Listing a KV V2 directory doesn't work when pointing to a Vault agent

[jordiclariana]

Describe the bug
Vault API documentation claims that using LIST method or ?list=true query string are interchangeable and produce the same result. That is true but when using a vault agent in between the client and the server it doesn't work.
Using the LIST method works as expected while the query string list=true returns a 404.

vault command uses only the query string list=true, so it doesn't work when pointing to an agent:

$ vault kv list kv/mydir
No value found at kv/metadata/mydir
$ vault kv list -output-curl-string kv/mydir
curl http://127.0.0.1:8200/v1/kv/metadata/mydir?list=true

While using curl with LIST method does work:

$ curl -X LIST -vs http://127.0.0.1:8200/v1/kv/metadata/mydir | jq '.'
*   Trying 127.0.0.1...
* Connected to 127.0.0.1 (127.0.0.1) port 8200 (#0)
> LIST /v1/kv/metadata/mydir HTTP/1.1
> Host: 127.0.0.1:8200
> User-Agent: curl/7.47.0
> Accept: */*
> 
< HTTP/1.1 200 OK
< Cache-Control: no-store
< Content-Length: 173
< Content-Type: application/json
< Date: Fri, 24 May 2019 13:59:30 GMT
< X-Cache: MISS
< 
{ [173 bytes data]
* Connection #0 to host 127.0.0.1 left intact
{
  "request_id": "b1a7b22d-fa76-e142-36b0-e4205a3687da",
  "lease_id": "",
  "renewable": false,
  "lease_duration": 0,
  "data": {
    "keys": [
      "mykey"
    ]
  },
  "wrap_info": null,
  "warnings": null,
  "auth": null
}

To Reproduce

1. You need to have the current setup, which is not easy to reproduce here:

• Machine A with Vault Server
• Machine B with Vault Agent connected and authenticated to Machine A Vault Server

3. Run on Machine A: vault kv put kv/mydir/mykey name=value
4. Run on Machine B: vault kv list kv/mydir. It returns: No value found at kv/metadata/mydir. This doesn't list the directory.
5. Run on Machine B: curl -XLIST -s http://127.0.0.1:8200/v1/kv/metadata/mydir. This does list the directory.

Expected behavior
vault kv list kv/mydir should list the keys in the directory when pointing to a Vault Agent

Environment:

• Vault Server Version (retrieve with vault status):

Key                      Value
---                      -----
Recovery Seal Type       shamir
Initialized              true
Sealed                   false
Total Recovery Shares    1
Threshold                1
Version                  1.1.2
Cluster Name             vault-cluster-4db0f02c
Cluster ID               b5cd54b2-7d43-0690-fe26-1daeec8e091e
HA Enabled               true
HA Cluster               https://vault.service.consul:8201
HA Mode                  active

• Vault CLI Version (retrieve with vault version):

Vault v1.1.2 ('0082501623c0b704b87b1fbc84c2d725994bac54')

• Server Operating System/Architecture: Ubuntu 16.04 x86_64

Vault server configuration file(s):
Given the fact that everything works well when run without the Vault agent, I'll post only the agent config.

Agent:

pid_file = "/var/run/vault-agent/vault-agent.pid"

auto_auth {
   method "aws" {
       mount_path = "auth/aws"
       config = {
           type = "iam"
           role = "myrole"
       }
   }

   sink "file" {
       config = {
           path = "/etc/vault/token"
       }
   }
}

vault {
   address = "https://vault:8200"
}

cache {
        use_auto_auth_token = true
}

listener "tcp" {
  address = "0.0.0.0:8200"
  tls_disable = true
}

[briankassouf]

already should be fixed by #6772

[jordiclariana]

Awesome, thanks! I missed that PR and its related ticket.