Recognize KOPS_BASE_URL, fallback to KOPS_URL

KOPS_URL feels a little too generic

docs/development/adding_a_feature.md

@@ -198,7 +198,7 @@ and then push nodeup using:
 export S3_BUCKET_NAME=<yourbucketname>
 make upload S3_BUCKET=s3://${S3_BUCKET_NAME} VERSION=dev
 
-export KOPS_URL=https://${S3_BUCKET_NAME}.s3.amazonaws.com/kops/dev/
+export KOPS_BASE_URL=https://${S3_BUCKET_NAME}.s3.amazonaws.com/kops/dev/
 
 kops create cluster <clustername> --zones us-east-1b
 ...

hack/dev-build.sh

@@ -75,7 +75,7 @@ cd $KOPS_DIRECTORY/..
 GIT_VER=git-$(git describe --always)
 [ -z "$GIT_VER" ] && echo "we do not have GIT_VER something is very wrong" && exit 1;
 
-KOPS_URL="https://${NODEUP_BUCKET}.s3.amazonaws.com/kops/${GIT_VER}/"
+KOPS_BASE_URL="https://${NODEUP_BUCKET}.s3.amazonaws.com/kops/${GIT_VER}/"
 
 echo ==========
 echo "Starting build"
@@ -94,7 +94,7 @@ kops delete cluster \
 echo ==========
 echo "Creating cluster ${CLUSTER_NAME}"
 
-KOPS_URL=${KOPS_URL} kops create cluster \
+KOPS_BASE_URL=${KOPS_BASE_URL} kops create cluster \
   --name $CLUSTER_NAME \
   --state $KOPS_STATE_STORE \
   --node-count $NODE_COUNT \

upup/pkg/fi/cloudup/urls.go

@@ -33,7 +33,15 @@ func BaseUrl() string {
 		return baseUrl
 	}
 
-	baseUrl = os.Getenv("KOPS_URL")
+	// We prefer KOPS_BASE_URL, but we will accept KOPS_URL (for now!)
+	baseUrl = os.Getenv("KOPS_BASE_URL")
+	if baseUrl == "" {
+		baseUrl = os.Getenv("KOPS_URL")
+		if baseUrl != "" {
+			glog.Warningf("Using deprecated KOPS_URL envrionment variable - please use KOPS_BASE_URL instead")
+		}
+	}
+
 	if baseUrl == "" {
 		baseUrl = "https://kubeupv2.s3.amazonaws.com/kops/" + kops.Version + "/"
 		glog.V(4).Infof("Using default base url: %q", baseUrl)