added --skip-dependencies and --only-dependencies options for facilit…

…ating installs where homebrew needs to be run as a different user

github brikis98/docker-osx-dev issue brikis98#152

src/docker-osx-dev

@@ -101,6 +101,28 @@ function assert_non_empty {
   fi
 }
 
+#
+# Usage: assert_mutually_exclusive VAR_NAME1 VAR_NAME2 ... VAR_NAMEn
+#
+# Asserts that at most one of $VAR_NAME1, $VAR_NAME2, ..., $VAR_NAMEn is defined
+#
+function assert_mutually_exclusive {
+  local found
+  while [[ $# > 0 ]]; do
+    local readonly var_name="$1"
+    if test -n "${!var_name+x}" ; then
+      if test -n "$found" ; then
+        log_error "$var_name conflicts with $found"
+        instructions
+        exit 1
+      else
+        found=$var_name
+      fi
+    fi
+    shift
+  done
+}
+
 #
 # Usage: index_of VALUE ARRAY
 #
@@ -871,6 +893,8 @@ function instructions {
   echo -e "  -e, --exclude-path PATH\t\tExclude PATH while syncing. Behaves identically to rsync's --exclude parameter. May be specified multiple times. Default: $DEFAULT_EXCLUDES"
   echo -e "  -c, --compose-file COMPOSE_FILE\tRead in this docker-compose file and sync any volumes specified in it. Default: $DEFAULT_COMPOSE_FILE"
   echo -e "  -i, --ignore-file IGNORE_FILE\t\tRead in this ignore file and exclude any paths within it while syncing (see --exclude). Default: $DEFAULT_IGNORE_FILE"
+  echo -e "  --only-dependencies\t\t\tDuring install, only install the homebrew dependencies. Useful if homebrew is needs to be run as a different user."
+  echo -e "  --skip-dependencies\t\t\tDuring install, don't install the homebrew dependencies. Useful if homebrew is needs to be run as a different user."
   echo -e "  -l, --log-level LOG_LEVEL\t\tSpecify the logging level. One of: $LOG_LEVELS. Default: ${DEFAULT_LOG_LEVEL}"
   echo -e "  -h, --help\t\t\t\tPrint this help text and exit."
   echo -e
@@ -1094,12 +1118,16 @@ function sync {
 #
 function install {
   log_info "Starting install of docker-osx-dev"
-  install_dependencies
-  init_docker_host
-  install_rsync_on_docker_host
-  add_docker_host
-  add_environment_variables
-  print_next_steps
+  if test -z "$SKIP_DEPENDENCIES" ; then
+    install_dependencies
+  fi
+  if test -z "$ONLY_DEPENDENCIES" ; then
+    init_docker_host
+    install_rsync_on_docker_host
+    add_docker_host
+    add_environment_variables
+    print_next_steps
+  fi
 }
 
 #
@@ -1208,6 +1236,12 @@ function handle_command {
         DOCKER_MACHINE_NAME="$2"
         shift
         ;;
+      --only-dependencies)
+        ONLY_DEPENDENCIES=true
+        ;;
+      --skip-dependencies)
+        SKIP_DEPENDENCIES=true
+        ;;
       -h|--help)
         instructions
         exit 0
@@ -1222,6 +1256,8 @@ function handle_command {
     shift
   done
 
+  assert_mutually_exclusive "ONLY_DEPENDENCIES" "SKIP_DEPENDENCIES"
+
   case "$cmd" in
     "$SYNC_COMMAND" | "$SYNC_ONLY_COMMAND" | "$WATCH_ONLY_COMMAND")
       configure_log_level "$log_level"

test/docker-osx-dev.bats

@@ -303,6 +303,37 @@ load test_helper
   assert_success
 }
 
+@test "assert_mutually_exclusive exits on conflicting variables" {
+  FOO=1
+  BAR=2
+  run assert_mutually_exclusive "FOO" "BAR"
+  assert_failure
+}
+
+@test "assert_mutually_exclusive exits on conflicting but empty variables" {
+  FOO=
+  BAR=
+  run assert_mutually_exclusive "FOO" "BAR"
+  assert_failure
+}
+
+@test "assert_mutually_exclusive doesn't exit without any variables" {
+  run assert_mutually_exclusive "FOO" "BAR"
+  assert_success
+}
+
+@test "assert_mutually_exclusive doesn't exit with only the first variable" {
+  FOO=1
+  run assert_mutually_exclusive "FOO" "BAR"
+  assert_success
+}
+
+@test "assert_mutually_exclusive doesn't exit with only the last variable" {
+  BAR=2
+  run assert_mutually_exclusive "FOO" "BAR"
+  assert_success
+}
+
 @test "env_is_defined returns true for USER variable being defined" {
   run env_is_defined "USER"
   assert_success