Add zap wrapper which implements opa logger (#240)

open-policy-agent/opa#6499

Signed-off-by: Alexander Mckenzie-Kelly <alexmk@uk.ibm.com>

logging/plugins/README.md

@@ -0,0 +1,5 @@
+Plug-ins
+===
+
+This directory contains plug-in support for external logging libraries
+to use as a `logging.Logger`.

logging/plugins/ozap/README.md

@@ -0,0 +1,11 @@
+ozap
+===
+
+ozap is a logging plug-in to wrap [zap](https://github.com/uber-go/zap)
+as a [`logging.Logger`](https://pkg.go.dev/github.com/open-policy-agent/opa/logging#Logger).
+
+```golang
+opa, err := sdk.New(context.Background(), sdk.Options{
+	Logger: ozap.Wrap(logger, level),
+})
+```

logging/plugins/ozap/go.mod

@@ -0,0 +1,14 @@
+module github.com/open-policy-agent/contrib/logging/plugins/ozap
+
+go 1.19
+
+require (
+	github.com/open-policy-agent/opa v0.59.0
+	go.uber.org/zap v1.26.0
+)
+
+require (
+	github.com/sirupsen/logrus v1.9.3 // indirect
+	go.uber.org/multierr v1.10.0 // indirect
+	golang.org/x/sys v0.15.0 // indirect
+)

logging/plugins/ozap/go.sum

@@ -0,0 +1,24 @@
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+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/google/uuid v1.4.0 h1:MtMxsa51/r9yyhkyLsVeVt0B+BGQZzpQiTQ4eHZ8bc4=
+github.com/open-policy-agent/opa v0.59.0 h1:1WFU/KUhJAr3qatm0Lf8Ea5jp10ZmlE2M07oaLiHypg=
+github.com/open-policy-agent/opa v0.59.0/go.mod h1:rdJSkEc4oQ+0074/3Fsgno5bkPsYxTjU5aLNmMujIvI=
+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/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ=
+github.com/sirupsen/logrus v1.9.3/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKsk=
+go.uber.org/goleak v1.2.0 h1:xqgm/S+aQvhWFTtR0XK3Jvg7z8kGV8P4X14IzwN3Eqk=
+go.uber.org/multierr v1.10.0 h1:S0h4aNzvfcFsC3dRF1jLoaov7oRaKqRGC/pUEJ2yvPQ=
+go.uber.org/multierr v1.10.0/go.mod h1:20+QtiLqy0Nd6FdQB9TLXag12DsQkrbs3htMFfDN80Y=
+go.uber.org/zap v1.26.0 h1:sI7k6L95XOKS281NhVKOFCUNIvv9e0w4BF8N3u+tCRo=
+go.uber.org/zap v1.26.0/go.mod h1:dtElttAiwGvoJ/vj4IwHBS/gXsEu/pZ50mUIRWuG0so=
+golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.15.0 h1:h48lPFYpsTvQJZF4EKyI4aLHaev3CxivZmv7yZig9pc=
+golang.org/x/sys v0.15.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=

logging/plugins/ozap/zap.go

@@ -0,0 +1,100 @@
+package ozap
+
+import (
+	"fmt"
+
+	"github.com/open-policy-agent/opa/logging"
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+)
+
+// Wrap this zap Logger and AtomicLevel as a logging.Logger.
+func Wrap(log *zap.Logger, level *zap.AtomicLevel) logging.Logger {
+	return &Wrapper{internal: log, level: level}
+}
+
+// Wrapper implements logging.Logger for a zap Logger.
+type Wrapper struct {
+	internal *zap.Logger
+	level    *zap.AtomicLevel
+}
+
+// Debug logs at debug level.
+func (w *Wrapper) Debug(f string, a ...interface{}) {
+	w.internal.Debug(fmt.Sprintf(f, a...))
+}
+
+// Info logs at info level.
+func (w *Wrapper) Info(f string, a ...interface{}) {
+	w.internal.Info(fmt.Sprintf(f, a...))
+}
+
+// Error logs at error level.
+func (w *Wrapper) Error(f string, a ...interface{}) {
+	w.internal.Error(fmt.Sprintf(f, a...))
+}
+
+// Warn logs at warn level.
+func (w *Wrapper) Warn(f string, a ...interface{}) {
+	w.internal.Warn(fmt.Sprintf(f, a...))
+}
+
+// WithFields provides additional fields to include in log output.
+func (w *Wrapper) WithFields(fields map[string]interface{}) logging.Logger {
+	return &Wrapper{
+		internal: w.internal.With(toZapFields(fields)...),
+		level:    w.level,
+	}
+}
+
+// toZapFields converts logging format fields to zap format Fields
+func toZapFields(fields map[string]interface{}) []zap.Field {
+	var zapFields []zap.Field
+	for k, v := range fields {
+		switch t := v.(type) {
+		case error:
+			zapFields = append(zapFields, zap.NamedError(k, t))
+		case string:
+			zapFields = append(zapFields, zap.String(k, t))
+		case bool:
+			zapFields = append(zapFields, zap.Bool(k, t))
+		case int:
+			zapFields = append(zapFields, zap.Int(k, t))
+		default:
+			zapFields = append(zapFields, zap.Any(k, v))
+		}
+	}
+	return zapFields
+}
+
+// SetLevel sets the logger level.
+func (w *Wrapper) GetLevel() logging.Level {
+	switch w.internal.Level() {
+	case zap.ErrorLevel:
+		return logging.Error
+	case zap.WarnLevel:
+		return logging.Warn
+	case zap.DebugLevel:
+		return logging.Debug
+	default:
+		return logging.Info
+	}
+}
+
+// SetLevel sets the logger level.
+func (w *Wrapper) SetLevel(l logging.Level) {
+	var newLevel zapcore.Level
+	switch l {
+	case logging.Error:
+		newLevel = zap.ErrorLevel
+	case logging.Warn:
+		newLevel = zap.WarnLevel
+	case logging.Info:
+		newLevel = zap.InfoLevel
+	case logging.Debug:
+		newLevel = zap.DebugLevel
+	default:
+		return
+	}
+	w.level.SetLevel(newLevel)
+}

logging/plugins/ozap/zap_test.go

@@ -0,0 +1,56 @@
+package ozap
+
+import (
+	"bytes"
+	"errors"
+	"log"
+	"strings"
+	"testing"
+
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+)
+
+func TestWrapWithFields(t *testing.T) {
+	tests := []struct {
+		name   string
+		fields map[string]interface{}
+		expect []string
+	}{
+		{
+			name: "Ex1",
+			fields: map[string]interface{}{
+				"bad_error":   errors.New("something went wrong"),
+				"context":     "everywhere",
+				"panic":       true,
+				"problems":    99,
+				"luftballons": int64(99),
+			},
+			expect: []string{
+				`"bad_error":"something went wrong"`,
+				`"context":"everywhere"`,
+				`"panic":true`,
+				`"problems":99`,
+				`"luftballons":99`,
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var buf bytes.Buffer
+			level := zap.NewAtomicLevelAt(zap.InfoLevel)
+			zaplogger := zap.New(zapcore.NewCore(zapcore.NewJSONEncoder(zap.NewDevelopmentEncoderConfig()), zapcore.AddSync(&buf), zap.LevelEnablerFunc(func(lvl zapcore.Level) bool {
+				return lvl >= level.Level()
+			})))
+			Wrap(zaplogger, &level).WithFields(tt.fields).Info("test")
+			out := buf.String()
+			for _, e := range tt.expect {
+				if !strings.Contains(out, e) {
+					t.Fail()
+					log.Printf("Missing %s in %s", e, out)
+				}
+			}
+		})
+	}
+}