[FLINK-18777][catalog] Supports schema registry catalog

[danny0405]

What is the purpose of the change

Supports a catalog that can read the kafka topics flexibly.
The demo code:

        String schemaRegistryURL = ...;
        Map<String, String> kafkaProps = ...;
        SchemaRegistryCatalog catalog = SchemaRegistryCatalog.builder()
                .schemaRegistryURL(schemaRegistryURL)
                .kafkaOptions(kafkaProps)
                .dbName("myDB")
                .build();
        tEnv.registerCatalog("myCatalog", catalog);
 
        // ---------- Consume stream from Kafka -------------------
 
        // Assumes there is a topic named 'transactions'
        String query = "SELECT\n" +
            " id, amount\n" +
            "FROM myCatalog.myDB.transactions";

Brief change log

• Add a new Catalog named SchemaRegistryCatalog
• Add tests for the table attributes

Verifying this change

Added UTs.

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): yes, schema registry client 5.4.2 -> 5.5.1
• The public API, i.e., is any changed class annotated with @Public(Evolving): no
• The serializers: no
• The runtime per-record code paths (performance sensitive): no
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Kubernetes/Yarn/Mesos, ZooKeeper: no
• The S3 file system connector: no

Documentation

• Does this pull request introduce a new feature? yes
• If yes, how is the feature documented? not documented

[danny0405]

Upgrade to new version client so that we can fetch for format type from the SchemaMetadata.

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Last check on commit b73c589 (Fri Jul 31 05:05:35 UTC 2020)

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• 18f6f1b Azure: FAILURE

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[maver1ck]

@danny0405
Any plans to have this included in Flink 1.12 ?

[danny0405]

@maver1ck The code seems straight-forward, @dawidwys said that he would like to review this PR, but i'm not sure if he has time.

[maver1ck]

@danny0405 I'll try to test this PR.
@dawidwys Do we have any plans to include this in 1.12 ?

[dawidwys]

I'd say it won't make it in 1.12. I talked with @knaufk some time ago that we should probably conclude the FLIP that was started around it first before proceeding with the contribution.

[maver1ck]

@dawidwys
Workaround ? Copy this code to own catalog implementation and register it ?

[dawidwys]

Yes, that is possible.

[maver1ck]

@danny0405
I'm seeing also two problems here.

1. How this would work with: FLIP-107
2. This is not compiling on current master.

[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR :
[INFO] -------------------------------------------------------------
[ERROR] /home/maverick/flink/flink-formats/flink-avro-confluent-registry/src/main/java/org/apache/avro/Schemas.java:[22,28] package org.codehaus.jackson does not exist
[ERROR] /home/maverick/flink/flink-formats/flink-avro-confluent-registry/src/main/java/org/apache/avro/Schemas.java:[23,28] package org.codehaus.jackson does not exist
[ERROR] /home/maverick/flink/flink-formats/flink-avro-confluent-registry/src/main/java/org/apache/avro/Schemas.java:[36,30] cannot find symbol
  symbol:   class JsonFactory
  location: class org.apache.avro.Schemas
[ERROR] /home/maverick/flink/flink-formats/flink-avro-confluent-registry/src/main/java/org/apache/avro/Schemas.java:[36,56] cannot find symbol
  symbol:   class JsonFactory
  location: class org.apache.avro.Schemas
[ERROR] /home/maverick/flink/flink-formats/flink-avro-confluent-registry/src/main/java/org/apache/avro/Schemas.java:[45,25] cannot find symbol
  symbol:   class JsonGenerator
  location: class org.apache.avro.Schemas

[danny0405]

@maver1ck When i write the code, the FLIP-107 was not started yet, i would fix the compile issue.

[maver1ck]

@dawidwys
Can we at least pick one change from this patch and merge to master ? This one ?

-		<confluent.version>5.4.2</confluent.version>
+		<confluent.version>5.5.1</confluent.version>

[dawidwys]

@maver1ck I'll look into it. What is the motivation for upgrading the version? Can't you simply upgrade the version in your job?

[maver1ck]

Motivation: to have possibility to run this code on ververica platform when version 1.12 will be available.

I can add dependency in my job.
But this will also probably need some shading as I will have two different version of confluent libraries.