Juan Cruz Viotti 3cdd925c41 refactor: get rid of is-elevated (#1262)
This commit implements our own version of the `is-elevated` module. The
reason behind this is that `is-elevated` relies on lots of unnecessary
modules, that eventually require `spawn-sync` and `try-thread-sleep`,
which conditionally require dependencies that are not even declared in
their `package.json`, causing issues when concatenating the Etcher CLI.

See: https://github.com/resin-io/etcher/pull/1235
See: https://github.com/resin-io/etcher/pull/1228
Signed-off-by: Juan Cruz Viotti <jviotti@openmailbox.org>
2017-04-08 20:15:17 -04:00
..

Etcher CLI

The Etcher CLI is a command line interface to the Etcher writer backend, and currently the only module in the "Etcher" umbrella that makes use of this backend directly.

This module also has the task of unmounting the drives before and after flashing.

Notice the Etcher CLI is not worried about elevation, and assumes it has enough permissions to continue, throwing an error otherwise. Consult the lib/child-writer module to understand how elevation works on Etcher.

The robot option

Setting the ETCHER_CLI_ROBOT environment variable allows other applications to easily consume the output of the Etcher CLI in real-time. When using the ETCHER_CLI_ROBOT option, the --yes option is implicit, therefore you need to manually specify --drive.

When ETCHER_CLI_ROBOT is used, the program will output JSON lines containing the progress state and other useful information. For example:

$ sudo ETCHER_CLI_ROBOT=1 etcher image.iso --drive /dev/disk2
{"command":"progress","data":{"type":"write","percentage":1,"eta":130,"speed":1703936}}
...
{"command":"progress","data":{"type":"check","percentage":100,"eta":0,"speed":17180514}}
{"command":"done","data":{"sourceChecksum":"27c39a5d"}}

See documentation about the robot mode at lib/shared/robot.

Exit codes

The Etcher CLI uses certain exit codes to signal the result of the operation. These are documented in lib/shared/exit-codes.js and are also printed on the Etcher CLI help page.