)
+	if err != nil {
+		defaultLogger.With("err", err).Error("Failed to parse log level")
+		os.Exit(1)
+	}
+	slog.SetDefault(defaultLogger)
+	return defaultLogger
+}
+
+// ContextWithLogger returns a new Context with the logger attached
+func ContextWithLogger(ctx context.Context, logger *slog.Logger) context.Context {
+	return context.WithValue(ctx, loggerKey, logger)
+}
+
+// LoggerFromContext returns a logger from the passed context or the default logger
+func LoggerFromContext(ctx context.Context) *slog.Logger {
+	logger := ctx.Value(loggerKey)
+	if l, ok := logger.(*slog.Logger); ok {
+		return l
+	}
+	return defaultLogger
+}

log_test.go

@@ -0,0 +1,33 @@
+package logging
+
+import (
+	"context"
+	"log/slog"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestSetupLogger(t *testing.T) {
+	for _, format := range []string{"text", "json"} {
+		l := SetupLogger("info", format, "test-service", "v0.0.0")
+		assert.NotNil(t, l)
+		assert.Same(t, l, slog.Default())
+	}
+}
+
+func TestContextLogger(t *testing.T) {
+	base := SetupLogger("info", "text", "svc", "v1")
+	assert.Same(t, base, LoggerFromContext(context.Background()))
+	custom := slog.New(slog.NewTextHandler(nil, nil))
+	ctx := ContextWithLogger(context.Background(), custom)
+	assert.Same(t, custom, LoggerFromContext(ctx))
+}
+
+func TestMockLogger(t *testing.T) {
+	m := NewMockLogger()
+	m.Logger().Info("hello", "k", "v")
+	m.Check(t, []string{`level=INFO msg=hello k=v`})
+	empty := NewMockLogger()
+	empty.Check(t, nil)
+}

middleware/request_logger.go

@@ -0,0 +1,38 @@
+package middleware
+
+import (
+	"bytes"
+	"io"
+	"log/slog"
+	"net/http"
+)
+
+func RequestLogger(logger *slog.Logger) func(handler http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			buff := &bytes.Buffer{}
+			req := r.Clone(r.Context())
+			req.Body = io.NopCloser(io.TeeReader(r.Body, buff))
+
+			rw := &responseWriter{ResponseWriter: w, statusCode: http.StatusOK}
+			next.ServeHTTP(rw, req)
+			logger.With("request", buff.String(), "response", rw.responseBody).Debug("http request")
+		})
+	}
+}
+
+type responseWriter struct {
+	http.ResponseWriter
+	statusCode   int
+	responseBody string
+}
+
+func (rw *responseWriter) WriteHeader(statusCode int) {
+	rw.statusCode = statusCode
+	rw.ResponseWriter.WriteHeader(statusCode)
+}
+
+func (rw *responseWriter) Write(b []byte) (int, error) {
+	rw.responseBody = string(b) // You may want to capture only part of the response or use a different method
+	return rw.ResponseWriter.Write(b)
+}

middleware/request_logger_test.go

@@ -0,0 +1,26 @@
+package middleware
+
+import (
+	"log/slog"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRequestLogger(t *testing.T) {
+	called := false
+	h := RequestLogger(slog.New(slog.NewTextHandler(nil, nil)))(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		called = true
+		w.WriteHeader(http.StatusCreated)
+		_, _ = w.Write([]byte("ok"))
+	}))
+	req := httptest.NewRequest(http.MethodPost, "/q", strings.NewReader("body"))
+	rw := httptest.NewRecorder()
+	h.ServeHTTP(rw, req)
+	assert.True(t, called)
+	assert.Equal(t, http.StatusCreated, rw.Code)
+	assert.Equal(t, "ok", rw.Body.String())
+}

mocklogger.go

@@ -0,0 +1,48 @@
+package logging
+
+import (
+	"bytes"
+	"log/slog"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func NewMockLogger() *MockLogger {
+	logged := &bytes.Buffer{}
+
+	return &MockLogger{
+		logged: logged,
+		logger: slog.New(slog.NewTextHandler(logged, &slog.HandlerOptions{
+			ReplaceAttr: func(groups []string, a slog.Attr) slog.Attr {
+				if a.Key == "time" {
+					return slog.Attr{}
+				}
+				return a
+			},
+		})),
+	}
+}
+
+type MockLogger struct {
+	logger *slog.Logger
+	logged *bytes.Buffer
+}
+
+func (m *MockLogger) Logger() *slog.Logger {
+	return m.logger
+}
+
+func (m *MockLogger) Check(t testing.TB, wantLogged []string) {
+	var gotLogged []string
+	if m.logged.String() != "" {
+		gotLogged = strings.Split(m.logged.String(), "\n")
+		gotLogged = gotLogged[:len(gotLogged)-1]
+	}
+	if len(wantLogged) == 0 {
+		assert.Empty(t, gotLogged)
+		return
+	}
+	assert.Equal(t, wantLogged, gotLogged)
+}