# Usage ## Getting started 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][minify] to concat and minify multiple CSS files into a single one. ```yaml 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: ```bash task assets build ``` Task uses [github.com/mvdan/sh](https://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 omit a task name, "default" will be assumed. ## Environment You can use `env` to set custom environment variables for a specific task: ```yaml version: '2' tasks: greet: cmds: - echo $GREETING env: GREETING: Hey, there! ``` Additionally, you can set globally environment variables, that'll be available to all tasks: ```yaml version: '2' env: GREETING: Hey, there! tasks: greet: cmds: - echo $GREETING ``` > NOTE: `env` supports expansion and retrieving output from a shell command > just like variables, as you can see on the [Variables](#variables) section. ## Operating System specific tasks If you add a `Taskfile_{{GOOS}}.yml` you can override or amend your Taskfile based on the operating system. Example: Taskfile.yml: ```yaml version: '2' tasks: build: cmds: - echo "default" ``` Taskfile_linux.yml: ```yaml version: '2' tasks: build: cmds: - echo "linux" ``` Will print out `linux` and not `default`. Keep in mind that the version of the files should match. Also, when redefining a task the whole task is replaced, properties of the task are not merged. It's also possible to have an OS specific `Taskvars.yml` file, like `Taskvars_windows.yml`, `Taskvars_linux.yml`, or `Taskvars_darwin.yml`. See the [variables section](#variables) below. ## Including other Taskfiles > This feature is still experimental and may have bugs. If you want to share tasks between different projects (Taskfiles), you can use the importing mechanism to include other Taskfiles using the `includes` keyword: ```yaml version: '2' includes: docs: ./documentation # will look for ./documentation/Taskfile.yml docker: ./DockerTasks.yml ``` The tasks described in the given Taskfiles will be available with the informed namespace. So, you'd call `task docs:serve` to run the `serve` task from `documentation/Taskfile.yml` or `task docker:build` to run the `build` task from the `DockerTasks.yml` file. > The included Taskfiles must be using the same schema version the main > Taskfile uses. > Also, for now included Taskfiles can't include other Taskfiles. > This was a deliberate decision to keep use and implementation simple. > If you disagree, open an GitHub issue and explain your use case. =) ## 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`: ```yaml version: '2' tasks: serve: dir: public/www cmds: # run http server - caddy ``` If the directory doesn't exist, `task` creates it. ## 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: ```yaml 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: ```yaml 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. > You can also make the tasks given by the command line run in parallel by > using the `--parallel` flag (alias `-p`). Example: `task --parallel js css`. If you want to pass information to dependencies, you can do that the same manner as you would to [call another task](#calling-another-task): ```yaml 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: ```yaml 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: ```yaml 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`. > NOTE: If you want to call a task declared in the root Taskfile from within an > [included Taskfile](#including-other-taskfiles), add a leading `:` like this: > `task: :task-name`. ## 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. ```yaml 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). ```yaml version: '2' tasks: build: cmds: - go build . sources: - ./*.go generates: - app{{exeExt}} method: checksum ``` > TIP: method `none` skips 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: ```yaml 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. If you need a certain set of conditions to be _true_ you can use the `preconditions` stanza. `preconditions` are very similar to `status` lines except they support `sh` expansion and they SHOULD all return 0. ```yaml version: '2' tasks: generate-files: cmds: - mkdir directory - touch directory/file1.txt - touch directory/file2.txt # test existence of files preconditions: - test -f .env - sh: "[ 1 = 0 ]" msg: "One doesn't equal Zero, Halting" ``` Preconditions can set specific failure messages that can tell a user what steps to take using the `msg` field. If a task has a dependency on a sub-task with a precondition, and that precondition is not met - the calling task will fail. Note that a task executed with a failing precondition will not run unless `--force` is given. Unlike `status` which will skip a task if it is up to date, and continue executing tasks that depend on it, a `precondition` will fail a task, along with any other tasks that depend on it. ```yaml version: '2' tasks: task_will_fail: preconditions: - sh: "exit 1" task_will_also_fail: deps: - task_will_fail task_will_still_fail: cmds: - task: task_will_fail - echo "I will not run" ``` ## 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 in the task definition - Variables given while calling a task from another. (See [Calling another task](#calling-another-task) above) - Variables declared in the `vars:` option in the `Taskfile` - Variables available in the `Taskvars.yml` file - Environment variables Example of sending parameters with environment variables: ```bash $ 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. ```bash $ task write-file FILE=file.txt "CONTENT=Hello, World!" print "MESSAGE=All done!" ``` If you want to set global variables using this syntax, give it before any task: ```bash $ task OUTPUT=file.txt generate-file ``` Example of locally declared vars: ```yaml version: '2' tasks: print-var: cmds: - echo "{{.VAR}}" vars: VAR: Hello! ``` Example of global vars in a `Taskfile.yml`: ```yaml version: '2' vars: GREETING: Hello from Taskfile! tasks: greet: cmds: - echo "{{.GREETING}}" ``` Example of `Taskvars.yml` file: ```yaml 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: ```yaml 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. ```yaml 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][gotemplate] before executing them. Variables are accessible through dot syntax (`.VARNAME`). All functions by the Go's [sprig lib](http://masterminds.github.io/sprig/) are available. The following example gets the current date in a given format: ```yaml 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`: Opposite of `toSlash`. 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: ```yaml 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: ```yaml 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: ```bash * build: Build the go binary. * test: Run all the go tests. ``` ## Display summary of task Running `task --summary task-name` will show a summary of a task The following Taskfile: ```yaml version: '2' tasks: release: deps: [build] summary: | Release your project to github It will build your project before starting the release it. Please make sure that you have set GITHUB_TOKEN before starting. cmds: - your-release-tool build: cmds: - your-build-tool ``` with running ``task --summary release`` would print the following output: ``` task: release Release your project to github It will build your project before starting the release it. Please make sure that you have set GITHUB_TOKEN before starting. dependencies: - build commands: - your-release-tool ``` If a summary is missing, the description will be printed. If the task does not have a summary or a description, a warning is printed. Please note: *showing the summary will not execute the command*. ## Silent mode Silent mode disables echoing of commands before Task runs it. For the following Taskfile: ```yaml version: '2' tasks: echo: cmds: - echo "Print something" ``` Normally this will be print: ```sh echo "Print something" Print something ``` With silent mode on, the below will be print instead: ```sh Print something ``` There are four ways to enable silent mode: * At command level: ```yaml version: '2' tasks: echo: cmds: - cmd: echo "Print something" silent: true ``` * At task level: ```yaml version: '2' tasks: echo: cmds: - echo "Print something" silent: true ``` * Globally at Taskfile level: ```yaml version: '2' silent: true tasks: echo: cmds: - echo "Print something" ``` * Or globally with `--silent` or `-s` flag If you want to suppress STDOUT instead, just redirect a command to `/dev/null`: ```yaml version: '2' tasks: echo: cmds: - echo "This will print nothing" > /dev/null ``` ## Dry run mode Dry run mode (`--dry`) compiles and steps through each task, printing the commands that would be run without executing them. This is useful for debugging your Taskfiles. ## Ignore errors You have the option to ignore errors during command execution. Given the following Taskfile: ```yaml version: '2' tasks: echo: cmds: - exit 1 - echo "Hello World" ``` Task will abort the execution after running `exit 1` because the status code `1` stands for `EXIT_FAILURE`. However it is possible to continue with execution using `ignore_error`: ```yaml version: '2' tasks: echo: cmds: - cmd: exit 1 ignore_error: true - echo "Hello World" ``` `ignore_error` can also be set for a task, which mean errors will be suppressed for all commands. But keep in mind this option won't propagate to other tasks called either by `deps` or `cmds`! ## Output syntax By default, Task just redirect the STDOUT and STDERR of the running commands to the shell in real time. This is good for having live feedback for log printed by commands, but the output can become messy if you have multiple commands running at the same time and printing lots of stuff. To make this more customizable, there are currently three different output options you can choose: - `interleaved` (default) - `group` - `prefixed` To choose another one, just set it to root in the Taskfile: ```yaml version: '2' output: 'group' tasks: # ... ``` The `group` output will print the entire output of a command once, after it finishes, so you won't have live feedback for commands that take a long time to run. The `prefix` output will prefix every line printed by a command with `[task-name] ` as the prefix, but you can customize the prefix for a command with the `prefix:` attribute: ```yaml version: '2' output: prefixed tasks: default: deps: - task: print vars: {TEXT: foo} - task: print vars: {TEXT: bar} - task: print vars: {TEXT: baz} print: cmds: - echo "{{.TEXT}}" prefix: "print-{{.TEXT}}" silent: true ``` ```bash $ task default [print-foo] foo [print-bar] bar [print-baz] baz ``` > The `output` option can also be specified by the `--output` or `-o` flags. ## 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. [gotemplate]: https://golang.org/pkg/text/template/ [minify]: https://github.com/tdewolff/minify/tree/master/cmd/minify