consolidate script, not going to put in build instructions

build

@@ -7,49 +7,43 @@ if ! [ -d .git ]; then
   exit 1
 fi
 
+if uname | grep -qe Linux; then
+  os=linux
+elif uname | grep -qe MINGW; then
+  os=windows
+else
+  os=other
+fi
+
 build_go() {
   go build -o out/$(go env GOOS)/listen .
 }
 
 build_docker() {
-  if [ $DOCKER_IMAGE ]; then
-    image=$DOCKER_IMAGE
-    if echo $image | grep -q server; then
-      os=windows
-      exe=C:/build/listen/listen.exe
-    else
-      os=linux
-      exe=/usr/src/listen/listen
-    fi
+  if [ $os = "windows" ]; then
+    /c/Program\ Files/Docker/Docker/DockerCli.exe -SwitchWindowsEngine
+    exe=C:/build/listen/listen.exe
   else
-    if [ -f /c/Program\ Files/Docker/Docker/DockerCli.exe ]; then
-      os=windows
-      exe=C:/build/listen/listen.exe
-      image=1-nanoserver
-    else
-      os=linux
-      exe=/usr/src/listen/listen
-      image=1-alpine
-    fi
+    exe=/usr/src/listen/listen
   fi
-
-  echo building with $os image golang:$image
-  mkdir -p out/docker
-  if docker build -t listen-build --build-arg IMAGE=$image -f docker/build.$os.Dockerfile .; then
+  
+  if docker build -t listen-build -f docker/build.$os.Dockerfile .; then
+    mkdir -p out/$os
     docker create --name listen-build-tmp listen-build
-    docker cp listen-build-tmp:$exe out/docker
+    docker cp listen-build-tmp:$exe out/$os
     docker rm listen-build-tmp
   fi
 }
 
-mkdir -p out
 # if an arg is specified, force building with the specified method
 [ $1 ] && build_$1 && exit
 
 # prefer building with local go install if it exists on path
 if which go &> /dev/null; then
-  build_go
-# otherwise, try building with docker
-elif which docker &> /dev/null; then
-  build_docker
+  build_go; exit
+# if windows or linux, try building with docker
+elif echo $os | grep -e linux -e windows; then
+  which docker &> /dev/null && (build_docker; exit)
 fi
+
+echo could not find valid build method for OS && exit 2

docker/build.linux.Dockerfile

@@ -1,7 +1,7 @@
 # This Dockerfile is meant for building listen for Linux ONLY
 # listen is currently not intended to run in a Docker container
 
-ARG IMAGE
+ARG IMAGE="1-alpine"
 
 FROM golang:${IMAGE} AS build
 

docker/build.windows.Dockerfile

@@ -1,7 +1,7 @@
 # This Dockerfile is meant for building listen for Windows ONLY
 # listen is currently not intended to run in a Docker container
 
-ARG IMAGE
+ARG IMAGE="1-nanoserver"
 
 FROM golang:${IMAGE} AS build