Generate the Rails application with the same user as the caller

Read the user id and group id of the caller and pass them to the Docker
so the generate folders are with the same user as the caller.

Fixes #4.

Cargo.toml

@@ -8,6 +8,7 @@ edition = "2021"
 
 [dependencies]
 clap = { version = "4.5.1", features = ["derive"] }
+users = "0.11.0"
 
 [dev-dependencies]
 assert_cmd = "2.0.14"

Dockerfile

@@ -1,5 +1,9 @@
 ARG RUBY_VERSION=3.2.3
 FROM ruby:${RUBY_VERSION}
+ARG USER_ID=1000
+ARG GROUP_ID=1000
+RUN groupadd -g $GROUP_ID app && useradd -u $USER_ID -g app -m app
+USER app
 ARG RAILS_VERSION
 # Install Rails based on the version specified but if not specified, install the latest version.
 RUN if [ -z "$RAILS_VERSION" ] ; then gem install rails ; else gem install rails -v $RAILS_VERSION ; fi

Dockerfile.windows

@@ -0,0 +1,5 @@
+ARG RUBY_VERSION=3.2.3
+FROM ruby:${RUBY_VERSION}
+ARG RAILS_VERSION
+# Install Rails based on the version specified but if not specified, install the latest version.
+RUN if [ -z "$RAILS_VERSION" ] ; then gem install rails ; else gem install rails -v $RAILS_VERSION ; fi

src/docker_client.rs

@@ -3,15 +3,25 @@ use std::process::{Command, Stdio};
 pub struct DockerClient {}
 
 impl DockerClient {
-    pub fn build_image(ruby_version: &str, rails_version: &str) -> Command {
+    pub fn build_image(
+        ruby_version: &str,
+        rails_version: &str,
+        user_id: Option<u32>,
+        group_id: Option<u32>,
+    ) -> Command {
         let mut command = Command::new("docker");
 
         command
             .arg("build")
             .arg("--build-arg")
             .arg(format!("RUBY_VERSION={}", ruby_version))
             .arg("--build-arg")
-            .arg(format!("RAILS_VERSION={}", rails_version))
+            .arg(format!("RAILS_VERSION={}", rails_version));
+
+        user_id.map(|id| command.args(["--build-arg", &format!("USER_ID={}", id)]));
+        group_id.map(|id| command.args(["--build-arg", &format!("GROUP_ID={}", id)]));
+
+        command
             .arg("-t")
             .arg(format!("rails-new-{}-{}", ruby_version, rails_version))
             .arg("-")

src/main.rs

@@ -13,15 +13,26 @@ use crate::docker_client::DockerClient;
 fn main() {
     let cli = Cli::parse();
 
-    // read the content of the DOCKERFILE and store it in a variable
-    let dockerfile = include_bytes!("../Dockerfile");
+    let dockerfile: &[u8];
+    let user_id: Option<u32>;
+    let group_id: Option<u32>;
+
+    if cfg!(windows) {
+        user_id = None;
+        group_id = None;
+        dockerfile = include_bytes!("../Dockerfile.windows");
+    } else {
+        user_id = Some(users::get_current_uid());
+        group_id = Some(users::get_current_gid());
+        dockerfile = include_bytes!("../Dockerfile");
+    }
 
     let ruby_version = cli.ruby_version;
     let rails_version = cli.rails_version;
 
     // Run docker build --build-arg RUBY_VERSION=$RUBY_VERSION --build-arg RAILS_VERSION=$RAILS_VERSION -t rails-new-$RUBY_VERSION-$RAILS_VERSION
     // passing the content of DOCKERFILE to the command stdin
-    let mut child = DockerClient::build_image(&ruby_version, &rails_version)
+    let mut child = DockerClient::build_image(&ruby_version, &rails_version, user_id, group_id)
         .spawn()
         .expect("Failed to execute process");