support other runtimes

services/clsi/app/coffee/DockerRunner.coffee

@@ -149,10 +149,12 @@ module.exports = DockerRunner =
 				"CapDrop": "ALL"
 				"SecurityOpt": ["no-new-privileges"]
 
-
 		if Settings.path?.synctexBinHostPath?
 			options["HostConfig"]["Binds"].push("#{Settings.path.synctexBinHostPath}:/opt/synctex:ro")
 
+		if Settings.clsi.docker.runtime?
+			options["HostConfig"]["Runtime"] = Settings.clsi.docker.runtime
+
 		if Settings.clsi.docker.seccomp_profile?
 			options.HostConfig.SecurityOpt.push "seccomp=#{Settings.clsi.docker.seccomp_profile}"
 

services/clsi/config/settings.defaults.coffee

@@ -50,6 +50,7 @@ if process.env["DOCKER_RUNNER"]
 	module.exports.clsi =
 		dockerRunner: process.env["DOCKER_RUNNER"] == "true"
 		docker:
+			runtime: process.env["DOCKER_RUNTIME"]
 			image: process.env["TEXLIVE_IMAGE"] or "quay.io/sharelatex/texlive-full:2017.1"
 			env:
 				HOME: "/tmp"