{"id":9951,"date":"2019-05-10T17:31:56","date_gmt":"2019-05-10T15:31:56","guid":{"rendered":"https:\/\/pi3g.com\/?p=9951"},"modified":"2019-05-10T17:31:56","modified_gmt":"2019-05-10T15:31:56","slug":"mongo_orm-exception-missing-bson-key-publish_acl-exception","status":"publish","type":"post","link":"https:\/\/pi3g.com\/de\/mongo_orm-exception-missing-bson-key-publish_acl-exception\/","title":{"rendered":"mongo_orm Exception: fehlender bson-Schl\u00fcssel: publish_acl (Exception)"},"content":{"rendered":"

When you extend your field definitions in the mongo_orm document classes, specifically with embedded documents, you might run into the following runtime (!) error:<\/p>\n

\n

Exception: missing bson key: <name> (Exception)<\/p>\n<\/blockquote>\n

This is not an error in your code \u2013 your code is raising, because the database structure is not as it expects it to be!<\/p>\n

Here\u2019s the sample code which I am using for creating a Mongo Auth & ACL DB for VerneMQ:<\/h3>\n
\n

class PublishACL < Mongo::ORM::EmbeddedDocument
     field pattern : String
     field max_qos : Int32
     field allowed_retain : Bool
     field max_payload_size : Int32
\nend<\/p>\n

class SubscribeACL < Mongo::ORM::EmbeddedDocument
     field pattern : String
     field max_qos : Int32
\nend<\/p>\n

\nclass MQTTCredentials < Mongo::ORM::Document
     collection_name “vmq_acl_auth”
     field mountpoint : String
     field client_id : String
     field username : String
     field passhash : String
     embeds_many :publish_acl, class_name: Papi::PublishACL 
     embeds_many :subscribe_acl, class_name: Papi::SubscribeACL<\/p>\n

\n<\/p>\n

# keys are unique per apikey_prefix
\ndef self.getcredentials(apikey_prefix : String, bcm_serial : String)
     success = false
     #if the credentials don’t exist yet, they are added
     creds = self.first({“client_id” => bcm_serial, “username” => apikey_prefix})
     if !creds
         creds = self.new()
     end<\/p>\n

     (snip)<\/p>\n

    publish_acl = PublishACL.new()
     subscribe_acl = SubscribeACL.new()
     # https:\/\/vernemq.com\/docs\/configuration\/db-auth.html<\/a>
     publish_acl.pattern = “#”
     publish_acl.max_qos = 2  # Int
     publish_acl.allowed_retain = true<\/p>\n

    subscribe_acl.pattern = “#”
     subscribe_acl.max_qos = 2
    
     creds.publish_acl <<  publish_acl
     creds.subscribe_acl << subscribe_acl 
     success = creds.save<\/p>\n

(snip)<\/p>\n

end<\/p>\n

end<\/p>\n<\/blockquote>\n

The ACLs were inserted after I already had database entries without them:<\/p>\n

\"image\"<\/a><\/p>\n

MongoORM error message:<\/strong><\/p>\n

\n

Exception: missing bson key: publish_acl (Exception)
   from src\/db.cr:0:4 in ‘from_bson’
   from lib\/mongo_orm\/src\/mongo_orm\/querying.cr:93:7 in ‘all’
   from lib\/mongo_orm\/src\/mongo_orm\/querying.cr:90:3 in ‘all’\n<\/p>\n

  (snip)<\/p>\n

  from \/usr\/share\/crystal\/src\/fiber.cr:47:34 in ‘->’
   from ???<\/p>\n

<\/p>\n<\/blockquote>\n

MongoORM does not find the expected fields publish_acl and subscribe_acl, which were added later.<\/p>\n

Solution: drop (or upgrade) the documents in the Collection, which do not conform to your new standard.<\/p>\n

This is, for instance, how a database entry looks like for the above:<\/p>\n

\"image\"<\/a><\/p>\n

\n

\n<\/p>\n<\/blockquote>\n

Bonus<\/h2>\n
\n

in lib\/mongo_orm\/src\/mongo_orm\/extended_bson.cr:40: no overload matches ‘BSON#[]=’ with types String, Array(Papi::PublishACL)<\/p>\n

Overloads are:<\/p>\n

– BSON#[]=(key, value : Int32)<\/p>\n

– BSON#[]=(key, value : Int64)<\/p>\n

– BSON#[]=(key, value : Binary)<\/p>\n

– BSON#[]=(key, value : Bool)<\/p>\n

– BSON#[]=(key, value : Float64 | Float32)<\/p>\n

– BSON#[]=(key, value : MinKey)<\/p>\n

– BSON#[]=(key, value : MaxKey)<\/p>\n

– BSON#[]=(key, value : Nil)<\/p>\n

– BSON#[]=(key, value : ObjectId)<\/p>\n

– BSON#[]=(key, value : String)<\/p>\n

– BSON#[]=(key, value : Symbol)<\/p>\n

– BSON#[]=(key, value : Time)<\/p>\n

– BSON#[]=(key, value : Timestamp)<\/p>\n

– BSON#[]=(key, value : Code)<\/p>\n

– BSON#[]=(key, value : BSON)<\/p>\n

– BSON#[]=(key, value : Regex)<\/p>\n

– BSON#[]=(key, value : Mongo::ORM::EmbeddedDocument)<\/p>\n

bson[_key] = value<\/p>\n<\/blockquote>\n

You cannot<\/strong> do this (currently) with MongoORM:<\/p>\n

\n

creds.publish_acl = [ publish_acl ]<\/p>\n<\/blockquote>\n

instead you have to use: <\/p>\n

\n

creds.publish_acl <<  publish_acl <\/p>\n<\/blockquote>\n","protected":false},"excerpt":{"rendered":"

Wenn Sie Ihre Felddefinitionen in den mongo_orm-Dokumentenklassen erweitern, insbesondere mit eingebetteten Dokumenten, k\u00f6nnen Sie auf den folgenden Laufzeitfehler (!) sto\u00dfen: Exception: missing bson key: (Exception) Dies ist kein Fehler in Ihrem Code - Ihr Code wird ausgel\u00f6st, weil die Datenbankstruktur nicht so ist, wie er sie erwartet!...<\/p>","protected":false},"author":830,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_links_to":"","_links_to_target":""},"categories":[416],"tags":[477,534,531,589],"class_list":["post-9951","post","type-post","status-publish","format-standard","hentry","category-crystal-language","tag-crystal-lang","tag-mongo_orm","tag-mongodb","tag-vernemq"],"_links":{"self":[{"href":"https:\/\/pi3g.com\/de\/wp-json\/wp\/v2\/posts\/9951","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pi3g.com\/de\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/pi3g.com\/de\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/pi3g.com\/de\/wp-json\/wp\/v2\/users\/830"}],"replies":[{"embeddable":true,"href":"https:\/\/pi3g.com\/de\/wp-json\/wp\/v2\/comments?post=9951"}],"version-history":[{"count":1,"href":"https:\/\/pi3g.com\/de\/wp-json\/wp\/v2\/posts\/9951\/revisions"}],"predecessor-version":[{"id":9952,"href":"https:\/\/pi3g.com\/de\/wp-json\/wp\/v2\/posts\/9951\/revisions\/9952"}],"wp:attachment":[{"href":"https:\/\/pi3g.com\/de\/wp-json\/wp\/v2\/media?parent=9951"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pi3g.com\/de\/wp-json\/wp\/v2\/categories?post=9951"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pi3g.com\/de\/wp-json\/wp\/v2\/tags?post=9951"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}