feat: adds context to transaction.

experimental/waf.go

@@ -0,0 +1,36 @@
+// Copyright 2024 Juan Pablo Tosso and the OWASP Coraza contributors
+// SPDX-License-Identifier: Apache-2.0
+
+package experimental
+
+import (
+	"context"
+	"strings"
+
+	"github.com/corazawaf/coraza/v3/internal/corazawaf"
+	"github.com/corazawaf/coraza/v3/types"
+)
+
+type Option func(*corazawaf.Options)
+
+// WithID sets the transaction ID
+func WithID(id string) Option {
+	return func(o *corazawaf.Options) {
+		o.ID = strings.TrimSpace(id)
+	}
+}
+
+// WithContext sets the transaction context, this is useful for passing
+// a context into the logger.
+// The transaction lifecycle isn't tied to the context lifecycle.
+func WithContext(ctx context.Context) Option {
+	return func(o *corazawaf.Options) {
+		o.Context = ctx
+	}
+}
+
+// WAFWithOptions is an interface that allows to create transactions
+// with options
+type WAFWithOptions interface {
+	NewTransactionWithOptions(opts ...Option) types.Transaction
+}

http/middleware.go

@@ -15,6 +15,7 @@ import (
 	"strings"
 
 	"github.com/corazawaf/coraza/v3"
+	"github.com/corazawaf/coraza/v3/experimental"
 	"github.com/corazawaf/coraza/v3/types"
 )
 
@@ -117,8 +118,18 @@ func WrapHandler(waf coraza.WAF, h http.Handler) http.Handler {
 		return h
 	}
 
+	newTX := func(*http.Request) types.Transaction {
+		return waf.NewTransaction()
+	}
+
+	if ctxwaf, ok := waf.(experimental.WAFWithOptions); ok {
+		newTX = func(r *http.Request) types.Transaction {
+			return ctxwaf.NewTransactionWithOptions(experimental.WithContext(r.Context()))
+		}
+	}
+
 	fn := func(w http.ResponseWriter, r *http.Request) {
-		tx := waf.NewTransaction()
+		tx := newTX(r)
 		defer func() {
 			// We run phase 5 rules and create audit logs (if enabled)
 			tx.ProcessLogging()

internal/corazarules/rule_match.go

@@ -4,6 +4,7 @@
 package corazarules
 
 import (
+	"context"
 	"fmt"
 	"strconv"
 	"strings"
@@ -30,6 +31,8 @@ type MatchData struct {
 	ChainLevel_ int
 }
 
+var _ types.MatchData = (*MatchData)(nil)
+
 func (m *MatchData) Variable() variables.RuleVariable {
 	return m.Variable_
 }
@@ -100,8 +103,12 @@ type MatchedRule struct {
 	MatchedDatas_ []types.MatchData
 
 	Rule_ types.RuleMetadata
+
+	Context_ context.Context
 }
 
+var _ types.MatchedRule = (*MatchedRule)(nil)
+
 func (mr *MatchedRule) Message() string {
 	return mr.Message_
 }
@@ -142,6 +149,35 @@ func (mr *MatchedRule) Rule() types.RuleMetadata {
 	return mr.Rule_
 }
 
+// Context returns the context associated with the transaction
+// This is useful for logging purposes where you want to add
+// additional information to the log.
+// The context can be easily retrieved in the logger using
+// an ancillary interface:
+// ```
+//
+//	 type Contexter interface {
+//			Context() context.Context
+//		}
+//
+// ```
+// and then using it like this:
+//
+// ```
+//
+//	func errorLogCb(mr types.MatchedRule) {
+//	     ctx := context.Background()
+//		 if ctxer, ok := mr.(Contexter); ok {
+//	    	ctx = ctxer.Context()
+//		 }
+//	     logger.Context(ctx).Error().Msg("...")
+//	}
+//
+// ```
+func (mr *MatchedRule) Context() context.Context {
+	return mr.Context_
+}
+
 const maxSizeLogMessage = 200
 
 func (mr MatchedRule) writeDetails(log *strings.Builder, matchData types.MatchData) {

internal/corazawaf/transaction.go

@@ -5,6 +5,7 @@ package corazawaf
 
 import (
 	"bufio"
+	"context"
 	"errors"
 	"fmt"
 	"io"
@@ -42,6 +43,9 @@ type Transaction struct {
 	// Transaction ID
 	id string
 
+	// The context associated to the transaction.
+	context context.Context
+
 	// Contains the list of matched rules and associated match information
 	matchedRules []types.MatchedRule
 
@@ -501,6 +505,7 @@ func (tx *Transaction) MatchRule(r *Rule, mds []types.MatchData) {
 		Rule_:            &r.RuleMetadata,
 		Log_:             r.Log,
 		MatchedDatas_:    mds,
+		Context_:         tx.context,
 	}
 	// Populate MatchedRule disruption related fields only if the Engine is capable of performing disruptive actions
 	if tx.RuleEngine == types.RuleEngineOn {

internal/corazawaf/waf.go

@@ -4,14 +4,14 @@
 package corazawaf
 
 import (
+	"context"
 	"errors"
 	"fmt"
 	"io"
 	"io/fs"
 	"os"
 	"regexp"
 	"strconv"
-	"strings"
 	"time"
 
 	"github.com/corazawaf/coraza/v3/debuglog"
@@ -133,24 +133,38 @@ type WAF struct {
 	ArgumentLimit int
 }
 
+// Options is used to pass options to the WAF instance
+type Options struct {
+	ID      string
+	Context context.Context
+}
+
 // NewTransaction Creates a new initialized transaction for this WAF instance
 func (w *WAF) NewTransaction() *Transaction {
-	return w.newTransactionWithID(stringutils.RandomString(19))
+	return w.newTransaction(Options{
+		ID:      stringutils.RandomString(19),
+		Context: context.Background(),
+	})
 }
 
-func (w *WAF) NewTransactionWithID(id string) *Transaction {
-	if len(strings.TrimSpace(id)) == 0 {
-		id = stringutils.RandomString(19)
-		w.Logger.Warn().Msg("Empty ID passed for new transaction")
+func (w *WAF) NewTransactionWithOptions(opts Options) *Transaction {
+	if opts.ID == "" {
+		opts.ID = stringutils.RandomString(19)
 	}
-	return w.newTransactionWithID(id)
+
+	if opts.Context == nil {
+		opts.Context = context.Background()
+	}
+
+	return w.newTransaction(opts)
 }
 
 // NewTransactionWithID Creates a new initialized transaction for this WAF instance
 // Using the specified ID
-func (w *WAF) newTransactionWithID(id string) *Transaction {
+func (w *WAF) newTransaction(opts Options) *Transaction {
 	tx := w.txPool.Get().(*Transaction)
-	tx.id = id
+	tx.id = opts.ID
+	tx.context = opts.Context
 	tx.matchedRules = []types.MatchedRule{}
 	tx.interruption = nil
 	tx.Logdata = "" // Deprecated, this variable is not used. Logdata for each matched rule is stored in the MatchData field.

internal/corazawaf/waf_test.go

@@ -15,7 +15,7 @@ func TestNewTransaction(t *testing.T) {
 	waf.ResponseBodyAccess = true
 	waf.RequestBodyLimit = 1044
 
-	tx := waf.NewTransactionWithID("test")
+	tx := waf.NewTransactionWithOptions(Options{ID: "test"})
 	if !tx.RequestBodyAccess {
 		t.Error("Request body access not enabled")
 	}
@@ -28,7 +28,7 @@ func TestNewTransaction(t *testing.T) {
 	if tx.id != "test" {
 		t.Error("ID not set")
 	}
-	tx = waf.NewTransactionWithID("")
+	tx = waf.NewTransactionWithOptions(Options{ID: ""})
 	if tx.id == "" {
 		t.Error("ID not set")
 	}

types/rule_match.go

@@ -45,5 +45,6 @@ type MatchedRule interface {
 	Rule() RuleMetadata
 
 	AuditLog() string
+
 	ErrorLog() string
 }

waf.go

@@ -4,8 +4,11 @@
 package coraza
 
 import (
+	"context"
 	"fmt"
+	"strings"
 
+	"github.com/corazawaf/coraza/v3/experimental"
 	"github.com/corazawaf/coraza/v3/internal/corazawaf"
 	"github.com/corazawaf/coraza/v3/internal/seclang"
 	"github.com/corazawaf/coraza/v3/types"
@@ -129,5 +132,19 @@ func (w wafWrapper) NewTransaction() types.Transaction {
 
 // NewTransactionWithID implements the same method on WAF.
 func (w wafWrapper) NewTransactionWithID(id string) types.Transaction {
-	return w.waf.NewTransactionWithID(id)
+	id = strings.TrimSpace(id)
+	if len(id) == 0 {
+		w.waf.Logger.Warn().Msg("Empty ID passed for new transaction")
+	}
+
+	return w.waf.NewTransactionWithOptions(corazawaf.Options{Context: context.Background(), ID: id})
+}
+
+// NewTransaction implements the same method on WAF.
+func (w wafWrapper) NewTransactionWithOptions(opts ...experimental.Option) types.Transaction {
+	o := corazawaf.Options{}
+	for _, opt := range opts {
+		opt(&o)
+	}
+	return w.waf.NewTransactionWithOptions(o)
 }