Hydrilla

# User manual

{{toc}}

## Installation

### Using Python wheel

You can install Hydrilla server and(or) builder using .whl files from the [[Releases]] page. Please consider [[hachette:Verifying signatures|verifying the downloads]] using provided cryptographic signatures.

#### Installing dependencies

##### Python3

Hydrilla requires Python interpreter in at least version 3.7. You'd typically use Python3 as provided by you operating system distribution. For example, on Debian-based systems (including Trisquel) you can install it with:

``` shell

sudo apt install python3

```

##### pip

Pip is the package manager for Python. While not a direct dependency of Hydrilla, it is needed to utilize .whl files. You most likely also want to install pip as provided by your distro, e.g. for APT-based ones:

``` shell

sudo apt install python3-pip

```

##### Python libraries

Hydrilla relies on the following Python packages:

* `jsonschema`

* `click`

* `flask` (needed for Hydrilla server only)

* `reuse` (optional, only needed for Hydrilla builder to generate SPDX report)

If you don't have those dependencies installed, pip will automatically pull them from [PyPI](https://pypi.org) (except for reuse which would need to be installed separately with a command like `python3 -m pip install reuse`).

Nevertheless, you are encouraged to instead install the respective packages from your operating system's official repositories because those usually have stricter policies on stability, security and free licensing. In case of APT-based distributions the packages to install would be `python3-jsonschema`, `python3-click`, `python3-flask` and `reuse`[^reuse].

[^reuse]: Reuse tool was first packaged for Debian Bookworm and is not yet available in Debian Bullseye nor in Trisquel Nabia.

#### Installing Hydrilla

Let's assume you want to install version 1.0 of Hydrilla server. First, download and verify both[^server_depends_on_builder] `hydrilla.builder-1.0-py3-none-any.whl` and `hydrilla-1.0-py3-none-any.whl`. Then, run:

``` shell

python3 -m pip install path/to/downloaded/hydrilla.builder-1.0-py3-none-any.whl path/to/downloaded/hydrilla-1.0-py3-none-any.whl

```

[^server_depends_on_builder]: Hydrilla server also depends on Hydrilla builder.

This will install Hydrilla **for the current user**. The commands `hydrilla` and `hydrilla-builder` will be made available in `~/.local/bin/`.

#### Installing in virtualenv

If for example you don't want pip to install things under `~/.local/`, you might choose to create a virtual Python environment. First, make sure you have the `virtualenv` tool installed[^virtualenv_tool] (for example from APT package `python3-virtualenv`). Then, choose the folder in which you'd like to install the environment and run:

``` shell

virtualenv -p python3 --system-site-packages path/to/chosen/folder

```

[^virtualenv_tool]: Since Python 3.3 a virtual environment can also be created without this tool.

The `--system-site-packages` flag is not strictly necessary for it to work but is needed if you want packages inside the virtual environment to be able to see globally-installed dependencies.

Once the environment is created, you need to enter it by sourcing a script created by the virtualenv command, e.g.:

``` shell

source path/to/chosen/folder/bin/activate

```

Afterwards, the `python3 -m pip` commands you enter in this shell will install packages inside this virtual environment. You can learn more about Python virtual environments from online tutorials and the [virtualenv documentation](https://virtualenv.pypa.io).

### Using APT

Hydrilla APT repository is hosted at https://hydrillarepos.koszko.org/apt/ and is signed with Wojtek's PGP key (fingerprint **E9727060E3C5637C8A4F4B424BC5221C5A79FD1A**). It is expected to work with modern releases of most APT-based distributions (including Debian bullseye and Trisquel nabia).

This APT repository can be used to install Hydrilla server and builder system-wide and to later update the installation. It has to be said that this also requires you to trust Wojtek's repository with your system's safety (a malicious APT repository could easily take over a system that uses it).

If you've decided you want to install the APT repository on your system, the easiest way to do so is by copy-pasting the following script into your POSIX shell (and then confirming with your password). You can of course modify it according to your needs.

``` shell

__install_hydrilla_apt_repo() {

    local TMP="$1"

    local LISTS="$(cat <<EOF

deb     https://hydrillarepos.koszko.org/apt/ koszko main

deb-src https://hydrillarepos.koszko.org/apt/ koszko main

EOF

)"

    if ! wget -O "$TMP/koszko-keyring.gpg" https://hydrillarepos.koszko.org/apt/koszko-keyring.gpg; then

	echo "Error! Failed to download keyring file!" >&2

	return 1

    elif ! gpg --no-default-keyring --keyring "$TMP/koszko-keyring.gpg" --list-key E9727060E3C5637C8A4F4B424BC5221C5A79FD1A; then

	echo "Error! Invalid keyring file! Someone might be doing something nasty!" >&2

	return 1

    elif ! sudo cp "$TMP/koszko-keyring.gpg" /etc/apt/trusted.gpg.d/; then

	echo "Error!" >&2

	return 1

    elif ! printf %s "$LISTS" | sudo tee /etc/apt/sources.list.d/hydrillarepos.list > /dev/null; then

	echo "Error!" >&2

	return 1

    fi

    sudo apt-get update

}

install_hydrilla_apt_repo() {

    local TMP="$(mktemp -d)"

    __install_hydrilla_apt_repo "$TMP"

    local RESULT="$?"

    rm -r "$TMP"

    return "$RESULT"

}

install_hydrilla_apt_repo

```

This snippet is idempotent (i.e. it can be run multiple times and the effect will be as if it was run once). In addition, it executes `apt-get update` command at the end so that your APT is immediately aware of the new repository and its contents.

After installing the repository you can install Hydrilla builder and server using the following commands:

``` shell

sudo apt install python3-hydrilla.builder

```

``` shell

sudo apt install python3-hydrilla # this alone will also pull the builder as a dependency

```

The packages install their modules under `/usr/lib/python3/dist-packages/` which is seen by Python3 interpreters installed from APT. The `hydrilla` and `hydrilla-builder` commands get placed in `/usr/bin/`.

In addition, the `python3-hydrilla` package also includes sample WSGI script and Apache2 config files for Hydrilla under `/usr/share/doc/python3-hydrilla/examples/`.

## Understanding the concepts

*TODO*

## Running

### With development server

*TODO*

### With Apache2

*TODO*