From 1538ec33f7c34dfae0c47f514fab98b2aa7de8de Mon Sep 17 00:00:00 2001
From: Oleg Kalachev <okalachev@gmail.com>
Date: Sun, 4 Aug 2019 00:40:27 +0300
Subject: [PATCH] Rework assigning hostname and service files (#150)

* Rework assigning hostname and service files

* docs: small fix in hostname article

* Correct path to setup.bash in clever.service

* docs: correct ip in hostname article

* init_rpi: put normal and .local hostname on one line in hosts

* docs: add English version of hostname article

* clever.service: use sh instead of bash

* docs: Spellcheck english version, add note about hostname vs SSID

* clever.service: return roscore requirement back
---
 builder/assets/clever.service  |  6 +++---
 builder/assets/clever_rename   | 35 ----------------------------------
 builder/assets/init_rpi.sh     |  6 +++++-
 builder/assets/roscore.env     | 10 ----------
 builder/assets/roscore.service |  3 +--
 builder/image-build.sh         |  2 --
 docs/en/SUMMARY.md             |  1 +
 docs/en/hostname.md            | 31 ++++++++++++++++++++++++++++++
 docs/ru/SUMMARY.md             |  1 +
 docs/ru/hostname.md            | 31 ++++++++++++++++++++++++++++++
 10 files changed, 73 insertions(+), 53 deletions(-)
 delete mode 100755 builder/assets/clever_rename
 delete mode 100644 builder/assets/roscore.env
 create mode 100644 docs/en/hostname.md
 create mode 100644 docs/ru/hostname.md

diff --git a/builder/assets/clever.service b/builder/assets/clever.service
index 84bd7987..b432e96b 100644
--- a/builder/assets/clever.service
+++ b/builder/assets/clever.service
@@ -1,12 +1,12 @@
 [Unit]
 Description=Clever ROS package
 Requires=roscore.service
-After=roscore.service
+After=network.target
 
 [Service]
 User=pi
-EnvironmentFile=/lib/systemd/system/roscore.env
-ExecStart=/opt/ros/kinetic/bin/roslaunch clever clever.launch --wait --screen
+ExecStart=/bin/sh -c ". /home/pi/catkin_ws/devel/setup.sh; \
+                      ROS_HOSTNAME=`hostname`.local exec roslaunch clever clever.launch --wait --screen --skip-log-check"
 Restart=on-failure
 RestartSec=3
 
diff --git a/builder/assets/clever_rename b/builder/assets/clever_rename
deleted file mode 100755
index 8312af36..00000000
--- a/builder/assets/clever_rename
+++ /dev/null
@@ -1,35 +0,0 @@
-#!/usr/bin/env bash
-
-# Set Clever hostname to the specified value
-
-set -e
-
-NEW_NAME_OPT=$1
-
-if [[ -z ${NEW_NAME_OPT} ]]; then
-  echo "Please specify new name for this Clever"
-  exit 1
-fi
-
-NEW_NAME=$(echo ${NEW_NAME_OPT} | tr '[:upper:]' '[:lower:]')
-
-echo "Setting name to ${NEW_NAME}"
-
-echo "Backing up /etc/hostname"
-cp /etc/hostname /etc/hostname.bak
-echo "Writing new /etc/hostname"
-echo ${NEW_NAME} > /etc/hostname
-
-echo "Backing up /etc/hosts"
-cp /etc/hosts /etc/hosts.bak
-echo "Rewriting /etc/hosts with new values"
-sed -i 's/127\.0\.1\.1.*/127.0.1.1\t'${NEW_NAME}'/g' /etc/hosts
-
-echo "Changing hostname in /lib/systemd/system/roscore.env"
-sed -i 's/ROS_HOSTNAME=.*/ROS_HOSTNAME='${NEW_NAME}'.local/g' /lib/systemd/system/roscore.env
-
-echo "Changing hostname in .bashrc"
-sed -i 's/export ROS_HOSTNAME=.*/export ROS_HOSTNAME='${NEW_NAME}'.local/g' /home/pi/.bashrc
-
-echo "Done, reboot your Clever to see the results"
-
diff --git a/builder/assets/init_rpi.sh b/builder/assets/init_rpi.sh
index f393ef9e..d900b60c 100755
--- a/builder/assets/init_rpi.sh
+++ b/builder/assets/init_rpi.sh
@@ -38,7 +38,11 @@ echo_stamp() {
 echo_stamp "Rename SSID"
 NEW_SSID='CLEVER-'$(head -c 100 /dev/urandom | xxd -ps -c 100 | sed -e "s/[^0-9]//g" | cut -c 1-4)
 sudo sed -i.OLD "s/CLEVER/${NEW_SSID}/" /etc/wpa_supplicant/wpa_supplicant.conf
-clever_rename ${NEW_SSID}
+
+echo_stamp "Rename hostname to $NEW_SSID"
+hostnamectl set-hostname $NEW_SSID
+sed -i 's/127\.0\.1\.1.*/127.0.1.1\t'${NEW_SSID}' '${NEW_SSID}'.local/g' /etc/hosts
+# .local (mdns) hostname added to make it accesable when wlan and ethernet interfaces down
 
 echo_stamp "Harware setup"
 /root/hardware_setup.sh
diff --git a/builder/assets/roscore.env b/builder/assets/roscore.env
deleted file mode 100644
index 28387bf1..00000000
--- a/builder/assets/roscore.env
+++ /dev/null
@@ -1,10 +0,0 @@
-ROS_ROOT=/opt/ros/kinetic/share/ros
-ROS_DISTRO=kinetic
-ROS_PACKAGE_PATH=/home/pi/catkin_ws/src:/opt/ros/kinetic/share
-ROS_PORT=11311
-ROS_MASTER_URI=http://localhost:11311
-CMAKE_PREFIX_PATH=/home/pi/catkin_ws/devel:/opt/ros/kinetic
-PATH=/opt/ros/kinetic/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin
-LD_LIBRARY_PATH=/opt/ros/kinetic/lib
-PYTHONPATH=/home/pi/catkin_ws/devel/lib/python2.7/dist-packages:/opt/ros/kinetic/lib/python2.7/dist-packages
-ROS_HOSTNAME=raspberrypi.local
diff --git a/builder/assets/roscore.service b/builder/assets/roscore.service
index 44575cac..ccbc92e0 100644
--- a/builder/assets/roscore.service
+++ b/builder/assets/roscore.service
@@ -4,8 +4,7 @@ After=network.target
 
 [Service]
 User=pi
-EnvironmentFile=/lib/systemd/system/roscore.env
-ExecStart=/opt/ros/kinetic/bin/roscore
+ExecStart=/bin/sh -c ". /opt/ros/kinetic/setup.sh; ROS_HOSTNAME=`hostname`.local exec roscore"
 Restart=on-failure
 RestartSec=3
 
diff --git a/builder/image-build.sh b/builder/image-build.sh
index 427d1e51..4d1c84e9 100755
--- a/builder/image-build.sh
+++ b/builder/image-build.sh
@@ -109,7 +109,6 @@ ${BUILDER_DIR}/image-chroot.sh ${IMAGE_PATH} exec ${SCRIPTS_DIR}'/image-network.
 [[ $(arch) == 'armv7l' ]] && NUMBER_THREADS=1 || NUMBER_THREADS=$(nproc --all)
 # Clever
 ${BUILDER_DIR}/image-chroot.sh ${IMAGE_PATH} copy ${SCRIPTS_DIR}'/assets/clever.service' '/lib/systemd/system/'
-${BUILDER_DIR}/image-chroot.sh ${IMAGE_PATH} copy ${SCRIPTS_DIR}'/assets/roscore.env' '/lib/systemd/system/'
 ${BUILDER_DIR}/image-chroot.sh ${IMAGE_PATH} copy ${SCRIPTS_DIR}'/assets/roscore.service' '/lib/systemd/system/'
 ${BUILDER_DIR}/image-chroot.sh ${IMAGE_PATH} copy ${SCRIPTS_DIR}'/assets/kinetic-rosdep-clever.yaml' '/etc/ros/rosdep/'
 ${BUILDER_DIR}/image-chroot.sh ${IMAGE_PATH} copy ${SCRIPTS_DIR}'/assets/ros_python_paths' '/etc/sudoers.d/'
@@ -118,7 +117,6 @@ ${BUILDER_DIR}/image-chroot.sh ${IMAGE_PATH} copy ${SCRIPTS_DIR}'/assets/pigpiod
 # Add PX4 udev rules
 ${BUILDER_DIR}/image-chroot.sh ${IMAGE_PATH} copy ${REPO_DIR}'/clever/config/99-px4fmu.rules' '/lib/udev/rules.d/'
 # Add rename script
-${BUILDER_DIR}/image-chroot.sh ${IMAGE_PATH} copy ${SCRIPTS_DIR}'/assets/clever_rename' '/usr/local/bin/clever_rename'
 ${BUILDER_DIR}/image-chroot.sh ${IMAGE_PATH} exec ${SCRIPTS_DIR}'/image-ros.sh' ${REPO_URL} ${IMAGE_VERSION} false false ${NUMBER_THREADS}
 ${BUILDER_DIR}/image-chroot.sh ${IMAGE_PATH} exec ${SCRIPTS_DIR}'/image-validate.sh'
 
diff --git a/docs/en/SUMMARY.md b/docs/en/SUMMARY.md
index 1927eeb0..bf8cb2a7 100644
--- a/docs/en/SUMMARY.md
+++ b/docs/en/SUMMARY.md
@@ -50,6 +50,7 @@
   * [Interfacing with a laser rangefinder](laser.md)
   * [PX4 Simulation](sitl.md)
   * [Software autorun](autolaunch.md)
+  * [Hostname](hostname.md)
   * [Controlling the copter from Arduino](arduino.md)
   * [Using an external 3G modem](3g.md)
 * Clever-based projects
diff --git a/docs/en/hostname.md b/docs/en/hostname.md
new file mode 100644
index 00000000..d8b32e0c
--- /dev/null
+++ b/docs/en/hostname.md
@@ -0,0 +1,31 @@
+# Hostname
+
+[By default](microsd_images.md) the hostname of the Clever drone is set to `clever-xxxx`, where `xxxx` are random numbers. These numbers are the same as in the [Wi-Fi SSID](wifi.md).
+
+Thus, Clever is accessible on machines that support mDNS as `clever-xxxx.local`. You can use this name to access Clever over SSH:
+
+```bash
+ssh pi@clever-xxxx.local
+```
+
+Also, this name can be used in place of IP-address to open Clever web pages in browser, accessing ROS master, etc.
+
+## Changing hostname
+
+In some situations it is necessary to change Clever's hostname. You can use the `hostnamectl` utility for that:
+
+```bash
+sudo hostnamectl set-hostname newname
+```
+
+Where `newname` is the new name of the machine. `hostnamectl` utility will change the name in `/etc/hostname` file.
+
+You should also put the new name to `/etc/hosts` file:
+
+```txt
+127.0.1.1	newname newname.local
+```
+
+Setting `newname.local` is necessary to allow ROS to resolve this name in situations where all the network interfaces are down (when Wi-Fi is turned off or disconnected).
+
+> **Note** Changing the hostname does not affect the Wi-Fi SSID (and vice versa, changing the Wi-Fi SSID won't affect the hostname).
diff --git a/docs/ru/SUMMARY.md b/docs/ru/SUMMARY.md
index b43cdb5b..a44d4b5a 100644
--- a/docs/ru/SUMMARY.md
+++ b/docs/ru/SUMMARY.md
@@ -54,6 +54,7 @@
   * [Работа с SITL](sitl.md)
   * [Контейнер с симулятором](sitl_docker.md)
   * [Автозапуск ПО](autolaunch.md)
+  * [Имя хоста](hostname.md)
   * [Взаимодействие с Arduino](arduino.md)
   * [3G-модем](3g.md)
   * [Установка ROS Kinetic](ros-install.md)
diff --git a/docs/ru/hostname.md b/docs/ru/hostname.md
new file mode 100644
index 00000000..11cb3511
--- /dev/null
+++ b/docs/ru/hostname.md
@@ -0,0 +1,31 @@
+# Имя хоста
+
+[По умолчанию](microsd_images.md) на Клевере установлено имя хоста (hostname) `clever-xxxx`, где `xxxx` – случайные цифры. Имя хоста соответствует SSID [точки доступа Wi-Fi](wifi.md).
+
+Таким образом, Клевер доступен на машинах, поддерживающих mDNS, под именем `clever-xxxx.local`. Вы можете использовать это имя для SSH-доступа на Клевер:
+
+```bash
+ssh pi@clever-xxxx.local
+```
+
+Также это имя может быть использовано вместо IP-адреса для открытия страницы Клевера в браузере и т. д.
+
+## Изменение имени хоста
+
+В некоторых ситуациях необходимо изменение имени хоста Клевера. Для это используйте утилиту `hostnamectl`:
+
+```bash
+sudo hostnamectl set-hostname newname
+```
+
+Где `newname` – новое имя машины. Утилита `hostnamectl` поменяет имя в файле `/etc/hostname`.
+
+Также необходимо прописывание нового имени в файл `/etc/hosts`:
+
+```txt
+127.0.1.1	newname newname.local
+```
+
+Прописывание `newname.local` необходимо, чтобы ROS смог разрешить это имя в ситуациях, когда все сетевые интерфейсы неактивны (отключение/разрыв связи Wi-Fi).
+
+> **Note** Изменение имени хоста не повлечёт за собой изменений SSID точки доступа Wi-Fi (и наоборот, изменение SSID точки доступа не поменяет имя хоста).