Live Query: --help documentation misleading

New Issue Checklist

[x] I am not disclosing a vulnerability.
[x] I am not just asking a question.
[x] I have searched through existing issues.
[x] I can reproduce the issue with the latest version of Parse Server.

Issue Description

As a new user, after running parse-server --help and reading through all the options, there are three relating to Live Query. Of these, --liveQueryServerOptions is the one which states it will start the Live Query server. While this is technically true, it is misleading.

In my experience (over the last 2 days) the liveQueryServerOptions option, starts live query server and allows client connections, but create/update/delete events are not pushed out to clients (though connected/subscribed messages are successfully responded to). Perhaps its that this option ignores the classNames property? I don't know - I really can't tell and don't have more time to burn finding out.

By contrast, supplying a configuration object with just the classNames array field to the option --liveQuery, and also supplying --startLiveQueryServer (no arguments), results in a functional server that both allows connections and pushes events to clients.

As such, I believe the --help command should print clearer information that --liveQuery "{ classNames: [...] }" --startLiveQueryServer is the correct set of options to make this work for simple-/first- use. My search of existing issues suggests that this may be the source of a number of people's problems, and that this earlier issue recognised the problem in 2017 but did not correct for it.

Steps to reproduce

Ask someone who has used parse-server before to read the guide, the documentation and run parse-server --help, to tell you what they think they should do to start Parse Server with Live Query enabled.
Watch as they get it wrong and get stumped for a while trying to figure out why their websocket connects, subscriptions are made (and logged, and subscribed responses come back) but not events arrive when edits are made.

Actual Outcome

2 days of wasted effort and a fair bit of frustration. No stress balls were harmed in the discovery or writing up of this issue.

Expected Outcome

The new user of Parse Server should quickly learn from parse-server --help that --liveQuery "{ classNames: [...] }" --startLiveQueryServer will achieve the intended result. They will also learn that --liveQueryServerOptions can be used in addition to specify further options.

Environment

Windows Command Prompt inside Windows Terminal. WFH with a Brewdog Dead Pony Club beer. Not enough pizza.

Server

Parse Server version: 4.3.0
Operating system: Windows 10 @ 2004
Local or remote host (AWS, Azure, Google Cloud, Heroku, Digital Ocean, etc): Local

Database

System (MongoDB or Postgres): MongoDB
Database version: 4.4.0 Community
Local or remote host (MongoDB Atlas, mLab, AWS, Azure, Google Cloud, etc): Local

Client

SDK (iOS, Android, JavaScript, PHP, Unity, etc): JavaScript
SDK version: Latest

Logs

The current output of --help:

Relevant bits of output:

--liveQuery [liveQuery]                                                parse-server's LiveQuery configuration
                                                                       object
--liveQueryServerOptions [liveQueryServerOptions]                      Live query server configuration options
                                                                       (will start the liveQuery server)
--startLiveQueryServer [startLiveQueryServer]                          Starts the liveQuery server

Full output:

>parse-server --help
Usage: parse-server [options] <path/to/configuration.json>                                                                                                                                                                              Options:
  --accountLockout [accountLockout]                                      account lockout policy for failed login
                                                                         attempts
  --allowClientClassCreation [allowClientClassCreation]                  Enable (or disable) client class creation,
                                                                         defaults to true
  --allowCustomObjectId [allowCustomObjectId]                            Enable (or disable) custom objectId
  --allowHeaders [allowHeaders]                                          Add headers to
                                                                         Access-Control-Allow-Headers
  --allowOrigin [allowOrigin]                                            Sets the origin to
                                                                         Access-Control-Allow-Origin
  --analyticsAdapter [analyticsAdapter]                                  Adapter module for the analytics
  --appId <appId>                                                        Your Parse Application ID
  --appName [appName]                                                    Sets the app name
  --auth [auth]                                                          Configuration for your authentication
                                                                         providers, as stringified JSON. See
                                                                         http://docs.parseplatform.org/parse-server/guide/#oauth-and-3rd-party-authentication
  --cacheAdapter [cacheAdapter]                                          Adapter module for the cache
  --cacheMaxSize [cacheMaxSize]                                          Sets the maximum size for the in memory
                                                                         cache, defaults to 10000
  --cacheTTL [cacheTTL]                                                  Sets the TTL for the in memory cache (in
                                                                         ms), defaults to 5000 (5 seconds)
  --clientKey [clientKey]                                                Key for iOS, MacOS, tvOS clients
  --cloud [cloud]                                                        Full path to your cloud code main.js
  --cluster [cluster]                                                    Run with cluster, optionally set the
                                                                         number of processes default to
                                                                         os.cpus().length
  --collectionPrefix [collectionPrefix]                                  A collection prefix for the classes
  --customPages [customPages]                                            custom pages for password validation and
                                                                         reset
  --databaseAdapter [databaseAdapter]                                    Adapter module for the database
  --databaseOptions [databaseOptions]                                    Options to pass to the mongodb client
  --databaseURI <databaseURI>                                            The full URI to your database. Supported
                                                                         databases are mongodb or postgres.
  --directAccess [directAccess]                                          Replace HTTP Interface when using JS SDK
                                                                         in current node runtime, defaults to
                                                                         false. Caution, this is an experimental
                                                                         feature that may not be appropriate for
                                                                         production.
  --dotNetKey [dotNetKey]                                                Key for Unity and .Net SDK
  --emailAdapter [emailAdapter]                                          Adapter module for email sending
  --emailVerifyTokenValidityDuration [emailVerifyTokenValidityDuration]  Email verification token validity
                                                                         duration, in seconds
  --enableAnonymousUsers [enableAnonymousUsers]                          Enable (or disable) anonymous users,
                                                                         defaults to true
  --enableExpressErrorHandler [enableExpressErrorHandler]                Enables the default express error handler
                                                                         for all errors
  --enableSingleSchemaCache [enableSingleSchemaCache]                    Use a single schema cache shared across
                                                                         requests. Reduces number of queries made
                                                                         to _SCHEMA, defaults to false, i.e. unique
                                                                         schema cache per request.
  --expireInactiveSessions [expireInactiveSessions]                      Sets wether we should expire the inactive
                                                                         sessions, defaults to true
  --fileKey [fileKey]                                                    Key for your files
  --filesAdapter [filesAdapter]                                          Adapter module for the files sub-system
  --graphQLPath [graphQLPath]                                            Mount path for the GraphQL endpoint,
                                                                         defaults to /graphql
  --graphQLSchema [graphQLSchema]                                        Full path to your GraphQL custom
                                                                         schema.graphql file
  --host [host]                                                          The host to serve ParseServer on, defaults
                                                                         to 0.0.0.0
  --idempotencyOptions [idempotencyOptions]                              Options for request idempotency to
                                                                         deduplicate identical requests that may be
                                                                         caused by network issues. Caution, this is
                                                                         an experimental feature that may not be
                                                                         appropriate for production.
  --javascriptKey [javascriptKey]                                        Key for the Javascript SDK
  --jsonLogs [jsonLogs]                                                  Log as structured JSON objects
  --liveQuery [liveQuery]                                                parse-server's LiveQuery configuration
                                                                         object
  --liveQueryServerOptions [liveQueryServerOptions]                      Live query server configuration options
                                                                         (will start the liveQuery server)
  --loggerAdapter [loggerAdapter]                                        Adapter module for the logging sub-system
  --logLevel [logLevel]                                                  Sets the level for logs
  --logsFolder [logsFolder]                                              Folder for the logs (defaults to
                                                                         './logs'); set to null to disable file
                                                                         based logging
  --masterKey <masterKey>                                                Your Parse Master Key
  --masterKeyIps [masterKeyIps]                                          Restrict masterKey to be used by only
                                                                         these ips, defaults to [] (allow all ips)
  --maxLimit [maxLimit]                                                  Max value for limit option on queries,
                                                                         defaults to unlimited
  --maxLogFiles [maxLogFiles]                                            Maximum number of logs to keep. If not
                                                                         set, no logs will be removed. This can be
                                                                         a number of files or number of days. If
                                                                         using days, add 'd' as the suffix.
                                                                         (default: null)
  --maxUploadSize [maxUploadSize]                                        Max file size for uploads, defaults to
                                                                         20mb
  --middleware [middleware]                                              middleware for express server, can be
                                                                         string or function
  --mountGraphQL [mountGraphQL]                                          Mounts the GraphQL endpoint
  --mountPath [mountPath]                                                Mount path for the server, defaults to
                                                                         /parse
  --mountPlayground [mountPlayground]                                    Mounts the GraphQL Playground - never use
                                                                         this option in production
  --objectIdSize [objectIdSize]                                          Sets the number of characters in generated
                                                                         object id's, default 10
  --passwordPolicy [passwordPolicy]                                      Password policy for enforcing password
                                                                         related rules
  --playgroundPath [playgroundPath]                                      Mount path for the GraphQL Playground,
                                                                         defaults to /playground
  --port [port]                                                          The port to run the ParseServer, defaults
                                                                         to 1337.
  --preserveFileName [preserveFileName]                                  Enable (or disable) the addition of a
                                                                         unique hash to the file names
  --preventLoginWithUnverifiedEmail [preventLoginWithUnverifiedEmail]    Prevent user from login if email is not
                                                                         verified and
                                                                         PARSE_SERVER_VERIFY_USER_EMAILS is true,
                                                                         defaults to false
  --protectedFields [protectedFields]                                    Protected fields that should be treated
                                                                         with extra security when fetching details.
  --publicServerURL [publicServerURL]                                    Public URL to your parse server with
                                                                         http:// or https://.
  --push [push]                                                          Configuration for push, as stringified
                                                                         JSON. See
                                                                         http://docs.parseplatform.org/parse-server/guide/#push-notifications
  --readOnlyMasterKey [readOnlyMasterKey]                                Read-only key, which has the same
                                                                         capabilities as MasterKey without writes
  --restAPIKey [restAPIKey]                                              Key for REST calls
  --revokeSessionOnPasswordReset [revokeSessionOnPasswordReset]          When a user changes their password, either
                                                                         through the reset password email or while
                                                                         logged in, all sessions are revoked if
                                                                         this is true. Set to false if you don't
                                                                         want to revoke sessions.
  --scheduledPush [scheduledPush]                                        Configuration for push scheduling,
                                                                         defaults to false.
  --schemaCacheTTL [schemaCacheTTL]                                      The TTL for caching the schema for
                                                                         optimizing read/write operations. You
                                                                         should put a long TTL when your DB is in
                                                                         production. default to 5000; set 0 to
                                                                         disable.
  --serverCloseComplete [serverCloseComplete]                            Callback when server has closed
  --serverStartComplete [serverStartComplete]                            Callback when server has started
  --serverURL <serverURL>                                                URL to your parse server with http:// or
                                                                         https://.
  --sessionLength [sessionLength]                                        Session duration, in seconds, defaults to
                                                                         1 year
  --silent [silent]                                                      Disables console output
  --startLiveQueryServer [startLiveQueryServer]                          Starts the liveQuery server
  --userSensitiveFields [userSensitiveFields]                            Personally identifiable information fields
                                                                         in the user table the should be removed
                                                                         for non-authorized users. Deprecated @see
                                                                         protectedFields
  --verbose [verbose]                                                    Set the logging to verbose
  --verifyUserEmails [verifyUserEmails]                                  Enable (or disable) user email validation,
                                                                         defaults to false
  --webhookKey [webhookKey]                                              Key sent with outgoing webhook calls
  -h, --help                                                             display help for command
  Configure From Environment:

    $ PARSE_SERVER_ACCOUNT_LOCKOUT='accountLockout'
    $ PARSE_SERVER_ALLOW_CLIENT_CLASS_CREATION='allowClientClassCreation'
    $ PARSE_SERVER_ALLOW_CUSTOM_OBJECT_ID='allowCustomObjectId'
    $ PARSE_SERVER_ALLOW_HEADERS='allowHeaders'
    $ PARSE_SERVER_ALLOW_ORIGIN='allowOrigin'
    $ PARSE_SERVER_ANALYTICS_ADAPTER='analyticsAdapter'
    $ PARSE_SERVER_APPLICATION_ID='appId'
    $ PARSE_SERVER_APP_NAME='appName'
    $ PARSE_SERVER_AUTH_PROVIDERS='auth'
    $ PARSE_SERVER_CACHE_ADAPTER='cacheAdapter'
    $ PARSE_SERVER_CACHE_MAX_SIZE='cacheMaxSize'
    $ PARSE_SERVER_CACHE_TTL='cacheTTL'
    $ PARSE_SERVER_CLIENT_KEY='clientKey'
    $ PARSE_SERVER_CLOUD='cloud'
    $ PARSE_SERVER_CLUSTER='cluster'
    $ PARSE_SERVER_COLLECTION_PREFIX='collectionPrefix'
    $ PARSE_SERVER_CUSTOM_PAGES='customPages'
    $ PARSE_SERVER_DATABASE_ADAPTER='databaseAdapter'
    $ PARSE_SERVER_DATABASE_OPTIONS='databaseOptions'
    $ PARSE_SERVER_DATABASE_URI='databaseURI'
    $ PARSE_SERVER_ENABLE_EXPERIMENTAL_DIRECT_ACCESS='directAccess'
    $ PARSE_SERVER_DOT_NET_KEY='dotNetKey'
    $ PARSE_SERVER_EMAIL_ADAPTER='emailAdapter'
    $ PARSE_SERVER_EMAIL_VERIFY_TOKEN_VALIDITY_DURATION='emailVerifyTokenValidityDuration'
    $ PARSE_SERVER_ENABLE_ANON_USERS='enableAnonymousUsers'
    $ PARSE_SERVER_ENABLE_EXPRESS_ERROR_HANDLER='enableExpressErrorHandler'
    $ PARSE_SERVER_ENABLE_SINGLE_SCHEMA_CACHE='enableSingleSchemaCache'
    $ PARSE_SERVER_EXPIRE_INACTIVE_SESSIONS='expireInactiveSessions'
    $ PARSE_SERVER_FILE_KEY='fileKey'
    $ PARSE_SERVER_FILES_ADAPTER='filesAdapter'
    $ PARSE_SERVER_GRAPHQL_PATH='graphQLPath'
    $ PARSE_SERVER_GRAPH_QLSCHEMA='graphQLSchema'
    $ PARSE_SERVER_HOST='host'
    $ PARSE_SERVER_EXPERIMENTAL_IDEMPOTENCY_OPTIONS='idempotencyOptions'
    $ PARSE_SERVER_JAVASCRIPT_KEY='javascriptKey'
    $ JSON_LOGS='jsonLogs'
    $ PARSE_SERVER_LIVE_QUERY='liveQuery'
    $ PARSE_SERVER_LIVE_QUERY_SERVER_OPTIONS='liveQueryServerOptions'
    $ PARSE_SERVER_LOGGER_ADAPTER='loggerAdapter'
    $ PARSE_SERVER_LOG_LEVEL='logLevel'
    $ PARSE_SERVER_LOGS_FOLDER='logsFolder'
    $ PARSE_SERVER_MASTER_KEY='masterKey'
    $ PARSE_SERVER_MASTER_KEY_IPS='masterKeyIps'
    $ PARSE_SERVER_MAX_LIMIT='maxLimit'
    $ PARSE_SERVER_MAX_LOG_FILES='maxLogFiles'
    $ PARSE_SERVER_MAX_UPLOAD_SIZE='maxUploadSize'
    $ PARSE_SERVER_MIDDLEWARE='middleware'
    $ PARSE_SERVER_MOUNT_GRAPHQL='mountGraphQL'
    $ PARSE_SERVER_MOUNT_PATH='mountPath'
    $ PARSE_SERVER_MOUNT_PLAYGROUND='mountPlayground'
    $ PARSE_SERVER_OBJECT_ID_SIZE='objectIdSize'
    $ PARSE_SERVER_PASSWORD_POLICY='passwordPolicy'
    $ PARSE_SERVER_PLAYGROUND_PATH='playgroundPath'
    $ PORT='port'
    $ PARSE_SERVER_PRESERVE_FILE_NAME='preserveFileName'
    $ PARSE_SERVER_PREVENT_LOGIN_WITH_UNVERIFIED_EMAIL='preventLoginWithUnverifiedEmail'
    $ PARSE_SERVER_PROTECTED_FIELDS='protectedFields'
    $ PARSE_PUBLIC_SERVER_URL='publicServerURL'
    $ PARSE_SERVER_PUSH='push'
    $ PARSE_SERVER_READ_ONLY_MASTER_KEY='readOnlyMasterKey'
    $ PARSE_SERVER_REST_API_KEY='restAPIKey'
    $ PARSE_SERVER_REVOKE_SESSION_ON_PASSWORD_RESET='revokeSessionOnPasswordReset'
    $ PARSE_SERVER_SCHEDULED_PUSH='scheduledPush'
    $ PARSE_SERVER_SCHEMA_CACHE_TTL='schemaCacheTTL'
    $ PARSE_SERVER_SERVER_CLOSE_COMPLETE='serverCloseComplete'
    $ PARSE_SERVER_SERVER_START_COMPLETE='serverStartComplete'
    $ PARSE_SERVER_URL='serverURL'
    $ PARSE_SERVER_SESSION_LENGTH='sessionLength'
    $ SILENT='silent'
    $ PARSE_SERVER_START_LIVE_QUERY_SERVER='startLiveQueryServer'
    $ PARSE_SERVER_USER_SENSITIVE_FIELDS='userSensitiveFields'
    $ VERBOSE='verbose'
    $ PARSE_SERVER_VERIFY_USER_EMAILS='verifyUserEmails'
    $ PARSE_SERVER_WEBHOOK_KEY='webhookKey'

  Get Started guide:

    Please have a look at the get started guide!
    http://docs.parseplatform.org/parse-server/guide/

  Usage with npm start

    $ npm start -- path/to/config.json
    $ npm start -- --appId APP_ID --masterKey MASTER_KEY --serverURL serverURL
    $ npm start -- --appId APP_ID --masterKey MASTER_KEY --serverURL serverURL

  Usage:

    $ parse-server path/to/config.json
    $ parse-server -- --appId APP_ID --masterKey MASTER_KEY --serverURL serverURL
    $ parse-server -- --appId APP_ID --masterKey MASTER_KEY --serverURL serverURL

parse-community / parse-server