feature/ssh-server (#1)

Co-authored-by: Márcio Fernandes <marcio.fernandes@outlook.pt>
Reviewed-on: #1

docker/ssh-server/app/users.py

@@ -0,0 +1,89 @@
+import yaml
+import subprocess
+import crypt
+import os
+import globals
+import pwd
+# users:
+#   - username: alice
+#     authorized_keys: publich ssh key
+#   - username: bob
+#     password: hunter2
+
+
+def user_exists(username):
+    try:
+        pwd.getpwnam(username)
+        return True
+    except KeyError:
+        return False
+
+def create_user(uid, username ,password, shell="/bin/bash"):
+
+    if not shell: shell = "/bin/bash"
+
+    if not username:
+        return
+
+    useradd_cmd = [ 
+            'useradd',
+            '-m', 
+            '-s', shell,
+           ]
+    
+    if uid: useradd_cmd.append("-u " + str(uid)) 
+    if password: useradd_cmd.append("-p" + crypt.crypt(password, crypt.mksalt(crypt.METHOD_SHA512)))    
+    useradd_cmd.append(username)
+    
+    try:
+        subprocess.run(useradd_cmd
+            , check=True)
+        print(f"✅ User '{username}' created with shell '{shell}' and password.")
+    except subprocess.CalledProcessError as e:
+        print(f"❌ Failed to create user '{username}': {e}")
+
+
+
+
+def setup_ssh(username, public_key):
+    ssh_dir = f"/home/{username}/.ssh"
+    auth_keys = os.path.join(ssh_dir, "authorized_keys")
+    uid = pwd.getpwnam(username).pw_uid
+    gid = pwd.getpwnam(username).pw_gid
+
+    os.makedirs(ssh_dir, mode=0o700, exist_ok=True)
+
+    # Check if key already exists
+    key_exists = False
+    if os.path.exists(auth_keys):
+        with open(auth_keys, "r") as f:
+            existing_keys = f.read().splitlines()
+            key_exists = public_key.strip() in existing_keys
+
+    if not key_exists:
+        with open(auth_keys, "a") as f:
+            f.write(public_key.strip() + "\n")
+        print(f"🔐 SSH key added for '{username}'.")
+    else:
+        print(f"⚠️ SSH key already exists for '{username}'. Skipping.")
+
+    os.chmod(ssh_dir, 0o700)
+    os.chmod(auth_keys, 0o600)
+    os.chown(ssh_dir, uid, gid)
+    os.chown(auth_keys, uid, gid)
+     
+def load():
+    users = globals.get_config()["users"] if globals.config_exits() else None
+    if users:
+        for user in users:
+            if not user_exists(user.get('username')):
+                create_user(user.get('uid'), user.get('username'),user.get('password'), user.get('shell'))
+                if user.get('public_keys'):
+                    for public_key in user.get('public_keys'):
+                        setup_ssh(user.get('username'), public_key)
+    else:
+        print(f"⚠️ missing users configuration")
+
+
+if __name__ == "__main__":
+    load()