diff --git a/plugins/docker-options/commands b/plugins/docker-options/commands
index c9661756c..a1756739c 100755
--- a/plugins/docker-options/commands
+++ b/plugins/docker-options/commands
@@ -1,118 +1,14 @@
 #!/usr/bin/env bash
-[[ " docker-options docker-options:add docker-options:remove help docker-options:help " == *" $1 "* ]] || exit $DOKKU_NOT_IMPLEMENTED_EXIT
+[[ " docker-options docker-options:add docker-options:remove help docker-options:help " == *" $1 "* ]] || exit "$DOKKU_NOT_IMPLEMENTED_EXIT"
 set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
 source "$PLUGIN_CORE_AVAILABLE_PATH/common/functions"
-
-get_app() {
-  [[ -z $1 ]] && dokku_log_fail "Please specify an app to run the command on"
-  verify_app_name "$1"
-  APP="$1"
-}
-
-get_phases() {
-  local passed_phases_list=$1
-  local phase
-  if [[ -n $passed_phases_list ]]; then
-    IFS=',' read -ra passed_phases <<< "$passed_phases_list"
-    for phase in "${passed_phases[@]}"; do
-      verify_phase $phase
-    done
-  fi
-}
-
-verify_phase() {
-  local phase
-  local phases=(build deploy run)
-  for phase in "${phases[@]}"; do
-    if [[ "$phase" = "$1" ]]; then
-      return 0
-    fi
-  done
-  dokku_log_fail "Phase(s) must be one of [${phases[*]}]"
-}
-
-get_phase_file_path() {
-  local phase=$1
-  local prefix="DOCKER_OPTIONS_"
-  phase_file_path="${DOKKU_ROOT}/${APP}/${prefix}${phase^^}"
-}
-
-create_phase_file_if_required() {
-  local phase_file_path=$1
-  [[ -f $phase_file_path ]] || {
-    touch $phase_file_path
-  }
-}
-
-display_phase_options() {
-  local phase=$1
-  local phase_file_path=$2
-  echo "${phase^} options:"
-  sed -e 's/^/    /' $phase_file_path
-}
-
-display_all_phases_options() {
-  local phases=(build deploy run)
-  for phase in "${phases[@]}"; do
-    get_phase_file_path $phase
-    if [[ -s $phase_file_path ]]; then
-       display_phase_options $phase $phase_file_path
-    fi
-  done
-}
-
-display_passed_phases_options() {
-  local passed_phases=("${!1}")
-  local phase
-  for phase in "${passed_phases[@]}"; do
-    get_phase_file_path $phase
-    if [[ ! -s $phase_file_path ]]; then
-      echo "${phase^} options: none"
-    else
-      display_phase_options $phase $phase_file_path
-    fi
-  done
-}
-
-get_passed_docker_option() {
-  [[ -z "$@" ]] && dokku_log_fail "Please specify docker options to add to the phase"
-  passed_docker_option=("$@")
-}
-
-add_passed_docker_option() {
-  local passed_phases=("${!1}")
-  shift
-  local passed_option_string="$*"
-  local phase
-  for phase in "${passed_phases[@]}"; do
-    get_phase_file_path $phase
-    create_phase_file_if_required $phase_file_path
-    echo "${passed_option_string}" >> $phase_file_path
-    all_phase_options=$(< $phase_file_path)
-    echo -e "${all_phase_options}" | sed '/^$/d' | sort -u > $phase_file_path
-  done
-}
-
-remove_passed_docker_option() {
-  local passed_phases=("${!1}")
-  shift
-  local passed_option_string="$*"
-  local phase
-  for phase in "${passed_phases[@]}"; do
-    get_phase_file_path $phase
-    [[ ! -s $phase_file_path ]] || {
-      all_phase_options=$(< $phase_file_path)
-      all_phase_options=$(echo -e "${all_phase_options}" | sed "s#^${passed_option_string}\$##")
-      echo -e "${all_phase_options}" | sed '/^$/d' | sort -u > $phase_file_path
-    }
-  done
-}
+source "$PLUGIN_CORE_AVAILABLE_PATH/docker-options/functions"
 
 case "$1" in
   # Display applications docker options
   docker-options)
-    get_app $2
-    get_phases $3
+    verify_app_name "$2" && APP="$2"
+    read -ra passed_phases <<< "$(get_phases "$3")"
     if [[ ! "${passed_phases[@]}" ]]; then
       display_all_phases_options
     else
@@ -122,19 +18,20 @@ case "$1" in
 
   # Add a docker option to application
   docker-options:add)
-    get_app $2
-    get_phases $3
+    verify_app_name "$2" && APP="$2"
+    read -ra passed_phases <<< "$(get_phases "$3")"
     shift 3 # everything else passed is the docker option
-    get_passed_docker_option "$@"
+    passed_docker_option="$*"
+    [[ -z "$passed_docker_option" ]] && dokku_log_fail "Please specify docker options to add to the phase"
     add_passed_docker_option passed_phases[@] "${passed_docker_option[@]}"
   ;;
 
   # Remove a docker option from application
   docker-options:remove)
-    get_app $2
-    get_phases $3
+    verify_app_name "$2" && APP="$2"
+    read -ra passed_phases <<< "$(get_phases "$3")"
     shift 3 # everything else passed is the docker option
-    get_passed_docker_option "$@"
+    [[ -z ${passed_docker_option="$@"} ]] && dokku_log_fail "Please specify docker options to add to the phase"
     remove_passed_docker_option passed_phases[@] "${passed_docker_option[@]}"
   ;;
 
@@ -149,7 +46,7 @@ EOF
   ;;
 
   *)
-    exit $DOKKU_NOT_IMPLEMENTED_EXIT
+    exit "$DOKKU_NOT_IMPLEMENTED_EXIT"
   ;;
 
 esac
diff --git a/plugins/docker-options/functions b/plugins/docker-options/functions
new file mode 100644
index 000000000..8abd82cb9
--- /dev/null
+++ b/plugins/docker-options/functions
@@ -0,0 +1,95 @@
+#!/usr/bin/env bash
+[[ " docker-options docker-options:add docker-options:remove help docker-options:help " == *" $1 "* ]] || exit "$DOKKU_NOT_IMPLEMENTED_EXIT"
+set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
+source "$PLUGIN_CORE_AVAILABLE_PATH/common/functions"
+
+AVAILABLE_PHASES=(build deploy run)
+
+get_phase_file_path() {
+  local phase_file_prefix="DOCKER_OPTIONS_"
+  echo "${DOKKU_ROOT}/${APP}/${phase_file_prefix}${phase^^}"
+}
+
+get_phases() {
+  local passed_phases_list="$1"
+  local -r phases_allowed=$(sed -e 's/ /\|/g' <<< "${AVAILABLE_PHASES[@]}")
+  local phase
+  local passed_phases
+  if [[ -n "$passed_phases_list" ]]; then
+    IFS=',' read -ra passed_phases <<< "$passed_phases_list"
+    for phase in "${passed_phases[@]}"; do
+      [[ "$phase" = @($phases_allowed) ]] || dokku_log_fail "Phase(s) must be one of [${AVAILABLE_PHASES[*]}]"
+    done
+    echo "${passed_phases[@]}"
+  fi
+}
+
+create_phase_file_if_required() {
+  local phase_file_path="$1"
+  [[ -f "$phase_file_path" ]] || {
+    touch "$phase_file_path"
+  }
+}
+
+display_phase_options() {
+  local phase="$1"
+  local phase_file_path="$2"
+  echo "${phase^} options:"
+  sed -e 's/^/    /' "$phase_file_path"
+}
+
+display_all_phases_options() {
+  local phases=("${AVAILABLE_PHASES[@]}")
+  for phase in "${phases[@]}"; do
+    local phase_file_path
+    phase_file_path="$(get_phase_file_path)"
+    if [[ -s "$phase_file_path" ]]; then
+       display_phase_options "$phase" "$phase_file_path"
+    fi
+  done
+}
+
+display_passed_phases_options() {
+  local passed_phases=("${!1}")
+  local phase
+  for phase in "${passed_phases[@]}"; do
+    local phase_file_path
+    phase_file_path="$(get_phase_file_path)"
+    if [[ ! -s "$phase_file_path" ]]; then
+      echo "${phase^} options: none"
+    else
+      display_phase_options "$phase" "$phase_file_path"
+    fi
+  done
+}
+
+add_passed_docker_option() {
+  local passed_phases=("${!1}")
+  shift
+  local passed_option_string="$*"
+  local phase
+  for phase in "${passed_phases[@]}"; do
+    local phase_file_path
+    phase_file_path="$(get_phase_file_path)"
+    create_phase_file_if_required "$phase_file_path"
+    echo "${passed_option_string}" >> "$phase_file_path"
+    all_phase_options="$(< "$phase_file_path")"
+    echo -e "${all_phase_options}" | sed '/^$/d' | sort -u > "$phase_file_path"
+  done
+}
+
+remove_passed_docker_option() {
+  local passed_phases=("${!1}")
+  shift
+  local passed_option_string="$*"
+  local phase
+  for phase in "${passed_phases[@]}"; do
+    local phase_file_path
+    phase_file_path="$(get_phase_file_path)"
+    [[ ! -s "$phase_file_path" ]] || {
+      all_phase_options="$(< "$phase_file_path")"
+      all_phase_options=$(echo -e "${all_phase_options}" | sed "s#^${passed_option_string}\$##")
+      echo -e "${all_phase_options}" | sed '/^$/d' | sort -u > "$phase_file_path"
+    }
+  done
+}