---
layout: layouts/base.njk
---

# Usage

Running the task file requires a shell alias: `alias task='./task'`\
Show the available commands with `task help`.\
From the specification the project can be installed with `task install`.\
Execute all commands with `task all`.

## Image

See [taskfile.build/image](/image) for details.

## Naming

The naming of functions is important. There are basically two styles:

1. Action + Object
2. Object + Action

The task file functions use the first style. The name of the function starts with an action followed by an object. The object name can be singular or plural.

**Examples for actions**: <span id="actions">activate, install, dev, develop, init, build, start, update, remove, delete, enable, disable, template, convert, create, edit, change, get, set, patch, fetch, generate, push, pull, import, export, list, publish, release, test, setup, prepare, restart, stop, store, restore, translate, upgrade, zip, visualize, sync, switch, run, reset, load, dump, checkout, commit, drop, deploy, handle, trigger, render, lint, uninstall, split, parse, fix, refactor, transform, cat, ls, rm, serve, help, show, filter, login, logout, encrypt, decrypt, upload, download, analyse, transpile, compile, minify, copy</span>

**Examples for objects**: <span id="objects">env, venv, submodule, container, database, snippet, model, module, repo, mail, doc, dependency, view, user, vault, file, host, node, log, password, hash, script, requirement, part, component, system, workspace, image, process, state, platform, dir, folder, readme, overview, lang, level, request, response, result, worker, server, proxy, workflow, volume, network, package, field, value, secret, chart, node, edge, function, method, firewall, html, css, image, svg, style, query, native, group, notebook</span>

**Objects can be tools**: <span id="object-tools">odoo, vupress, nodejs, zsh, bash, fish, podman, kind, minikube, helm, nvim, docker, podman, rust, python, tmux, vim, helix, system, git, pass, llm, sql, dotenv, javascript, vue, vite, astro, typescript, turbo, pnpm, eslint, jenkins, k8s, nextcloud, postgres, metabase, ansible, prometheus, grafana, hugo, deno, bun, babel, panda, gulp, grunt, electron, react, express, mongodb, angular, ionic, meteor, webpack, bower, jupyter</span>

<button id="generate-function-names">Generate Function Names</button> <ul id="function-names"> <!-- Random function names will be inserted here by JS --> </ul>

## Style

The bash scripts follow the [Bash Style Guide | ysap.sh](https://style.ysap.sh/). Have a look at the [AGENTS.md](/AGENTS) for details on the applied styling.

## Patterns

The task file showed above is very basic. Commands can have parameters and call each other. The following is a collection of more complex task file patterns.

### Set default parameter

Fallback to a default value for a parameter.

```bash
build() {
    local platform="amd64"
    if [[ -n "$1" ]]; then
        platform="$1"
    fi
```

### Ensure parameter is not empty

Check the first param and exit if it is empty.

```bash
deploy() {
    if [[ -z "$1" ]]; then echo "\$1 is empty."; exit; fi
```

### Prompt for input

Use `read` to ask for inputs.

```bash
if [[ -z "$2" ]]; then
	read -p "Enter the task description: " task_description
else
	task_description="$2"
fi
```

### Setup local env vars

Define env vars at the beginning of the task file.

```bash
CONFIGURATION_FILE="file.conf"
GIT_BRANCH=$(git symbolic-ref --short -q HEAD)
```

### Template with env vars

Create a parameterized file from a template. Requires `envsubst`.

```bash
template-with-env() {
    echo "Template $CONFIGURATION_FILE"

    export CONFIGURATION_1
    export CONFIGURATION_2=${CONFIGURATION_2:="value"}

    envsubst < "file.conf.template" > "$CONFIGURATION_FILE"
}
```

### Create Python virtual env

Initialize Python virtual env with uv.

```bash
init-venv() {
    if [[ ! -d "venv$GIT_BRANCH" ]]; then
        echo "Init venv$GIT_BRANCH with $(uv --version)."
        uv venv "venv$GIT_BRANCH"
    fi
}
```

### Activate Python virtual env

```bash
activate-venv() {
    echo "Source virtualenv venv$GIT_BRANCH."
    source "venv$GIT_BRANCH/bin/activate"
    echo "$(python --version) is active."
}
```

### Call a Python script

Run a Python script.

```bash
generate-password-hash() {
    activate-venv
    if [[ -z "$1" ]]; then echo "\$1 is empty."; exit; fi
    export PASSWORD_PLAIN="$1"
    bin/password-hash
}
```

The Python script: `bin/password-hash`

```python
#!/usr/bin/env python3

import os
from passlib.context import CryptContext
crypt_context = CryptContext(schemes=['pbkdf2_sha512', 'plaintext'], deprecated=['plaintext'])

password = os.environ.get('PASSWORD_PLAIN')
print(crypt_context.hash(password))
```

### Command with named parameters

Assuming you have a `docker-compose.yml` and would like to start selected or all containers.

```bash
start() {
    if [[ "$1" =~ "db" ]]; then
        docker compose up -d db
    fi

    if [[ "$1" =~ "admin" ]]; then
        docker compose up -d admin
        echo "Open http://localhost:8000 url in your browser."
    fi

    if [[ "$1" =~ "odoo" ]]; then
        docker compose up -d odoo
        echo "Open http://localhost:8069 url in your browser."
    fi

    if [[ "$1" =~ "mail" ]]; then
	    docker compose up -d mail
        echo "Open http://localhost:8025 url in your browser."
    fi
}
```

Start all containers with `task start` and selected with `task start db,admin`.

### Run commands in container

Use `docker exec -i` to run commands in a container.

```bash
drop-db() {
    local database="$1"
    if [[ -z "$database" ]]; then
        database="example"
    fi

    docker exec -i db psql "postgres://odoo:odoo@localhost:5432/postgres" -c "SELECT pg_terminate_backend(pid) FROM pg_stat_activity WHERE datname = '$database';"
    docker exec -i db psql "postgres://odoo:odoo@localhost:5432/postgres" -c "DROP DATABASE \"$database\";"
}
```

### Loop over files and folders

Use `for` to loop over file, folders or arrays.

```bash
render() {
    echo "Update index.html for all folders"
    for folder in ./*; do
        if [[ -f "$folder/README.md" ]]; then
            cd "$folder" || exit
            md2html README.md _site/index.html
            cd .. || exit
        fi
    done
}
```

### Parse and convert a file

With this function you can split a file into multiple parts whenever a specific keyword is matching. In this example the keyword is `!vault`.

```bash
convert-vault-file() {
    local file_path="$1"
    local temp_file=$(mktemp)
    local temp_part_file=$(mktemp)
    local write_finished=false
    local current_key=""

    while IFS= read -r line; do
        # Check for keyword
        if [[ "$line" =~ "!vault" ]]; then
            # Process previous vault entry if it exists
            if [[ "$write_finished" = true ]] && [[ -n "$current_key" ]] && [[ -s "$temp_part_file" ]]; then
                # Decrypt part file and write to assemble file
                ansible-vault decrypt "$temp_part_file"
                local value=$(cat "$temp_part_file")
                echo "$current_key: $value" >> "$temp_file"
            fi

            # Set up for new vault entry
            current_key=$(echo "$line" | cut -d':' -f1)
            # Clear the file
            : > "$temp_part_file"
            # Flag as ready to write
            write_finished=true
        else
            if [[ "$write_finished" = true ]]; then
                # Pipe into part file
                echo "$line" >> "$temp_part_file"
            fi
        done
    done < "$file_path"

    # Process the final vault entry
    if [[ "$write_finished" = true ]] && [[ -n "$current_key" ]] && [[ -s "$temp_part_file" ]]; then
        ansible-vault decrypt "$temp_part_file"
        local value=$(cat "$temp_part_file")
        echo "$current_key: $value" >> "$temp_file"
    fi

    # Output assembled file
    cat "$temp_file"
    # Cleanup temp files
    rm -f "$temp_file"
    rm -f "$temp_part_file"
}
```

### Process data

This pattern tries to match the worklow of a jupyter notebook. Create a folder with the data processing scripts:

```
scripts
├── 01_import-mail-data
├── 02_transform-mail-data
└── 03_export-mail-data
```

The following function lists the scripts and asks for the number of scripts to run. Every script until the entered number is concatenated and executed.

```bash
process-data() {
    while true; do
        local scripts=($(ls scripts))

        echo -e "Available scripts:\n"
        for index in "${!scripts[@]}"; do
            echo "$((index+1)): ${scripts[$index]}"
        done
        echo ""
        read -p "Enter the number of scripts to run (or 'q' to quit): " user_input
        if [[ "$user_input" = "q" ]]; then
            break
        fi

        local temp_file=$(mktemp)
        for index in "${!scripts[@]}"; do
            if (( $user_input >= $((index+1)) )); then
                cat "scripts/${scripts[$index]}" >> "$temp_file"
                echo >> "$temp_file"
            fi
        done

        clear
        echo -e "\nPython Output:\n\n---"
        python "$temp_file"
        local exit_code=$?
        echo -e "---\n"
        echo -e "Exit code: $exit_code\n"
        rm "$temp_file"
    done
}
```

## Integration

The task file is intended to be integrated into the shell setup. Where applications provides a domain specific language (DSL) ensure that the DSL only calls the task file.

### Completion

With the output of `task help` the task commands can be completed.

Completion for bash: `/etc/bash_completion.d/task_completions`

```bash
#!/usr/bin/env bash

_task_completions() {
    local cur prev commands
    cur="${COMP_WORDS[COMP_CWORD]}"
    prev="${COMP_WORDS[COMP_CWORD-1]}"

    commands=$(./task help | grep -A999 -e '---' | awk '{print $2}' | sed 's/^[[:space:]]*//' | grep -v '^$' | tr '\n' ' ')

    if [[ ${COMP_CWORD} == 1 ]]; then
        COMPREPLY=( $(compgen -W "${commands}" -- "${cur}") )
    elif [[ ${COMP_CWORD} == 2 ]]; then
        COMPREPLY=( $(compgen -f -- "${cur}") )
    else
        COMPREPLY=()
    fi
}

complete -F _task_completions task
complete -F _task_completions t
```

Completion for zsh: `~/.oh-my-zsh/completions/_task`

```bash
#compdef task t

_arguments '1: :->tasks' '*: :_files'

case "$state" in
    tasks)
        args=$(./task help | grep -A999 -e '---' | awk '{print $2}' | sed 's/^[[:space:]]*//' | grep -v '^$' | tr '\n' ' ')
        args="$args help"
        _arguments "1:profiles:($args)"
        ;;
esac
```

The completion also works for task alias `alias t='./task'`.

### GitHub Actions

Running task file commands in GitHub Actions is highly recommended. This way you can run the same CI/CD procedures in the GitHub runner as you do on your localhost.

The GitHub Actions config is simple: `.github/workflows/test.yml `

```yml
on:
    pull_request:
        branches:
            - 'main'
    push:
        branches:
            - 'main'

jobs:
    task-all:
        runs-on: ubuntu-latest
        steps:
            - uses: actions/checkout@v4
            - uses: actions/setup-python@v5
              with:
                  python-version: '3.12'
            - name: Install uv
              uses: astral-sh/setup-uv@v5
            - name: Install
              run: ./task install
            - name: Lint
              run: ./task lint
```

### Jenkins

Run task file commands in Jenkins: `Jenkinsfile`

```groovy
pipeline {

    agent any

    stages {
        stage('version') {
            steps {
                script {
                    currentBuild.description = sh (script: 'git log -1 --pretty=%B', returnStdout: true).trim()
                }
                sh './task version'
            }
        }
        stage('install') {
            steps {
                sh './task install'
            }
        }
        stage('lint') {
            steps {
                sh './task lint'
            }
        }
    }
}%
```