How to fix Traefik “command traefik error: field not found, node: dnsProvider”

Problem:

You are trying to configure your Traefik server but you see an error message like

traefik    | 2020/09/20 22:07:11 command traefik error: field not found, node: dnsProvider

Solution:

dnsProvider is a configuration option from Traefik 1.x. You need to useĀ provider for Traefik 2.x. Example:

[certificatesResolvers.lecloudflare.acme.dnsChallenge]
provider = "cloudflare"

Full example:

[certificatesResolvers.lecloudflare.acme]
email = "email@domain.com"
storage = "/etc/traefik/acme/acme.json"

[certificatesResolvers.lecloudflare.acme.dnsChallenge]
provider = "cloudflare"