Add ability to update git-based project

src/bin/devbox/commands/build.rs

@@ -12,7 +12,7 @@ pub fn exec(args: &ArgMatches) -> CliResult {
     let mut project = args.project()?;
 
     if let Some(name) = args.value_of("SERVICE") {
-        let mut service = project.find_service(name)?;
+        let service = project.find_service(name)?;
         let _ = service.clone_repo();
         service.build()
     } else {

src/bin/devbox/commands/mod.rs

@@ -8,6 +8,7 @@ pub fn builtins() -> Vec<App> {
         logs::cli(),
         new::cli(),
         ps::cli(),
+        renew::cli(),
         start::cli(),
         stop::cli(),
         tasks::cli(),
@@ -23,6 +24,7 @@ pub fn builtin_exec(cmd: &str) -> Option<fn(&ArgMatches) -> CliResult> {
         "logs" => logs::exec,
         "new" => new::exec,
         "ps" => ps::exec,
+        "renew" => renew::exec,
         "start" => start::exec,
         "stop" => stop::exec,
         "tasks" => tasks::exec,
@@ -38,6 +40,7 @@ pub mod doctor;
 pub mod logs;
 pub mod new;
 pub mod ps;
+pub mod renew;
 pub mod start;
 pub mod stop;
 pub mod tasks;

src/bin/devbox/commands/renew.rs

@@ -0,0 +1,22 @@
+use prelude::*;
+
+pub fn cli() -> App {
+    subcommand("renew")
+        .about("Re-generates an existing devbox project template from a git repository")
+        .arg(project())
+        .arg(
+            Arg::with_name("git")
+                .long("git")
+                .takes_value(true)
+                .required(true)
+                .help("A URL to a git repository containing configuration for this project"),
+        )
+}
+
+pub fn exec(args: &ArgMatches) -> CliResult {
+    let name = args.value_of("PROJECT")
+        .ok_or_else(|| format_err!("Missing project name"))?;
+    let repo = args.value_of("git")
+        .ok_or_else(|| format_err!("Missing git repository URL!"))?;
+    Project::update_from_git(name, repo)
+}

src/project.rs

@@ -189,6 +189,31 @@ impl Project {
         Ok(())
     }
 
+    pub fn update_from_git(name: &str, git: &str) -> Result<()> {
+
+        let dir = TempDir::new("devbox")?;
+
+        let _ = Command::new("git")
+            .arg("clone")
+            .arg(git)
+            .arg(&dir.path())
+            .spawn()?
+            .wait();
+
+        let toml_path = &dir.path().join("config.toml");
+        let yaml_path = &dir.path().join("docker-compose.yml");
+        let toml_contents = read_file(&toml_path)?;
+        let yaml_contents = read_file(&yaml_path)?;
+
+        ensure_directory_exists(&devbox_dir(name)?);
+        create_or_overwrite_file(&toml_config_path(name)?, &toml_contents)?;
+        create_or_overwrite_file(&yaml_config_path(name)?, &yaml_contents)?;
+
+        dir.close()?;
+
+        Ok(())
+    }
+
     pub fn find_service(&mut self, name: &str) -> Result<&mut Service> {
         let service = self.services
             .iter_mut()
@@ -255,3 +280,17 @@ fn create_file_if_not_exists(path: &Path, content: &str) -> Result<()> {
 
     Ok(())
 }
+
+fn create_or_overwrite_file(path: &Path, content: &str) -> Result<()> {
+    if path.exists() {
+        let mut file = OpenOptions::new().write(true).truncate(true).open(path)?;
+
+        println!("Overwriting file {:?}", &path);
+
+        file.write_all(content.as_bytes())?;
+    } else {
+        create_file_if_not_exists(&path, &content)?;
+    }
+
+    Ok(())
+}