Add support for service hostname

Plus several small bug fixes:

* Allow target states with apps with no release

* Fix lock override and a TypeError in compareServicesForUpdate

* Lowercase service names when doing migrations and legacy preload

* Fix deltas from scratch

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

src/application-manager.coffee

@@ -383,7 +383,7 @@ module.exports = class ApplicationManager extends EventEmitter
 		removePairs = []
 		installPairs = []
 		updatePairs = []
-		if currentServices.length == 1 and targetServices.length == 1 and
+		if currentServices?.length == 1 and targetServices?.length == 1 and
 			targetServices[0].serviceName == currentServices[0].serviceName and
 			checkTruthy(currentServices[0].labels['io.resin.legacy-container'])
 				# This is a legacy preloaded app or container, so we didn't have things like serviceId.
@@ -880,7 +880,7 @@ module.exports = class ApplicationManager extends EventEmitter
 			return Promise.resolve()
 		@config.get('lockOverride')
 		.then (lockOverride) ->
-			return lockOverride or force
+			return checkTruthy(lockOverride) or force
 		.then (force) ->
 			updateLock.lock(appId, { force }, fn)
 

src/compose/images.coffee

@@ -54,7 +54,7 @@ module.exports = class Images extends EventEmitter
 					if validation.checkTruthy(opts.delta)
 						@logger.logSystemEvent(logTypes.downloadImageDelta, { image })
 						Promise.try =>
-							if opts.deltaSource
+							if opts.deltaSource and opts.deltaSource != 'resin/scratch'
 								@inspectByName(opts.deltaSource)
 								.then (srcImage) ->
 									opts.deltaSourceId = srcImage.Id

src/compose/service.coffee

@@ -1,5 +1,6 @@
 _ = require 'lodash'
 path = require 'path'
+os = require 'os'
 { checkTruthy, checkInt } = require '../lib/validation'
 updateLock = require '../lib/update-lock'
 constants = require '../lib/constants'
@@ -138,7 +139,6 @@ module.exports = class Service
 			@exposedPorts
 			@portBindings
 			@networks
-
 			@memLimit
 			@memReservation
 			@shmSize
@@ -162,6 +162,7 @@ module.exports = class Service
 			@healthcheck
 			@readOnly
 			@sysctls
+			@hostname
 		} = _.mapKeys(serviceProperties, (v, k) -> _.camelCase(k))
 
 		@networks ?= {}
@@ -205,6 +206,8 @@ module.exports = class Service
 
 		@sysctls ?= {}
 
+		@hostname ?= ''
+
 		# If the service has no containerId, it is a target service and has to be normalised and extended
 		if !@containerId?
 			@networkMode ?= 'default'
@@ -405,6 +408,12 @@ module.exports = class Service
 		nameComponents = container.Name.match(/.*_(\d+)_(\d+)$/)
 		imageId = checkInt(nameComponents?[1])
 		releaseId = checkInt(nameComponents?[2])
+		hostname = container.Config.Hostname
+		# A hostname equal to the first part of the container ID actually
+		# means no hostname was specified
+		if hostname == container.Id.substr(0, 12) or
+			(container.HostConfig.NetworkMode == 'host' and hostname == os.hostname())
+				hostname = ''
 		service = {
 			appId: appId
 			serviceId: serviceId
@@ -453,6 +462,7 @@ module.exports = class Service
 			init: container.HostConfig.Init
 			readOnly: container.HostConfig.ReadonlyRootfs
 			sysctls: container.HostConfig.Sysctls
+			hostname: hostname
 		}
 		# I've seen docker use either 'no' or '' for no restart policy, so we normalise to 'no'.
 		if service.restartPolicy.Name == ''
@@ -582,6 +592,7 @@ module.exports = class Service
 			'init'
 			'readOnly'
 			'sysctls'
+			'hostname'
 		]
 		arraysToCompare = [
 			'volumes'

src/device-state.coffee

@@ -72,7 +72,7 @@ singleToMulticontainerApp = (app) ->
 		{
 			serviceId: 1
 			appId: appId
-			serviceName: app.name
+			serviceName: app.name.toLowerCase()
 			imageId: 1
 			commit: app.commit
 			releaseId: 1

src/lib/validation.coffee

@@ -61,7 +61,7 @@ exports.isValidAppsObject = (obj) ->
 	return false if !_.isObject(obj)
 	return false if !_.every obj, (val, appId) ->
 		return false if !isValidShortText(appId) or !checkInt(appId)?
-		return false if !isValidShortText(val.name) or !checkInt(val.releaseId)?
+		return false if !isValidShortText(val.name) or (val.releaseId? and !checkInt(val.releaseId)?)
 		return false if !_.isObject(val.services)
 		return false if !_.every(val.services, isValidService)
 		return true

src/migrations/20171129064057_multicontainer.js

@@ -49,7 +49,7 @@ var singleToMulticontainerApp = function (app, appId) {
 		{
 			serviceId: 1,
 			appId: appId,
-			serviceName: app.name,
+			serviceName: app.name.toLowerCase(),
 			imageId: 1,
 			commit: app.commit,
 			releaseId: 1,