feat(installers): Added docker installer

installers/install_docker.sh

@@ -0,0 +1,72 @@
+#!/usr/bin/env bash
+# Tool: docker
+# DisplayName: Docker
+# Description: Container runtime and orchestration platform
+#
+# Docker Installer Script
+#
+
+# Prevent standalone execution
+if [ -z "${_LIB_COMMON_SOURCED:-}" ]; then
+    echo "Error: This script must be run through the 'b' CLI." >&2
+    exit 1
+fi
+
+set -euo pipefail
+
+# ─── Installation Logic ──────────────────────────────────────────────
+
+install_docker() {
+    if has_command docker; then
+        if ! confirm "Docker is already installed. Reinstall/Upgrade?"; then
+            log_info "Skipping Docker installation."
+            return
+        fi
+    else
+        if ! confirm "Install Docker?"; then
+            log_info "Skipping Docker installation."
+            return
+        fi
+    fi
+
+    # Use pkg_install for distro packages (it automatically handles rollback hooks for the packages!)
+    pkg_install "arch:docker|debian:docker.io|fedora:docker"
+
+    # Ensure docker group exists (some distros might not create it immediately)
+    if ! getent group docker >/dev/null 2>&1; then
+        log_info "Creating docker group..."
+        add_rollback_cmd "sudo groupdel docker || true"
+        sudo groupadd docker
+    fi
+
+    # Configure user group
+    if ! groups "$USER" | grep -q "\bdocker\b"; then
+        log_info "Adding $USER to the docker group..."
+        add_rollback_cmd "sudo gpasswd -d $USER docker || true"
+        sudo usermod -aG docker "$USER"
+        log_warn "You will need to log out and log back in, or run 'newgrp docker' for the group changes to take effect."
+    fi
+
+    # Enable and start systemd services
+    if has_command systemctl; then
+        log_info "Enabling and starting Docker services..."
+        
+        # Add rollback cmds for systemd
+        add_rollback_cmd "sudo systemctl disable --now docker.service || true"
+        add_rollback_cmd "sudo systemctl disable --now containerd.service || true"
+        
+        sudo systemctl enable --now docker.service || true
+        sudo systemctl enable --now containerd.service || true
+    fi
+}
+
+# ─── Main ─────────────────────────────────────────────────────────────
+
+main() {
+    install_docker
+
+    echo
+    log_success "Docker installation and configuration complete."
+}
+
+main "$@"