Don't run IsFederatedGraph before running SubgraphFetchQuery

[glasser]

All the checks done by IsFederatedGraph are also done by SubgraphFetchQuery (checking to see if graph/variant exists and to see if the graph is federated). This is just an additional round-trip adding latency and potential errors. Additionally, with rover supergraph compose which is commonly run against many subgraphs of a single graph, these will run fully redundantly on every subgraph that is fetched.

[glasser]

This code was first added in #1056 and it's not clear to me why.

[glasser]

(want to check to make sure that in the non-federated case the right error comes out the other side still — looks like it from code examination though)

[glasser]

OK, here's some manual QA. The graph I'm poking at is non-federated on current but federated on p-1.

Rover 0.25.0:

☸ prod (router) in 󰯭/rover on  glasser/just-fetch-it-do-not-check-first [⇡1] is 📦 v0.25.0 via 🦀 v1.79.0  p= 󰦜 at 12:01:26-07 ❯ rover --version                                                
Rover 0.25.0

☸ prod (router) in 󰯭/rover on  glasser/just-fetch-it-do-not-check-first [⇡1] is 📦 v0.25.0 via 🦀 v1.79.0  p= 󰦜 at 12:01:31-07 ❯ rover subgraph fetch Apollo-Fullstack-Demo-o3tsz8 --name x
Fetching SDL from Apollo-Fullstack-Demo-o3tsz8@current (subgraph: x) using credentials from the default profile.
error[E007]: The graph `Apollo-Fullstack-Demo-o3tsz8@current` is a non-federated graph. This operation is only possible for federated graphs.
        Try running the command on a valid federated graph, or use the appropriate `rover graph` command instead of `rover subgraph`.

☸ prod (router) in 󰯭/rover on  glasser/just-fetch-it-do-not-check-first [⇡1] is 📦 v0.25.0 via 🦀 v1.79.0  p= 󰦜 at 12:01:40-07 ❌1 ❯ rover subgraph fetch nonexistent --name x                 
Fetching SDL from nonexistent@current (subgraph: x) using credentials from the default profile.
error[E010]: Could not find graph with name "nonexistent@current"
        Make sure your graph name is typed correctly, and that your API key is valid.
        You can run `rover config whoami` to check if you are authenticated.
        If you are trying to create a new graph, you must do so online at https://studio.apollographql.com, by clicking "New Graph".

☸ prod (router) in 󰯭/rover on  glasser/just-fetch-it-do-not-check-first [⇡1] is 📦 v0.25.0 via 🦀 v1.79.0  p= 󰦜 at 12:01:49-07 ❌1 ❯ rover subgraph fetch Apollo-Fullstack-Demo-o3tsz8@p-1 --name x
Fetching SDL from Apollo-Fullstack-Demo-o3tsz8@p-1 (subgraph: x) using credentials from the default profile.
error[E009]: Could not find subgraph "x".
        Try running this command with one of the following valid subgraphs: [subgraph]

☸ prod (router) in 󰯭/rover on  glasser/just-fetch-it-do-not-check-first [⇡1] is 📦 v0.25.0 via 🦀 v1.79.0  p= 󰦜 at 12:01:56-07 ❌1 ❯ rover subgraph fetch Apollo-Fullstack-Demo-o3tsz8@p-1 --name subgraph   
Fetching SDL from Apollo-Fullstack-Demo-o3tsz8@p-1 (subgraph: subgraph) using credentials from the default profile.
Schema: 

type Maya {
  name: String
}

type MayaIsSOCOOL {
  howCool: Int
}

extend type Query {
  me: User
}

type User @key(fields: "id") {
  id: ID!
  name: String
  username: String
}


☸ prod (router) in 󰯭/rover on  glasser/just-fetch-it-do-not-check-first [⇡1] is 📦 v0.25.0 via 🦀 v1.79.0  p= 󰦜 at 12:02:04-07 ❯ rover --log=debug subgraph fetch Apollo-Fullstack-Demo-o3tsz8 --name x |& grep IsFederated
  DEBUG rover_client::blocking::client: Request Body: {"variables":{"graph_id":"Apollo-Fullstack-Demo-o3tsz8","variant":"current"},"query":"query IsFederatedGraph($graph_id: ID!, $variant: String!) {\n  graph(id: $graph_id) {\n    variant(name: $variant) {\n      subgraphs {\n        name\n      }\n    }\n  }\n}\n","operationName":"IsFederatedGraph"}

Rover from this branch:

☸ prod (router) in 󰯭/rover on  glasser/just-fetch-it-do-not-check-first [⇡1] is 📦 v0.25.0 via 🦀 v1.79.0  p= 󰦜 at 12:02:30-07 ❯ target/debug/rover subgraph fetch Apollo-Fullstack-Demo-o3tsz8 --name x                   
Fetching SDL from Apollo-Fullstack-Demo-o3tsz8@current (subgraph: x) using credentials from the default profile.
error[E007]: The graph `Apollo-Fullstack-Demo-o3tsz8@current` is a non-federated graph. This operation is only possible for federated graphs.
        If you are sure you want to convert a non-federated graph to a subgraph, you can re-run the same command with a `--convert` flag.

☸ prod (router) in 󰯭/rover on  glasser/just-fetch-it-do-not-check-first [⇡1] is 📦 v0.25.0 via 🦀 v1.79.0  p= 󰦜 at 12:02:50-07 ❌1 ❯ target/debug/rover subgraph fetch nonexistent --name x                                    
Fetching SDL from nonexistent@current (subgraph: x) using credentials from the default profile.
error[E010]: Could not find graph with name "nonexistent@current"
        Make sure your graph name is typed correctly, and that your API key is valid.
        You can run `rover config whoami` to check if you are authenticated.
        If you are trying to create a new graph, you must do so online at https://studio.apollographql.com, by clicking "New Graph".

☸ prod (router) in 󰯭/rover on  glasser/just-fetch-it-do-not-check-first [⇡1] is 📦 v0.25.0 via 🦀 v1.79.0  p= 󰦜 at 12:02:55-07 ❌1 ❯ target/debug/rover subgraph fetch Apollo-Fullstack-Demo-o3tsz8@p-1 --name x               
Fetching SDL from Apollo-Fullstack-Demo-o3tsz8@p-1 (subgraph: x) using credentials from the default profile.
error[E009]: Could not find subgraph "x".
        Try running this command with one of the following valid subgraphs: [subgraph]

☸ prod (router) in 󰯭/rover on  glasser/just-fetch-it-do-not-check-first [⇡1] is 📦 v0.25.0 via 🦀 v1.79.0  p= 󰦜 at 12:03:02-07 ❌1 ❯ target/debug/rover subgraph fetch Apollo-Fullstack-Demo-o3tsz8@p-1 --name subgraph        
Fetching SDL from Apollo-Fullstack-Demo-o3tsz8@p-1 (subgraph: subgraph) using credentials from the default profile.
Schema: 

type Maya {
  name: String
}

type MayaIsSOCOOL {
  howCool: Int
}

extend type Query {
  me: User
}

type User @key(fields: "id") {
  id: ID!
  name: String
  username: String
}


☸ prod (router) in 󰯭/rover on  glasser/just-fetch-it-do-not-check-first [⇡1] is 📦 v0.25.0 via 🦀 v1.79.0  p= 󰦜 at 12:03:07-07 ❯ target/debug/rover --log=debug subgraph fetch Apollo-Fullstack-Demo-o3tsz8 --name x |& grep IsFederated 

The actual commands return the same thing. The log grep shows we are not doing the IsFederatedGraph operation with the new build.

[aaronArinder]

this looks pretty sensible, but I don't understand why it was introduced originally; maybe we can get to the bottom of it on monday together when we talk with the other rover people? It definitely gives me pause because it looks pretty intentional