plugins/request-transformer: missing migrations

[deltheil]

As of #824 schema.lua has been modified. Still there is no schema/migrations.lua file for this plugin.

This breaks at runtime, e.g. from an instance of Kong migrated from 0.5.4 to 0.7.0, for a call over an API that uses the request-transformer with config.add.headers only (i.e. no config.remove.headers, etc):

[error] 476#0: *110 lua entry thread aborted: runtime error: ...hare/lua/5.1/kong/plugins/request-transformer/access.lua:86: attempt to index field 'remove' (a nil value)
stack traceback:
coroutine 0:
        ...hare/lua/5.1/kong/plugins/request-transformer/access.lua: in function 'transform_headers'
        ...hare/lua/5.1/kong/plugins/request-transformer/access.lua:309: in function 'execute'
        ...are/lua/5.1/kong/plugins/request-transformer/handler.lua:12: in function 'access'
        /usr/local/share/lua/5.1/kong.lua:173: in function 'access'

See this line.

As a workaround I removed and re-added the plugin.

[thibaultcha]

Dang. @shashiranjan84 Could you add the appropriate migrations for this?

[thibaultcha]

Another option could be to handle this in the plugin's logic. Doing so would probably be safer, plus the performance overhead might not be significant since all schemas after #824 do have the remove (and others) fields, so branch prediction should step in here. A migration would still be useful for users though.

Thanks @deltheil for the report!