Understood. This is great, appreciate the guidance.
I'll work on implementing it this way and update this thread once the code is
pushed.
Regards
Hamid Maadani
June 15, 2022 3:40 PM, "Viktor Dukhovni" <postfix-us...@dukhovni.org> wrote:
> On Wed, Jun 15, 2022 at 10:12:57PM +0000, Hamid Maadani wrote:
>
>> Let's say I have a database called 'mail' in my MongoDB cluster, and there
>> is a collection (table) named 'mailbox' inside of it.
>> Each object in this collection holds a mailbox, and also includes it's
>> aliases (real world example from my mail server):
>>
>> {
>> "_id" : ObjectId(REDACTED),
>> "username" : "ha...@dexo.tech",
>> "password" : "REDACTED",
>> "name" : "Hamid Maadani",
>> "maildir" : "ha...@dexo.tech/",
>> "quota" : REDACTED,
>> "local_part" : "hamid",
>> "domain" : "dexo.tech",
>> "created" : ISODate("2016-11-07T21:07:21.000Z"),
>> "modified" : ISODate("2017-05-02T22:10:00.000Z"),
>> "active" : 1,
>> "alias" : [
>> {
>> "address" : "ab...@dexo.tech",
>> "created" : ISODate("2016-11-07T21:04:16.000Z"),
>> "modified" : ISODate("2016-11-07T21:04:16.000Z"),
>> "active" : 1
>> },
>> {
>> "address" : "hostmas...@dexo.tech",
>> "created" : ISODate("2016-11-07T21:04:16.000Z"),
>> "modified" : ISODate("2016-11-07T21:04:16.000Z"),
>> "active" : 1
>> }
>> ]
>> },
>>
>> {
>> "_id" : ObjectId(REDACTED),
>> "username" : "ad...@dexo.tech",
>> "password" : "REDACTED",
>> "name" : "Site Admin",
>> "maildir" : "ad...@dexo.tech/",
>> "quota" : REDACTED,
>> "local_part" : "admin",
>> "domain" : "dexo.tech",
>> "created" : ISODate("2017-04-12T22:24:17.000Z"),
>> "modified" : ISODate("2021-06-03T02:54:35.000Z"),
>> "active" : 1
>> }
>
> See LDAP_README which talks about structurally similar use-cases.
>
>> Now, if I want to query for 'ha...@dexo.tech', or any of it's aliases, I
>> would use
>> this filter:
>> filter = {"$$or": [{"username":"%s"}, {"alias.address": "%s"}], "active": 1}
>>
>> of course, this will return an entire JSON document.
>
> JSON documents will be fairly useless in Postfix, so there should always
> be a projection, and its syntax should be more user-friendly by default,
> so similar to "result_attribute" in LDAP, i.e. just a key to extract
> from the JSON document, which should be either a string-valued scalar,
> or a list of string values (which you would internally combine with
> commas).
>
>> So I would use Mongo projections to
>> limit it to just one key-value pair, in which case, the driver will only
>> return the value:
>> options = {"projection": {"_id": 0, "username": 1}}
>
> Using explicit "projections" should be an advanced feature, far better
> to ask users to write:
>
> result_attribute = username
>
> (As a side question, Why is "_id" part of the "projection"???)
>
>> If I change the query to:
>> filter = {"active": 1}
>>
>> and keep the same projection, it will return:
>> {"username":"ha...@dexo.tech"}
>> {"username":"ad...@dexo.tech"}
>>
>> from what you just described, the result should be returned as:
>> ha...@dexo.tech,ad...@dexo.tech
>
> Yes.
>
>> That's the easy part. Question is, should I allow users to use the
>> filter/options combination
>> to search however they need? The reason I ask is, if someone uses this
>> projection:
>> {"projection": {"_id": 0, "username": 1, "name" : 1}}
>>
>> The results would be:
>> {"username":"ha...@dexo.tech", "name":"hamid"}
>> {"username":"ad...@dexo.tech", "name":"admin"}
>>
>> and I am unsure how to handle that. Limit it by requiring a key?
>
> Returning compound JSON objects should be an error. Only string and
> list of string values should be supported. The result is obtained
> by flattening all lists to a comma-separated string, and then combining
> these (again comma-separated) across the returned JSON "documents".
>
>> Or just return the string representation of the JSON documents for the
>> user to parse by 'jq' or similar utilities?
>
> No, because Postfix dictionaries are not for use in MongoDB query CLIs,
> they are for the MTA to resolve email lists, transports, ... where
> only scalar results and sometimes comma-separated lists are supported.
>
>> Would there be a use case for that (postmap -q ... | jq)?
>
> No.
>
>> I assume I should limit it by key, but want to run it by you guys first..
>
> Read LDAP_README, virtual(5), aliases(5), transport(5), ...
>
> Note also that with e.g. LDAP there's also a way to specify an expansion
> limit (e.g. 1), so that queries returning more than the expected number
> of rows fail instead of returning garbage.
>
> So, also see ldap_table(5) for any additional table attributes (like
> the previously mentioned "domain") that may apply.
>
> --
> Viktor.
