Don't put Go directory at the same level than source

Currently when we build the container image we put the source code in
the home directory of the `builder` user. That means that the source
code will be in `/home/builder` and the Go module cache will be in
`/home/builder/go/pkg`. A side effect of that is that tools like
`controller-gen` that scan directories looking for Go code will find our
source code, but also the source code of the modules in that module
cache. That results in errors because the tool will not find the
dependencies of those incorrect source files. To avoid that this patch
changes the `Containerfile` so that the source code will be in
`/home/builder/project` and the Go module cache in
`/home/builder/go/pkg`, that way `controller-gen` will run inside
`/home/builder/project` and will not find the Go module cache source
files.

Note that we are not yet using `controller-gen` in the affected
`Containerfile`, but we will use it in the future.

Signed-off-by: Juan Hernandez <[email protected]>

Containerfile

@@ -34,15 +34,18 @@ RUN \
   useradd -c "Builder" builder
 USER \
   builder
-WORKDIR \
-  /home/builder
 ENV \
   PATH="${PATH}:/usr/local/go/bin"
 
-# Copy the source:
+# Run the rest of the steps inside the directory containing the source code of the project. Note
+# that it is important to use a directory that is not the home of the user. Go will create`go/pkg`
+# directory inside that home directory, and tools like `conroller-gen` get very confused and fail
+# when they find the `go.mod` and `go.sum` files inside that package cache.
+WORKDIR \
+  /home/builder/project
 COPY \
   --chown=builder:builder \
-  . /home/builder
+  . .
 
 # Download the Go dependencies. We do this in a separate step so that hopefully that large set of
 # dependencies will be in a cached layer, and we will not need to download them for every build.
@@ -57,7 +60,7 @@ FROM registry.access.redhat.com/ubi9-minimal:9.2 AS runtime
 
 COPY \
   --from=builder \
- /home/builder/oran-o2ims /usr/bin/oran-o2ims
+ /home/builder/project/oran-o2ims /usr/bin/oran-o2ims
 
 ENTRYPOINT \
   ["/usr/bin/oran-o2ims"]