bad gateway 502 KES

When importing a key, you may see this issue and it can be due to sealed Vault. Solution is to unseal vault so that key can be imported:

curl -v -sSL -k \
    --key client.key \
    --cert client.crt \
    --data '{"bytes":"ZGFsc2tkamFsa3NqZGthbGpzZGxrYXNqZGtsYXNk"}' \
    -X POST 'https://:7373/v1/key/import/cesar-key'

NOTE: A Vault must be unsealed before it can access its data. Hint: Look for KES pods logs after your perform the POST with CURL so you can see more data on the 502