feat: [#10] add Rust installation to cloud-init configuration

- Install Rust using rustup following official documentation
- Configure Rust installation as torrust user for proper ownership
- Add Rust's cargo bin directory to PATH in .bashrc and .profile
- Include verification commands for rustc and cargo
- Update final message to reflect Rust installation
- Add Rust-related terms to project-words.txt for spell checking

This enables future source compilation of Torrust Tracker for better
performance, moving away from the current Docker-based approach.

Author: josecelano

infrastructure/cloud-init/user-data.yaml.tpl

@@ -150,6 +150,21 @@ runcmd:
   - docker --version
   - docker compose version
 
+  # Install Rust using rustup (official method)
+  # Install as torrust user to ensure proper ownership
+  - >
+    sudo -u torrust bash -c 'curl --proto "=https" --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y'
+
+  # Add Rust to PATH for torrust user
+  - >
+    echo 'export PATH="$HOME/.cargo/bin:$PATH"' >> /home/torrust/.bashrc
+  - >
+    echo 'export PATH="$HOME/.cargo/bin:$PATH"' >> /home/torrust/.profile
+
+  # Verify Rust installation
+  - sudo -u torrust bash -c 'source ~/.cargo/env && rustc --version'
+  - sudo -u torrust bash -c 'source ~/.cargo/env && cargo --version'
+
   # CRITICAL: Configure UFW firewall SAFELY (allow SSH BEFORE enabling)
   - ufw --force reset
   - ufw default deny incoming
@@ -183,6 +198,7 @@ final_message: |
   - OS: Ubuntu 24.04 LTS
   - User: torrust (with sudo privileges and SSH key access only)
   - Docker: Installed and configured
+  - Rust: Installed via rustup (latest stable version)
   - Firewall: UFW enabled with proper SSH rules
   - Security: Automatic updates enabled
   - Torrust Tracker dependencies: pkg-config, libssl-dev, make, build-essential, libsqlite3-dev, sqlite3

project-words.txt

@@ -63,6 +63,8 @@ qcow
 repomix
 rmem
 runcmd
+rustc
+rustup
 rwxr
 SAMEORIGIN
 secp
@@ -74,6 +76,7 @@ testpass
 testuser
 tfstate
 tfvars
+tlsv
 UEFI
 usermod
 vcpu