Golang project uses compile_go_fuzzer script (#4685)

* Golang project uses compile_go_fuzzer script

* Kubernetes project uses compile_go_fuzzer script

* Adds golang to ci covergae builds

* fixup

* Golang coverage with go modules

cf coredns project

7 files changed, 17 insertions, 10 deletions

diff --git a/infra/base-images/base-builder/compile_go_fuzzer b/infra/base-images/base-builder/compile_go_fuzzer
index 5fc8b70f..c6cc3dd8 100755
--- a/infra/base-images/base-builder/compile_go_fuzzer
+++ b/infra/base-images/base-builder/compile_go_fuzzer
@@ -24,7 +24,13 @@ if [[ $#  -eq 4 ]]; then
 fi
 
 if [[ $SANITIZER = *coverage* ]]; then
-  cd $GOPATH/src/$path
+  if [[ $GO111MODULE = on ]]; then
+    basemod=`echo $path | cut -d/ -f1-3`
+    cd $GOPATH/pkg/mod/`go list -m $basemod | sed 's/ /@/'`
+    cd ./`echo $path | cut -d/ -f4-`
+  else
+    cd $GOPATH/src/$path
+  fi
   fuzzed_package=`pwd | rev | cut -d'/' -f 1 | rev`
   cp $GOPATH/ossfuzz_coverage_runner.go ./"${function,,}"_test.go
   sed -i -e 's/FuzzFunction/'$function'/' ./"${function,,}"_test.go
diff --git a/infra/ci/build.py b/infra/ci/build.py
index 67a97587..a1a22836 100755
--- a/infra/ci/build.py
+++ b/infra/ci/build.py
@@ -32,7 +32,7 @@ DEFAULT_ENGINES = ['afl', 'honggfuzz', 'libfuzzer']
 DEFAULT_SANITIZERS = ['address', 'undefined']
 
 # Languages from project.yaml that have code coverage support.
-LANGUAGES_WITH_COVERAGE_SUPPORT = ['c', 'c++']
+LANGUAGES_WITH_COVERAGE_SUPPORT = ['c', 'c++', 'go']
 
 
 def get_changed_files():
diff --git a/infra/ci/build_test.py b/infra/ci/build_test.py
index ef2d3a80..59fa3cf5 100644
--- a/infra/ci/build_test.py
+++ b/infra/ci/build_test.py
@@ -73,11 +73,11 @@ class TestShouldBuild(unittest.TestCase):
     self.assertTrue(build.should_build(project_yaml))
 
   def test_go_coverage_build(self):
-    """Tests that should_build returns False for coverage build of a project
+    """Tests that should_build returns True for coverage build of a project
     specifying 'libfuzzer' and for fuzzing_engines."""
     _set_coverage_build()
     project_yaml = {'language': 'go'}
-    self.assertFalse(build.should_build(project_yaml))
+    self.assertTrue(build.should_build(project_yaml))
 
   def test_engine_project_none_build(self):
     """Tests that should_build returns False for an engine: 'none' build when
diff --git a/projects/go-coredns/Dockerfile b/projects/go-coredns/Dockerfile
index f77a4629..824e6d8f 100644
--- a/projects/go-coredns/Dockerfile
+++ b/projects/go-coredns/Dockerfile
@@ -15,7 +15,8 @@
 ################################################################################
 
 FROM gcr.io/oss-fuzz-base/base-builder
-RUN git clone --depth 1 https://github.com/coredns/coredns coredns
+ENV GO111MODULE=on
+RUN go get github.com/coredns/coredns
 
 COPY build.sh $SRC/
 WORKDIR $SRC/
diff --git a/projects/go-coredns/build.sh b/projects/go-coredns/build.sh
index d1d021b7..16b10cae 100755
--- a/projects/go-coredns/build.sh
+++ b/projects/go-coredns/build.sh
@@ -17,13 +17,13 @@
 
 # Same as usual except for added -tags gofuzz.
 
+cd $GOPATH/pkg/mod/`go list -m github.com/coredns/coredns | sed 's/ /@/'`
 
-cd coredns
 #make
 ls plugin/*/fuzz.go | while read target
 do
     fuzzed_plugin=`echo $target | cut -d'/' -f 2`
-    compile_go_fuzzer github.com/coredns/coredns/plugin/$fuzzed_plugin Fuzz fuzz_plugin_$fuzzed_plugin
+    compile_go_fuzzer github.com/coredns/coredns/plugin/$fuzzed_plugin Fuzz fuzz_plugin_$fuzzed_plugin gofuzz
 done
 
-compile_go_fuzzer github.com/coredns/coredns/test Fuzz fuzz_core
+compile_go_fuzzer github.com/coredns/coredns/test Fuzz fuzz_core gofuzz
diff --git a/projects/golang/build.sh b/projects/golang/build.sh
index 70972fa4..064378aa 100755
--- a/projects/golang/build.sh
+++ b/projects/golang/build.sh
@@ -15,7 +15,7 @@
 function compile_fuzzer {
   fuzzer=$(basename $1)
 
-  compile_fuzzer "github.com/dvyukov/go-fuzz-corpus/$fuzzer" Fuzz $fuzzer
+  compile_go_fuzzer "github.com/dvyukov/go-fuzz-corpus/$fuzzer" Fuzz $fuzzer
 
   # Pack the seed corpus
   zip -r $OUT/fuzzer-${fuzzer}_seed_corpus.zip \
diff --git a/projects/kubernetes/build.sh b/projects/kubernetes/build.sh
index 4e6bded1..3b331ae9 100755
--- a/projects/kubernetes/build.sh
+++ b/projects/kubernetes/build.sh
@@ -25,7 +25,7 @@ function compile_fuzzer {
   local function=$2
   local fuzzer="${pkg}_${function}"
 
-  compile_fuzzer "k8s.io/kubernetes/test/fuzz/${pkg}" $function $fuzzer
+  compile_go_fuzzer "k8s.io/kubernetes/test/fuzz/${pkg}" $function $fuzzer
 }
 
 compile_fuzzer "yaml" "FuzzDurationStrict"