fuzz: Use build script from upstream and fix fuzzers

go.mod

@@ -202,7 +202,7 @@ require (
  github.com/prometheus/procfs v0.8.0 // indirect
  github.com/russross/blackfriday v1.6.0 // indirect
  github.com/ryanuber/go-glob v1.0.0 // indirect
- github.com/sirupsen/logrus v1.8.1 // indirect
+ github.com/sirupsen/logrus v1.9.0 // indirect
  github.com/spf13/cobra v1.6.1 // indirect
  github.com/xeipuuv/gojsonpointer v0.0.0-20180127040702-4e3ac2762d5f // indirect
  github.com/xeipuuv/gojsonreference v0.0.0-20180127040603-bd5ef7bd5415 // indirect

go.sum

@@ -591,8 +591,9 @@ github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPx
 github.com/sirupsen/logrus v1.4.2/go.mod h1:tLMulIdttU9McNUspp0xgXVQah82FyeX6MwdIuYE2rE=
 github.com/sirupsen/logrus v1.6.0/go.mod h1:7uNnSEd1DgxDLC74fIahvMZmmYsHGZGEOFrfsX/uA88=
 github.com/sirupsen/logrus v1.7.0/go.mod h1:yWOB1SBYBC5VeMP7gHvWumXLIWorT60ONWic61uBYv0=
-github.com/sirupsen/logrus v1.8.1 h1:dJKuHgqk1NNQlqoA6BTlM1Wf9DOH3NBjQyu0h9+AZZE=
 github.com/sirupsen/logrus v1.8.1/go.mod h1:yWOB1SBYBC5VeMP7gHvWumXLIWorT60ONWic61uBYv0=
+github.com/sirupsen/logrus v1.9.0 h1:trlNQbNUG3OdDrDil03MCb1H2o9nJ1x4/5LYw7byDE0=
+github.com/sirupsen/logrus v1.9.0/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
 github.com/spaolacci/murmur3 v0.0.0-20180118202830-f09979ecbc72/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
 github.com/spf13/cobra v1.6.1 h1:o94oiPyS4KD1mPy2fmcYYHHfCxLqYjJOhGsCHFZtEzA=
 github.com/spf13/cobra v1.6.1/go.mod h1:IOw/AERYS7UzyrGinqmz6HLUo219MORXGxhbaJUqzrY=

tests/fuzz/Dockerfile.builder

@@ -1,6 +1,9 @@
 FROM gcr.io/oss-fuzz-base/base-builder-go
 
-COPY ./ $GOPATH/src/github.com/fluxcd/kustomize-controller/
-COPY ./tests/fuzz/oss_fuzz_build.sh $SRC/build.sh
+ENV SRC=$GOPATH/src/github.com/fluxcd/kustomize-controller
+ENV FLUX_CI=true
+
+COPY ./ $SRC
+RUN wget https://raw.githubusercontent.com/google/oss-fuzz/master/projects/fluxcd/build.sh -O $SRC/build.sh
 
 WORKDIR $SRC

tests/fuzz/README.md

@@ -6,8 +6,6 @@ open source projects.
 The long running fuzzing execution is configured in the [oss-fuzz repository].
 Shorter executions are done on a per-PR basis, configured as a [github workflow].
 
-For fuzzers to be called, they must be compiled within [oss_fuzz_build.sh](./oss_fuzz_build.sh).
-
 ### Testing locally
 
 Build fuzzers:
@@ -19,12 +17,12 @@ All fuzzers will be built into `./build/fuzz/out`.
 
 Smoke test fuzzers:
 
+All the fuzzers will be built and executed once, to ensure they are fully functional.
+
 ```bash
 make fuzz-smoketest
 ```
 
-The smoke test runs each fuzzer once to ensure they are fully functional.
-
 Run fuzzer locally:
 ```bash
 ./build/fuzz/out/fuzz_conditions_match
@@ -39,6 +37,27 @@ Run fuzzer inside a container:
  /out/fuzz_conditions_match
 ```
 
+### Caveats of creating oss-fuzz compatible tests
+
+#### Segregate fuzz tests
+
+OSS-Fuzz does not properly support mixed `*_test.go` files, in which there is a combination
+of fuzz and non-fuzz tests. To mitigate this problem, ensure your fuzz tests are not in the
+same file as other Go tests. As a pattern, call your fuzz test files `*_fuzz_test.go`.
+
+#### Build tags to avoid conflicts when running Go tests
+
+Due to the issue above, code duplication will occur when creating fuzz tests that rely on
+helper functions that are shared with other tests. To avoid build issues, add a conditional
+build tag at the top of the `*_fuzz_test.go` file:
+```go
+//go:build gofuzz_libfuzzer
+// +build gofuzz_libfuzzer
+```
+
+The build tag above is set at [go-118-fuzz-build].
+At this point in time we can't pass on specific tags from [compile_native_go_fuzzer].
+
 ### Running oss-fuzz locally
 
 The `make fuzz-smoketest` is meant to be an easy way to reproduce errors that may occur
@@ -59,3 +78,5 @@ For latest info on testing oss-fuzz locally, refer to the [upstream guide].
 [oss-fuzz repository]: https:/google/oss-fuzz/tree/master/projects/fluxcd
 [github workflow]: .github/workflows/cifuzz.yaml
 [upstream guide]: https://google.github.io/oss-fuzz/getting-started/new-project-guide/#testing-locally
+[go-118-fuzz-build]: https:/AdamKorcz/go-118-fuzz-build/blob/b2031950a318d4f2dcf3ec3e128f904d5cf84623/main.go#L40
+[compile_native_go_fuzzer]: https:/google/oss-fuzz/blob/c2d827cb78529fdc757c9b0b4fea0f1238a54814/infra/base-images/base-builder/compile_native_go_fuzzer#L32

tests/fuzz/oss_fuzz_run.sh

@@ -17,4 +17,4 @@
 set -euxo pipefail
 
 # run each fuzzer once to ensure they are working properly
-find /out -type f -name "fuzz*" -exec echo {} -runs=1 \; | bash -e
+find /out -type f -iname "fuzz*" -exec echo {} -runs=1 \; | bash -e