[infra] Update base-builder image to support go-fuzz (#2714). (#2735)

* [infra] Update base-builder image to support go-fuzz (#2714).

* address review comments

infra/base-images/base-builder/Dockerfile

@@ -27,6 +27,25 @@ RUN apt-get install -y git \
     libblocksruntime-dev \
     libc6-dev-i386
 
+# Download and install the latest stable Go.
+ADD https://storage.googleapis.com/golang/getgo/installer_linux $SRC/
+RUN chmod +x $SRC/installer_linux && \
+    SHELL="bash" $SRC/installer_linux && \
+    rm $SRC/installer_linux
+
+# Set up Golang environment variables (copied from /root/.bash_profile).
+ENV GOPATH /root/go
+
+# /root/.go/bin is for the standard Go binaries (i.e. go, gofmt, etc).
+# $GOPATH/bin is for the binaries from the dependencies installed via "go get".
+ENV PATH $PATH:/root/.go/bin:$GOPATH/bin
+
+# Dependency of go-fuzz.
+RUN go get golang.org/x/tools/go/packages
+
+# go-fuzz-build is the tool that instruments Go files.
+RUN go get github.com/dvyukov/go-fuzz/go-fuzz-build
+
 # Default build flags for various sanitizers.
 ENV SANITIZER_FLAGS_address "-fsanitize=address -fsanitize-address-use-after-scope"
 

projects/syzkaller/Dockerfile

@@ -16,19 +16,9 @@
 
 FROM gcr.io/oss-fuzz-base/base-builder
 MAINTAINER [email protected]
-ADD https://dl.google.com/go/go1.12.9.linux-amd64.tar.gz go.tar.gz
-RUN tar xzf go.tar.gz -C $SRC/
-ENV GOPATH $SRC
-ENV PATH $SRC/go/bin:$GOPATH/bin:$PATH
 
 RUN go get -u -d github.com/google/syzkaller/...
 
-# Dependency of go-fuzz
-RUN go get golang.org/x/tools/go/packages
-
-# go-fuzz-build is the tool that instruments Go files.
-RUN go get github.com/dvyukov/go-fuzz/go-fuzz-build
-
 # Dependency for one of the fuzz targets.
 RUN go get github.com/ianlancetaylor/demangle