NAME

Concierge - Extensible service layer orchestrator of operational resources for applications, with built-in provisions for authentication, sessions, and user data.

VERSION

v0.11.0

SYNOPSIS

use Concierge;

# Open an existing desk (created by Concierge::Desk::Setup)
my $desk = Concierge->open_desk('./desk');
my $concierge = $desk->{concierge};

# Register a user
$concierge->add_user({
    user_id  => 'alice',
    moniker  => 'Alice',
    email    => 'alice@example.com',
    password => 'secret123',
});

# Log in -- returns a Concierge::Desk::User object
my $login = $concierge->login_user({
    user_id  => 'alice',
    password => 'secret123',
});
my $user = $login->{user};

# User object provides direct access
say $user->moniker;         # "Alice"
say $user->session_id;      # random hex string
say $user->is_logged_in;    # 1

# Restore user from a cookie on next request
my $restore = $concierge->restore_user($user->user_key);
my $same_user = $restore->{user};

# Log out
$concierge->logout_user($user->session_id);

CONCEPTS

Concierge is built around four ideas: it is extensible, it behaves as a service layer, it orchestrates rather than reimplements, and it exists to simplify an application's access to operational resources. The sections below define each term as used throughout this documentation; "Architecture" and "EXTENSIBILITY" further down build on them.

Extensible

Concierge is extensible in two independent ways:

  • Each identity-core component (Auth, Sessions, Users) is itself extensible as to backend and storage configuration -- see each component's own POD, and "Component Substitution" for replacing a component outright.

  • Components beyond the identity core may be added to a desk. Concierge can treat an added component purely as a pass-through:

    my $res = $concierge->{'OthComp'}->OthCompMthd();
    my $res = $concierge->OthComp->OthCompMthd();
    my $OthCompObj = $concierge->OthComp;
    # or my $OthCompObj = $concierge->{'OthComp'};
    my $res = $OthCompObj->OthCompMthd(); # $concierge no longer involved

    Additionally, selected methods of a component may be promoted to be direct methods of the concierge object.

    # OthComp's OthCompMthd specified in setup to be promoted
    my $res = $concierge->OthCompMthd();

    See "Additional Components" and "Component Method Promotion".

Service Layer

Concierge is a service layer: application code depends on it to manage the configured components without crashing or interfering with the application's control flow. It is designed so that a partially-working concierge is never returned, and failures are never silent.

  • The setup methods (build_desk() or build_quick_desk()) must validate their entire configuration or fail with messages. If setup succeeds, the Concierge config for the app is saved.

  • The runtime method, open_desk() must fully instantiate the desk's saved configuration or fail with messages. If open_desk() succeeds, it will return a fully capable concierge to the app.

  • Nearly every setup validation failure -- a missing or unknown backend, a missing required setting, a component's setup() failing -- returns a structured { success => 0, message => '...' } response rather than raising an exception. The one exception is a failure to create a storage directory on disk, which is treated as an unrecoverable environment problem and raises an exception instead.

    Most open_desk() instantiation problems (an outdated config format, a corrupt config file, an auth backend that fails to initialize) are likewise returned as structured failures. Two cases are stricter and raise an exception instead: the desk directory itself does not exist, or a non-optional added component fails to instantiate. An added component marked optional does not raise in this case -- see Concierge::Desk::UnavailableComponent.

    Failure of open_desk() itself is the sole post-setup exception.

  • With the protections in setup methods and open_desk(), any failure is always clearly reported, and a concierge desk location or object is only ever handed back to the application if it is fully functional.

  • Once a desk is open, the concierge suite's API methods are never fatal to the application: every API method returns a structured response indicating success or failure (see "Return Values"), so the application always retains control flow.

Orchestration

Concierge's job is to coordinate access to services and resources an application needs, not to reimplement them. Depending on the component, this takes one of two forms:

  • For the identity core, Concierge directly provides the capability: login_user() authenticates via Auth, retrieves a record from Users, and creates a session via Sessions in one coordinated call.

  • For an added component, Concierge's involvement can end at handoff: the component satisfies the minimal contract in Concierge::Desk::Component so it can be loaded and reached through the concierge, but Concierge does not inherit from it or in any way intervene in its operations - that is for the application as it uses the component.

    Alternatively, if useful to the application, methods from added components may be promoted to be methods of the concierge object itself. Promoted methods may be called with their own names if not conflicting with built-ins, and may be aliased to avoid conflicts or provide recognizable names. See Extensibility, above.

Operational Resources

An application's "operational resources" are the services and data stores that support its main purpose without being that purpose -- authentication, sessions, and user records are the built-in examples, but the term applies equally to anything an application uses to support its main functionality.

Concierge is deliberately agnostic about what an operational resource actually is: other than the identity core components, an added component needs only to satisfy the contract in Concierge::Desk::Component to be set up, deployed, and provided to the application the same way.

DESCRIPTION

Concierge is an extensible service layer orchestrator of operational resources for applications -- see "CONCEPTS" above for what that means. Out of the box, its identity core coordinates three component modules behind a single API:

  • Concierge::Auth -- password authentication (Argon2)

  • Concierge::Sessions -- session management (SQLite or file backends)

  • Concierge::Users -- user data storage (SQLite, YAML, or CSV/TSV backends)

Applications primarily interact with Concierge and the Concierge::Desk::User objects it returns; most operations never require touching a component module directly. When a needed operation isn't exposed as a Concierge-level method, any component -- identity-core or added -- remains reachable through its own accessor (see "Component Accessors" and "EXTENSIBILITY").

What the Suite Provides

Concierge handles orchestration -- coordinating components and returning consistent structured results.

The core capabilities of the suite live in the three components:

Authentication (Concierge::Auth): Argon2id password hashing and verification; no plaintext credentials are ever written to disk. Also provides random token, UUID, word-passphrase, and hex-ID generators. The component is substitutable: any replacement implementing the same method contract (authenticate, enroll, change_credentials, etc. -- see Concierge::Auth::Base) can replace it for LDAP, OAuth, or any other scheme.

Sessions (Concierge::Sessions): Full session lifecycle -- creation, retrieval, expiry, and cleanup -- with SQLite, file, or in-memory storage. Sessions carry arbitrary key/value data. A single-session-per-user policy is enforced: creating a new session automatically removes any prior session for that user. Expired sessions are cleaned up each time a desk is opened.

User Records (Concierge::Users): User data store with a configurable field schema. Standard fields (moniker, email, phone, access_level, user_status, term_ends, and others) are built in and can be selectively overridden. Applications add their own fields via app_fields at setup time. Provides built-in SQLite, YAML, and CSV/TSV backends, with filtering and listing operations.

For the full API of any component, see its own documentation.

Desks

A desk is a storage directory containing the configuration for the application's concierge. Normally the data and any config files for the identity core components are kept there, and any additional components may be configured for that as well. At the same time, paths may be provided to other locations to accommodate considerations such as security and interfacing with existing systems.

Use Concierge::Desk::Setup to create a desk, then open_desk() to load it at runtime.

User Participation Levels

Concierge provides three graduated levels of user participation, each returning a Concierge::Desk::User object:

Visitor -- admit_visitor()

Assigned a unique identifier only. No session, no stored data. Suitable for anonymous tracking (e.g., cookies).

Guest -- checkin_guest()

Assigned an identifier and a session. Can store temporary data (e.g., a shopping cart). No authentication or persistent user record.

Logged-in user -- login_user()

Authenticated with credentials. Has a session, persistent user data, and full access to the User object's data methods.

A guest can be converted to a logged-in user with login_guest(), transferring any session data accumulated during the guest session.

User Keys

Each active user (guest or logged-in) is tracked by a user_key -- a random token stored in the concierge's user_keys mapping alongside the user's user_id and session_id. This mapping is persisted to user_keys.json in the desk directory and synchronized against active sessions when the desk is opened.

Return Values

All methods return a hashref with at least success (0 or 1) and message:

# Success
{ success => 1, message => '...', ... }

# Failure
{ success => 0, message => 'error description' }

Success responses include additional fields relevant to the operation:

  • User lifecycle methods (login_user(), restore_user(), checkin_guest(), admit_visitor(), login_guest()) return user, a Concierge::Desk::User object. Guest and visitor results also set is_guest or is_visitor to 1.

  • open_desk() returns concierge, the ready-to-use Concierge object.

  • User management methods return user_id. remove_user() also returns deleted_from (arrayref of component names) and, if any deletion failed, warnings (arrayref).

  • verify_user() returns verified (0 or 1), exists_in_auth, and exists_in_users.

  • list_users() returns user_ids (arrayref) and count. With include_data => 1, also returns users (hashref keyed by user_id).

See the individual method descriptions below for the complete field list.

Methods never die during normal operation. The one exception is open_desk(), which uses Carp::croak to locate the problem -- either the desk directory does not exist, or a non-optional added component (see "Additional Components") fails to load.

Architecture

Concierge ships with three identity core components:

Concierge::Auth -- credential storage and verification
Concierge::Sessions -- session lifecycle and persistence
Concierge::Users -- user records with configurable field schemas

These three are tightly orchestrated: a single login_user() call authenticates via Auth, retrieves a record from Users, and creates a session through Sessions. This coordination is the purpose of Concierge -- applications interact with the Concierge API and the Concierge::Desk::User objects it returns, not with the components directly.

The identity core is designed to be sufficient on its own, but the component pattern it follows -- backend abstraction, setup-time configuration, and Concierge-level orchestration -- is intentionally replicable. Each identity core component can also be substituted with a conforming replacement, and additional components (Organizations, Assets, etc.) can be added by following the same conventions. See "EXTENSIBILITY" for details, and "CONCEPTS" for the ideas behind it.

METHODS

Desk Management

open_desk

my $result = Concierge->open_desk($desk_location);
my $concierge = $result->{concierge};

Opens an existing desk directory created by Concierge::Desk::Setup. Reads the configuration file, instantiates all component modules, loads the user_keys mapping, and runs session cleanup.

Croaks if $desk_location is not an existing directory, or if a non-optional added component (see "Additional Components") fails to load.

Returns { success => 1, concierge => $obj } on success.

new_concierge

my $concierge = Concierge->new_concierge();

Low-level constructor: returns a bare, uninitialized Concierge object with no components attached. Used internally by open_desk(). Application code should use open_desk() (or Concierge::Desk::Setup::build_desk() for first-time setup) rather than calling this directly.

save_user_keys

my $result = $concierge->save_user_keys();

Writes the in-memory user_keys mapping (user_key => session/user_id lookup data, used by restore_user()) to persistent storage as JSON. Called automatically after any operation that changes the mapping (login, logout, guest promotion, user removal, etc.); applications do not normally need to call it directly.

Returns { success => 1 } on success, or { success => 0, message => '...' } if the file cannot be written.

Component Accessors

auth, sessions, users

my $auth_obj     = $concierge->auth;
my $sessions_obj = $concierge->sessions;
my $users_obj    = $concierge->users;

Read-only accessors returning the live, already-instantiated component object ( Concierge::Auth, Concierge::Sessions, or Concierge::Users, or a substitute -- see "EXTENSIBILITY" ) for direct use when an operation isn't exposed as a Concierge-level convenience method. This is the same "bare accessor" direct component access described in "Component Substitution" and Concierge::Desk::Component's promote mechanism -- it remains available regardless of what a component chooses to promote onto $concierge directly.

User Lifecycle

admit_visitor

my $result = $concierge->admit_visitor();
my $user = $result->{user};    # Concierge::Desk::User (visitor)

Creates a visitor with a generated identifier. No session is created and no data is stored.

checkin_guest

my $result = $concierge->checkin_guest(\%session_opts);
my $user = $result->{user};    # Concierge::Desk::User (guest)

Creates a guest with a generated identifier and a session. The optional %session_opts hashref may include timeout (in seconds; defaults to 1800).

login_user

my $result = $concierge->login_user(\%credentials, \%session_opts);
my $user = $result->{user};    # Concierge::Desk::User (logged-in)

Authenticates user_id and password from %credentials, retrieves the user's data record, creates a session, and returns a fully-equipped User object. If the user already has an active session, the previous session is replaced.

restore_user

my $result = $concierge->restore_user($user_key);
my $user = $result->{user};    # Concierge::Desk::User (guest or logged-in)

Reconstructs a User object from a user_key (typically stored in a cookie or URL token). Looks up the key in the concierge mapping, validates the session, and determines whether the user is a guest or logged-in user.

Logged-in users are restored with their full user data snapshot and backend closures. Guests are restored with their session only.

If the session has expired, the stale mapping entry is cleaned up and the method returns failure. The application can then redirect to login or create a new guest as appropriate.

Returns { success => 1, user => $user } on success. Guest restores also include is_guest => 1.

login_guest

my $result = $concierge->login_guest(\%credentials, $guest_user_key);
my $user = $result->{user};    # Concierge::Desk::User (logged-in)

Converts a guest to a logged-in user. Authenticates with %credentials, transfers any data from the guest's session to the new session, then deletes the guest session and removes the guest's user_key mapping.

logout_user

my $result = $concierge->logout_user($session_id);

Deletes the session and removes the user_key mapping entry.

Admin Operations

add_user

my $result = $concierge->add_user(\%user_input);

Registers a new user. %user_input must include user_id, moniker, and password. Any additional fields (email, phone, application- defined fields, etc.) are stored in the Users component. The password is stored separately in the Auth component and never reaches the user data store.

If password validation fails, the Users record is rolled back.

remove_user

my $result = $concierge->remove_user($user_id);

Removes the user from all components: Users, Auth, Sessions, and the user_keys mapping. Attempts all deletions; the response includes deleted_from (arrayref) and warnings (arrayref, if any component deletion failed).

verify_user

my $result = $concierge->verify_user($user_id);

Checks whether $user_id exists in both Auth and Users components. Returns verified => 1 only if present in both. Includes exists_in_auth and exists_in_users flags, and a warning if the user exists in one component but not the other.

list_users

# IDs only
my $result = $concierge->list_users($filter, \%options);
my @ids = @{ $result->{user_ids} };

# With full data
my $result = $concierge->list_users('', { include_data => 1 });
my %users = %{ $result->{users} };

Returns user IDs from the Users component. $filter is a string passed through to Concierge::Users. With include_data => 1, fetches each user's full record into a users hash keyed by user_id. With fields => [...], returns only the specified fields per user.

get_user_data

my $result = $concierge->get_user_data($user_id, @fields);
my $data = $result->{user};

Retrieves user data from the Users component. If @fields is provided, returns only those fields; otherwise returns all fields.

update_user_data

my $result = $concierge->update_user_data($user_id, \%updates);

Updates the user's record in the Users component. The user_id and password fields are filtered out and cannot be changed through this method.

Password Operations

Initial password registration is handled by add_user(), which sets the password atomically with user creation. The methods here operate on passwords for existing users.

verify_password

my $result = $concierge->verify_password($user_id, $password);

Checks whether $password is correct for $user_id. Returns success => 1 if the password matches.

reset_password

my $result = $concierge->reset_password($user_id, $new_password);

Sets a new password for an existing user. The application is responsible for verifying the user's identity before calling this method.

PARAMETER FILTERS

Concierge uses Params::Filter to enforce data segregation at method boundaries:

$auth_data_filter -- extracts only user_id and password
$user_data_filter -- extracts everything except password
$session_data_filter -- extracts user_id plus non-credential fields
$user_update_filter -- excludes user_id and password from updates

These ensure that credentials never leak into user data stores and that identity fields cannot be changed via update operations.

EXTENSIBILITY

See "CONCEPTS" for the ideas behind extensibility, service-layer guarantees, and orchestration that this section implements.

Component Substitution

Each identity core component can be replaced with a drop-in alternative as long as the replacement implements the methods Concierge calls on it.

Auth -- Concierge calls:

$auth->authenticate($user_id, $credential)
$auth->is_id_known($user_id)
$auth->enroll($user_id, $credential, \%opts?)
$auth->change_credentials($user_id, $new_credential)
$auth->revoke($user_id)

A substitute backend must implement this contract -- see Concierge::Auth::Base, which also provides working default Concierge::Auth::Generators methods (used for visitor/guest identifiers, independent of authentication) to any backend that inherits from it; a substitute only needs to override these if it wants different generation logic.

Sessions -- Concierge calls:

Concierge::Sessions->new(%args) -- constructor; accepts storage_dir and backend_class
$sessions->new_session(%args) -- returns { success => 1, session => $obj }
$sessions->get_session($session_id) -- returns { success => 1, session => $obj }
$sessions->delete_session($session_id) -- returns { success => 1|0, ... }
$sessions->cleanup_sessions() -- returns { success => 1, deleted_count => N, active => [...] }

Users -- Concierge calls:

Concierge::Users->new($config_file) -- constructor
$users->register_user(\%data) -- returns { success => 1|0, message => '...' }
$users->get_user($user_id) -- returns { success => 1, user => \%data }
$users->update_user($user_id, \%updates) -- returns { success => 1|0, ... }
$users->delete_user($user_id) -- returns { success => 1|0, ... }
$users->list_users($filter) -- returns { success => 1, user_ids => [...] }

Additional Components

Beyond the identity core, a desk can declare additional components -- Organizations, Assets, Catalog, etc. -- via a components block passed to Concierge::Desk::Setup::build_desk():

my $result = Concierge::Desk::Setup::build_desk({
    base_dir => './desk',
    auth     => { backend => 'pwd' },
    sessions => { backend => 'database' },
    users    => { backend => 'database' },
    components => {
        organizations => {
            class    => 'Concierge::Organizations',
            optional => 0,
            dir      => 'organizations',   # optional; resolved like
                                            # other components' dirs
            # ...any other setup() args for this component...
        },
    },
});

Each entry is resolved once, at build time: build_desk() creates the component's storage directory, requires class, calls my $comp = $class->new(), then calls $comp->setup(\%entry_config). The hashref setup() returns is persisted verbatim into concierge.conf as that component's payload -- this is never recomputed at open_desk()/runtime. A setup() failure always fails the entire build, regardless of the optional flag.

At open_desk() time, Concierge reads each component's persisted payload back out of concierge.conf, requires its class, and calls $class->new($payload):

  • If new() succeeds, the component is attached at $concierge->{$name}, and a same-named accessor is installed automatically (e.g., $concierge->organizations) if one doesn't already exist.

  • If new() dies and the component is not optional, the exception propagates uncaught out of open_desk() -- a desk must never open half-instantiated.

  • If new() dies and the component is optional, a Concierge::Desk::UnavailableComponent stand-in is attached instead. Any method called on it returns { success => 0, message => "Component '$name' unavailable: ..." }.

Access the component through the concierge object once the desk is open:

my $c = Concierge->open_desk($desk_dir)->{concierge};
my $r = $c->organizations->add_record('acme', \%data);
unless ($r->{success}) {
    # handles both a genuine failure and an UnavailableComponent
    # substitution identically
}

A component only needs to satisfy the duck-typed contract documented in Concierge::Desk::Component -- there is no isa check anywhere in this mechanism. A component whose job is per-record CRUD is responsible for its own CRUD methods; Concierge does not standardize or scaffold them.

Sessions, Auth, and Users are not wired through this generic mechanism -- they remain hardcoded core affordances, loaded unconditionally by open_desk() as described above. The components block is only for components genuinely additional to that identity core.

Component Method Promotion

A component's own bare accessor ($concierge->{name}->method(...) or $concierge->name->method(...)) always exposes its complete API -- this is the standard access Concierge provides the application for using the component, and needs no configuration. promote is an optional, convenience layer on top of it: a curated allowlist of a component's methods forwarded directly onto $concierge, declared in the same components config block:

components => {
    reports => {
        class   => 'Concierge::Reports',
        promote => ['get_signal_report'],                   # same-name
        # or:
        promote => { fetch_signal_report => 'get_signal_report' },  # aliased
    },
},

my $c = Concierge->open_desk($desk_dir)->{concierge};
$c->fetch_signal_report(...);               # promoted sugar, using alias
$c->{reports}->get_signal_report(...);      # direct component access,
                                             # always works, promoted or not

In other words, the concierge may use its own alias to call the component's real method -- e.g. $concierge->fetch_signal_report(...) calls the component's get_signal_report().

promote is not access control -- it never restricts what's reachable via direct component access. All validation (shape, method-existence, and name-collision checks against core methods and other components) happens once, at build_desk() time; open_desk() trusts the persisted result completely. See "PROMOTION: EXPOSING COMPONENT METHODS ON $concierge" in Concierge::Desk::Component for the full contract.

Future Components

Concierge::Organizations is the first component built on this mechanism -- a simple JSON-file-backed records store for multi-tenancy (users belonging to organizations), installed and namespaced independently of this distribution, exactly like Auth/Sessions/Users. The following illustrate other kinds of components the Concierge:: namespace is suited for. These are not roadmap commitments -- they are examples of what the component pattern enables:

  • Concierge::Assets -- files, images, or other owned resources

  • Concierge::Guides -- role and permission records

  • Concierge::Catalog -- product or content records

  • Concierge::Calendar -- event and booking records

The backend_class Pattern

Concierge::Auth, Concierge::Sessions, and Concierge::Users each support multiple interchangeable storage/backend implementations of their own (e.g. Auth's password vs. future LDAP/OAuth backends, Sessions' database vs. file backends, Users' database/file/YAML backends). All three follow the same convention: the component itself accepts only backend_class, an already-resolved, fully-qualified class name, and never guesses a class from a short friendly name -- that resolution happens one layer up, in Concierge::Desk::Setup's internal per-component catalogs (%AUTH_BACKENDS, %SESSIONS_BACKENDS, %USERS_BACKENDS), which map a desk config's friendly backend name ('pwd', 'database', 'yaml', etc.) to its class and any settings that backend requires.

A new component with multiple interchangeable backend implementations of its own should adopt this same backend_class convention: accept only a fully-qualified class name at the component layer, and leave friendly-name-to-class resolution to whatever builds the desk config around it.

Contributing

If you build a component that might be useful to others, contributions to the Concierge:: namespace on CPAN are welcome. The conventions to follow are: satisfy the duck-typed contract in Concierge::Desk::Component, use the { success = 1|0, message => '...' }> return convention, accept a desk config block via setup(), and include comprehensive tests and POD. Open an issue or pull request at https://github.com/bwva/Concierge to discuss before publishing.

SEE ALSO

Concierge::Desk::Setup -- desk creation and configuration

Concierge::Desk::User -- user objects returned by lifecycle methods

Concierge::Desk::Component -- contract documentation for additional components

Concierge::Desk::UnavailableComponent -- stand-in for a failed optional component

Concierge::Auth, Concierge::Sessions, Concierge::Users -- identity core component modules

Concierge::Organizations -- example additional component (multi-tenancy records store)

AUTHOR

Bruce Van Allen <bva@cruzio.com>

LICENSE

This module is free software; you can redistribute it and/or modify it under the terms of the Artistic License 2.0.