Fuzzing: Initial set up

[AdamKorcz]

This PR adds the initial set up for fuzzing of the source-controller.

It is currently work in progress that is being shared to allow for any feedback, comments or suggestions that anyone should have along the way. The files in this pull request will be modified.

There are 5 fuzzers available at this moment, and these are all built in the Dockerfile. They can be run when building the image, or they can be run in a Docker shell.

The 5 fuzzers are:

1: FuzzRandomGitFiles

Creates a git repository with pseudo-random files and dirs and instructs the git controller to reconcile.

2: FuzzGitResourceObject

Creates a GitRepository object with pseudo-random values and instructs the git controller to reconcile.

3: FuzzHelmchartController

Creates pseudo-random helm charts and instructs the controller to reconcile.

4: FuzzStorageArchive

Tests the storage archive util api.

5: FuzzStorageCopy

Tests the storage copy util api.

To run the fuzzers without a docker shell:

git clone https://github.com/AdamKorcz/source-controller --branch=fuzz1
cd source-controller/fuzzing
# Now uncomment either of the fuzzers in the bottom of the Dockerfile
sudo docker build . --tag flux-fuzzing-image

The fuzzers will now build and the selected fuzzer will run.

To run the fuzzers in a docker shell:

git clone https://github.com/AdamKorcz/source-controller --branch=fuzz1
cd source-controller/fuzzing
sudo docker build . --tag flux-fuzzing-image
sudo docker run -it flux-fuzzing-image
cd controllers
/fuzzers/$FUZZER_NAME

The fuzzer will now run.

[stefanprodan]

Superseded by #572