Node.js is a JavaScript platform for general programming that allows users to quickly build web applications. By leveraging JavaScript on the front and back ends, development can be more consistent and designed in the same system.
In this tutorial, we will show you how to start using Node.js on Ubuntu 16.04 server.
sudo to set permissions on the system. You can learn how to do this by completing steps 1-4 in [Ubuntu 16.04 Initial Server Setup] (https://cloud.tencent.com/developer/article/1007167?from=10680).Ubuntu 16.04 includes a version of Node.js in its default repository, which can be used to easily provide a consistent experience across multiple systems. At the time of writing, the version in the repository is v4.2.6. This is not the latest version, but it should be very stable enough for quick language experiments.
To get this version, we just need to use the apt package manager. We should first refresh the local package index and then install from the repository:
sudo apt-get update
sudo apt-get install nodejs
If the packages in the repository meet your needs, all you need to do is set it up with Node.js. In most cases, you also need to install npm, the Node.js package manager. You can execute by entering the following:
sudo apt-get install npm
This will allow you to easily install modules and packages for use with Node.js.
Due to a conflict with another package, the executable file nodejs in the Ubuntu repository is called instead of node. Please keep this in mind when running the software.
To check which version of Node.js is installed after these initial steps, enter:
nodejs -v
Once you have determined which version of Node.js is installed from the Ubuntu repository, you can decide whether to use a different version, package archive or version manager. Next, we will discuss these elements and more flexible and robust installation methods.
An alternative that can provide you with an updated version of Node.js is to add a PPA (Personal Package Archive) maintained by NodeSource. This will have more Node.js versions than the official Ubuntu repositories and will allow you to choose between Node.js v4.x (the old long-term support version, which will be supported until April 2018). Node.js v6.x (support until April 2019) and Node.js v8.x (current LTS version, support until December 2019).
First, you need to install PPA to access its content. Make sure you are in your home directory and use curl to retrieve the installation script for the preferred version, making sure to replace 8.x with the preferred version string (if different):
cd ~
curl -sL https://deb.nodesource.com/setup_8.x -o nodesource_setup.sh
You can use nano (or your favorite text editor) to check the contents of this script:
nano nodesource_setup.sh
Use sudo and run the script:
sudo bash nodesource_setup.sh
The PPA will be added to your configuration, and your local package cache will be automatically updated. After running the installation script from nodesource, you can install the Node.js package as above:
sudo apt-get install nodejs
To check which version of Node.js is installed after these initial steps, enter:
nodejs -v
The output is as follows:
v8.10.0
The nodejs package contains the nodejs binary file npm, so you don't need to install npm separately.
npm uses the configuration file in the home directory to track updates. It will create npm the first time you run it. Execute this command to verify whether npm is installed and create a configuration file:
npm -v
The output is as follows:
5.6.0
In order for certain npm packages to work (for example, to compile code from source), you need to install the build-essential package:
sudo apt-get install build-essential
You now have the necessary tools to process npm packages that need to be compiled from source code.
Another way to install Node.js is to use a specially designed tool nvm through apt, which stands for "Node.js Version Manager". Instead of working at the operating system level nvm, work at the independent directory level in the home directory. This means you can install multiple self-contained versions of Node.js without affecting the entire system.
By controlling your environment, nvm you can access the latest version of Node.js and retain and manage previous versions. However, it is a different apt-get utility, and the version of Node.js you manage through it is different from the release version of Node.js available in the Ubuntu repository.
First, we need to get the package from our Ubuntu repository so that we can build the source package. The nvm script will use these tools to build the necessary components:
sudo apt-get update
sudo apt-get install build-essential libssl-dev
After installing the prerequisite software package, you can download the (https://github.com/creationix/nvm) nvm installation script from the [project's GitHub page]. The version number may be different, but in general, you can use curl to download:
curl -sL https://raw.githubusercontent.com/creationix/nvm/v0.33.8/install.sh -o install_nvm.sh
Use nano to check the installation script:
nano install_nvm.sh
bash run the script:
bash install_nvm.sh
It will install the software into a subdirectory of the main directory ~/.nvm. It will also add the necessary lines to your ~/.profile file to use it.
To access the nvm function, you need to log out and log in again, or you can get the ~/.profile file so that the current session can understand the changes:
source ~/.profile
Now that you have installed nvm, you can install the isolated version of Node.js.
To find out the Node.js version available for installation, you can enter:
nvm ls-remote
The output is as follows:
...
v8.5.0
v8.6.0
v8.7.0
v8.8.0
v8.8.1
v8.9.0
v8.9.1
v8.9.2
v8.9.3-> v8.9.4(Latest LTS: Carbon)
As you can see, the latest LTS version at the time of writing is v8.9.4. You can install it by entering the following command:
nvm install 8.9.4
Normally, nvm will switch to use the most recently installed version. You can explicitly tell nvm to use the version we just downloaded by typing:
nvm use 8.9.4
When installing Node.js using nvm, the executable file node will be called. You can check the version currently used by the shell by typing:
node -v
The output is as follows:
v8.9.4
If you have multiple versions of Node.js, you can view the installed content by entering the following:
nvm ls
If you want to default one of the versions, you can enter:
nvm alias default8.9.4
When a new session is created, this version will be automatically selected. You can also refer to it through the following aliases:
nvm use default
Each version of Node.js keeps track of its own packages, and npm can manage them.
You can use the npm normal format to install the package into the ./node_modules directory of the Node.js project. For example, for the express module:
npm install express
If you want to install it globally (make it use the same Node.js version for other projects to use), you can add the -g flag:
npm install -g express
This will install the package:
~ /.nvm/node_version/lib/node_modules/package_name
Global installation will allow you to run commands from the command line, but you must link the package to the local scope to request it from the program:
npm link express
You can learn more about the options available for nvm by typing:
nvm help
You can uninstall Node.js with apt-get or nvm, depending on the version you want to target. To delete the release version, you need apt-get to use the utility at the system level.
To delete the release version, enter the following:
sudo apt-get remove nodejs
This command will delete the package and keep the configuration file. If you plan to install the package again later, these may be useful to you. However, if you do not want to save the configuration file for later use, run the following command:
sudo apt-get purge nodejs
This will uninstall the package and delete the configuration file associated with it. In the last step, you can delete all unused packages that are automatically installed with the removed packages:
sudo apt-get autoremove
To uninstall the Node.js version that has been enabled with nvm, first determine whether the version to be deleted is the currently active version:
nvm current
If the version you want to target** is not** the current active version, you can run:
nvm uninstall node_version
This command will uninstall the selected Node.js version.
If the version you want to delete is** the currently active version, you must first deactivate nvm to enable the changes:
nvm deactivate
You can now uninstall the current version using the uninstall command above, which will delete all files associated with the target version of Node.js, except for the cache files that can be used for reinstallation.
As you can see, there are many ways to get Node.js up and running on an Ubuntu 16.04 server. Your situation will determine which of the above methods is best for your situation. Although the packaged version in the Ubuntu repository is the simplest, the nvm method is definitely more flexible.
To learn more about Linux open source information tutorial, please go to [Tencent Cloud + Community] (https://cloud.tencent.com/developer?from=10680) to learn more.
Reference: "How To Install Node.js on Ubuntu 16.04"
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