config - Deep merge semantics?

[HelloGrayson]

I don't see any docs or tests that describe how deep merge semantics work - are maps and objects merged, or is this just top-level?

https://github.com/uber-go/fx/tree/master/config

[dmcaulay]

I have noticed an issue during my development. Here's the the example yaml:

# config/base.yaml

modules:
  rpc:
    name: mormont
    tchannel:
      listenOn: localhost
      advertise: true
      peerList: /etc/uber/hyperbahn/hosts.json
    inbounds:
      - tchannel:
          port: ${UBER_PORT_TCHANNEL:0}
    outbounds:
      - service: rosetta
        http:
          host: localhost
          port: 14797
          path: /thrift
      - services:
          - populous
          - safari
          - treatment
          - trident
        tchannel:
          host: 127.0.0.1
          port: ${UBER_PORT_TCHANNEL:0}

# config/development.yaml

modules:
  rpc:
    name: mormont
    tchannel:
      listenOn: localhost
      advertise: false
    inbounds:
      - tchannel:
          port: ${UBER_PORT_TCHANNEL:0}
    outbounds:
      - service: rosetta
        http:
          host: localhost
          port: 14797
          path: /thrift
      - services:
          - populous
          - safari
          - treatment
          - trident
        tchannel:
          host: 127.0.0.1
          port: ${UBER_PORT_TCHANNEL:0}

The issue that I'm seeing is that advertise is still true when I run in development. Other keys are updated properly:

# config/base.yaml

uconfig:
  enabled: true

# config/development.yaml

uconfig:
  enabled: true
  UConfigDir: mormont-config/crc_configs

I haven't had time to dig in and determine the root cause.

[ghost]

Isn't advertise: false in the development.yaml?

[glibsm]

Thanks for reporting this, guys. I believe our intention is to deep merge (for yaml), otherwise having base.yaml becomes pointless really quick.

@alsamylkin it's false in development.yaml, but I think what Dan is saying is having loaded config, the key still returns true.

[ghost]

As for Grayson question, Merging works only for yaml provider and you should expect it to be the same as you'll Unmarshal two configs to the same variable.

We don't do merges between different providers, need to document it more clearly.

[dmcaulay]

The config issue that I was seeing was on my side. Thanks for the help @alsamylkin.

Do we still need to add docs?

[ghost]

Yep, created ticket to track GFM-340

[dmcaulay]

i'm not sure what the protocol is. should we close this and track in jira or keep both issues open?

[ascandella]

Moving to JIRA