Allow user to define a default account as an environment variable

qiskit_ibm_runtime/accounts/management.py

@@ -48,6 +48,7 @@ def save(
         verify: Optional[bool] = None,
         overwrite: Optional[bool] = False,
         channel_strategy: Optional[str] = None,
+        set_as_default: Optional[bool] = None,
     ) -> None:
         """Save account on disk."""
         channel = channel or os.getenv("QISKIT_IBM_CHANNEL") or _DEFAULT_CHANNEL_TYPE
@@ -69,6 +70,7 @@ def save(
             )
             # avoid storing invalid accounts
             .validate().to_saved_format(),
+            set_as_default=set_as_default,
         )
 
     @staticmethod
@@ -137,6 +139,21 @@ def get(
             filename: Full path of the file from which to get the account.
             name: Account name.
             channel: Channel type.
+            Order of precedence for selecting the account:
+            1. If name is specified, get account with that name
+            2. If the environment variables define an account, get that one
+            3. If the channel parameter is defined,
+               a. get the account of this channel type defined as "is_default_account"
+               b. get the account of this channel type with default name
+               c. get any account of this channel type
+            4. If the channel is defined in "QISKIT_IBM_CHANNEL"
+               a. get the account of this channel type defined as "is_default_account"
+               b. get the account of this channel type with default name
+               c. get any account of this channel type
+            5. If a default account is defined in the json file, get that account
+            6. Get any account that is defined in the json file with
+               preference for _DEFAULT_CHANNEL_TYPE.
+
 
         Returns:
             Account information.
@@ -157,18 +174,20 @@ def get(
         if env_account is not None:
             return env_account
 
-        if channel:
-            saved_account = read_config(
-                filename=filename,
-                name=cls._get_default_account_name(channel=channel),
-            )
-            if saved_account is None:
-                if os.path.isfile(_QISKITRC_CONFIG_FILE):
-                    return cls._from_qiskitrc_file()
-                raise AccountNotFoundError(f"No default {channel} account saved.")
+        all_config = read_config(filename=filename)
+        # Get the default account for the given channel.
+        # If channel == None, get the default account, for any channel, if it exists
+        saved_account = cls._get_default_account(all_config, channel)
+
+        if saved_account is not None:
             return Account.from_saved_format(saved_account)
 
-        all_config = read_config(filename=filename)
+        # Get the default account from the channel defined in the environment variable
+        account = cls._get_default_account(all_config, channel=channel_)
+        if account is not None:
+            return Account.from_saved_format(account)
+
+        # check for any account
         for channel_type in _CHANNEL_TYPES:
             account_name = cls._get_default_account_name(channel=channel_type)
             if account_name in all_config:
@@ -209,6 +228,34 @@ def _from_env_variables(cls, channel: Optional[ChannelType]) -> Optional[Account
             channel=channel,
         )
 
+    @classmethod
+    def _get_default_account(
+        cls, all_config: dict, channel: Optional[str] = None
+    ) -> Optional[dict]:
+        default_channel_account = None
+        any_channel_account = None
+
+        for account_name in all_config:
+            account = all_config[account_name]
+            if channel:
+                if account.get("channel") == channel and account.get("is_default_account"):
+                    return account
+                if account.get(
+                    "channel"
+                ) == channel and account_name == cls._get_default_account_name(channel):
+                    default_channel_account = account
+                if account.get("channel") == channel:
+                    any_channel_account = account
+            else:
+                if account.get("is_default_account"):
+                    return account
+
+        if default_channel_account:
+            return default_channel_account
+        elif any_channel_account:
+            return any_channel_account
+        return None
+
     @classmethod
     def _get_default_account_name(cls, channel: ChannelType) -> str:
         return (

qiskit_ibm_runtime/accounts/storage.py

@@ -22,7 +22,9 @@
 logger = logging.getLogger(__name__)
 
 
-def save_config(filename: str, name: str, config: dict, overwrite: bool) -> None:
+def save_config(
+    filename: str, name: str, config: dict, overwrite: bool, set_as_default: Optional[bool] = None
+) -> None:
     """Save configuration data in a JSON file under the given name."""
     logger.debug("Save configuration data for '%s' in '%s'", name, filename)
     _ensure_file_exists(filename)
@@ -35,8 +37,24 @@ def save_config(filename: str, name: str, config: dict, overwrite: bool) -> None
             f"Named account ({name}) already exists. " f"Set overwrite=True to overwrite."
         )
 
+    data[name] = config
+
+    # if set_as_default, but another account is defined as default, user must specify overwrite to change
+    # the default account.
+    if set_as_default:
+        data[name]["is_default_account"] = True
+        for account_name in data:
+            account = data[account_name]
+            if account_name != name and account.get("is_default_account"):
+                if overwrite:
+                    del account["is_default_account"]
+                else:
+                    raise AccountAlreadyExistsError(
+                        f"default_account ({name}) already exists. "
+                        f"Set overwrite=True to overwrite."
+                    )
+
     with open(filename, mode="w", encoding="utf-8") as json_out:
-        data[name] = config
         json.dump(data, json_out, sort_keys=True, indent=4)
 
 

qiskit_ibm_runtime/qiskit_runtime_service.py

@@ -139,6 +139,7 @@ def __init__(
             - Account with the input `name`, if specified.
             - Default account for the `channel` type, if `channel` is specified but `token` is not.
             - Account defined by the input `channel` and `token`, if specified.
+            - Account defined by the `default_channel` if defined in filename
             - Account defined by the environment variables, if defined.
             - Default account for the ``ibm_cloud`` account, if one is available.
             - Default account for the ``ibm_quantum`` account, if one is available.
@@ -287,6 +288,7 @@ def _discover_account(
                 "'channel' is required if 'token', or 'url' is specified but 'name' is not."
             )
 
+        # channel is not defined yet, get it from the AccountManager
         if account is None:
             account = AccountManager.get(filename=filename)
 
@@ -689,6 +691,7 @@ def save_account(
         verify: Optional[bool] = None,
         overwrite: Optional[bool] = False,
         channel_strategy: Optional[str] = None,
+        set_as_default: Optional[bool] = None,
     ) -> None:
         """Save the account to disk for future use.
 
@@ -709,6 +712,8 @@ def save_account(
             verify: Verify the server's TLS certificate.
             overwrite: ``True`` if the existing account is to be overwritten.
             channel_strategy: Error mitigation strategy.
+            set_as_default: If ``True``, the account is saved in filename,
+                as the default account.
         """
 
         AccountManager.save(
@@ -722,6 +727,7 @@ def save_account(
             verify=verify,
             overwrite=overwrite,
             channel_strategy=channel_strategy,
+            set_as_default=set_as_default,
         )
 
     @staticmethod

releasenotes/notes/default_account-13d86d50f5b1d972.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    Added the option to define a default account in the account json file.
+    The select an account as default, define ``set_as_default=True`` in 
+    ``QiskitRuntimeService.save_account()``.

test/account.py

@@ -152,6 +152,7 @@ def get_account_config_contents(
     instance=None,
     verify=None,
     proxies=None,
+    set_default=None,
 ):
     """Generate qiskitrc content"""
     if instance is None:
@@ -177,4 +178,6 @@ def get_account_config_contents(
         out[name]["verify"] = verify
     if proxies is not None:
         out[name]["proxies"] = proxies
+    if set_default:
+        out[name]["is_default_account"] = True
     return out