try {
computeServiceContext = ContextBuilder.newBuilder("aws-ec2")
.credentials(username, password)
.modules(ImmutableSet.<Module>of(
new SshjSshClientModule(),
new SLF4JLoggingModule()))
.overrides(overrides)
.buildView(ComputeServiceContext.class);
// since the compute service context doesn't try to auth against AWS until it
// needs to, make a call to listNodes() to force the auth.