- force to set `DNS_UPSTREAM_RESOLVER_TYPE=plain` to avoid any confusion/security hole
- force to set `DNS_UPSTREAM_PLAIN_ADDRESSES` to addresses only with port 53
- main reason being it's a burden to always define sentinel errors at global scope, wrap them with `%w` instead of using a string directly
- only use sentinel errors when it has to be checked using `errors.Is`
- replace all usage of these sentinel errors in `fmt.Errorf` with direct strings that were in the sentinel error
- exclude the sentinel error definition requirement from .golangci.yml
- update unit tests to use ContainersError instead of ErrorIs so it stays as a "not a change detector test" without requiring a sentinel error
- start DNS server before healthcheck
- do not fallback to plaintext anymore
- allow to use plain addresses with a port different than 53, system-wide
- do not wait for the DNS server and rely on healtcheck only
- Remove `DNS_SERVER` (aka DOT) option: the DNS server forwarder part is now always enabled (see below why)
- Remove `DNS_KEEP_NAMESERVER`: the container will always use the built-in DNS server forwarder, because it can handle now local names with local resolvers (see #2970), it can use the `plain` upstream type (see https://github.com/qdm12/gluetun/commit/5ed6e8292278b54bb5081de0e8ccd0d63a275b3c) AND you can use `DNS_UPSTREAM_PLAIN_ADDRESSES` (see below)
- Replace `DNS_ADDRESS` with `DNS_UPSTREAM_PLAIN_ADDRESSES`:
- New CSV format with port, for example `ip1:port1,ip2:port2`
- requires `DNS_UPSTREAM_TYPE=plain` to be set to use `DNS_UPSTREAM_PLAIN_ADDRESSES` (unless using retro `DNS_ADDRESS`)
- retrocompatibility with `DNS_ADDRESS`. If set, force upstream type to plain and empty user-picked providers. 127.0.0.1 is now ignored since it's always set to this value internally.
- Warning log on using private upstream resolvers updated
- Warning log if using a private IP address for the plain DNS server which is not in your local subnets
All in all, this greatly simplifies code and available options (less options for the same features is a win). It also allows you to specify multiple plain DNS resolvers on ports other than 53 if needed.
- Migrate `DOT` to `DNS_SERVER`
- Migrate `DOT_PROVIDERS` to `DNS_UPSTREAM_RESOLVERS`
- Migrate `DOT_PRIVATE_ADDRESS` to `DNS_PRIVATE_ADDRESSES`
- Migrate `DOT_CACHING` to `DNS_CACHING`
- Migrate `DOT_IPV6` to `DNS_UPSTREAM_IPV6`
- do not log dial error twice
- DNS subserver shuts down without waiting for connections to finish (UDP server would hang sometimes)
- DNS over TLS dialer uses tls.Dialer instead of wrapping connection with tls.Client
- connection type is just `tls` instead of `dns over tls` to reduce repetition in logs
- exchange errors contain the request question in their context
- Faster start up
- Clearer error messages
- Allow for more Gluetun-specific customization
- DNSSEC validation is dropped for now (it's sort of unneeded)
- Fix#137
- Better settings tree structure logged using `qdm12/gotree`
- Read settings from environment variables, then files, then secret files
- Settings methods to default them, merge them and override them
- `DNS_PLAINTEXT_ADDRESS` default changed to `127.0.0.1` to use DoT. Warning added if set to something else.
- `HTTPPROXY_LISTENING_ADDRESS` instead of `HTTPPROXY_PORT` (with retro-compatibility)
Quentin McGaw