nf-core_modules/README.md

# ![nf-core/modules](docs/images/nfcore-modules_logo.png)

A repository for hosting nextflow [`DSL2`](https://www.nextflow.io/docs/edge/dsl2.htmlhttps://www.nextflow.io/docs/edge/dsl2.html) module files containing tool-specific process definitions and associated documentation.

> DSL2 IS AN EXPERIMENTAL FEATURE UNDER DEVELOPMENT. SYNTAX, ORGANISATION AND LAYOUT OF THIS REPOSITORY MAY CHANGE IN THE NEAR FUTURE!

## Table of contents
* [Using an existing module](#using-an-existing-module)
    * [Configuration and parameters](#configuration-and-parameters)
    * [Offline usage](#offline-usage)
* [Adding a new module](#adding-a-new-module)
    * [Testing](#testing)
    * [Documentation](#documentation)
    * [Uploading to `nf-core/modules`](#uploading-to-nf-coremodules)
* [Help](#help)

## Using an existing module

The Nextflow [`include`](https://www.nextflow.io/docs/edge/dsl2.html#modules-include) statement can be used within your pipelines in order to load module files that you have available locally.

You should be able to get a good idea as to how other people are using module files by looking at pipelines available in nf-core e.g. [`nf-core/rnaseq`](https://github.com/nf-core/rnaseq/pull/162)

### Configuration and parameters

The module files hosted in this repository define a set of processes for software tools such as `fastc`, `trimgalore`, `bwa` etc. This allows you to share and add common functionality across multiple pipelines in a modular fashion.

### Offline usage

If you want to use an existing module file available in `nf-core/modules`, and you're running on a system that has no internet connection, you'll need to download the repository (e.g. `git clone https://github.com/nf-core/modules.git`) and place it in a location that is visible to the file system on which you are running the pipeline. Then run the pipeline by creating a custom config file called e.g. `custom_module.conf` containing the following information:

```bash
include /path/to/downloaded/modules/directory/
```

Then you can run the pipeline by directly passing the additional config file with the `-c` parameter:

```bash
nextflow run /path/to/pipeline/ -c /path/to/custom_module.conf
```

> Note that the nf-core/tools helper package has a `download` command to download all required pipeline
> files + singularity containers + institutional configs + modules in one go for you, to make this process easier.

## Adding a new module file

If you decide to upload your module file to `nf-core/modules` then this will ensure that it will be automatically downloaded, and available at run-time to all nf-core pipelines, and to everyone within the Nextflow community! See [`nf-core/modules`](https://github.com/nf-core/modules/tree/master/nf) for examples.

The definition and standards for module files is still under discussion amongst the community but hopefully, a description should be added here soon!

### Testing

If you want to add a new module config file to `nf-core/modules` please test that your pipeline of choice runs as expected by using the [`-include`](https://www.nextflow.io/docs/edge/dsl2.html#modules-include) statement with a local version of the module file.

### Documentation

You will have to create a [Markdown document](https://www.markdownguide.org/getting-started/) outlining the details required to use the module file and extensive links to documentation for the tool(s) used in the module file. You can use the provided [`template.md`](docs/template.md) to guide you as to how to do this appropriately.

See [`nf-core/modules/docs`](https://github.com/nf-core/modules/tree/master/docs) for examples.

### Uploading to `nf-core/modules`

[Fork](https://help.github.com/articles/fork-a-repo/) the `nf-core/modules` repository to your own GitHub account. Within the local clone of your fork add the module file to the [`nf/`](https://github.com/nf-core/modules/tree/master/nf) directory, and the documentation file to the [`docs/`](https://github.com/nf-core/modules/tree/master/docs) directory. Please keep the naming consistent between the module and documentation files e.g. `bwa.nf` and `bwa.md`, respectively.

Commit and push these changes to your local clone on GitHub, and then [create a pull request](https://help.github.com/articles/creating-a-pull-request-from-a-fork/) on `nf-core/modules` GitHub repo with the appropriate information.

We will be notified automatically when you have created your pull request, and providing that everything adheres to nf-core guidelines we will endeavour to approve your pull request as soon as possible.

## Help

If you have any questions or issues please send us a message on [Slack](https://nf-core-invite.herokuapp.com/).