# Install AWS ParallelCluster on Linux
<a name="install-linux"></a>

You can install AWS ParallelCluster and its dependencies on most Linux distributions by using `pip`, a package manager for Python. First, determine if Python and `pip` are installed:

1. To determine if your version of Linux includes Python and `pip`, run `pip --version`.

   ```
   $ pip --version
   ```

   If you have `pip` installed, go on to the [Install AWS ParallelCluster with pip](install.md) topic. Otherwise, continue with Step 2.

1. To determine if Python is installed, run `python --version`.

   ```
   $ python --version
   ```

   If you have Python 3 version 3.6\$1 or Python 2 version 2.7 installed, go on to the [Install AWS ParallelCluster with pip](install.md) topic. Otherwise, [install Python](install-linux-python.md), and then return to this procedure to install `pip`.

1. Install `pip` by using the script that the *Python Packaging Authority* provides. 

1. Use the `curl` command to download the installation script.

   ```
   $ curl -O https://bootstrap.pypa.io/get-pip.py
   ```

1. Run the script with Python to download and install the latest version of `pip` and other required support packages.

   ```
   $ python get-pip.py --user
   ```

   or

   ```
   $ python3 get-pip.py --user
   ```

   When you include the `--user` switch, the script installs `pip` to the path `~/.local/bin`.

1. To verify that the folder that contains `pip` is part of your `PATH` variable, do the following:

   1. Find your shell's profile script in your user folder. If you're not sure which shell you have, run `basename $SHELL`.

      ```
      $ ls -a ~
      .  ..  .bash_logout  .bash_profile  .bashrc  Desktop  Documents  Downloads
      ```
      + **Bash** – `.bash_profile`, `.profile`, or `.bash_login`
      + **Zsh** – `.zshrc`
      + **Tcsh** – `.tcshrc`, `.cshrc` or `.login`

   1. Add an export command at the end of your profile script that's similar to the following example.

      ```
      export PATH=~/.local/bin:$PATH
      ```

      The export command inserts the path, which is `~/.local/bin` in this example, at the front of the existing `PATH` variable.

   1. To put these changes into effect, reload the profile into your current session.

      ```
      $ source ~/.bash_profile
      ```

1. Verify that `pip` is installed correctly.

   ```
   $ pip3 --version
   pip 21.3.1 from ~/.local/lib/python3.6/site-packages (python 3.6)
   ```

**Topics**
+ [Install AWS ParallelCluster with `pip`](#install-linux-with-pip)
+ [Add the AWS ParallelCluster executable to your command line path](#install-linux-path)
+ [Installing Python on Linux](install-linux-python.md)

## Install AWS ParallelCluster with `pip`
<a name="install-linux-with-pip"></a>

Use `pip` to install AWS ParallelCluster.

```
$ python3 -m pip install "aws-parallelcluster<3.0" --upgrade --user
```

When you use the `--user` switch, `pip` installs AWS ParallelCluster to `~/.local/bin`. 

Verify that AWS ParallelCluster installed correctly.

```
$ pcluster version
2.11.9
```

To upgrade to the latest version, run the installation command again.

```
$ python3 -m pip install "aws-parallelcluster<3.0" --upgrade --user
```

## Add the AWS ParallelCluster executable to your command line path
<a name="install-linux-path"></a>

After installing with `pip`, you might need to add the `pcluster` executable to your operating system's `PATH` environment variable.

To verify the folder in which `pip` installed AWS ParallelCluster, run the following command.

```
$ which pcluster
/home/username/.local/bin/pcluster
```

If you omitted the `--user` switch when you installed AWS ParallelCluster, the executable might be in the `bin` folder of your Python installation. If you don't know where Python is installed, run this command.

```
$ which python
/usr/local/bin/python
```

Note that the output might be the path to a symlink, not to the actual executable. To see where the symlink points, run `ls -al`.

```
$ ls -al $(which python)
/usr/local/bin/python -> ~/.local/Python/3.6/bin/python3.6
```

If this is the same folder that you added to the path in step 3 in [Installing AWS ParallelCluster](install.md), you're done with the installation. Otherwise, you must perform steps 3a – 3c again, adding this additional folder to the path.

# Installing Python on Linux
<a name="install-linux-python"></a>

If your distribution didn't come with Python, or came with an earlier version, install Python before installing `pip` and AWS ParallelCluster.

**To install Python 3 on Linux**

1. Check to see if Python is already installed.

   ```
   $ python3 --version
   ```

   or

   ```
   $ python --version
   ```
**Note**  
If your Linux distribution came with Python, you might need to install the Python developer package. The developer package includes the headers and libraries that are required to compile extensions and to install AWS ParallelCluster. Use your package manager to install the developer package. It is typically named `python-dev` or `python-devel`.

1. If Python 2.7 or later is not installed, install Python with your distribution's package manager. The command and package name varies:
   + On Debian derivatives such as Ubuntu, use `apt`.

     ```
     $ sudo apt-get install python3
     ```
   + On Red Hat and derivatives, use `yum`.

     ```
     $ sudo yum install python3
     ```
   + On SUSE and derivatives, use `zypper`.

     ```
     $ sudo zypper install python3
     ```

1. To verify that Python installed correctly, open a command prompt or shell and run the following command.

   ```
   $ python3 --version
   Python 3.8.11
   ```