Add MUTAGEN_PROJECT_FILE env variable

By default `mutagen project` looks for a config file named 'mutagen.yml'
to load project configuration. This change gives us the ability to
customize that with an environment variable.

Signed-off-by: Julich Mera <julich.mera@gmail.com>

cmd/mutagen/project/flush.go

@@ -28,7 +28,7 @@ func flushMain(command *cobra.Command, arguments []string) error {
 	// relative paths (including relative synchronization paths and relative
 	// Unix Domain Socket paths) to be resolved relative to the project
 	// configuration file.
-	configurationFileName := project.DefaultConfigurationFileName
+	configurationFileName := project.ConfigurationFileName()
 	if flushConfiguration.projectFile != "" {
 		var directory string
 		directory, configurationFileName = filepath.Split(flushConfiguration.projectFile)

cmd/mutagen/project/list.go

@@ -29,7 +29,7 @@ func listMain(command *cobra.Command, arguments []string) error {
 	// relative paths (including relative synchronization paths and relative
 	// Unix Domain Socket paths) to be resolved relative to the project
 	// configuration file.
-	configurationFileName := project.DefaultConfigurationFileName
+	configurationFileName := project.ConfigurationFileName()
 	if listConfiguration.projectFile != "" {
 		var directory string
 		directory, configurationFileName = filepath.Split(listConfiguration.projectFile)

cmd/mutagen/project/pause.go

@@ -30,7 +30,7 @@ func pauseMain(command *cobra.Command, arguments []string) error {
 	// relative paths (including relative synchronization paths and relative
 	// Unix Domain Socket paths) to be resolved relative to the project
 	// configuration file.
-	configurationFileName := project.DefaultConfigurationFileName
+	configurationFileName := project.ConfigurationFileName()
 	if pauseConfiguration.projectFile != "" {
 		var directory string
 		directory, configurationFileName = filepath.Split(pauseConfiguration.projectFile)

cmd/mutagen/project/reset.go

@@ -28,7 +28,7 @@ func resetMain(command *cobra.Command, arguments []string) error {
 	// relative paths (including relative synchronization paths and relative
 	// Unix Domain Socket paths) to be resolved relative to the project
 	// configuration file.
-	configurationFileName := project.DefaultConfigurationFileName
+	configurationFileName := project.ConfigurationFileName()
 	if resetConfiguration.projectFile != "" {
 		var directory string
 		directory, configurationFileName = filepath.Split(resetConfiguration.projectFile)

cmd/mutagen/project/resume.go

@@ -30,7 +30,7 @@ func resumeMain(command *cobra.Command, arguments []string) error {
 	// relative paths (including relative synchronization paths and relative
 	// Unix Domain Socket paths) to be resolved relative to the project
 	// configuration file.
-	configurationFileName := project.DefaultConfigurationFileName
+	configurationFileName := project.ConfigurationFileName();
 	if resumeConfiguration.projectFile != "" {
 		var directory string
 		directory, configurationFileName = filepath.Split(resumeConfiguration.projectFile)

cmd/mutagen/project/run.go

@@ -33,7 +33,7 @@ func runMain(_ *cobra.Command, arguments []string) error {
 	// relative paths (including relative synchronization paths and relative
 	// Unix Domain Socket paths) to be resolved relative to the project
 	// configuration file.
-	configurationFileName := project.DefaultConfigurationFileName
+	configurationFileName := project.ConfigurationFileName()
 	if runConfiguration.projectFile != "" {
 		var directory string
 		directory, configurationFileName = filepath.Split(runConfiguration.projectFile)

cmd/mutagen/project/start.go

@@ -39,7 +39,7 @@ func startMain(command *cobra.Command, arguments []string) error {
 	// relative paths (including relative synchronization paths and relative
 	// Unix Domain Socket paths) to be resolved relative to the project
 	// configuration file.
-	configurationFileName := project.DefaultConfigurationFileName
+	configurationFileName := project.ConfigurationFileName()
 	if startConfiguration.projectFile != "" {
 		var directory string
 		directory, configurationFileName = filepath.Split(startConfiguration.projectFile)

cmd/mutagen/project/terminate.go

@@ -30,7 +30,7 @@ func terminateMain(command *cobra.Command, arguments []string) error {
 	// relative paths (including relative synchronization paths and relative
 	// Unix Domain Socket paths) to be resolved relative to the project
 	// configuration file.
-	configurationFileName := project.DefaultConfigurationFileName
+	configurationFileName := project.ConfigurationFileName()
 	if terminateConfiguration.projectFile != "" {
 		var directory string
 		directory, configurationFileName = filepath.Split(terminateConfiguration.projectFile)

pkg/project/paths.go

@@ -1,5 +1,7 @@
 package project
 
+import "os"
+
 const (
 	// DefaultConfigurationFileName is the name of the Mutagen project
 	// configuration file.
@@ -8,3 +10,11 @@ const (
 	// order to compute the corresponding lock file.
 	LockFileExtension = ".lock"
 )
+
+func ConfigurationFileName() string {
+  fileName := os.Getenv("MUTAGEN_PROJECT_FILE")
+  if fileName == "" {
+    return DefaultConfigurationFileName
+  }
+  return fileName
+}