We accidentally removed the code for maximum complexity in commit
c984e666f. As mentioned in the documentation:
> The main risk factor is multiple collections of resources being
> requested in the same query.
We reject these requests by limiting the complexity.
The `max_complexity` option depends on the page size being set. Without
it, we get an error:
```
Can't calculate complexity for User.public_debates, no `first:`,
`last:`, `max_page_size` or `default_max_page_size`
```
So we're also adding a default max page size.
Note that the documentation mentioned that the default page size was 25.
However, before commit c984e666f, we were using a page size of 50 in
some cases. We're going with the one mentioned in the documentation
since we don't fully understand the old code.
We accidentally removed this code in commit c984e666f. As mentioned in
our GraphQL documentation, limiting the depth of the queries helps
against DoS attacks.
These modules are used by default in version 1.12.14 and so we were
getting deprecation warnings:
```
DEPRECATION WARNING: GraphQL::Execution::Interpreter is now the
default; remove `use GraphQL::Execution::Interpreter` from the schema
definition (app/graphql/consul_schema.rb:6)
DEPRECATION WARNING: GraphQL::Analysis::AST is now the default; remove
`use GraphQL::Analysis::AST` from the schema definition
(app/graphql/consul_schema.rb:7)
DEPRECATION WARNING: GraphQL::Pagination::Connections is now the
default, remove `use GraphQL::Pagination::Connections` from
app/graphql/consul_schema.rb:10
```
The current consul GraphQL API has two problems.
1) It uses some unnecessary complicated magic to automatically create
the GraphQL types and querys using an `api.yml` file. This approach
is over-engineered, complex and has no benefits. It's just harder to
understand the code for people which are not familiar with the
project (like me, lol).
2) It uses a deprecated DSL [1] that is soon going to be removed from
`graphql-ruby` completely. We are already seeing deprecation warning
because of this (see References).
There was one problem. I wanted to create the API so that it is fully
backwards compatible with the old one, BUT the old one uses field names
which are directly derived from the ruby code, which results in
snake_case field names - not the GraphQL way. When I'm using the
graphql-ruby Class-based syntax, it automatically creates the fields in
camelCase, which breaks backwards-compatibility.
So I've added deprecated snake_case field names to keep it
backwards-compatible.
[1] https://graphql-ruby.org/schema/class_based_api.html
