Gitlab::UrlBlocker::BlockedUrlError: Host cannot be resolved or invalid

https://sentry.gitlab.net/gitlab/gitlabcom/issues/1218788/

SocketError: getaddrinfo: Name or service not known
  gitlab/url_blocker.rb:111:in `getaddrinfo'
    Addrinfo.getaddrinfo(uri.hostname, get_port(uri), nil, :STREAM).map do |addr|
  gitlab/url_blocker.rb:111:in `get_address_info'
    Addrinfo.getaddrinfo(uri.hostname, get_port(uri), nil, :STREAM).map do |addr|
  gitlab/url_blocker.rb:48:in `validate!'
    address_info = get_address_info(uri, dns_rebind_protection)
  gitlab/kubernetes/kube_client.rb:155:in `validate_url!'
    Gitlab::UrlBlocker.validate!(api_prefix, allow_local_network: false)
  gitlab/kubernetes/kube_client.rb:100:in `initialize'
    validate_url!
...
(199 additional frame(s) were not displayed)

Gitlab::UrlBlocker::BlockedUrlError: Host cannot be resolved or invalid
  gitlab/url_blocker.rb:127:in `rescue in get_address_info'
    raise BlockedUrlError, "Host cannot be resolved or invalid"
  gitlab/url_blocker.rb:110:in `get_address_info'
    def get_address_info(uri, dns_rebind_protection)
  gitlab/url_blocker.rb:48:in `validate!'
    address_info = get_address_info(uri, dns_rebind_protection)
  gitlab/kubernetes/kube_client.rb:155:in `validate_url!'
    Gitlab::UrlBlocker.validate!(api_prefix, allow_local_network: false)
  gitlab/kubernetes/kube_client.rb:100:in `initialize'
    validate_url!
...
(199 additional frame(s) were not displayed)

Gitlab::UrlBlocker::BlockedUrlError: Host cannot be resolved or invalid