Ubantu18安装ros，排除很多的坑

1.配置更新仓库

2.添加ROS源和秘钥

sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'

sudo apt-key adv --keyserver hkp://ha.pool.sks-keyservers.net:80 --recv-key 421C365BD9FF1F717815A3895523BAEEB01FA116

3.安装ROS

sudo apt-get update

sudo apt-get install ros-melodic-desktop-full

4.以防初始化找不到文件，再次打开文件更新，然后会有提醒更新。之后

apt-cache search rosdep

sudo apt install python-rosdep

添加一个内容，避免初始化ros时出错
#打开hosts文件

sudo gedit /etc/hosts

#末尾添加

151.101.84.133  raw.githubusercontent.com

#保存后退出再尝试
5.初始化rosde

sudo rosdep init

rosdep update

6.设置环境变量

echo "source /opt/ros/melodic/setup.bash" >> ~/.bashrc

source ~/.bashrc

7.安装rosinstall

sudo apt-get install python-rosinstall python-rosinstall-generator python-wstool build-essential