Allow all config variables to take truthy or falsy values

Config variables now use a checkTruthy validation function,
and can be "1", "on", "true" or true to be considered true, or
"0", "off", "false" or false to be considered false.

Change-Type: minor
Signed-off-by: Pablo Carranza Velez <pablo@resin.io>

src/application.coffee

@@ -15,7 +15,7 @@ TypedError = require 'typed-error'
 fs = Promise.promisifyAll(require('fs'))
 JSONStream = require 'JSONStream'
 proxyvisor = require './proxyvisor'
-{ checkInt } = require './lib/validation'
+{ checkInt, checkTruthy } = require './lib/validation'
 deviceConfig = require './device-config'
 
 class UpdatesLockedError extends TypedError
@@ -405,7 +405,7 @@ apiPollInterval = (val) ->
 	application.poll()
 
 setLocalMode = (val) ->
-	mode = (val == '1')
+	mode = checkTruthy(val) ? false
 	Promise.try ->
 		if mode and !application.localMode
 			logSystemMessage('Entering local mode, app will be forcefully stopped', {}, 'Enter local mode')

src/device.coffee

@@ -10,6 +10,7 @@ configPath = '/boot/config.json'
 execAsync = Promise.promisify(require('child_process').exec)
 fs = Promise.promisifyAll(require('fs'))
 bootstrap = require './bootstrap'
+{ checkTruthy } = require './lib/validation'
 
 memoizePromise = _.partial(memoizee, _, promise: true)
 
@@ -78,7 +79,7 @@ exports.setHostConfig = (env, oldEnv, logMessage) ->
 
 setLogToDisplay = (env, oldEnv, logMessage) ->
 	if env['RESIN_HOST_LOG_TO_DISPLAY']?
-		enable = env['RESIN_HOST_LOG_TO_DISPLAY'] != '0'
+		enable = checkTruthy(env['RESIN_HOST_LOG_TO_DISPLAY']) ? true
 		utils.gosuper.postAsync('/v1/set-log-to-display', { json: true, body: Enable: enable })
 		.spread (response, body) ->
 			if response.statusCode != 200

src/lib/validation.coffee

@@ -14,4 +14,11 @@ exports.checkString = (s) ->
 	# This might happen if the parsing of config.json on the host using jq is wrong (it is buggy in some versions).
 	if !s? or s == 'null' or s == 'undefined' or s == ''
 		return
-	return s
+	return s
+
+exports.checkTruthy = (v) ->
+	if v == '1' or v == 'true' or v == true or v == 'on'
+		return true
+	if v == '0' or v == 'false' or v == false or v == 'off'
+		return false
+	return

src/utils.coffee

@@ -13,6 +13,7 @@ logger = require './lib/logger'
 TypedError = require 'typed-error'
 execAsync = Promise.promisify(require('child_process').exec)
 device = require './device'
+{ checkTruthy } = require './lib/validation'
 
 # Parses package.json and returns resin-supervisor's version
 version = require('../package.json').version
@@ -179,13 +180,14 @@ exports.extendEnvVars = (env, uuid, appId, appName, commit) ->
 
 # Callback function to enable/disable tcp pings
 exports.enableConnectivityCheck = (val) ->
-	bool = val is 'false'
-	disableCheck(bool)
+	enabled = checkTruthy(val) ? true
+	disableCheck(!enabled)
 	console.log("Connectivity check enabled: #{not bool}")
 
 # Callback function to enable/disable logs
 exports.resinLogControl = (val) ->
-	logger.disableLogPublishing(val == 'false')
+	logEnabled = checkTruthy(val) ? true
+	logger.disableLogPublishing(!logEnabled)
 	console.log('Logs enabled: ' + val)
 
 emptyHostRequest = request.defaults({ headers: Host: '' })
@@ -208,7 +210,7 @@ exports.gosuper = gosuper =
 
 # Callback function to enable/disable VPN
 exports.vpnControl = (val) ->
-	enable = val != 'false'
+	enable = checkTruthy(val) ? true
 	gosuper.postAsync('/v1/vpncontrol', { json: true, body: Enable: enable })
 	.spread (response, body) ->
 		if response.statusCode == 202