Add codec to http source

[oeyh]

Description

Add codec to http source so it can use the functionality introduced in #5054 to parse CloudWatch Logs data.
The config would look like this:

    http:
      codec:
        json:
          key_name: "logEvents"
          include_keys: [ 'owner', 'logGroup', 'logStream' ]
          include_keys_metadata: [ 'owner', 'logGroup', 'logStream' ]

Issues Resolved

N/A

Check List

• New functionality includes testing.
• New functionality has a documentation issue. Please link to it in this PR.
  • New functionality has javadoc added
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[sb2k16]

Can we initialize the json codec here itself.

[oeyh]

I'm not sure I follow here. Can you clarify a bit more?

Do you mean you want it to be a JsonInputCodec and disallow other type of input codecs? If so, we can add a validation on the sourceConfig to prevent the use of other codecs that don't fit here.

[oeyh]

Sync'ed up and resolved offline.

[dlvenable]

@oeyh , The current implementation is pretty much the same as the json codec. What codec did you need here?

[oeyh]

@oeyh , The current implementation is pretty much the same as the json codec. What codec did you need here?

@dlvenable I needed the functionality introduced in #5054 in JsonInputCodec to parse CloudWatch Logs data