Add config file and defaults support, and then for each config_file/dir,

if there is a values/apiserver-env.yaml, attempt to look at a buildName
setting, which then becomes the volume name.

@@ -2,17 +2,37 @@
 
 set -e
 
-INKLUSTER_IMAGE=brainfood/inkluster-dev
+declare -A defaults=(
+	[INKLUSTER_IMAGE]=brainfood/inkluster-dev
+	[INKLUSTER_VOLUME_NAME]=""
+)
+
+declare -a config_files=()
 
 if [[ -e .inkluster.env ]]; then
-	. .inkluster.env
+	config_files+=("$PWD/.inkluster.env")
 fi
 
+declare -A config=()
+
+# This copies ENV settings into the config, that haven't been set on the command line.
+for setting in "${!defaults[@]}"; do
+	[[ ${!setting} ]] && eval config[$setting]="${!setting}"
+done
+
 declare -a REST=()
 while [[ $# -gt 0 ]]; do
 	case "$1" in
+		(-c)
+			config_files+=("$2")
+			shift 2
+			;;
+		(-i)
+			config[INKLUSTER_IMAGE]="$2"
+			shift 2
+			;;
 		(-v)
-			INKLUSTER_VOLUME_NAME="$2"
+			config[INKLUSTER_VOLUME_NAME]="$2"
 			shift 2
 			;;
 		(*)
@@ -21,6 +41,28 @@ while [[ $# -gt 0 ]]; do
 	esac
 done
 
+# Now we copy the config settings into ENV
+for config_file in "${config_files[@]}"; do
+	if [[ ! -e $config_file ]]; then
+		echo "Config file $config_file does not exist!" 1>&2
+		exit 1
+	fi
+	. "$config_file"
+	config_dir="${config_file%/*}"
+	[[ $config_dir = $config_file ]] && config_dir="$PWD"
+	if [[ -e $config_dir/values/apiserver-env.yaml ]]; then
+		buildName="$(sed -n -e 's/^buildName: "\(.*\)"$/\1/p' "$config_dir/values/apiserver-env.yaml")"
+		[[ $buildName && -z $INKLUSTER_VOLUME_NAME ]] && INKLUSTER_VOLUME_NAME="$buildName"
+	fi
+done
+
+# Any settings read from the config files, but not yet set, get applied.
+for setting in "${!defaults[@]}"; do
+	[[ -n ${!setting} && -z ${config[$setting]} ]] && eval config[$setting]="${!setting}"
+	[[ -z ${config[$setting]} ]] && eval config[$setting]="${defaults[$setting]}"
+	eval $setting=\"\${config[$setting]}\"
+done
+
 has_volume=
 if [[ $INKLUSTER_VOLUME_NAME ]]; then
 	docker volume inspect "inkluster-$INKLUSTER_VOLUME_NAME" 1>/dev/null 2>/dev/null || has_volume=1