# 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: '3' 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. ## Supported file names Task will look for the following file names, in order of priority: - Taskfile.yml - Taskfile.yaml - Taskfile.dist.yml - Taskfile.dist.yaml The intention of having the `.dist` variants is to allow projects to have one committed version (`.dist`) while still allowing individual users to override the Taskfile by adding an additional `Taskfile.yml` (which would be on `.gitignore`). ## Environment variables ### Task You can use `env` to set custom environment variables for a specific task: ```yaml version: '3' 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: '3' 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. ### .env files You can also ask Task to include `.env` like files by using the `dotenv:` setting: ``` # .env KEYNAME=VALUE ``` ``` # testing/.env ENDPOINT=testing.com ``` ```yaml # Taskfile.yml version: '3' env: ENV: testing dotenv: ['.env', '{{.ENV}}/.env.', '{{.HOME}}/.env'] tasks: greet: cmds: - echo "Using $KEYNAME and endpoint $ENDPOINT" ``` ## Including other Taskfiles 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: '3' 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. ### OS-specific Taskfiles With `version: '2'`, task automatically includes any `Taskfile_{{OS}}.yml` if it exists (for example: `Taskfile_windows.yml`, `Taskfile_linux.yml` or `Taskfile_darwin.yml`). Since this behavior was a bit too implicit, it was removed on version 3, but you still can have a similar behavior by explicitly importing these files: ```yaml version: '3' includes: build: ./Taskfile_{{OS}}.yml ``` ### Directory of included Taskfile By default, included Taskfile's tasks are ran in the current directory, even if the Taskfile is in another directory, but you can force its tasks to run in another directory by using this alternative syntax: ```yaml version: '3' includes: docs: taskfile: ./docs/Taskfile.yml dir: ./docs ``` > The included Taskfiles must be using the same schema version the main > Taskfile uses. ### Optional includes Includes marked as optional will allow Task to continue execution as normal if the included file is missing. ```yaml version: '3' includes: tests: taskfile: ./tests/Taskfile.yml optional: true tasks: greet: cmds: - echo "This command can still be successfully executed if ./tests/Taskfile.yml does not exist" ``` ### Vars of included Taskfiles You can also specify variables when including a Taskfile. This may be useful for having reusable Taskfile that can be tweaked or even included more than once: ```yaml version: '3' includes: backend: taskfile: ./taskfiles/Docker.yml vars: DOCKER_IMAGE: backend_image frontend: taskfile: ./taskfiles/Docker.yml vars: DOCKER_IMAGE: frontend_image ``` > NOTE: Vars declared in the included Taskfile have preference over the included ones! If you want a variable in an included Taskfile to be overridable use the [default function](https://go-task.github.io/slim-sprig/defaults.html): `MY_VAR: '{{.MY_VAR | default "my-default-value"}}'`. ## 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: '3' tasks: serve: dir: public/www cmds: # run http server - caddy ``` If the directory doesn't exist, `task` creates it. ## Task dependencies > Dependencies run in parallel, so dependencies of a task shouldn't depend one > another. If you want to force tasks to run serially take a look at the > [Calling Another Task](#calling-another-task) section below. 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: '3' 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: '3' 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: '3' 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: '3' 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: '3' tasks: greet: vars: RECIPIENT: '{{default "World" .RECIPIENT}}' cmds: - echo "Hello, {{.RECIPIENT}}!" greet-pessimistically: cmds: - task: greet vars: {RECIPIENT: "Cruel World"} ``` 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 ### By fingerprinting locally generated files and their sources 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: '3' 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 given, Task will compare the checksum of the source 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`. You will probably want to ignore the `.task` folder in your `.gitignore` file (It's there that Task stores the last checksum). If you prefer this check to be made by the modification timestamp of the files, instead of its checksum (content), just set the `method` property to `timestamp`. ```yaml version: '3' tasks: build: cmds: - go build . sources: - ./*.go generates: - app{{exeExt}} method: checksum ``` > TIP: method `none` skips any validation and always run the task. > NOTE: for the `checksum` (default) method to work, it's only necessary to > inform the source files, but if you want to use the `timestamp` method, you > also need to inform the generated files with `generates`. ### Using programmatic checks to indicate a task is up to date. 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: '3' 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 ``` Normally, you would use `sources` in combination with `generates` - but for tasks that generate remote artifacts (Docker images, deploys, CD releases) the checksum source and timestamps require either access to the artifact or for an out-of-band refresh of the `.checksum` fingerprint file. Two special variables `{{.CHECKSUM}}` and `{{.TIMESTAMP}}` are available for interpolation within `status` commands, depending on the method assigned to fingerprint the sources. Only `source` globs are fingerprinted. Note that the `{{.TIMESTAMP}}` variable is a "live" Go `time.Time` struct, and can be formatted using any of the methods that `time.Time` responds to. See [the Go Time documentation](https://golang.org/pkg/time/) for more information. 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. ### Using programmatic checks to cancel execution of an task and it's dependencies In addition to `status` checks, there are also `preconditions` checks, which are the logical inverse of `status` checks. That is, if you need a certain set of conditions to be _true_ you can use the `preconditions` stanza. `preconditions` are similar to `status` lines except they support `sh` expansion and they SHOULD all return 0. ```yaml version: '3' 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: '3' 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" ``` ### Limiting when tasks run If a task executed by multiple `cmds` or multiple `deps` you can control when it is executed using `run`. `run` can also be set at the root of the Taskfile to change the behavior of all the tasks unless explicitly overridden. Supported values for `run`: * `always` (default) always attempt to invoke the task regardless of the number of previous executions * `once` only invoke this task once regardless of the number of references * `when_changed` only invokes the task once for each unique set of variables passed into the task ```yaml version: '3' tasks: default: cmds: - task: generate-file vars: { CONTENT: '1' } - task: generate-file vars: { CONTENT: '2' } - task: generate-file vars: { CONTENT: '2' } generate-file: run: when_changed deps: - install-deps cmds: - echo {{.CONTENT}} install-deps: run: once cmds: - sleep 5 # long operation like installing packages ``` ## 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 of the [included Taskfile](#including-other-taskfiles) (when the task is included) - Variables of the [inclusion of the Taskfile](#vars-of-included-taskfiles) (when the task is included) - Global variables (those declared in the `vars:` option in the Taskfile) - Environment variables Example of sending parameters with environment variables: ```bash $ TASK_VARIABLE=a-value task do-something ``` > TIP: A special variable `.TASK` is always available containing the task name. 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. ```bash $ task write-file FILE=file.txt "CONTENT=Hello, World!" print "MESSAGE=All done!" ``` Example of locally declared vars: ```yaml version: '3' tasks: print-var: cmds: - echo "{{.VAR}}" vars: VAR: Hello! ``` Example of global vars in a `Taskfile.yml`: ```yaml version: '3' vars: GREETING: Hello from Taskfile! tasks: greet: cmds: - echo "{{.GREETING}}" ``` ### 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: '3' 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. ## Forwarding CLI arguments to commands If `--` is given in the CLI, all following parameters are added to a special `.CLI_ARGS` variable. This is useful to forward arguments to another command. The below example will run `yarn install`. ```bash $ task yarn -- install ``` ```yaml version: '3' tasks: yarn: cmds: - yarn {{.CLI_ARGS}} ``` ## Doing task cleanup with `defer` With the `defer` keyword, it's possible to schedule cleanup to be run once the task finishes. The difference with just putting it as the last command is that this command will run even when the task fails. In the example below `rm -rf tmpdir/` will run even if the third command fails: ```yaml version: '3' tasks: default: cmds: - mkdir -p tmpdir/ - defer: rm -rf tmpdir/ - echo 'Do work on tmpdir/' ``` If you want to move the cleanup command into another task, that's possible as well: ```yaml version: '3' tasks: default: cmds: - mkdir -p tmpdir/ - defer: { task: cleanup } - echo 'Do work on tmpdir/' cleanup: rm -rf tmpdir/ ``` > NOTE: Due to the nature of how the [Go's own `defer` work](https://go.dev/tour/flowcontrol/13), the deferred commands are executed in the reverse order if you schedule multiple of them. ## 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 [slim-sprig lib](https://go-task.github.io/slim-sprig/) are available. The following example gets the current date in a given format: ```yaml version: '3' 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). - `shellQuote`: Quotes a string to make it safe for use in shell scripts. Task uses [this Go function](https://pkg.go.dev/mvdan.cc/sh/v3@v3.4.0/syntax#Quote) for this. The Bash dialect is assumed. Example: ```yaml version: '3' 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: '3' 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. ``` If you want to see all tasks, there's a `--list-all` (alias `-a`) flag as well. ## Display summary of task Running `task --summary task-name` will show a summary of a task. The following Taskfile: ```yaml version: '3' tasks: release: deps: [build] summary: | Release your project to github It will build your project before starting the release. 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. 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*. ## Overriding task name Sometimes you may want to override the task name print on summary, up-to-date messages to STDOUT, etc. In this case you can just set `label:`, which can also be interpolated with variables: ```yaml version: '3' tasks: default: - task: print vars: MESSAGE: hello - task: print vars: MESSAGE: world print: label: 'print-{{.MESSAGE}}' cmds: - echo "{{.MESSAGE}}" ``` ## Silent mode Silent mode disables echoing of commands before Task runs it. For the following Taskfile: ```yaml version: '3' 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: '3' tasks: echo: cmds: - cmd: echo "Print something" silent: true ``` * At task level: ```yaml version: '3' tasks: echo: cmds: - echo "Print something" silent: true ``` * Globally at Taskfile level: ```yaml version: '3' 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: '3' 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: '3' 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: '3' 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: '3' 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. When using the `group` output, you can optionally provide a templated message to print at the start and end of the group. This can be useful for instructing CI systems to group all of the output for a given task, such as with [GitHub Actions' `::group::` command](https://docs.github.com/en/actions/learn-github-actions/workflow-commands-for-github-actions#grouping-log-lines) or [Azure Pipelines](https://docs.microsoft.com/en-us/azure/devops/pipelines/scripts/logging-commands?expand=1&view=azure-devops&tabs=bash#formatting-commands). ```yaml version: '3' output: group: begin: '::begin::{{.TASK}}' end: '::endgroup::' tasks: default: cmds: - echo 'Hello, World!' silent: true ``` ```bash $ task default ::begin::default Hello, World! ::endgroup:: ``` 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: '3' 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. ## Interactive CLI application When running interactive CLI applications inside Task they can sometimes behave weirdly, specially when the [output mode](#output-syntax) is set to something other than `interleaved` (the default), or when interactive apps are ran in parallel with other tasks. The `interactive: true` tells Task this is an interactive application, and Task will try to optimize for it: ```yaml version: '3' tasks: cmds: - vim my-file.txt interactive: true ``` If you still have problem running an interactive app through Task, please open an issue about it. ## Short task syntax Starting on Task v3, you can now write tasks with a shorter syntax if they have the default settings (e.g. no custom `env:`, `vars:`, `desc:`, `silent:` , etc): ```yaml version: '3' tasks: build: go build -v -o ./app{{exeExt}} . run: - task: build - ./app{{exeExt}} -h localhost -p 8080 ``` ## Watch tasks With the flags `--watch` or `-w` task will watch for file changes and run the task again. This requires the `sources` attribute to be given, so task knows which files to watch. [gotemplate]: https://golang.org/pkg/text/template/ [minify]: https://github.com/tdewolff/minify/tree/master/cmd/minify