If a device is already provisioned but the key exchange fails, retry it until it succeeds

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

src/bootstrap.coffee

@@ -179,13 +179,7 @@ hasDeviceApiKeySupport = (osVersion) ->
 		console.error('Unable to determine if device has deviceApiKey support', err, err.stack)
 		false
 
-bootstrapper.done = new Promise (resolve) ->
-	bootstrapper.doneBootstrapping = ->
-		bootstrapper.bootstrapped = true
-		resolve(userConfig)
-		# If we're still using an old api key we can try to exchange it for a valid device key
-		# This will only be the case when the supervisor/OS has been updated.
-		if userConfig.apiKey?
+exchangeKeyAndUpdateConfig = ->
 	# Only do a key exchange and delete the provisioning key if we're on a Resin OS version
 	# that supports using the deviceApiKey (2.0.2 and above)
 	# or if we're in a non-Resin OS (which is assumed to be updated enough).
@@ -209,7 +203,26 @@ bootstrapper.done = new Promise (resolve) ->
 				utils.setConfig('apiKey', userConfig.deviceApiKey)
 			.then ->
 				writeAndSyncFile(configPath, JSON.stringify(userConfig))
-			# We return immediately, and eventually the API key will be exchanged and replaced.
+
+exchangeKeyOrRetry = do ->
+	_failedExchanges = 0
+	return ->
+		exchangeKeyAndUpdateConfig()
+		.catch (err) ->
+			console.error('Error exchanging API key, will retry', err, err.stack)
+			delay = Math.min((2 ** _failedExchanges) * config.bootstrapRetryDelay, 24 * 60 * 60 * 1000)
+			_failedExchanges += 1
+			setTimeout(exchangeKeyOrRetry, delay)
+		return
+
+bootstrapper.done = new Promise (resolve) ->
+	bootstrapper.doneBootstrapping = ->
+		bootstrapper.bootstrapped = true
+		resolve(userConfig)
+		# If we're still using an old api key we can try to exchange it for a valid device key
+		# This will only be the case when the supervisor/OS has been updated.
+		if userConfig.apiKey?
+			exchangeKeyOrRetry()
 		return
 
 bootstrapper.bootstrapped = false