fix(builder): properly escape backticks

Author: Matthew Fisher

builder/image/templates/builder

@@ -113,7 +113,7 @@ if [ ! -f Dockerfile ]; then
     BUILD_OPTS+=' deis/slugbuilder'
 
     # build the application and attach to the process
-    JOB=$(eval $(parse-string "${BUILD_OPTS[@]}") )
+    JOB=$(eval '$(parse-string "${BUILD_OPTS[@]}")' )
     docker attach $JOB
 
     # copy out the compiled slug

tests/config_test.go

@@ -13,6 +13,7 @@ var (
 	configSetCmd   = "config:set FOO=讲台 --app={{.AppName}}"
 	configSet2Cmd  = "config:set FOO=10 --app={{.AppName}}"
 	configSet3Cmd  = "config:set POWERED_BY=\"the Deis team\" --app={{.AppName}}"
+	configSet4Cmd  = "config:set CAR='`star' --app={{.AppName}}"
 	configUnsetCmd = "config:unset FOO --app={{.AppName}}"
 )
 
@@ -44,6 +45,9 @@ func configSetup(t *testing.T) *utils.DeisTestConfig {
 	// ensure envvars with spaces work fine on `git push`
 	// https://github.com/deis/deis/issues/2477
 	utils.Execute(t, configSet3Cmd, cfg, false, "the Deis team")
+	// ensure envvars with backticks work too
+	// https://github.com/deis/deis/issues/2980
+	utils.Execute(t, configSet4Cmd, cfg, false, "`star")
 	utils.Execute(t, gitPushCmd, cfg, false, "")
 	utils.CurlWithFail(t, cfg, false, "the Deis team")
 	if err := utils.Chdir(".."); err != nil {
@@ -59,13 +63,13 @@ func configListTest(
 
 func configSetTest(t *testing.T, params *utils.DeisTestConfig) {
 	utils.Execute(t, configSetCmd, params, false, "讲台")
-	utils.CheckList(t, appsInfoCmd, params, "(v4)", false)
-	utils.Execute(t, configSet2Cmd, params, false, "10")
 	utils.CheckList(t, appsInfoCmd, params, "(v5)", false)
+	utils.Execute(t, configSet2Cmd, params, false, "10")
+	utils.CheckList(t, appsInfoCmd, params, "(v6)", false)
 }
 
 func configUnsetTest(t *testing.T, params *utils.DeisTestConfig) {
 	utils.Execute(t, configUnsetCmd, params, false, "")
-	utils.CheckList(t, appsInfoCmd, params, "(v6)", false)
+	utils.CheckList(t, appsInfoCmd, params, "(v7)", false)
 	utils.CheckList(t, "run env --app={{.AppName}}", params, "FOO", true)
 }