Return 404s intead of 500s for invalid cluster ids for many endpoints

[dmitrizagidulin]

Not urgent, but let's clean up some of these 500 errors when passing an invalid cluster id (and return 404 Not Found / {"error": "Invalid cluster id, or cluster is unavailable."} instead).

• List nodes - curl localhost:9000/explore/clusters/invalid/nodes returns 500
• List bucket types - curl localhost:9000/explore/clusters/invalid/bucket_types returns 500
• Get bucket type props, invalid cluster - curl localhost:9000/explore/clusters/invalid/bucket_types/default returns 500
• Get bucket type jobs, invalid cluster - curl localhost:9000/explore/clusters/invalid/bucket_types/default/jobs returns 500
• Get bucket type's buckets, invalid cluster - curl localhost:9000/explore/clusters/invalid/bucket_types/default/buckets returns 500
• Get a bucket's jobs - localhost:9000/explore/clusters/invalid/bucket_types/default/buckets/$bucket/jobs - returns 500
• Get a bucket's key cache - localhost:9000/explore/clusters/invalid/bucket_types/default/buckets/$bucket/keys returns 500
• All the Riak proxy endpoints - localhost:9000/riak/clusters/invalid/... return 500.

[dmitrizagidulin]

Tested, on latest master. Results:

Fixed:

• All the Riak proxy endpoints - localhost:9000/riak/clusters/invalid/... - Perfect. Returns 404, with JSON error: {"error":"Node is not running."}.
• List nodes - curl localhost:9000/explore/clusters/invalid/nodes now returns 404 (though with an HTML 'not found', rather than a JSON error).
• Get bucket type's buckets, invalid cluster - curl localhost:9000/explore/clusters/invalid/bucket_types/default/buckets now returns 404 (though with an HTML 'not found', rather than a JSON error).
• Get a bucket's key cache - localhost:9000/explore/clusters/invalid/bucket_types/default/buckets/$bucket/keys now returns 404 (though with an HTML 'not found', rather than a JSON error).

Not quite fixed:

• Get bucket type jobs, invalid cluster - curl localhost:9000/explore/clusters/invalid/bucket_types/default/jobs returns a 200 OK, with an empty jobs list. Should probably still be a 404 with the json error.
• Get a bucket's jobs - localhost:9000/explore/clusters/invalid/bucket_types/default/buckets/$bucket/jobs - returns a 200 OK, with an empty jobs list. Should probably still be a 404 with the json error.

Still returns 500:

• List bucket types - curl localhost:9000/explore/clusters/invalid/bucket_types returns 500
• Get bucket type props, invalid cluster - curl localhost:9000/explore/clusters/invalid/bucket_types/default returns 500

[drewkerrigan]

Ok, I've addressed your comments.

[dmitrizagidulin]

Perfect, all fixed.

• curl localhost:9000/riak/clusters/invalid/ping -> 404 Not Found, {"error":"Cluster doesn't exist."}
• curl localhost:9000/explore/clusters/invalid/nodes -> 404 Not Found, {"error":"Cluster doesn't exist."}
• curl localhost:9000/explore/clusters/invalid/bucket_types/default/buckets -> 404 Not Found, {"error":"Cluster doesn't exist."}
• curl localhost:9000/explore/clusters/invalid/bucket_types/default/buckets/users/keys -> 404 Not Found, {"error":"Cluster doesn't exist."}
• curl localhost:9000/explore/clusters/invalid/bucket_types/default/jobs -> 404 Not Found, {"error":"Cluster doesn't exist."}
• curl localhost:9000/explore/clusters/invalid/bucket_types/default/buckets/users/jobs -> 404 Not Found, {"error":"Cluster doesn't exist."}
• curl localhost:9000/explore/clusters/invalid/bucket_types -> 404 Not Found, {"error":"Cluster doesn't exist."}
• curl localhost:9000/explore/clusters/invalid/bucket_types/default -> 404 Not Found, {"error":"Cluster doesn't exist."}

Closing.