diff --git a/.dockerignore b/.dockerignore
index 49dc76f..8e071a0 100644
--- a/.dockerignore
+++ b/.dockerignore
@@ -1 +1,3 @@
-make.sh
+*
+!requirements.txt
+!flask_control.py
diff --git a/Dockerfile b/Dockerfile
index c64d236..3a483b8 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,15 +1,18 @@
 FROM golang:1.10.1-alpine3.7
 
-RUN apk add --no-cache build-base git linux-headers python python-dev py-pip py-setuptools
+ARG GOVMOMI_CHECKOUT=dee49fa3694c5aff05e4b340b0686772f65c1fe1
 
 ADD requirements.txt /root/requirements.txt
-RUN pip install -r /root/requirements.txt
-ADD flask_control.py /root/flask_control.py
 
-RUN go get -d github.com/vmware/govmomi && \
+RUN apk add --no-cache build-base git linux-headers python python-dev py-pip py-setuptools && \
+    pip install -r /root/requirements.txt && \
+    go get -d github.com/vmware/govmomi && \
     cd ${GOPATH}/src/github.com/vmware/govmomi && \
-    git checkout dee49fa3694c5aff05e4b340b0686772f65c1fe1 && \
-    go install github.com/vmware/govmomi/govc github.com/vmware/govmomi/vcsim
+    git checkout ${GOVMOMI_CHECKOUT} && \
+    go install github.com/vmware/govmomi/govc github.com/vmware/govmomi/vcsim && \
+    apk del build-base git linux-headers python-dev py-pip py-setuptools
+
+ADD flask_control.py /root/flask_control.py
 
 EXPOSE 5000 8989 443 80 8080
 CMD ["/root/flask_control.py"]
diff --git a/README.md b/README.md
index 2ffeb17..3d7fe4b 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,16 @@
 # vcenter-test-container
 vCenter simulator container for testing.
+
+## Usage ##
+
+### Building the image locally ###
+
+```bash
+docker image build -t local/ansible/vcenter-test-container:latest .
+```
+
+### Building the image locally with a different version of govmomi checked out ###
+
+```bash
+docker image build --build-arg GOVMOMI_CHECKOUT=<hash|branch|tag> -t local/ansible/vcenter-test-container:<hash|branch|tag> .
+```
diff --git a/make.sh b/make.sh
deleted file mode 100755
index 589d949..0000000
--- a/make.sh
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/bin/bash
-
-docker build --no-cache -t ansible:vcenter-simulator .