feat: a script add public keys from github

Debian/import-pubkeys-from-github.sh

@@ -0,0 +1,62 @@
+#!/bin/bash
+
+# Ensure a list of usernames is provided
+if [ -z "$1" ]; then
+    echo "Error: No usernames provided."
+    echo "Usage: bash $0 username1,username2"
+    exit 1
+fi
+
+TARGET_FILE="$HOME/.ssh/authorized_keys"
+
+# Initialising: Ensure .ssh directory exists with correct secure permissions
+mkdir -p "$HOME/.ssh"
+chmod 700 "$HOME/.ssh"
+
+# Ensure the authorised keys file exists so we can safely check its content later
+touch "$TARGET_FILE"
+chmod 600 "$TARGET_FILE"
+
+# Split the first argument by commas into an array
+IFS=',' read -r -a USERNAMES <<< "$1"
+
+for USERNAME in "${USERNAMES[@]}"; do
+    # Trim potential leading/trailing whitespaces from username
+    USERNAME=$(echo "$USERNAME" | xargs)
+    
+    if [ -z "$USERNAME" ]; then
+        continue
+    fi
+
+    echo "Fetching SSH public keys for GitHub user: ${USERNAME}..."
+
+    # Fetch keys from GitHub API (following redirects)
+    KEYS=$(curl -sSL "https://github.com/${USERNAME}.keys")
+
+    # Check if the user exists or has any public keys
+    if [ -z "$KEYS" ] || [[ "$KEYS" == *"Not Found"* ]]; then
+        echo "Warning: No public keys found for user '${USERNAME}' or user does not exist. Skipping."
+        continue
+    fi
+
+    # Format the header exactly as required
+    HEADER="# === SSH PUB KEY FOR ${USERNAME} ==="
+
+    # Check if this specific header already exists to avoid duplicate entries
+    if grep -qF "$HEADER" "$TARGET_FILE"; then
+        echo "Notice: Keys for '${USERNAME}' have already been imported previously. Skipping to prevent duplicates."
+        continue
+    fi
+
+    # Append the formatted block to the authorised keys file safely
+    # The awk block ensures that the keys always end with a proper newline character
+    {
+        echo ""
+        echo "$HEADER"
+        echo "$KEYS" | awk '1; END {if (NR && !/\n$/) print ""}'
+    } >> "$TARGET_FILE"
+
+    echo "Successfully appended keys for ${USERNAME}."
+done
+
+echo "SSH key import process completed."