docs/development/tools/ffx/getting-started.md - fuchsia - Git at Google

 # Getting started with ffx

 This doc will guide you through some of the features of `ffx`. For an overview
 of the design and components of `ffx`, see [the ffx overview](/docs/development/tools/ffx/overview.md).

 Warning: **`ffx` is currently in alpha. Its APIs, command-line surface, and
 documentation are subject to change.**


 ## Contacting the ffx team

 If you discover possible bugs or have questions or suggestions,
 [file a bug](https://bugs.fuchsia.dev/p/fuchsia/issues/entry?template=ffx+User+Bug).

 ## Prerequisites

 To follow the examples in this doc, you'll need a Fuchsia device running. If you
 don't have a physical device connected, you can use an emulator with networking
 enabled (`-N`).

 Tip: To start a headless emulator, run `fx emu --headless --software-gpu -N`.

 Your device must be running a `core`
 [product configuration](/docs/concepts/build_system/boards_and_products.md)
 or a product configuration that extends `core` (such as `workstation`).

 Optionally, you can run `fx log`, which will provide some additional information
 about the interactions between `ffx` and your Fuchsia target device.

 ## Introduction

 After following all the prerequisites, run the following in a terminal:

 ```sh
 fx ffx help
 ```

 This will list all of the available `ffx` subcommands. You'll see something
 like:

 ```
 Usage: ffx [-c <config>] [-e <env>] [-t <target>] [<command>] [<args>]

 Fuchsia's developer tool

 Options:
   -c, --config      override default configuration
   -e, --env         override default environment settings
   -t, --target      apply operations across single or multiple targets
   --help            display usage information

 Commands:
   component         Discover and manage components
   config            View and switch default and user configurations
   daemon            Interact with/control the ffx daemon
   diagnostic        Run diagnostic tests on Fuchsia targets
   docs              View suite of docs for ffx and for Fuchsia
   doctor            Run common checks for the ffx tool and host environment
   emulator          Start and manage Fuchsia emulators
   overnet           Interact with the Overnet mesh
   package           Create and publish Fuchsia packages
   sdk               Modify or query the installed SDKs
   target            Interact with a target device or emulator
   vendor            Run partner plugins
   version           Print out ffx tool and daemon versions
 ```

 You can use `fx ffx help <subcommand>` or `fx ffx <subcommand> --help` to see
 more about any subcommand.

 ## Interacting with target devices

 In a terminal, run the following:

 ```sh
 fx ffx target list
 ```

 You'll see a list of devices that `ffx` has discovered. For example, with a
 single emulator running, output looks like:

 ```
 NAME                    TYPE       STATE      ADDRS/IP                       AGE     CS
 fuchsia-5254-0063-5e7a  Unknown    Unknown    [fe80::5054:ff:fe63:5e7a%4]    0m0s    N
 ```

 NOTE: Ignore the `TYPE` and `STATE` columns - they have no values besides
 `UNKNOWN` right now.

 A couple of columns are worth explanation:

 - `AGE`: This is the time since `ffx` was last able to reach the device.
 - `RCS`: Indicates whether there is a reachable instance of the
   Remote Control Service (RCS) running on the device.

 In order to get `ffx` to automatically connect to a device, you must either have
 set the target's nodename to be the default target, or attempt to interact with the
 device.

 To set the target to be the default, run:

 ```sh
 fx ffx target default set $NODENAME
 ```

 If the default target has been set prior to starting the daemon, waiting a few seconds
 should yield a change to the `RCS` status to show `Y`.

 If the default target has been set after starting the daemon, attempting to interact
 with the target should be sufficient to kick off a connection, like the following

 ```sh
 fx ffx component list
 ```

 NOTE: if the default target has been set, and you are unable to run that command
 against the target, [reach out](#contacting_the_ffx_team) to the `ffx` team.

 Then the next time you list targets you should see that an `RCS` connection
 is active.

 ```sh
 $ fx ffx target list
 NAME                    TYPE       STATE      ADDRS/IP                       AGE     RCS
 fuchsia-5254-0063-5e7a  Unknown    Unknown    [fe80::5054:ff:fe63:5e7a%4]    0m6s    Y
 ```

 If a target has been set as default there will be a `*` next to it.

 If you had `fx log` running, you should also see something like the following in
 the logs:

 ```
 [00009.776170][28540][28542][remote-control, remote_control_bin] INFO: published remote control service to overnet
 ```

 NOTE: if the `RCS` column remains `N` for an extended amount of time and you have
 already set this target's nodename to `target.default` _before_ initially starting
 ffx, [reach out](#contacting_the_ffx_team) to the `ffx` team.

 #### On Default Targets

 Above we covered setting the default target using the command

 ```sh
 fx ffx target default set
 ```

 It is also possible to set the default target on a per-command basis using the
 `--target` flag like so.

 ```sh
 fx ffx --target $NODENAME component list
 ```

 ### Interacting with multiple devices
 TODO: fill this out.

 ### Controlling the state of target devices

 You can use the `target off` and `target reboot` subcommands to power-off or
 reboot a device, respectively.

 ## Configuration

 See documentation for the [config command](/docs/development/tools/ffx/commands/config.md).

 ## Interacting with Components

 ### Selectors

 Many `ffx` commands that use components take selectors as a parameter. You can read more about selectors and their syntax
 in [component selector documentation](/docs/development/tools/ffx/commands/component-select.md).

 ### Inspecting the component topology

 You can use the `component select` command to
 * inspect services in the
 [component topology](/docs/concepts/components/v2/topology.md)
 * search for components that expose a service.

 For example, the following command will display all services offered by
 [components v1](/docs/glossary/README.md#components-v1):

 ```sh
 $ fx ffx component select moniker 'core/appmgr:out:*'`

 core/appmgr
 |
 --out
    |
    --chromium.cast.ApplicationConfigManager
    --fuchsia.bluetooth.avrcp.PeerManager
    --fuchsia.bluetooth.avrcp.test.PeerManagerExt
    --fuchsia.bluetooth.bredr.Profile
    --fuchsia.bluetooth.control.Control
    --fuchsia.bluetooth.gatt.Server
    --fuchsia.bluetooth.le.Central
    --fuchsia.bluetooth.le.Peripheral
    --fuchsia.bluetooth.snoop.Snoop
    --fuchsia.bluetooth.sys.Access
    --fuchsia.bluetooth.sys.HostWatcher
    --fuchsia.boot.Arguments
    --fuchsia.boot.FactoryItems
    --fuchsia.boot.Items
    --fuchsia.boot.ReadOnlyLog
    --fuchsia.boot.RootJobForInspect
    --fuchsia.boot.RootResource
    [truncated]
 ```

 Note: this command can be slow (~10-15s), especially for selectors that match a
 large number of services.

 The following command will display all components that expose `diagnostics`:

 ```sh
 $ fx ffx component select capability diagnostics

 /bootstrap/archivist
 /bootstrap/driver_manager
 /bootstrap/fshost
 /bootstrap/power_manager
 /core/appmgr
 /core/detect
 /core/last_reboot
 /core/log-stats
 /core/pkg-cache
 /core/sampler
 /core/system-update-committer
 ```

 ### Verifying a service is up

 You can use the `component knock` command to verify that a service starts
 successfully: `knock` will open a channel to the service and return success if
 and only if the channel isn't closed.

 The component framework will start the component that provides the service
 on-demand.

 Note: the selector you pass to `knock` may contain a wildcard but must match
 _exactly one_ service. You cannot `knock` on multiple services at once.

 For example:

 ```
 $ fx ffx component knock 'core/appmgr:out:fuchsia.hwinfo.P*'
 Success: service is up. Connected to 'core/appmgr:out:fuchsia.hwinfo.Product'.

 $ fx ffx component knock 'core/appmgr:out:not.a.real.service'
 Failed to connect to service: NoMatchingServices
 ```

 ### Running a CML component

 `ffx` can run CML components in an isolated realm given their package URL. Currently, this isolated
 realm provides the following capabilities:

 * `fuchsia.logger.LogSink` protocol
 * `fuchsia.process.Launcher` protocol
 * `tmp` storage
 * `data` storage
 * [`dev` directory](/docs/concepts/process/namespaces.md#typical_directory_structure): the root
 device tree of the system
 * [`boot` directory](/docs/concepts/process/namespaces.md#typical_directory_structure): the full
 bootfs filesystem used by the system during bootup

 CML components are run with the `ffx component run` subcommand. These components are automatically
 destroyed when they stop.

 Note: `fx serve` must be running in order to run a package that is not
 [in base or cached](/docs/concepts/build_system/boards_and_products.md#dependency_sets).

 Here's an example of running the Rust hello-world component. First, you'll need
 the hello-world package in your universe:

 ```
 $ fx set <product>.<board> --with //examples/hello_world/rust:hello-world-rust && fx build
 ...
 $ fx ffx component run fuchsia-pkg://fuchsia.com/hello-world#meta/hello-world-rust.cm
 URL: fuchsia-pkg://fuchsia.com/hello-world#meta/hello-world-rust.cm
 Moniker: /core/ffx-laboratory:hello-world-rust
 Creating component instance...
 ...
 $ fx ffx component show hello-world-rust
 Moniker: /core/ffx-laboratory:hello-world-rust
 URL: fuchsia-pkg://fuchsia.com/hello-world#meta/hello-world-rust.cm
 Type: v2 dynamic component
 Execution State: Running
 Job ID: 50775
 Process ID: 50819
 ...
 ```

 ### Running a CMX component

 `ffx` can run CMX components on a device given their package URL and arguments.

 CMX components are run with the `ffx component run-legacy` subcommand. `stdout` and `stderr` will
 be streamed to the corresponding descriptor on the host terminal.

 Note: `fx serve` must be running in order to run a package that is not
 [in base or cached](/docs/concepts/build_system/boards_and_products.md#dependency_sets).

 Here's an example of running the Dart hello-world component. First, you'll need
 the hello-world package in your universe:

 ```
 $ fx set <product>.<board> --with //examples/hello_world && fx build
 ...
 $ fx ffx component run-legacy fuchsia-pkg://fuchsia.com/hello-world#meta/hello-world-dart.cmx
 Hello, world!
 ```


 ## Resolving connectivity issues

 If you're experiencing problems communicating with a target device using `ffx`,
 you can use the `doctor` command to diagnose and attempt to resolve them. If you
 file a bug that involves a target device, we'll typically ask for the output
 from `ffx doctor` to provide information about where the problem is.

 `doctor` will attempt to communicate with the ffx daemon, killing
 and restarting it if needed. If this is successful, it will attempt to SSH into
 a target device and start the Remote Control Service.

 If you try running `ffx doctor` under normal circumstances, you should see:

 ```
 $ fx ffx doctor
 Checking for a running daemon...none running.
 Attempting to kill any zombie daemons...killed at least one daemon.
 Starting a new daemon instance...success
 Attempting to connect to the daemon. This may take a couple seconds...success
 Attempting to communicate with the daemon...success
 Attempting to list targets...success
 Attempting to get an RCS connection...success
 Attempting to communicate with RCS...success


 SUCCESS. You should be able to run ffx commands now.
 ```

 If `doctor` fails, it will try to suggest a resolution to the problem. It will
 also provide a link to the Monorail component in which you can file a bug if you
 persistently have problems. For example, if `doctor` is unable to start the RCS,
 you would see the following:

 ```
 $ fx ffx doctor
 Checking for a running daemon...found
 Attempting to connect to the daemon. This may take a couple seconds...success
 Attempting to communicate with the daemon...success
 Attempting to list targets...success
 Attempting to get an RCS connection...success
 Attempting to communicate with RCS...FAILED. Timed out.


 Attempt 2 of 3
 Attempting to list targets...success
 Attempting to get an RCS connection...success
 Attempting to communicate with RCS...FAILED. Timed out.


 Attempt 3 of 3
 Attempting to list targets...success
 Attempting to get an RCS connection...success
 Attempting to communicate with RCS...FAILED. Timed out.


 Connecting to RCS failed after maximum attempts. To resolve this issue, try
 rebooting your device. If this persists, please file a bug at the link below
 and include 1) all output
 above and 2) device syslog if available.Bug link: ...
 ```

 ## Next steps

 - Please provide feedback on this doc by [reaching out to the ffx team](#contacting_the_ffx_team)!
 - Learn how to [extend `ffx`](/docs/development/tools/ffx/development/plugins.md).
	# Getting started with ffx

	This doc will guide you through some of the features of `ffx`. For an overview
	of the design and components of `ffx`, see [the ffx overview](/docs/development/tools/ffx/overview.md).

	Warning: **`ffx` is currently in alpha. Its APIs, command-line surface, and
	documentation are subject to change.**


	## Contacting the ffx team

	If you discover possible bugs or have questions or suggestions,
	[file a bug](https://bugs.fuchsia.dev/p/fuchsia/issues/entry?template=ffx+User+Bug).

	## Prerequisites

	To follow the examples in this doc, you'll need a Fuchsia device running. If you
	don't have a physical device connected, you can use an emulator with networking
	enabled (`-N`).

	Tip: To start a headless emulator, run `fx emu --headless --software-gpu -N`.

	Your device must be running a `core`
	[product configuration](/docs/concepts/build_system/boards_and_products.md)
	or a product configuration that extends `core` (such as `workstation`).

	Optionally, you can run `fx log`, which will provide some additional information
	about the interactions between `ffx` and your Fuchsia target device.

	## Introduction

	After following all the prerequisites, run the following in a terminal:

	```sh
	fx ffx help
	```

	This will list all of the available `ffx` subcommands. You'll see something
	like:

	```
	Usage: ffx [-c <config>] [-e <env>] [-t <target>] [<command>] [<args>]

	Fuchsia's developer tool

	Options:
	-c, --config override default configuration
	-e, --env override default environment settings
	-t, --target apply operations across single or multiple targets
	--help display usage information

	Commands:
	component Discover and manage components
	config View and switch default and user configurations
	daemon Interact with/control the ffx daemon
	diagnostic Run diagnostic tests on Fuchsia targets
	docs View suite of docs for ffx and for Fuchsia
	doctor Run common checks for the ffx tool and host environment
	emulator Start and manage Fuchsia emulators
	overnet Interact with the Overnet mesh
	package Create and publish Fuchsia packages
	sdk Modify or query the installed SDKs
	target Interact with a target device or emulator
	vendor Run partner plugins
	version Print out ffx tool and daemon versions
	```

	You can use `fx ffx help <subcommand>` or `fx ffx <subcommand> --help` to see
	more about any subcommand.

	## Interacting with target devices

	In a terminal, run the following:

	```sh
	fx ffx target list
	```

	You'll see a list of devices that `ffx` has discovered. For example, with a
	single emulator running, output looks like:

	```
	NAME TYPE STATE ADDRS/IP AGE CS
	fuchsia-5254-0063-5e7a Unknown Unknown [fe80::5054:ff:fe63:5e7a%4] 0m0s N
	```

	NOTE: Ignore the `TYPE` and `STATE` columns - they have no values besides
	`UNKNOWN` right now.

	A couple of columns are worth explanation:

	- `AGE`: This is the time since `ffx` was last able to reach the device.
	- `RCS`: Indicates whether there is a reachable instance of the
	Remote Control Service (RCS) running on the device.

	In order to get `ffx` to automatically connect to a device, you must either have
	set the target's nodename to be the default target, or attempt to interact with the
	device.

	To set the target to be the default, run:

	```sh
	fx ffx target default set $NODENAME
	```

	If the default target has been set prior to starting the daemon, waiting a few seconds
	should yield a change to the `RCS` status to show `Y`.

	If the default target has been set after starting the daemon, attempting to interact
	with the target should be sufficient to kick off a connection, like the following

	```sh
	fx ffx component list
	```

	NOTE: if the default target has been set, and you are unable to run that command
	against the target, [reach out](#contacting_the_ffx_team) to the `ffx` team.

	Then the next time you list targets you should see that an `RCS` connection
	is active.

	```sh
	$ fx ffx target list
	NAME TYPE STATE ADDRS/IP AGE RCS
	fuchsia-5254-0063-5e7a Unknown Unknown [fe80::5054:ff:fe63:5e7a%4] 0m6s Y
	```

	If a target has been set as default there will be a `*` next to it.

	If you had `fx log` running, you should also see something like the following in
	the logs:

	```
	[00009.776170][28540][28542][remote-control, remote_control_bin] INFO: published remote control service to overnet
	```

	NOTE: if the `RCS` column remains `N` for an extended amount of time and you have
	already set this target's nodename to `target.default` _before_ initially starting
	ffx, [reach out](#contacting_the_ffx_team) to the `ffx` team.

	#### On Default Targets

	Above we covered setting the default target using the command

	```sh
	fx ffx target default set
	```

	It is also possible to set the default target on a per-command basis using the
	`--target` flag like so.

	```sh
	fx ffx --target $NODENAME component list
	```

	### Interacting with multiple devices
	TODO: fill this out.

	### Controlling the state of target devices

	You can use the `target off` and `target reboot` subcommands to power-off or
	reboot a device, respectively.

	## Configuration

	See documentation for the [config command](/docs/development/tools/ffx/commands/config.md).

	## Interacting with Components

	### Selectors

	Many `ffx` commands that use components take selectors as a parameter. You can read more about selectors and their syntax
	in [component selector documentation](/docs/development/tools/ffx/commands/component-select.md).

	### Inspecting the component topology

	You can use the `component select` command to
	* inspect services in the
	[component topology](/docs/concepts/components/v2/topology.md)
	* search for components that expose a service.

	For example, the following command will display all services offered by
	[components v1](/docs/glossary/README.md#components-v1):

	```sh
	$ fx ffx component select moniker 'core/appmgr:out:*'`

	core/appmgr
	\|
	--out
	\|
	--chromium.cast.ApplicationConfigManager
	--fuchsia.bluetooth.avrcp.PeerManager
	--fuchsia.bluetooth.avrcp.test.PeerManagerExt
	--fuchsia.bluetooth.bredr.Profile
	--fuchsia.bluetooth.control.Control
	--fuchsia.bluetooth.gatt.Server
	--fuchsia.bluetooth.le.Central
	--fuchsia.bluetooth.le.Peripheral
	--fuchsia.bluetooth.snoop.Snoop
	--fuchsia.bluetooth.sys.Access
	--fuchsia.bluetooth.sys.HostWatcher
	--fuchsia.boot.Arguments
	--fuchsia.boot.FactoryItems
	--fuchsia.boot.Items
	--fuchsia.boot.ReadOnlyLog
	--fuchsia.boot.RootJobForInspect
	--fuchsia.boot.RootResource
	[truncated]
	```

	Note: this command can be slow (~10-15s), especially for selectors that match a
	large number of services.

	The following command will display all components that expose `diagnostics`:

	```sh
	$ fx ffx component select capability diagnostics

	/bootstrap/archivist
	/bootstrap/driver_manager
	/bootstrap/fshost
	/bootstrap/power_manager
	/core/appmgr
	/core/detect
	/core/last_reboot
	/core/log-stats
	/core/pkg-cache
	/core/sampler
	/core/system-update-committer
	```

	### Verifying a service is up

	You can use the `component knock` command to verify that a service starts
	successfully: `knock` will open a channel to the service and return success if
	and only if the channel isn't closed.

	The component framework will start the component that provides the service
	on-demand.

	Note: the selector you pass to `knock` may contain a wildcard but must match
	_exactly one_ service. You cannot `knock` on multiple services at once.

	For example:

	```
	$ fx ffx component knock 'core/appmgr:out:fuchsia.hwinfo.P*'
	Success: service is up. Connected to 'core/appmgr:out:fuchsia.hwinfo.Product'.

	$ fx ffx component knock 'core/appmgr:out:not.a.real.service'
	Failed to connect to service: NoMatchingServices
	```

	### Running a CML component

	`ffx` can run CML components in an isolated realm given their package URL. Currently, this isolated
	realm provides the following capabilities:

	* `fuchsia.logger.LogSink` protocol
	* `fuchsia.process.Launcher` protocol
	* `tmp` storage
	* `data` storage
	* [`dev` directory](/docs/concepts/process/namespaces.md#typical_directory_structure): the root
	device tree of the system
	* [`boot` directory](/docs/concepts/process/namespaces.md#typical_directory_structure): the full
	bootfs filesystem used by the system during bootup

	CML components are run with the `ffx component run` subcommand. These components are automatically
	destroyed when they stop.

	Note: `fx serve` must be running in order to run a package that is not
	[in base or cached](/docs/concepts/build_system/boards_and_products.md#dependency_sets).

	Here's an example of running the Rust hello-world component. First, you'll need
	the hello-world package in your universe:

	```
	$ fx set <product>.<board> --with //examples/hello_world/rust:hello-world-rust && fx build
	...
	$ fx ffx component run fuchsia-pkg://fuchsia.com/hello-world#meta/hello-world-rust.cm
	URL: fuchsia-pkg://fuchsia.com/hello-world#meta/hello-world-rust.cm
	Moniker: /core/ffx-laboratory:hello-world-rust
	Creating component instance...
	...
	$ fx ffx component show hello-world-rust
	Moniker: /core/ffx-laboratory:hello-world-rust
	URL: fuchsia-pkg://fuchsia.com/hello-world#meta/hello-world-rust.cm
	Type: v2 dynamic component
	Execution State: Running
	Job ID: 50775
	Process ID: 50819
	...
	```

	### Running a CMX component

	`ffx` can run CMX components on a device given their package URL and arguments.

	CMX components are run with the `ffx component run-legacy` subcommand. `stdout` and `stderr` will
	be streamed to the corresponding descriptor on the host terminal.

	Note: `fx serve` must be running in order to run a package that is not
	[in base or cached](/docs/concepts/build_system/boards_and_products.md#dependency_sets).

	Here's an example of running the Dart hello-world component. First, you'll need
	the hello-world package in your universe:

	```
	$ fx set <product>.<board> --with //examples/hello_world && fx build
	...
	$ fx ffx component run-legacy fuchsia-pkg://fuchsia.com/hello-world#meta/hello-world-dart.cmx
	Hello, world!
	```


	## Resolving connectivity issues

	If you're experiencing problems communicating with a target device using `ffx`,
	you can use the `doctor` command to diagnose and attempt to resolve them. If you
	file a bug that involves a target device, we'll typically ask for the output
	from `ffx doctor` to provide information about where the problem is.

	`doctor` will attempt to communicate with the ffx daemon, killing
	and restarting it if needed. If this is successful, it will attempt to SSH into
	a target device and start the Remote Control Service.

	If you try running `ffx doctor` under normal circumstances, you should see:

	```
	$ fx ffx doctor
	Checking for a running daemon...none running.
	Attempting to kill any zombie daemons...killed at least one daemon.
	Starting a new daemon instance...success
	Attempting to connect to the daemon. This may take a couple seconds...success
	Attempting to communicate with the daemon...success
	Attempting to list targets...success
	Attempting to get an RCS connection...success
	Attempting to communicate with RCS...success


	SUCCESS. You should be able to run ffx commands now.
	```

	If `doctor` fails, it will try to suggest a resolution to the problem. It will
	also provide a link to the Monorail component in which you can file a bug if you
	persistently have problems. For example, if `doctor` is unable to start the RCS,
	you would see the following:

	```
	$ fx ffx doctor
	Checking for a running daemon...found
	Attempting to connect to the daemon. This may take a couple seconds...success
	Attempting to communicate with the daemon...success
	Attempting to list targets...success
	Attempting to get an RCS connection...success
	Attempting to communicate with RCS...FAILED. Timed out.


	Attempt 2 of 3
	Attempting to list targets...success
	Attempting to get an RCS connection...success
	Attempting to communicate with RCS...FAILED. Timed out.


	Attempt 3 of 3
	Attempting to list targets...success
	Attempting to get an RCS connection...success
	Attempting to communicate with RCS...FAILED. Timed out.


	Connecting to RCS failed after maximum attempts. To resolve this issue, try
	rebooting your device. If this persists, please file a bug at the link below
	and include 1) all output
	above and 2) device syslog if available.Bug link: ...
	```

	## Next steps

	- Please provide feedback on this doc by [reaching out to the ffx team](#contacting_the_ffx_team)!
	- Learn how to [extend `ffx`](/docs/development/tools/ffx/development/plugins.md).