Vault secrets script client inc new 'keyring' client (#27669)

This adds a new type of vault-password script  (a 'client') that takes advantage of and enhances the 
multiple vault password support.

If a vault password script basename ends with the name '-client', consider it a vault password script client. 

A vault password script 'client' just means that the script will take a '--vault-id' command line arg.

The previous vault password script (as invoked by --vault-password-file pointing to an executable) takes
no args and returns the password on stdout. But it doesnt know anything about --vault-id or multiple vault
passwords.

The new 'protocol' of the vault password script takes a cli arg ('--vault-id') so that it can lookup that specific
vault-id and return it's password.

Since existing vault password scripts don't know the new 'protocol', a way to distinguish password scripts
that do understand the protocol was needed.  The convention now is to consider password scripts that are
named like 'something-client.py' (and executable) to be vault password client scripts.

The new client scripts get invoked with the '--vault-id' they were requested for. An example:

     ansible-playbook --vault-id my_vault_id@contrib/vault/vault-keyring-client.py some_playbook.yml

That will cause the 'contrib/vault/vault-keyring-client.py' script to be invoked as:

     contrib/vault/vault-keyring-client.py --vault-id my_vault_id

The previous vault-keyring.py password script was extended to become vault-keyring-client.py. It uses
the python 'keyring' module to request secrets from various backends. The plain 'vault-keyring.py' script
would determine which key id and keyring name to use based on values that had to be set in ansible.cfg.
So it was also limited to one keyring name.

The new vault-keyring-client.py will request the secret for the vault id provided via the '--vault-id' option.
The script can be used without config and can be used for multiple keyring ids (and keyrings).

On success, a vault password client script will print the password to stdout and exit with a return code of 0.
If the 'client' script can't find a secret for the --vault-id, the script will exit with return code of 2 and print an error to stderr.

lib/ansible/cli/__init__.py

@@ -293,7 +293,7 @@ class CLI(with_metaclass(ABCMeta, object)):
             display.vvvvv('Reading vault password file: %s' % vault_id_value)
             # read vault_pass from a file
             file_vault_secret = get_file_vault_secret(filename=vault_id_value,
-                                                      vault_id_name=vault_id_name,
+                                                      vault_id=vault_id_name,
                                                       loader=loader)
 
             # an invalid password file will error globally

lib/ansible/parsing/vault/__init__.py

@@ -303,14 +303,33 @@ class PromptVaultSecret(VaultSecret):
             raise AnsibleError("Passwords do not match")
 
 
-def get_file_vault_secret(filename=None, vault_id_name=None, encoding=None, loader=None):
+def script_is_client(filename):
+    '''Determine if a vault secret script is a client script that can be given --vault-id args'''
+
+    # if password script is 'something-client' or 'something-client.[sh|py|rb|etc]'
+    # script_name can still have '.' or could be entire filename if there is no ext
+    script_name, dummy = os.path.splitext(filename)
+
+    # TODO: for now, this is entirely based on filename
+    if script_name.endswith('-client'):
+        return True
+
+    return False
+
+
+def get_file_vault_secret(filename=None, vault_id=None, encoding=None, loader=None):
     this_path = os.path.realpath(os.path.expanduser(filename))
 
     if not os.path.exists(this_path):
         raise AnsibleError("The vault password file %s was not found" % this_path)
 
     if loader.is_executable(this_path):
-        # TODO: pass vault_id_name to script via cli
+        if script_is_client(filename):
+            display.vvvv('The vault password file %s is a client script.' % filename)
+            # TODO: pass vault_id_name to script via cli
+            return ClientScriptVaultSecret(filename=this_path, vault_id=vault_id,
+                                           encoding=encoding, loader=loader)
+        # just a plain vault password script. No args, returns a byte array
         return ScriptVaultSecret(filename=this_path, encoding=encoding, loader=loader)
 
     return FileVaultSecret(filename=this_path, encoding=encoding, loader=loader)
@@ -370,25 +389,89 @@ class ScriptVaultSecret(FileVaultSecret):
         if not self.loader.is_executable(filename):
             raise AnsibleVaultError("The vault password script %s was not executable" % filename)
 
+        command = self._build_command()
+
+        stdout, stderr, p = self._run(command)
+
+        self._check_results(stdout, stderr, p)
+
+        vault_pass = stdout.strip(b'\r\n')
+
+        empty_password_msg = 'Invalid vault password was provided from script (%s)' % filename
+        verify_secret_is_not_empty(vault_pass,
+                                   msg=empty_password_msg)
+
+        return vault_pass
+
+    def _run(self, command):
         try:
             # STDERR not captured to make it easier for users to prompt for input in their scripts
-            p = subprocess.Popen(filename, stdout=subprocess.PIPE)
+            p = subprocess.Popen(command, stdout=subprocess.PIPE)
         except OSError as e:
             msg_format = "Problem running vault password script %s (%s)." \
                 " If this is not a script, remove the executable bit from the file."
-            msg = msg_format % (filename, e)
+            msg = msg_format % (self.filename, e)
 
             raise AnsibleError(msg)
 
         stdout, stderr = p.communicate()
+        return stdout, stderr, p
 
-        if p.returncode != 0:
-            raise AnsibleError("Vault password script %s returned non-zero (%s): %s" % (filename, p.returncode, stderr))
+    def _check_results(self, stdout, stderr, popen):
+        if popen.returncode != 0:
+            raise AnsibleError("Vault password script %s returned non-zero (%s): %s" %
+                               (self.filename, popen.returncode, stderr))
 
-        vault_pass = stdout.strip(b'\r\n')
-        verify_secret_is_not_empty(vault_pass,
-                                   msg='Invalid vault password was provided from script (%s)' % filename)
-        return vault_pass
+    def _build_command(self):
+        return [self.filename]
+
+
+class ClientScriptVaultSecret(ScriptVaultSecret):
+    VAULT_ID_UNKNOWN_RC = 2
+
+    def __init__(self, filename=None, encoding=None, loader=None, vault_id=None):
+        super(ClientScriptVaultSecret, self).__init__(filename=filename,
+                                                      encoding=encoding,
+                                                      loader=loader)
+        self._vault_id = vault_id
+        display.vvvv('Executing vault password client script: %s --vault-id=%s' % (filename, vault_id))
+
+    def _run(self, command):
+        try:
+            p = subprocess.Popen(command,
+                                 stdout=subprocess.PIPE,
+                                 stderr=subprocess.PIPE)
+        except OSError as e:
+            msg_format = "Problem running vault password client script %s (%s)." \
+                " If this is not a script, remove the executable bit from the file."
+            msg = msg_format % (self.filename, e)
+
+            raise AnsibleError(msg)
+
+        stdout, stderr = p.communicate()
+        return stdout, stderr, p
+
+    def _check_results(self, stdout, stderr, popen):
+        if popen.returncode == self.VAULT_ID_UNKNOWN_RC:
+            raise AnsibleError('Vault password client script %s did not find a secret for vault-id=%s: %s' %
+                               (self.filename, self._vault_id, stderr))
+
+        if popen.returncode != 0:
+            raise AnsibleError("Vault password client script %s returned non-zero (%s) when getting secret for vault-id=%s: %s" %
+                               (self.filename, popen.returncode, self._vault_id, stderr))
+
+    def _build_command(self):
+        command = [self.filename]
+        if self._vault_id:
+            command.extend(['--vault-id', self._vault_id])
+
+        return command
+
+    def __repr__(self):
+        if self.filename:
+            return "%s(filename='%s', vault_id='%s')" % \
+                (self.__class__.__name__, self.filename, self._vault_id)
+        return "%s()" % (self.__class__.__name__)
 
 
 def match_secrets(secrets, target_vault_ids):