build against libre2-dev if found

Dockerfile

@@ -7,9 +7,19 @@ WORKDIR /go/src/crowdsec
 
 COPY . .
 
+# Alpine does not ship a static version of re2, we can build it ourselves
+# Later versions require 'abseil', which is likewise not available in its static form
+ENV RE2_VERSION=2023-03-01
+
 # wizard.sh requires GNU coreutils
-RUN apk add --no-cache git gcc libc-dev make bash gettext binutils-gold coreutils && \
+RUN apk add --no-cache git g++ gcc libc-dev make bash gettext binutils-gold coreutils icu-static re2-dev pkgconfig && \
+    wget https://github.com/google/re2/archive/refs/tags/${RE2_VERSION}.tar.gz && \
+    tar -xzf ${RE2_VERSION}.tar.gz && \
+    cd re2-${RE2_VERSION} && \
+    make && \
+    make install && \
     echo "githubciXXXXXXXXXXXXXXXXXXXXXXXX" > /etc/machine-id && \
+    cd - && \
     make clean release DOCKER_BUILD=1 && \
     cd crowdsec-v* && \
     ./wizard.sh --docker-mode && \

Dockerfile.debian

@@ -12,7 +12,7 @@ ENV DEBCONF_NOWARNINGS="yes"
 
 # wizard.sh requires GNU coreutils
 RUN apt-get update && \
-    apt-get install -y -q git gcc libc-dev make bash gettext binutils-gold coreutils tzdata && \
+    apt-get install -y -q git gcc libc-dev make bash gettext binutils-gold coreutils tzdata libre2-dev && \
     echo "githubciXXXXXXXXXXXXXXXXXXXXXXXX" > /etc/machine-id && \
     make clean release DOCKER_BUILD=1 && \
     cd crowdsec-v* && \

Makefile

@@ -3,6 +3,9 @@ include mk/platform.mk
 BUILD_REQUIRE_GO_MAJOR ?= 1
 BUILD_REQUIRE_GO_MINOR ?= 20
 
+GOCMD = go
+GOTEST = $(GOCMD) test
+
 BUILD_CODENAME ?= alphaga
 
 CROWDSEC_FOLDER = ./cmd/crowdsec
@@ -14,8 +17,21 @@ PLUGINS_DIR = ./plugins/notifications
 CROWDSEC_BIN = crowdsec$(EXT)
 CSCLI_BIN = cscli$(EXT)
 
+# Directory for the release files
+RELDIR = crowdsec-$(BUILD_VERSION)
+
 GO_MODULE_NAME = github.com/crowdsecurity/crowdsec
 
+# see if we have libre2-dev installed for C++ optimizations
+RE2_CHECK := $(shell pkg-config --libs re2 2>/dev/null)
+
+#--------------------------------------
+#
+# Define MAKE_FLAGS and LD_OPTS for the sub-makefiles in cmd/ and plugins/
+#
+
+MAKE_FLAGS = --no-print-directory GOARCH=$(GOARCH) GOOS=$(GOOS) RM="$(RM)" WIN_IGNORE_ERR="$(WIN_IGNORE_ERR)" CP="$(CP)" CPR="$(CPR)" MKDIR="$(MKDIR)"
+
 LD_OPTS_VARS= \
 -X 'github.com/crowdsecurity/go-cs-lib/pkg/version.Version=$(BUILD_VERSION)' \
 -X 'github.com/crowdsecurity/go-cs-lib/pkg/version.BuildDate=$(BUILD_TIMESTAMP)' \
@@ -28,30 +44,37 @@ ifneq (,$(DOCKER_BUILD))
 LD_OPTS_VARS += -X '$(GO_MODULE_NAME)/pkg/cwversion.System=docker'
 endif
 
-ifdef BUILD_STATIC
-$(warning WARNING: The BUILD_STATIC variable is deprecated and has no effect. Builds are static by default since v1.5.0.)
+GO_TAGS := netgo,osusergo,sqlite_omit_load_extension
+
+ifneq (,$(RE2_CHECK))
+# += adds a space that we don't want
+GO_TAGS := $(GO_TAGS),re2_cgo
+LD_OPTS_VARS += -X '$(GO_MODULE_NAME)/pkg/cwversion.Libre2=C++'
 endif
 
 export LD_OPTS=-ldflags "-s -w -extldflags '-static' $(LD_OPTS_VARS)" \
-	-trimpath -tags netgo,osusergo,sqlite_omit_load_extension
+	-trimpath -tags $(GO_TAGS)
 
 ifneq (,$(TEST_COVERAGE))
 LD_OPTS += -cover
 endif
 
-GOCMD = go
-GOTEST = $(GOCMD) test
-
-RELDIR = crowdsec-$(BUILD_VERSION)
-
-# flags for sub-makefiles
-MAKE_FLAGS = --no-print-directory GOARCH=$(GOARCH) GOOS=$(GOOS) RM="$(RM)" WIN_IGNORE_ERR="$(WIN_IGNORE_ERR)" CP="$(CP)" CPR="$(CPR)" MKDIR="$(MKDIR)"
+#--------------------------------------
 
 .PHONY: build
 build: pre-build goversion crowdsec cscli plugins
 
+.PHONY: pre-build
 pre-build:
+ifdef BUILD_STATIC
+	$(warning WARNING: The BUILD_STATIC variable is deprecated and has no effect. Builds are static by default since v1.5.0.)
+endif
 	$(info Building $(BUILD_VERSION) ($(BUILD_TAG)) for $(GOOS)/$(GOARCH))
+ifneq (,$(RE2_CHECK))
+	$(info Using C++ regexp library)
+else
+	$(info Fallback to WebAssembly regexp library. To use the C++ version, make sure you have installed libre2-dev and pkg-config.)
+endif
 	$(info )
 
 .PHONY: all
@@ -75,10 +98,11 @@ clean: testclean
 		$(MAKE) -C $(PLUGINS_DIR)/$(plugin) clean $(MAKE_FLAGS); \
 	)
 
-
+.PHONY: cscli
 cscli: goversion
 	@$(MAKE) -C $(CSCLI_FOLDER) build $(MAKE_FLAGS)
 
+.PHONY: crowdsec
 crowdsec: goversion
 	@$(MAKE) -C $(CROWDSEC_FOLDER) build $(MAKE_FLAGS)
 

pkg/cwversion/version.go

@@ -20,6 +20,7 @@ var (
 	Constraint_scenario = ">= 1.0, < 3.0"
 	Constraint_api      = "v1"
 	Constraint_acquis   = ">= 1.0, < 2.0"
+	Libre2              = "WebAssembly"
 )
 
 func ShowStr() string {
@@ -38,6 +39,7 @@ func Show() {
 	log.Printf("BuildDate: %s", version.BuildDate)
 	log.Printf("GoVersion: %s", version.GoVersion)
 	log.Printf("Platform: %s\n", System)
+	log.Printf("libre2: %s\n", Libre2)
 	log.Printf("Constraint_parser: %s", Constraint_parser)
 	log.Printf("Constraint_scenario: %s", Constraint_scenario)
 	log.Printf("Constraint_api: %s", Constraint_api)