15 KiB
Task - A task runner / simpler Make alternative written in Go
We recently released version 2.0.0 of Task. The Taskfile changed a bit. Please, check the Taskfile versions document to see what changed and how to upgrade.
Task is a simple tool that allows you to easily run development and build tasks. Task is written in Golang, but can be used to develop any language. It aims to be simpler and easier to use then GNU Make.
Installation
Go
If you have a Golang environment setup, you can simply run:
go get -u -v github.com/go-task/task/cmd/task
Homebrew
If you're on macOS and have Homebrew installed, getting Task is as simple as running:
brew install go-task/tap/go-task
Snap
Task is available for Snapcraft, but keep in mind that your Linux distribution should allow classic confinement for Snaps to Task work right:
sudo snap install task
Install script
We also have a install script, which is very useful on scanarios like CIs. Many thanks to godownloader for easily generating this script.
curl -s https://raw.githubusercontent.com/go-task/task/master/install-task.sh | sh
Binary
Or you can download the binary from the releases page and add to
your PATH. DEB and RPM packages are also available.
The task_checksums.txt file contains the sha256 checksum for each file.
Usage
Create a file called Taskfile.yml in the root of your project.
The cmds attribute should contain the commands of a task.
The example below allows compiling a Go app and uses Minify to concat
and minify multiple CSS files into a single one.
version: '2'
tasks:
build:
cmds:
- go build -v -i main.go
assets:
cmds:
- minify -o public/style.css src/css
Running the tasks is as simple as running:
task assets build
Task uses github.com/mvdan/sh, a native Go sh
interpreter. So you can write sh/bash commands and it will work even on
Windows, where sh or bash are usually not available. Just remember any
executable called must be available by the OS or in PATH.
If you ommit a task name, "default" will be assumed.
Environment
You can specify environment variables that are added when running a command:
version: '2'
tasks:
build:
cmds:
- echo $hallo
env:
hallo: welt
OS specific task
If you add a Taskfile_{{GOOS}}.yml you can override or amend your taskfile
based on the operating system.
Example:
Taskfile.yml:
version: '2'
tasks:
build:
cmds:
- echo "default"
Taskfile_linux.yml:
tasks:
build:
cmds:
- echo "linux"
Will print out linux and not default.
It's also possible to have an OS specific Taskvars.yml file, like
Taskvars_windows.yml, Taskfile_linux.yml, or Taskvars_darwin.yml. See the
variables section below.
Task directory
By default, tasks will be executed in the directory where the Taskfile is
located. But you can easily make the task run in another folder informing
dir:
version: '2'
tasks:
serve:
dir: public/www
cmds:
# run http server
- caddy
Task dependencies
You may have tasks that depend on others. Just pointing them on deps will
make them run automatically before running the parent task:
version: '2'
tasks:
build:
deps: [assets]
cmds:
- go build -v -i main.go
assets:
cmds:
- minify -o public/style.css src/css
In the above example, assets will always run right before build if you run
task build.
A task can have only dependencies and no commands to group tasks together:
version: '2'
tasks:
assets:
deps: [js, css]
js:
cmds:
- minify -o public/script.js src/js
css:
cmds:
- minify -o public/style.css src/css
If there is more than one dependency, they always run in parallel for better performance.
If you want to pass information to dependencies, you can do that the same manner as you would to call another task:
version: '2'
tasks:
default:
deps:
- task: echo_sth
vars: {TEXT: "before 1"}
- task: echo_sth
vars: {TEXT: "before 2"}
cmds:
- echo "after"
echo_sth:
cmds:
- echo {{.TEXT}}
Calling another task
When a task has many dependencies, they are executed concurrently. This will often result in a faster build pipeline. But in some situations you may need to call other tasks serially. In this case, just use the following syntax:
version: '2'
tasks:
main-task:
cmds:
- task: task-to-be-called
- task: another-task
- echo "Both done"
task-to-be-called:
cmds:
- echo "Task to be called"
another-task:
cmds:
- echo "Another task"
Overriding variables in the called task is as simple as informing vars
attribute:
version: '2'
tasks:
main-task:
cmds:
- task: write-file
vars: {FILE: "hello.txt", CONTENT: "Hello!"}
- task: write-file
vars: {FILE: "world.txt", CONTENT: "World!"}
write-file:
cmds:
- echo "{{.CONTENT}}" > {{.FILE}}
The above syntax is also supported in deps.
Prevent unnecessary work
If a task generates something, you can inform Task the source and generated files, so Task will prevent to run them if not necessary.
version: '2'
tasks:
build:
deps: [js, css]
cmds:
- go build -v -i main.go
js:
cmds:
- minify -o public/script.js src/js
sources:
- src/js/**/*.js
generates:
- public/script.js
css:
cmds:
- minify -o public/style.css src/css
sources:
- src/css/**/*.css
generates:
- public/style.css
sources and generates can be files or file patterns. When both are given,
Task will compare the modification date/time of the files to determine if it's
necessary to run the task. If not, it will just print a message like
Task "js" is up to date.
If you prefer this check to be made by the content of the files, instead of
its timestamp, just set the method property to checksum.
You will probably want to ignore the .task folder in your .gitignore file
(It's there that Task stores the last checksum).
This feature is still experimental and can change until it's stable.
version: '2'
tasks:
build:
cmds:
- go build .
sources:
- ./*.go
generates:
- app{{exeExt}}
method: checksum
TIP: method
noneskips any validation and always run the task.
Alternatively, you can inform a sequence of tests as status. If no error
is returned (exit status 0), the task is considered up-to-date:
version: '2'
tasks:
generate-files:
cmds:
- mkdir directory
- touch directory/file1.txt
- touch directory/file2.txt
# test existence of files
status:
- test -d directory
- test -f directory/file1.txt
- test -f directory/file2.txt
You can use --force or -f if you want to force a task to run even when
up-to-date.
Also, task --status [tasks]... will exit with a non-zero exit code if any of
the tasks are not up-to-date.
Variables
When doing interpolation of variables, Task will look for the below. They are listed below in order of importance (e.g. most important first):
- Variables declared locally in the task
- Variables given while calling a task from another. (See Calling another task above)
- Variables declared in the
vars:option in theTaskfile - Variables available in the
Taskvars.ymlfile - Environment variables
Example of sending parameters with environment variables:
$ TASK_VARIABLE=a-value task do-something
Since some shells don't support above syntax to set environment variables (Windows) tasks also accepts a similar style when not in the beginning of the command. Variables given in this form are only visible to the task called right before.
$ task write-file FILE=file.txt "CONTENT=Hello, World!" print "MESSAGE=All done!"
Example of locally declared vars:
version: '2'
tasks:
print-var:
cmds:
echo "{{.VAR}}"
vars:
VAR: Hello!
Example of global vars in a Taskfile.yml:
version: '2'
vars:
GREETING: Hello from Taskfile!
tasks:
greet:
cmds:
- echo "{{.GREETING}}"
Example of Taskvars.yml file:
PROJECT_NAME: My Project
DEV_MODE: production
GIT_COMMIT: {sh: git log -n 1 --format=%h}
Variables expansion
Variables are expanded 2 times by default. You can change that by setting the
expansions: option. Change that will be necessary if you compose many
variables together:
version: '2'
expansions: 3
vars:
FOO: foo
BAR: bar
BAZ: baz
FOOBAR: "{{.FOO}}{{.BAR}}"
FOOBARBAZ: "{{.FOOBAR}}{{.BAZ}}"
tasks:
default:
cmds:
- echo "{{.FOOBARBAZ}}"
Dynamic variables
The below syntax (sh: prop in a variable) is considered a dynamic variable.
The value will be treated as a command and the output assigned. If there is one
or more trailing newlines, the last newline will be trimmed.
version: '2'
tasks:
build:
cmds:
- go build -ldflags="-X main.Version={{.GIT_COMMIT}}" main.go
vars:
GIT_COMMIT:
sh: git log -n 1 --format=%h
This works for all types of variables.
Go's template engine
Task parse commands as Go's template engine before executing
them. Variables are accessible through dot syntax (.VARNAME).
All functions by the Go's sprig lib are available. The following example gets the current date in a given format:
version: '2'
tasks:
print-date:
cmds:
- echo {{now | date "2006-01-02"}}
Task also adds the following functions:
OS: Returns operating system. Possible values are "windows", "linux", "darwin" (macOS) and "freebsd".ARCH: return the architecture Task was compiled to: "386", "amd64", "arm" or "s390x".splitLines: Splits Unix (\n) and Windows (\r\n) styled newlines.catLines: Replaces Unix (\n) and Windows (\r\n) styled newlines with a space.toSlash: Does nothing on Unix, but on Windows converts a string from\path format to/.fromSlash: Oposite oftoSlash. Does nothing on Unix, but on Windows converts a string from\path format to/.exeExt: Returns the right executable extension for the current OS (".exe"for Windows,""for others).
Example:
version: '2'
tasks:
print-os:
cmds:
- echo '{{OS}} {{ARCH}}'
- echo '{{if eq OS "windows"}}windows-command{{else}}unix-command{{end}}'
# This will be path/to/file on Unix but path\to\file on Windows
- echo '{{fromSlash "path/to/file"}}'
enumerated-file:
vars:
CONTENT: |
foo
bar
cmds:
- |
cat << EOF > output.txt
{{range $i, $line := .CONTENT | splitLines -}}
{{printf "%3d" $i}}: {{$line}}
{{end}}EOF
Help
Running task --list (or task -l) lists all tasks with a description.
The following taskfile:
version: '2'
tasks:
build:
desc: Build the go binary.
cmds:
- go build -v -i main.go
test:
desc: Run all the go tests.
cmds:
- go test -race ./...
js:
cmds:
- minify -o public/script.js src/js
css:
cmds:
- minify -o public/style.css src/css
would print the following output:
* build: Build the go binary.
* test: Run all the go tests.
Silent mode
Silent mode disables echoing of commands before Task runs it. For the following Taskfile:
version: '2'
tasks:
echo:
cmds:
- echo "Print something"
Normally this will be print:
echo "Print something"
Print something
With silent mode on, the below will be print instead:
Print something
There's three ways to enable silent mode:
- At command level:
version: '2'
tasks:
echo:
cmds:
- cmd: echo "Print something"
silent: true
- At task level:
version: '2'
tasks:
echo:
cmds:
- echo "Print something"
silent: true
- Or globally with
--silentor-sflag
If you want to suppress stdout instead, just redirect a command to /dev/null:
version: '2'
tasks:
echo:
cmds:
- echo "This will print nothing" > /dev/null
Watch tasks
If you give a --watch or -w argument, task will watch for file changes
and run the task again. This requires the sources attribute to be given,
so task know which files to watch.
Examples
The go-task/examples intends to be a collection of Taskfiles for various use cases. (It still lacks many examples, though. Contributions are welcome).
Alternative task runners
- YAML based:
- Go based:
- Make based:
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