Add login display module

2025-10-10 00:59:16 +02:00 · 2025-10-10 00:59:16 +02:00 · 5786ff6cee
commit 5786ff6cee
parent b6121b1252
2 changed files with 155 additions and 7 deletions
--- a/modules/login-display.nix
+++ b/modules/login-display.nix
@ -0,0 +1,148 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.services.login-display;
+in
+
+{
+  options.services.login-display = {
+    enable = mkEnableOption "login information display on SSH sessions";
+
+    showSmartStatus = mkOption {
+      type = types.bool;
+      default = false;
+      description = "Show SMART disk health status";
+    };
+
+    smartDrives = mkOption {
+      type = types.attrsOf types.str;
+      default = {};
+      description = "Drives to monitor for SMART status (device path -> name mapping)";
+      example = {
+        "/dev/disk/by-id/ata-Samsung_SSD" = "System_SSD";
+      };
+    };
+
+    showSystemInfo = mkOption {
+      type = types.bool;
+      default = true;
+      description = "Show basic system information (hostname, uptime, load)";
+    };
+
+    showDiskUsage = mkOption {
+      type = types.bool;
+      default = false;
+      description = "Show disk usage information";
+    };
+
+    diskUsagePaths = mkOption {
+      type = types.listOf types.str;
+      default = [ "/" ];
+      description = "Paths to check for disk usage";
+    };
+  };
+
+  config = mkIf cfg.enable {
+    # Add smartmontools if SMART status is enabled
+    environment.systemPackages = mkIf cfg.showSmartStatus [ pkgs.smartmontools ];
+
+    # Configure shell login initialization
+    programs.zsh.loginShellInit = mkIf config.programs.zsh.enable (
+      let
+        # Build SMART status display
+        smartStatusCode = optionalString cfg.showSmartStatus ''
+          # Only show on SSH sessions
+          if [[ -n "$SSH_CONNECTION" ]] || [[ -n "$SSH_TTY" ]]; then
+            echo ""
+            echo "=== Disk Health Status ==="
+
+            ${concatStringsSep "\n" (mapAttrsToList (device: name: ''
+              if [[ -e "${device}" ]]; then
+                # Determine if NVMe
+                SMART_OPTS=""
+                if [[ "${device}" == *"nvme"* ]]; then
+                  SMART_OPTS="-d nvme"
+                fi
+
+                # Get health status (using sudo for disk access)
+                HEALTH=$(sudo ${pkgs.smartmontools}/bin/smartctl $SMART_OPTS -H "${device}" 2>/dev/null | ${pkgs.gnugrep}/bin/grep -o "PASSED\|FAILED" | head -1 || echo "UNKNOWN")
+
+                # Get temperature
+                TEMP="N/A"
+                if [[ "$HEALTH" == "PASSED" ]]; then
+                  SMART_DATA=$(sudo ${pkgs.smartmontools}/bin/smartctl $SMART_OPTS -A "${device}" 2>/dev/null)
+                  if [[ "${device}" == *"nvme"* ]]; then
+                    TEMP=$(echo "$SMART_DATA" | ${pkgs.gawk}/bin/awk '/^Temperature:/ {print $2}' | head -1)
+                    [[ -n "$TEMP" && "$TEMP" =~ ^[0-9]+$ ]] && TEMP="''${TEMP}°C" || TEMP="N/A"
+                  else
+                    TEMP=$(echo "$SMART_DATA" | ${pkgs.gawk}/bin/awk '/Temperature_Celsius/ {print $10}' | head -1)
+                    [[ -n "$TEMP" && "$TEMP" =~ ^[0-9]+$ ]] && TEMP="''${TEMP}°C" || TEMP="N/A"
+                  fi
+                fi
+
+                # Display status with color
+                if [[ "$HEALTH" == "PASSED" ]]; then
+                  echo "  ✓ ${name}: $HEALTH (Temp: $TEMP)"
+                else
+                  echo "  ✗ ${name}: $HEALTH"
+                fi
+              else
+                echo "  ⚠ ${name}: Device not found"
+              fi
+            '') cfg.smartDrives)}
+          fi
+        '';
+
+        # Build system info display
+        systemInfoCode = optionalString cfg.showSystemInfo ''
+          # Only show on SSH sessions
+          if [[ -n "$SSH_CONNECTION" ]] || [[ -n "$SSH_TTY" ]]; then
+            echo ""
+            echo "=== System Information ==="
+            echo "  Hostname: $(hostname)"
+            # Parse uptime output to get readable format
+            UPTIME_STR=$(uptime | ${pkgs.gawk}/bin/awk '{
+              # Extract the uptime part (between "up" and "user" or "load")
+              match($0, /up\s+(.+?),\s+[0-9]+\s+user/, arr)
+              if (arr[1] != "") {
+                print arr[1]
+              }
+            }')
+            echo "  Uptime: $UPTIME_STR"
+            echo "  Load: $(uptime | ${pkgs.gawk}/bin/awk -F'load average:' '{print $2}')"
+          fi
+        '';
+
+        # Build disk usage display
+        diskUsageCode = optionalString cfg.showDiskUsage ''
+          # Only show on SSH sessions
+          if [[ -n "$SSH_CONNECTION" ]] || [[ -n "$SSH_TTY" ]]; then
+            echo ""
+            echo "=== Disk Usage ==="
+            ${concatMapStringsSep "\n" (path: ''
+              df -h "${path}" | ${pkgs.gawk}/bin/awk 'NR==2 {printf "  ${path}: %s / %s (%s used)\n", $3, $2, $5}'
+            '') cfg.diskUsagePaths}
+          fi
+        '';
+
+      in ''
+        ${systemInfoCode}
+        ${smartStatusCode}
+        ${diskUsageCode}
+
+        # Add blank line after all info
+        if [[ -n "$SSH_CONNECTION" ]] || [[ -n "$SSH_TTY" ]]; then
+          echo ""
+        fi
+      ''
+    );
+
+    # Also support bash if needed
+    programs.bash.loginShellInit = mkIf (!config.programs.zsh.enable) (
+      # Same content as zsh
+      programs.zsh.loginShellInit
+    );
+  };
+}