Aerogramme can be run in 2 modes: `provider` and `companion`.
`provider` is the "traditional" daemon that is run by the service provider on their servers.
`companion` is an optional, local proxy a user can run on their local computer to have better privacy.
This is an Aerogramme-specific concept that is explained in details in the concept page entitled [Per-user encryption](@/documentation/design/per-user-encryption.md).
🔑 `role` - *Required, Enum (String)* - Either `Provider` or `Companion`, here only `Provider` is valid. It's a [poka-yoke](https://en.wikipedia.org/wiki/Poka-yoke) to make
sure people run Aerogramme in the intended mode.
🔑 `pid` - *Optional, Path (String)* - The path to the file where the daemon PID will be stored. It's required to use the `aerogramme provider reload` command.
🗃️ `auth` - *Optional* - A socket implementing the [Dovecot SASL protocol](https://doc.dovecot.org/developer_manual/design/auth_protocol/), it can be used by some SMTP servers like Postfix, Chasquid or Maddy to delegate their authentication.
🔑 `bind_addr` - *Required, Socket (String)* - On which IP address and port the Dovecot SASL protocol should listen. Please note that this protocol is not encrypted, and thus you should only bind to localhost.
🗃️ `imap_unsecure` - *Optional* - The cleartext IMAP configuration block, if not set, the IMAP cleartext service is not started. Be careful, it is dangerous to run IMAP without transport encryption.
🔑 `bind_addr` - *Required, Socket (String)* - On which IP address and port the cleartext IMAP service must bind, can be IPv6 or IPv4 syntax. (Port 143 is reserved for this use).
🗃️ `imap` - *Optional* - The TLS IMAP configuration block, if not set, the IMAP TLS service is not started. This is the recommanded way to expose your IMAP service.
🔑 `bind_addr` - *Required, Socket (String)* - On which IP address and port the IMAP service must bind, can be IPv6 or IPv4 syntax. (Port 993 is reserved for this use).
🔑 `certs` - *Required, Path (String)* - A path to the PEM encoded certificate list
🔑 `key` - *Required, Path (String)* - A path to the PEM encoded private key
🔑 `user_driver` - *Required, Enum (String)* - Define which user driver must be used, the rest of the configuration depends on it. Valid values are: `Ldap` and `Static`.
🔑 `pre_bind_on_login` - *Optional, boolean, default to false* - Sometimes users can't login directly on the LDAP server and require a service account that will bind to LDAP and be in charge of checking users' credentials. If this is your case, set it to true.
🔑 `bind_dn` - *Optional, LDAP distinguished name (String)* - The distinguished name of your service account (ignored if `pre_bind_on_login` is not set to true)
🔑 `bind_password` - *Optional, Password (String)* - The password of your service account (ignored if `pre_bind_on_login` is not set to true)
🔑 `search_base` - *Optional, LDAP distinguished name (String)* - Once logged with the service account, where the user entries must be searched. (ignored if `pre_bind_on_login` is not set to true)
🔑 `storage_driver` - *Required, Enum (String)* - For now, only `Garage` is supported as a value (`InMemory` can be used for test purposes only)
🔑 `s3_endpoint` - *Required, String* - The S3 endpoint of the Garage instance
🔑 `k2v_endpoint` - *Required, String* - The K2V endpoint of the Garage instance
🔑 `aws_region` - *Required, String* - Regions are an AWS thing, for example `us-east-1`. If you followed Garage's documentation, you probably configured `garage` as your region.
🔑 `aws_access_key_id_attr` - *Required, String* - The LDAP attribute that will contain user's key id: each user has its own key, its own bucket, and so on.
🔑 `aws_secret_access_key_attr` - *Required, String* - The LDAP attribute that will contain user's secret key.
🔑 `bucket_attr` - *Optional, String* - The LDAP attribute that will contain user's bucket that is dedicated to Aerogramme. Again, each user has its own bucket.
🔑 `default_bucket` - *Optional, String* - If `bucket_attr` is not set, we assume that all users have a bucket named following this parameter (as Garage has a local bucket namespace in addition to the global namespace, so it's possible for different users to have independant buckets with the same name).
🔑 `user_driver="Static"` - to configure user management through LDAP, the `user_driver` value introduced in the previous section must be set to `Ldap`.
🔑 `user_list` - *Required, Path (String)* - the path to the file that will contain the list of your users, the hash of their password, and where their data is stored. The file must exist, but it can be blank.
