CNF-13590: Use the vendor directory when building images (#128)

Description:
- remove the vendor directory from .gitignore and .containerignore
  so that it gets copied into the image with the rest of the
  content
- add -mod=vendor to go build commands

.containerignore

@@ -9,3 +9,4 @@
 !/cmd
 !/api
 !/bundle
+!/vendor

.gitignore

@@ -1,5 +1,4 @@
 *.log
 /__debug*
 /oran-o2ims
-/vendor
 /bin/*

Containerfile

@@ -47,11 +47,6 @@ COPY \
   --chown=builder: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.
-RUN \
-  go mod download
-
 # Build the binary:
 RUN \
   make binary

Dockerfile

@@ -7,10 +7,6 @@ WORKDIR /workspace
 # Copy the Go Modules manifests
 COPY go.mod go.sum ./
 
-# cache deps before building and copying source so that we don't need to re-download as much
-# and so that source changes don't invalidate our downloaded layer
-RUN go mod download
-
 # Copy the go source
 COPY . .
 
@@ -19,7 +15,7 @@ COPY . .
 # was called. For example, if we call make docker-build in a local env which has the Apple Silicon M1 SO
 # the docker BUILDPLATFORM arg will be linux/arm64 when for Apple x86 it will be linux/amd64. Therefore,
 # by leaving it empty we can ensure that the container and binary shipped on it will have the same platform.
-RUN CGO_ENABLED=0 GOOS=${TARGETOS:-linux} GOARCH=${TARGETARCH} go build -a
+RUN CGO_ENABLED=0 GOOS=${TARGETOS:-linux} GOARCH=${TARGETARCH} go build -mod=vendor -a
 
 # Use distroless as minimal base image to package the manager binary
 # Refer to https://github.com/GoogleContainerTools/distroless for more details

Makefile

@@ -289,7 +289,7 @@ catalog-push: ## Push a catalog image.
 ##@ Binary
 .PHONY: binary
 binary:
-	go build
+	go build -mod=vendor
 
 .PHONY: image
 image: