add support for passing additional environment parameters to command runner

includes an example of passing environment variables to chktex

app/coffee/CommandRunner.coffee

@@ -4,13 +4,18 @@ logger = require "logger-sharelatex"
 logger.info "using standard command runner"
 
 module.exports = CommandRunner =
-	run: (project_id, command, directory, image, timeout, callback = (error) ->) ->
+	run: (project_id, command, directory, image, timeout, environment, callback = (error) ->) ->
 		command = (arg.replace('$COMPILE_DIR', directory) for arg in command)
 		logger.log project_id: project_id, command: command, directory: directory, "running command"
 		logger.warn "timeouts and sandboxing are not enabled with CommandRunner"
 
+		# merge environment settings
+		env = {}
+		env[key] = value for key, value of process.env
+		env[key] = value for key, value of environment
+
 		# run command as detached process so it has its own process group (which can be killed if needed)
-		proc = spawn command[0], command.slice(1), stdio: "inherit", cwd: directory, detached: true
+		proc = spawn command[0], command.slice(1), stdio: "inherit", cwd: directory, detached: true, env: env
 
 		proc.on "error", (err)->
 			logger.err err:err, project_id:project_id, command: command, directory: directory, "error running command"

app/coffee/CompileManager.coffee

@@ -41,7 +41,14 @@ module.exports = CompileManager =
 					DraftModeManager.injectDraftMode Path.join(compileDir, request.rootResourcePath), callback
 				else
 					callback()
-			
+
+			# set up environment variables for chktex
+			env = {}
+			if request.chktex?
+				env['CHKTEX_OPTIONS'] =  '-nall -e9 -e10 -e15 -e16 -e27'
+				if request.chktex is 'error'
+					env['CHKTEX_EXIT_ON_ERROR'] =  1
+
 			injectDraftModeIfRequired (error) ->
 				return callback(error) if error?
 				timer = new Metrics.Timer("run-compile")
@@ -57,6 +64,7 @@ module.exports = CompileManager =
 					compiler:  request.compiler
 					timeout:   request.timeout
 					image:     request.imageName
+					environment: env
 				}, (error, output, stats, timings) ->
 					# compile was killed by user
 					if error?.terminated

app/coffee/LatexRunner.coffee

@@ -8,11 +8,11 @@ ProcessTable = {}  # table of currently running jobs (pids or docker container n
 
 module.exports = LatexRunner =
 	runLatex: (project_id, options, callback = (error) ->) ->
-		{directory, mainFile, compiler, timeout, image} = options
+		{directory, mainFile, compiler, timeout, image, environment} = options
 		compiler ||= "pdflatex"
 		timeout  ||= 60000 # milliseconds
 
-		logger.log directory: directory, compiler: compiler, timeout: timeout, mainFile: mainFile, "starting compile"
+		logger.log directory: directory, compiler: compiler, timeout: timeout, mainFile: mainFile, environment: environment, "starting compile"
 
 		# We want to run latexmk on the tex file which we will automatically
 		# generate from the Rtex/Rmd/md file.
@@ -34,7 +34,7 @@ module.exports = LatexRunner =
 
 		id = "#{project_id}" # record running project under this id
 
-		ProcessTable[id] = CommandRunner.run project_id, command, directory, image, timeout, (error, output) ->
+		ProcessTable[id] = CommandRunner.run project_id, command, directory, image, timeout, environment, (error, output) ->
 			delete ProcessTable[id]
 			return callback(error) if error?
 			runs = output?.stderr?.match(/^Run number \d+ of .*latex/mg)?.length or 0