Error core: failed to lookup token: error=failed to read entry, dial tcp [::1]:8500: getsockopt: connection refused in Vault log - kubernetes

Question

We are performing load test on our application using Jmeter, our application uses consul and vault as a backend service for reading/storing application configuration related data. While performing load testing, our application queries the vault for authentication data and this happens for each incoming request. Initially it runs fine for some duration (10 to 15 minutes) and I can see the success response in Jmete, but eventually after sometime the responses starts failing for all the requests. I see the following error in the vault log for each request but do not see any error/exception in the consul log.
Error in Vault log
[ERROR] core: failed to lookup token: error=failed to read entry: Get http://localhost:8500/v1/kv//vault/sys/token/id/87f7b82131cb8fa1ef71aa52579f155d4cf9f095: dial tcp [::1]:8500: getsockopt: connection refused
As of now the load is 100 request (users) in each 10 milliseconds with a ramp-up period of 60 seconds. And this executes over a loop. What could be the cause of this error? Is it due to the limited connection to port 8500
Below is my vault and consul configuration
Vault
backend "consul" {
address = "localhost:8500"
path = "app/vault/"
}
listener "tcp" {
address = "10.88.97.216:8200"
cluster_address = "10.88.97.216:8201"
tls_disable = 0
tls_min_version = "tls12"
tls_cert_file = "/var/certs/vault.crt"
tls_key_file = "/var/certs/vault.key"
}
Consul
{
"data_dir": "/var/consul",
"log_level": "info",
"server": true,
"leave_on_terminate": true,
"ui": true,
"client_addr": "127.0.0.1",
"ports": {
"dns": 53,
"serf_lan": 8301,
"serf_wan" : 8302
},
"disable_update_check": true,
"enable_script_checks": true,
"disable_remote_exec": false,
"domain": "primehome",
"limits": {
"http_max_conns_per_client": 1000,
"rpc_max_conns_per_client": 1000
},
"service": {
"name": "nginx-consul-https",
"port": 443,
"checks": [{
"http": "https://localhost/nginx_status",
"tls_skip_verify": true,
"interval": "10s",
"timeout": "5s",
"status": "passing"
}]
}
}
I have also configured the http_max_conns_per_client & rpc_max_conns_per_client, thinking that it might be due to the limited connection perclicent. But still I am seeing this error in vault log.

Answer 1

After taking another look at this, the issue appears to be that Vault is attempting to contact Consul over the IPv6 loopback address–likely due to the v4 and v6 addresses being present in /etc/hosts–but Consul is only listening on the IPv4 loopback address.
You can likely resolve this through one of the following methods.
Use 127.0.0.1 instead of localhost for Consul's address in the Vault config.
backend "consul" {
address = "127.0.0.1:8500"
path = "app/vault/"
}
Configure Consul to listen on both the IPv4 and IPv6 loopback addresses.
{
"client_addr": "127.0.0.1 [::1]"
}
(Rest of the config omitted for brevity.)
Remove the localhost hostname from the IPv6 loopback in /etc/hosts
127.0.0.1 localhost
# Old hosts entry for ::1
#::1 localhost ip6-localhost ip6-loopback
# New entry
::1 ip6-localhost ip6-loopback