DNS Troubleshooting for Connector

Private DNS Support for Connector

There can be cases where a public or host machine DNS resolver are not enough, and custom DNS resolving is needed. Such scenarios can be service mesh and DNS-based service discovery. The Harmony Connect Application-Level Connector can support additional resolvers by using docker core DNS capabilities.

Upon Connector setup, you can add the following:

If your machine is hosted in AWS, add the following parameters to the above command:

--dns 169.254.169.253 --dns <PRIVATE-DNS-SERVER-IP> --dns <PUBLIC-DNS-SERVER-IP>

Otherwise, add these parameters to the above command:

--dns <PRIVATE-DNS-SERVER-IP> --dns <PUBLIC-DNS-SERVER-IP>

These parameters use the default DNS port 53. If you use any other port, you need to do port forwarding.

Additional DNS Servers

The connectorClosed It is a lightweight Docker container that provides a secure tunnel between your data center and the Harmony Connect cloud. needs additional DNS servers to resolve addresses properly.

In this case, you can add DNS resolvers to the Connector with DockerClosed Docker is a set of platform as a service products that use OS-level virtualization to deliver software in packages called containers. mechanisms.

Consider two options:

  • Add the DNS resolvers addresses using the --dns flag.

  • As the Docker container inherits the resolver configuration file from the host machine, set the /etc/resolve.conf file on the host machine of the Connector and then re-run the Connector container.

For more information on these options, see the Docker documentation at: https://docs.docker.com/config/containers/container-networking/

Inaccessible DNS Resolver

The DNS resolver is not accessible to the connector throughout the network.

  • Adjust your network configuration to allow the Connector access to the DNS resolvers.

No Available DNS Resolver

No DNS resolver exists for resolving DNS names to be used by the Connector.

  • If you do not want to use a DNS resolver or do not have a DNS resolver for the DNS addresses, and the IP for the DNS name never changes, you can use the --add-host flag of Docker.

For more information, see the Docker documentation at: https://docs.docker.com/engine/reference/commandline/run/#add-entries-to-container-hosts-file---add-host