AdGuardDNS/CHANGELOG.md

 #  AdGuard DNS Changelog

All notable environment, configuration file, and other changes to this project
will be documented in this file.

The format is **not** based on [Keep a Changelog][kec], since the project
**doesn't** currently adhere to [Semantic Versioning][sem].

[kec]: https://keepachangelog.com/en/1.0.0/
[sem]: https://semver.org/spec/v2.0.0.html



##  AGDNS-1954 / Build 719

 *  The objects within `server_groups` array have a new property
    `block_page_redirect`:

    ```yaml
    block_page_redirect:
        enabled: true
        ipv4:
          - address: '127.0.0.1'
          - address: '127.0.0.2'
        ipv6:
          - address: '::1'
          - address: '::2'
        apply:
            client:
              - address: '192.168.0.0/16'
              - address: '1.2.3.4'
        skip:
            client:
              - address: '1.2.0.0/16'
            question:
              - domain: 'do-not-show-block.site.example'
        probability: 0.01
    ```

    For server groups that do not require a block-page redirect, set:

    ```yaml
    block_page_redirect:
        enabled: false
    ```



##  AGDNS-1888 / Build 717

 *  The new environment variable `PROFILES_ENABLED` has been added.  With `0`
    value it disables user profiles and devices recognition, and billing.  Its
    default value is `1`.  Adjust the value, if necessary.



##  AGDNS-1761 / Build 702

 *  The property `upstream` has been modified. Its property `timeout` has been
    replaced with the new property `servers.timeout` for each server in the
    `servers` list. Concomitantly the `fallback.timeout` has been replaced with
    `fallback.servers.timeout` for each fallback server. The `fallback.servers`
    now supports not only the addresses of the servers, but URLs in the
    `[scheme://]ip:port` format like it's done with the main servers. So replace
    this:

    ```yaml
    upstream:
        # …
        servers:
          - 'tcp://1.1.1.1:53'
          - '127.0.0.1:5358'
        timeout: 2s
        fallback:
            servers:
              - 8.8.4.4:53
            timeout: 1s
    ```

    with this:

    ```yaml
    upstream:
        # …
        servers:
          - address: 'tcp://1.1.1.1:53'
            timeout: 2s
          - address: '127.0.0.1:5358'
            timeout: 2s
        fallback:
            servers:
              - address: '8.8.4.4:53'
                timeout: 1s
    ```

    Adjust the value and add new ones, if necessary.



##  AGDNS-698 / Build 701

 *  The object `dns` has new properties: `read_timeout`, `tcp_idle_timeout`, and
    `write_timeout`.  So replace this:

    ```yaml
    dns:
        max_udp_response_size: 1024B
    ```

    with this:

    ```yaml
    dns:
        read_timeout: 2s
        tcp_idle_timeout: 30s
        write_timeout: 2s
        handle_timeout: 1s
        max_udp_response_size: 1024B
    ```

    The values in the example are previous defaults.



##  AGDNS-1751 / Build 691

 *  The property `upstream.server` has been removed.  Its former content is
    moved to the newly added property `servers`, which now extended to contain
    a list of URLs of main upstream servers.  So replace this:

    ```yaml
    upstream:
        # …
        server: `8.8.8.8:53`
    ```

    with this:

    ```yaml
    upstream:
        # …
        servers:
          - `8.8.8.8:53`
    ```

    Adjust the value and add new ones, if necessary.



##  AGDNS-1759 / Build 684

 *  The object `backend` has a new property, `full_refresh_retry_interval`.  So
    replace this:

    ```yaml
    backend:
        # …
        full_refresh_interval: 24h
    ```

    with this:

    ```yaml
    backend:
        # …
        full_refresh_interval: 24h
        full_refresh_retry_interval: 1h
    ```

    Adjust the value, if necessary.



##  AGDNS-1744 / Build 681

 *  Metric `forward_request_total` has a new label `network`.  This label
    describes the network type (`tcp` or `udp`), over which an upstream has
    finished processing request.



##  AGDNS-1738 / Build 678

 *  Object `dns` has a new property, describing maximum size of DNS response
    over UDP protocol.

    ```yaml
    dns:
        max_udp_response_size: 1024B
        handle_timeout: 1s
    ```



##  AGDNS-1735 / Build 677

 *  The property `upstream.fallback` has been changed.  Its former content is
    moved to the newly added property `servers`.  The new property `timeout`,
    which describes query timeout to fallback servers, was added.  So replace
    this:

    ```yaml
    upstream:
        fallback:
        - 1.1.1.1:53
        - 8.8.8.8:53
    ```

    with this:

    ```yaml
    upstream:
        fallback:
            servers:
            - 1.1.1.1:53
            - 8.8.8.8:53
            timeout: 1s
    ```

   Adjust the new values, if necessary.  Note that the query timeout to fallback
   servers was previously defined with `upstream.timeout` property, which now
   describes the query timeout to the primary servers only.



##  AGDNS-1178 / Build 676

 *  The new object `dns` has been added:

    ```yaml
    dns:
        handle_timeout: 1s
    ```



##  AGDNS-1620 / Build 673

 *  Object `ratelimit` has two new properties: `quic` and `tcp`.  They configure
    QUIC and TCP connection limits.  Example configuration:

    ```yaml
    ratelimit:
        # …
        quic:
            enabled: true
            max_streams_per_peer: 100
        tcp:
            enabled: true
            max_pipeline_count: 100
    ```



##  AGDNS-1684 / Build 661

 *  Profile's file cache version was incremented.  The new field `access` has
    been added.



##  AGDNS-1664 / Build 636

 *  The environment variables `BILLSTAT_URL` and `PROFILES_URL` no longer
    support HTTP(s) endpoints.  Use GRPC(S) instead.



##  AGDNS-1667 / Build 633

*  `ratelimit` configuration properties `back_off_count`, `back_off_duration`
   and `back_off_period` have been renamed to `backoff_count`,
   `backoff_duration` and `backoff_period`.  So replace this:

   ```yaml
   ratelimit:
       back_off_period: 10m
       back_off_count: 1000
       back_off_duration: 30m
   ```

   with this:

   ```yaml
   ratelimit:
       backoff_period: 10m
       backoff_count: 1000
       backoff_duration: 30m
   ```



##  AGDNS-1607 / Build 617

 *  New configuration `access` has been added, it has an a list of AdBlock rules
    to block requests, and a lists of client subnets to block access from.
    Example configuration:

    ```yaml
    access:
        blocked_question_domains:
          - 'test.org'
          - '||example.org^$dnstype=AAAA'
        blocked_client_subnets:
          - '1.1.1.1'
          - '2.2.2.0/8'
    ```



##  AGDNS-1619 / Build 611

 *  Added a new metric `bill_stat_upload_duration` that counts the duration of
    billing statistics upload.

 *  The environment variable `BILLSTAT_URL`, which describes the endpoint for
    backend billing statistics uploader API, now supports GRPC endpoints.



##  AGDNS-1600 / Build 582

 *  The environment variable `PROFILES_CACHE_PATH` no longer supports JSON
    files.  Use protobuf with `.pb` extension instead.  The default value has
    been changed to `./profilecache.pb`.



##  AGDNS-1539 / Build 581

 *  The environment variable `PROFILES_URL`, which describes the endpoint for
    profiles sync API, now supports GRPC endpoints.



##  AGDNS-1579 / Build 580

 *  The optional property `bind_interfaces` of `server_groups.*.servers`
    objects has been changed, property `subnet` is now an array and has been
    renamed to `subnets`.  So replace this:

    ```yaml
    bind_interfaces:
      - id: 'dns'
        subnet: '10.0.0.1/32'
      - id: 'dns'
        subnet: '10.0.0.2/32'
      - id: 'dns'
        subnet: '10.0.0.3/32'
      - id: 'dns_secondary'
        subnet: '10.0.0.1/32'
    ```

    with this:

    ```yaml
    bind_interfaces:
      - id: 'dns'
        subnets:
          - '10.0.0.1/32'
          - '10.0.0.2/32'
          - '10.0.0.3/32'
      - id: 'dns_secondary'
        subnets:
          - '10.0.0.1/32'
    ```



##  AGDNS-1537 / Build 566

 *  The configuration property `filtering_groups.safe_browsing` has been changed,
    new properties have been added: `block_dangerous_domains` and
    `block_newly_registered_domains`.



##  AGDNS-1580 / Build 562

 *  The environment variable `DNSDB_PATH` has been removed.

 *  New configuration `dnsdb` has been added, it has an enabled/disabled flag
    and the property `max_size` which describes the maximum amount of records in
    the in-memory buffer.  Example configuration:

    ```yaml
    dnsdb:
        enabled: true
        max_size: 500000
    ```



##  AGDNS-1537 / Build 559

 *  Configuration properties `safe_browsing.url` and `adult_blocking.url` are
    now removed.  Use newly added environment variables `ADULT_BLOCKING_URL` and
    `SAFE_BROWSING_URL`.
 *  New environment variable `NEW_REG_DOMAINS_URL` has been added, this is the
    link to the source list of the newly registered domains.



##  AGDNS-1567 / Build 557

 *  The environment variable `BACKEND_ENDPOINT` was replaced with three
    environment variables:

     *  `LINKED_IP_TARGET_URL`: the target URL to which linked IP API requests
        are proxied.
     *  `PROFILES_URL`: the endpoint for profiles sync API.
     *  `BILLSTAT_URL`: the endpoint for backend billing statistics uploader.



##  AGDNS-1561 / Build 554

 *  The `filters` object has a new property, `max_size`, which describes the
    maximum size of the downloadable content for a rule-list in a human-readable
    format.  Example configuration:

    ```yaml
    filters:
        # …
        max_size: 256MB
    ```



##  AGDNS-1561 / Build 550

 *  Properties `so_sndbuf` and `so_rcvbuf` of object `network` have been changed.
    Now they are in a human-readable format.  Example configuration:

    ```yaml
    network:
        so_sndbuf: 2MB
        so_rcvbuf: 0
    ```

 *  The object `filters` has been changed. Two properties,
    `rule_list_cache_size` and `use_rule_list_cache` have been extracted to the
    new object `rule_list_cache` and renamed to `size` and `enabled`.  So
    replace this:

    ```yaml
    filters:
        response_ttl: 5m
        custom_filter_cache_size: 1024
        safe_search_cache_size: 1024
        rule_list_cache_size: 10000
        refresh_interval: 1h
        refresh_timeout: 5m
        use_rule_list_cache: true
    ```

    with this:

    ```yaml
    filters:
        response_ttl: 5m
        custom_filter_cache_size: 1024
        safe_search_cache_size: 1024
        refresh_interval: 1h
        refresh_timeout: 5m
        rule_list_cache:
            enabled: true
            size: 10000
    ```

    Adjust the values, if necessary.



##  AGDNS-1566 / Build 549

 *  There is now a new env variable `RESEARCH_LOGS` that controls whether
    logging of additional info for research purposes is enabled.  These log
    records can be filtered out by `research:` prefix.  The default value is
    `0`, i.e. additional logging is disabled.  The first thing that is logged
    in this version is domains which responses have ECH config.  The log will
    only be recorded when both `RESEARCH_LOGS` and `RESEARCH_METRICS` are set
    to `1`.

 *  Added a new research metric `dns_research_response_ech` that counts the
    number of responses with a ECH configuration.



##  AGDNS-1556 / Build 547

 *  The object `cache` has a new property `ttl_override`.  It describes the TTL
    override settings, such as the minimum TTL for cache items and the `enabled`
    switch.  It overwrites the TTL from DNS response in case it's less than this
    minimum value.  So replace this:

    ```yaml
    cache:
        type: "simple"
        size: 10000
        ecs_size: 10000
    ```

    with this:

    ```yaml
    cache:
        type: "simple"
        size: 10000
        ecs_size: 10000
        ttl_override:
            enabled: true
            # The minimum duration of TTL for a cache item.
            min: 60s
    ```

    Adjust the values, if necessary.



##  AGDNS-1498 / Build 527

 *  Object `ratelimit` has a new property, `connection_limit`, which allows
    setting stream-connection limits.  Example configuration:

    ```yaml
    ratelimit:
        # …
        connection_limit:
            enabled: true
            stop: 1000
            resume: 800
    ```



##  AGDNS-1383 / Build 525

 *  The environment variable `PROFILES_CACHE_PATH` is now sensitive to the file
    extension.  Use `.json` for the previous behavior of encoding the cache into
    a JSON file or `.pb` for encoding it into protobuf.  Other extensions are
    invalid.



##  AGDNS-1381 / Build 518

 *  The new object `network` has been added:

    ```yaml
    network:
        so_sndbuf: 0
        so_rcvbuf: 0
    ```



##  AGDNS-1383 / Build 515

 *  The environment variable `PROFILES_CACHE_PATH` now has a new special value,
    `none`, which disables profile caching entirely.  The default value of
    `./profilecache.json` has not been changed.



##  AGDNS-1479 / Build 513

 *  The profile-cache version has been changed to `6`.  Versions of the profile
    cache from `3` to `5` are invalid and should not be reused.



##  AGDNS-1473 / Build 506

 *  The profile-cache version has been changed to `5`.



##  AGDNS-1247 / Build 484

 *  The new object `interface_listeners` has been added:

    ```yaml
    interface_listeners:
        channel_buffer_size: 1000
        list:
            eth0_plain_dns:
                interface: 'eth0'
                port': 53
            eth0_plain_dns_secondary:
                interface: 'eth0'
                port': 5353
    ```

 *  The objects within the `server_groups.*.servers` array have a new optional
    property, `bind_interfaces`:

    ```yaml
    server_groups:
    -
        # …
        servers:
          - name: 'default_dns'
            # …
            bind_interfaces:
              - id: 'eth0_plain_dns'
                subnet: '127.0.0.0/8'
              - id: 'eth0_plain_dns_secondary'
                subnet: '127.0.0.0/8'
    ```

    It is mutually exclusive with the current `bind_addresses` field.



##  AGDNS-1406 / Build 480

 *  The default behavior of the environment variable `DNSDB_PATH` has been
    changed.  Previously, if the variable was unset then the default value,
    `./dnsdb.bolt`, was used, but if it was an empty string, DNSDB was disabled.
    Now both unset and empty value disable DNSDB, which is consistent with the
    documentation.

    This means that DNSDB is disabled by default.

 *  The default configuration file path has been changed from `config.yml` to
    <code>./config.y<strong>a</strong>ml</code> for consistency with other
    services.



##  AGDNS-916 / Build 456

 *  `ratelimit` now defines rate of requests per second for IPv4 and IPv6
    addresses separately.  So replace this:

    ```yaml
    ratelimit:
        rps: 30
        ipv4_subnet_key_len: 24
        ipv6_subnet_key_len: 48
    ```

    with this:

    ```yaml
    ratelimit:
        ipv4:
            rps: 30
            subnet_key_len: 24
        ipv6:
            rps: 300
            subnet_key_len: 48
    ```



##  AGDNS-907 / Build 449

 *  The objects within the `filtering_groups` have a new property,
    `block_firefox_canary`.  So replace this:

    ```yaml
    filtering_groups:
    -
        id: default
        # …
    ```

    with this:

    ```yaml
    filtering_groups:
    -
        id: default
        # …
        block_firefox_canary: true
    ```

    The recommended default value is `true`.



##  AGDNS-1308 / Build 447

 *  There is now a new env variable `RESEARCH_METRICS` that controls whether
    collecting research metrics is enabled or not.  Also, the first research
    metric is added: `dns_research_blocked_per_country_total`, it counts the
    number of blocked requests per country.  Its default value is `0`, i.e.
    research metrics collection is disabled by default.



##  AGDNS-1051 / Build 443

 *  There are two changes in the keys of the `static_content` map.  Firstly,
    properties `allow_origin` and `content_type` are removed.  Secondly, a new
    property, called `headers`, is added.  So replace this:

    ```yaml
    static_content:
        '/favicon.ico':
            # …
            allow_origin: '*'
            content_type: 'image/x-icon'
    ```

    with this:

    ```yaml
    static_content:
        '/favicon.ico':
            # …
            headers:
                'Access-Control-Allow-Origin':
                  - '*'
                'Content-Type':
                  - 'image/x-icon'
    ```

    Adjust or add the values, if necessary.



##  AGDNS-1278 / Build 423

 *  The object `filters` has two new properties, `rule_list_cache_size` and
    `use_rule_list_cache`.  So replace this:

    ```yaml
    filters:
        response_ttl: 5m
        custom_filter_cache_size: 1024
        safe_search_cache_size: 1024
        refresh_interval: 1h
        refresh_timeout: 5m
    ```

    with this:

    ```yaml
    filters:
        response_ttl: 5m
        custom_filter_cache_size: 1024
        safe_search_cache_size: 1024
        rule_list_cache_size: 10000
        refresh_interval: 1h
        refresh_timeout: 5m
        use_rule_list_cache: true
    ```

    Adjust the values, if necessary.



##  AGDNS-1278 / Build 422

 *  The object `filters` has a new property, `safe_search_cache_size`.  So
    replace this:

    ```yaml
    filters:
        response_ttl: 5m
        custom_filter_cache_size: 1024
        refresh_interval: 1h
        refresh_timeout: 5m
    ```

    with this:

    ```yaml
    filters:
        response_ttl: 5m
        custom_filter_cache_size: 1024
        safe_search_cache_size: 1024
        refresh_interval: 1h
        refresh_timeout: 5m
    ```

    Adjust the values, if necessary.



##  AGDNS-1174 / Build 397

 *  DNS Server Check now responds with NODATA message to all non-A neither non-AAAA requests.



##  AGDNS-911 / Build 375

 *  Added support for running a DoH3 server.  No configuration changes are
    required to run it.  If there was a DoH server configured, it will start
    listening for HTTP/3 connections on the same port where it listens for
    HTTP/2.  Make sure that udp/443 is allowed in the iptables configuration on
    the server.



##  AGDNS-842 / Build 372

 *  The new environment variable `PROFILES_CACHE_PATH` has been added.  Its
    default value is `./profilecache.json`.  Adjust the value, if necessary.



##  AGDNS-891 / Build 371

 *  The property `server` of `upstream` object has been changed.  Now it
    is a URL optionally starting with `tcp://` or `udp://`, and then an address
    in `ip:port` format.

    ```yaml
    upstream:
       server: 'tcp://8.8.8.8:53'
    ```

    Adjust the value, if necessary.



##  AGDNS-1032 / Build 363

 *  The new optional field `static_content.*.allow_origin` has been added:

    ```yaml
    static_content:
        '/favicon.ico':
            allow_origin: '*'
    ```



##  AGDNS-898 / Build 359

 *  The new optional object `additional_metrics_info` has been added:

    ```yaml
    additional_metrics_info:
        test_key: 'test_value'
    ```



##  AGDNS-986 / Build 346

 *  The new object `upstream.healthcheck` now contains all healthcheck-related
    fields, including the new field `domain_template`.  Property
    `upstream.healthcheck_backoff_time` has been moved to
    `upstream.healthcheck.backoff_duration`.  So replace this:

    ```yaml
    upstream:
        server: 127.0.0.1:53
        timeout: 2s
        healthcheck_enabled: true
        healthcheck_interval: 2s
        healthcheck_timeout: 1s
        healthcheck_backoff_time: 30s
        fallback:
          - 1.1.1.1:53
          - 8.8.8.8:53
    ```

    with this:

    ```yaml
    upstream:
        server: 127.0.0.1:53
        timeout: 2s
        fallback:
          - 1.1.1.1:53
          - 8.8.8.8:53
        healthcheck:
            enabled: true
            interval: 2s
            timeout: 1s
            backoff_duration: 30s
            domain_template: '${RANDOM}.neverssl.com'
    ```

    Adjust the new value, if necessary.



##  AGDNS-960 / Build 342

 *  The property `domain` of `check` object has been changed to `domains`.
    So replace this:

    ```yaml
    check:
       domain: "example.com"
    ```

    with this:

    ```yaml
    check:
       domains:
       - 'example.com'
       - 'example.org'
    ```

    Adjust the news values, if necessary.



##  AGDNS-838 / Build 338

 *  The object `upstream` has new properties, `healthcheck_enabled`,
    `healthcheck_interval`, `healthcheck_timeout`, and
    `healthcheck_backoff_time`.
    So replace this:

    ```yaml
    upstream:
        server: 127.0.0.9:53
        timeout: 2s
        fallback:
        - 1.1.1.1:53
        - 8.8.8.8:53
    ```

    with this:

    ```yaml
    upstream:
        server: 127.0.0.9:53
        timeout: 2s
        healthcheck_enabled: true
        healthcheck_interval: 2s
        healthcheck_timeout: 1s
        healthcheck_backoff_time: 30s
        fallback:
        - 1.1.1.1:53
        - 8.8.8.8:53
    ```

    Adjust the new values, if necessary.



##  Build 336

 *  The environment variable `SSLKEYLOGFILE` has been renamed to
    `SSL_KEY_LOG_FILE`.



##  AGDNS-915 / Build 334

 *  The properties `subnet_key_ip_4_mask_len` and `subnet_key_ip_6_mask_len` of
    object `ratelimit` have been renamed to `ipv4_subnet_key_len` and
    `ipv6_subnet_key_len` correspondingly.  So replace this:

    ```yaml
    ratelimit:
        # …
        subnet_key_ip_4_mask_len: 24
        subnet_key_ip_6_mask_len: 48
    ```

    with this:

    ```yaml
    ratelimit:
        # …
        ipv4_subnet_key_len: 24
        ipv6_subnet_key_len: 48
    ```



##  AGDNS-915 / Build 333

 *  The `ratelimit` object has two new properties, `subnet_key_ip_4_mask_len`
    and `subnet_key_ip_6_mask_len`.  So replace this:

    ```yaml
    ratelimit:
        # …
    ```

    with this:

    ```yaml
    ratelimit:
        # …
        subnet_key_ip_4_mask_len: 24
        subnet_key_ip_6_mask_len: 48
    ```



##  AGDNS-897 / Build 329

 *  The objects within the `filtering_groups` have a new property,
    `block_private_relay`.

    ```yaml
    filtering_groups:
    -
        id: default
        # …
    ```

    with this:

    ```yaml
    filtering_groups:
    -
        id: default
        # …
        block_private_relay: false
    ```

    The recommended default value is `false`.



##  AGDNS-624 / Build 320

 *  The objects within `server_groups` array had a change in their DDR
    configuration.  There was an opinion that the previous configuration was too
    limiting and that denormalized configuration is more self-describing. So
    replace this:

    ```yaml
    server_groups:
    -
        # …
        ddr_names:
        - 'dns.example.com'
        # …
    ```

    with this:

    ```yaml
    server_groups:
    -
        # …
        ddr:
            enabled: true
            device_records:
                '*.d.dns.example.com':
                    doh_path: '/dns-query{?dns}'
                    https_port: 443
                    quic_port: 853
                    tls_port: 853
                    ipv4_hints:
                    - 127.0.0.1
                    ipv6_hints:
                    - '::1'
            public_records:
                'dns.example.com':
                    doh_path: '/dns-query{?dns}'
                    https_port: 443
                    quic_port: 853
                    tls_port: 853
                    ipv4_hints:
                    - 127.0.0.1
                    ipv6_hints:
                    - '::1'
        # …
    ```

    Adjust the values, if necessary.  Make sure to synchronize and keep in sync
    the addresses and ports with the values of the server groups' servers.



##  AGDNS-624 / Build 317

 *  The objects within `server_groups` array have a new property `ddr_names`:

    ```yaml
    server_groups:
    -
        # …
        ddr_names:
        - 'dns.example.com'
        # …
    ```

    It is empty by default.  These values will be used for constructing a
    response for Discovery of Designated Resolvers.  Empty value leads to a
    NODATA response.  Adjust the new value, if necessary.



##  AGDNS-624 / Build 314

 *  The property `tls` of objects within the `server_groups.*.servers.*` array
    has been moved to the `server_group` object becoming common for the whole
    group.  Any group having at least a single server of DoH/DoT/DoQ protocols
    will require the `tls` property specified.  Any group having no encrypted
    resolvers will require the `tls` property absence.  So replace this:

    ```yaml
    server_groups:
    -
        # …
        servers:
        -
            name: default_dot
            protocol: tls
            tls:
                # …
            # …
    ```

    with this:

    ```yaml
    server_groups:
    -
        tls:
            # …
        # …
        servers:
        -
            name: default_dot
            protocol: tls
            # …
    ```

    Adjust the new value, if necessary.



##  AGDNS-829 / Build 308

 *  The object `upstream` has a new property, `timeout`.  So replace this:

    ```yaml
    upstream:
        server: 127.0.0.9:53
        fallback:
        - 1.1.1.1:53
        - 8.8.8.8:53
    ```

    with this:

    ```yaml
    upstream:
        server: 127.0.0.9:53
        timeout: 2s
        fallback:
        - 1.1.1.1:53
        - 8.8.8.8:53
    ```

    Adjust the new value, if necessary.



##  AGDNS-286 / Build 307

 *  The new object `connectivity_check` has been added:

    ```yaml
    connectivity_check:
        probe_ipv4: '8.8.8.8:53'
        probe_ipv6: '[2001:4860:4860::8888]:53'
    ```



##  AGDNS-745 / Build 298

 *  The object `filters` has a new property, `refresh_timeout`.  So replace
    this:

    ```yaml
    filters:
        response_ttl: 5m
        custom_filter_cache_size: 1024
        refresh_interval: 1h
    ```

    with this:

    ```yaml
    filters:
        response_ttl: 5m
        custom_filter_cache_size: 1024
        refresh_interval: 1h
        refresh_timeout: 5m
    ```

    Adjust the values, if necessary.



##  AGDNS-608 / Build 273

 *  The object `cache` has two new properties, `type` and `ecs_size`.  So
    replace this:

    ```yaml
    cache:
        size: 10000
    ```

    with this:

    ```yaml
    cache:
        type: "simple"
        size: 10000
        ecs_size: 10000
    ```

    Adjust the values, if necessary.



##  AGDNS-327 / Build 259

 *  Prometheus metric `dns_tls_handshake_total` has been updated with
    `server_name` label.  This label represents "Server Name Indication"
    identifiers, grouped by endpoint identifier and known server names.  All
    unknown server names are grouped in `other` label:

    ```none
    # TYPE dns_tls_handshake_total counter
    dns_tls_handshake_total{cipher_suite="TLS_AES_128_GCM_SHA256",did_resume="0",negotiated_proto="",proto="tls",server_name="default_dot: other",tls_version="tls1.3"} 4
    ```



##  AGDNS-607 / Build 258

 *  The special "disallow-all" response is served on `/robots.txt` requests to
    `web` module.



##  AGDNS-506 / Build 242

 *  The property `cache_size` of object `geoip` has been renamed to
    `ip_cache_size`.  Also, a new property named `host_cache_size` has been
    added.  So replace this:

    ```yaml
    geoip:
        cache_size: 100000
        refresh_interval: 1h
    ```

    with this:

    ```yaml
    geoip:
        host_cache_size: 100000
        ip_cache_size: 100000
        refresh_interval: 1h
    ```

    Adjust the new value, if necessary.



##  AGDNS-505 / Build 238

 *  The object `backend` has a new property, `bill_stat_interval`.  So replace
    this:

    ```yaml
    backend:
        timeout: 10s
        refresh_interval: 15s
        full_refresh_interval: 24h
    ```

    with this:

    ```yaml
    backend:
        timeout: 10s
        refresh_interval: 15s
        full_refresh_interval: 24h
        bill_stat_interval: 15s
    ```

    Adjust the value, if necessary.



##  AGDNS-187 / Build 228

 *  The new required environment variables `GENERAL_SAFE_SEARCH_URL` and
    `YOUTUBE_SAFE_SEARCH_URL` has been added.  Those are expected to lead to
    plain text filters, for example:

    ```sh
    GENERAL_SAFE_SEARCH_URL='https://adguardteam.github.io/HostlistsRegistry/assets/engines_safe_search.txt'
    YOUTUBE_SAFE_SEARCH_URL='https://adguardteam.github.io/HostlistsRegistry/assets/youtube_safe_search.txt'
    ```



##  AGDNS-344 / Build 226

 *  The environment variables `CONSUL_DNSCHECK_KV_URL` and
    `CONSUL_DNSCHECK_SESSION_URL` are now unset by default.  Which means that by
    default HTTP key-value database isn't used.



##  AGDNS-431 / Build 211

 *  The object `web` has a new optional property, `linked_ip`:

    ```yaml
    web:
        linked_ip:
            bind:
            -
                address: 127.0.0.1:80
            -
                address: 127.0.0.1:443
                certificates:
                -
                    certificate: ./test/cert.crt
                    key: ./test/cert.key
    ```



##  AGDNS-425 / Build 209

 *  The objects within the `server_groups.*.servers` array have a new optional
    property, `linked_ip_enabled`.  It is `false` by default.  Set to `true` to
    enable linked IP address detection on that server:

    ```yaml
    server_groups:
    -
        # …
        servers:
        -
            name: default_dns
            protocol: dns
            linked_ip_enabled: true
            # …
    ```



##  AGDNS-405 / Build 195

 *  Used our fork of miekg/dns library to fix the EDNS0 TCP keep-alive issue.



##  AGDNS-341 / Build 183

 *  Removed the static DNS check `/info.txt`.  Now that `web` module is
    available, it is no more needed since it can be configured via the `web`
    module.



##  AGDNS-341 / Build 179

 *  The object `doh` has been removed.

 *  The new optional object `web` has been added:

    ```yaml
    web:
        safe_browsing:
            bind:
            -
                address: 127.0.0.1:80
            -
                address: 127.0.0.1:443
                certificates:
                -
                    certificate: ./test/cert.crt
                    key: ./test/cert.key
            block_page: /path/to/block_page.html
        adult_blocking:
            bind:
            -
                address: 127.0.0.1:80
            -
                address: 127.0.0.1:443
                certificates:
                -
                    certificate: ./test/cert.crt
                    key: ./test/cert.key
            block_page: /path/to/block_page.html
        non_doh_bind:
        -
            address: 127.0.0.1:80
        -
            address: 127.0.0.1:443
            certificates:
            -
                certificate: ./test/cert.crt
                key: ./test/cert.key
        static_content:
            '/favicon.ico':
                content_type: image/x-icon
                content: base64content
        root_redirect_url: "https://adguard-dns.com"
        error_404: /path/to/error_404.html
        error_500: /path/to/error_500.html
        timeout: 1m
    ```



##  AGDNS-367 / Build 164

 *  The object `geoip` has a new property, `cache_size`.



##  AGDNS-310 / Build 153

 *  The environment variable `LOG_OUTPUT` has been removed.  Logs are now always
    written to stdout.



##  AGDNS-339 / Build 136

 *  The environment variable `DNSDB_PATH` is now unset by default.  Which means
    that by default DNSDB is disabled.



## AGDNS-350 / Build 135

 *  The new optional environment variable `SSLKEYLOGFILE` has been added.



##  AGDNS-345 / Build 133

 *  The object `check` has a new property, `node_location`.



##  AGDNS-322 / Build 116

 *  The property `device_id_wildcard_domains` in the objects within the
    `server_groups.*.servers` array has been renamed to the shorter
    `device_id_wildcards`.

 *  The DNS names from certificates are not used to detect device IDs and
    perform additional validations anymore.



##  AGDNS-305 / Build 114

 *  The new required environment variable `BLOCKED_SERVICE_INDEX_URL` has been
    added.  It has no default value, so it's necessary to set it.



##  AGDNS-319 / Build 113

 *  The objects within the `server_groups.*.servers` array have a new property,
    `tls.device_id_wildcard_domains`.  It is an array of domain name wildcards
    used to detect device IDs.  If necessary, add them:

    ```yaml
    server_groups:
    -
        # …
        servers:
        -
            name: default_dot
            # …
            tls:
                # …
                device_id_wildcard_domains:
                - *.dns.adguard.com
    ```



##  AGDNS-292 / Build 111

 *  The environment variable `CONSUL_URL` has been renamed to
    `CONSUL_ALLOWLIST_URL`.

 *  The new required environment variables `CONSUL_DNSCHECK_KV_URL` and
    `CONSUL_DNSCHECK_SESSION_URL` are added.  They have no default value, so
    it's necessary to set them.

 *  The object `check` has a new property, `ttl`.  Set it to a human-readable
    duration, for example `1m`.



##  AGDNS-296 / Build 110

 *  The property `parental.safe_search` of objects within the `filtering_groups`
    array is renamed to `parental.general_safe_search` to synchronize it with
    the backend.



##  Build 109

 *  The object `log` has been removed.  Its properties have been moved to the
    environment.

 *  The new environment variable `LOG_OUTPUT` has been added.  It is the path to
    the plain text log file.  If `stdout`, writes to standard output.  If
    `stderr`, writes to standard error.

    The default value is `stdout`, adjust the value, if necessary.

 *  The new environment variable `LOG_TIMESTAMP` has been added.  When it is set
    to `1`, timestamps are shown in the plain text logs.  When set to `0`, they
    are
    not shown.

    The default value is `1`, adjust the value, if necessary.

 *  The environment variable `VERBOSE` doesn't support a set but empty value.
    Unset the value or replace it with a `0`.



##  AGDNS-295 / Build 105

 *  Another change in the objects within the `filtering_groups`.  Before:

    ```yaml
    filtering_groups:
    -
        id: default
        filters:
        - adguard_dns_filter
        parental: true
        block_adult: true
        safe_browsing: true
        safe_search: true
        youtube_safe_search: true
    ```

    After:

    ```yaml
    filtering_groups:
    -
        id: default
        parental:
            enabled: true
            block_adult: true
            safe_search: true
            youtube_safe_search: true
        rule_lists:
            enabled: true
            ids:
            - adguard_dns_filter
        safe_browsing:
            enabled: true
    ```



##  AGDNS-290 / Build 97

 *  The object `check` has a new property, `node_name`.



##  AGDNS-287 / Build 96

 *  The objects within the `server_groups.*.servers` array have a new optional
    property in their `dnscrypt` objects, `inline`.  Also, the property `config`
    is renamed to `config_path`.  So replace this:

    ```yaml
    server_groups:
    -
        name: adguard_dns_default
        filtering_group: default
        servers:
        -
            name: default_dnscrypt
            # …
            dnscrypt:
                config: './test/dnscrypt.yml'
        # …
    ```

    with this:

    ```yaml
    server_groups:
    -
        name: adguard_dns_default
        filtering_group: default
        servers:
        -
            name: default_dnscrypt
            # …
            dnscrypt:
                inline:
                    provider_name: 2.dnscrypt-cert.example.org
                    public_key: F11DDBCC4817E543845FDDD4CB881849B64226F3DE397625669D87B919BC4FB0
                    private_key: 5752095FFA56D963569951AFE70FE1690F378D13D8AD6F8054DFAA100907F8B6F11DDBCC4817E543845FDDD4CB881849B64226F3DE397625669D87B919BC4FB0
                    resolver_secret: 9E46E79FEB3AB3D45F4EB3EA957DEAF5D9639A0179F1850AFABA7E58F87C74C4
                    resolver_public: 9327C5E64783E19C339BD6B680A56DB85521CC6E4E0CA5DF5274E2D3CE026C6B
                    es_version: 1
                    certificate_ttl: 8760h
        # …
    ```

    or this:

    ```yaml
    server_groups:
    -
        name: adguard_dns_default
        filtering_group: default
        servers:
        -
            name: default_dnscrypt
            # …
            dnscrypt:
                config_path: './test/dnscrypt.yml'
        # …
    ```

    Adjust the values, if necessary.



##  AGDNS-290 / Build 95

 *  The property `server_name` of object `check` is removed.



##  AGDNS-272 / Build 94

 *  The new optional object `doh` has been added, which supplements the
    DNS-over-HTTP server configuration.  Example:

    ```yaml
    doh:
        root_redirect_url: "https://adguard-dns.com/"
    ```



##  AGDNS-140 / Build 90

 *  The objects within the `server_groups.*.servers` array have a new property,
    `tls.session_keys`.  So, if necessary, replace this:

    ```yaml
    server_groups:
    -
        name: adguard_dns_default
        filtering_group: default
        servers:
        -
            name: default_dot
            # …
            tls:
                certificates:
                -
                    certificate: ./test/cert.crt
                    key: ./test/cert.key
        # …
    ```

    with this:

    ```yaml
    server_groups:
    -
        name: adguard_dns_default
        filtering_group: default
        servers:
        -
            name: default_dot
            # …
            tls:
                certificates:
                -
                    certificate: ./test/cert.crt
                    key: ./test/cert.key
                session_keys:
                - ./private/key_1
        # …
    ```



##  AGDNS-233 / Build 88

 *  The object `backend` has a new property, `full_refresh_interval`.  So
    replace this:

    ```yaml
    backend:
        timeout: 10s
        refresh_interval: 1m
    ```

    with this:

    ```yaml
    backend:
        timeout: 10s
        refresh_interval: 1m
        full_refresh_interval: 24h
    ```

    Adjust the value, if necessary.



##  AGDNS-247 / Build 86

 *  The new object `check` has been added, which configures the DNS checks
    mechanism.  Example:

    ```yaml
    check:
        domain: "dnscheck.adguard.com"
        ipv4:
        - 1.2.3.4
        - 5.6.7.8
        ipv6:
        - 1234::cdee
        - 1234::cdef
        server_name: "AdGuard DNS Default"
    ```



##  AGDNS-246 / Build 83

 *  The new environment variable `RULESTAT_URL` has been added.  Its default
    value is <code></code>, which means that no statistics are gathered.  Adjust
    the value, if necessary.



##  AGDNS-245 / Build 74

 *  The new environment variable `DNSDB_PATH` has been added.  Its default value
    is `./dnsdb.bolt`.  Adjust the value, if necessary.



##  AGDNS-139 / Build 73

 *  The new required environment variable `CONSUL_URL` has been added.  It has
    no default value, so it's necessary to set it.

 *  The ratelimit configuration for a server has changed from this:

    ```yaml
    ratelimit:
        refuseany: true
        response_size_limit: 1KB
        rate_limit_cache_ttl: 10m
        back_off_cache_ttl: 30m
        rps: 30
        backoff_limit: 1000
    ```

    to this:

    ```yaml
    ratelimit:
        allowlist:
            list:
            - '127.0.0.1'
            - '127.0.0.1/24'
            refresh_interval: 30s
        back_off_count: 1000
        back_off_duration: 30m
        back_off_period: 10m
        refuseany: true
        response_size_estimate: 1KB
        rps: 30
    ```

    See README.md for documentation.



##  AGDNS-154 / Build 71

 *  The property `backend` of the `query_log` object is removed.



##  AGDNS-230 / Build 67

 *  The new required environment variable `FILTER_INDEX_URL` has been added.  It
    has no default value, so it's necessary to set it.

 *  The environment variable `BACKEND_ENDPOINT` is now required and has no
    default value.

 *  Property `lists` of the `filters` object is removed.

 *  A new property `refresh_interval` has been added to the `filters` object.



##  AGDNS-229 / Build 62

 *  The new environment variable `FILTER_CACHE_PATH` has been added.  Its
    default value is `./filters/`.  Adjust the value, if necessary.

 *  The `list` property of `safe_browsing` and `adult_blocking` objects as well
    as the `path` property of the `filters.lists` objects are removed.

 *  Property `url` of the `filters.lists` objects is now required.



##  AGDNS-188 / Build 61

 *  The type of the `cache.size` property was changed from bytes to integer.  So
    replace this:

    ```yaml
    cache:
        size: 50KB
    ```

    with this:

    ```yaml
    cache:
        size: 10000
    ```

    Set the new values accordingly.



##  AGDNS-149, AGDNS-150, AGDNS-189 / Build 52

 *  The top-level object `parental` was renamed to `adult_blocking`.

 *  The objects `safe_browsing` and `adult_blocking` have four new properties,
    `cache_size`, `cache_ttl`, `refresh_interval`, and `url`.  So replace this:

    ```yaml
    safe_browsing:
        block_host: standard-block.dns.adguard.com
        list: ./test/safe_browsing.txt

    adult_blocking:
        block_host: family-block.dns.adguard.com
        list: ./test/parental.txt
    ```

    with this:

    ```yaml
    safe_browsing:
        url: https://static.example.com/safe_browsing.txt
        block_host: standard-block.dns.adguard.com
        cache_size: 1024
        cache_ttl: 1h
        list: ./test/safe_browsing.txt
        refresh_interval: 1h

    adult_blocking:
        url: https://static.example.com/adult_blocking.txt
        block_host: family-block.dns.adguard.com
        cache_size: 1024
        cache_ttl: 1h
        list: ./test/parental.txt
        refresh_interval: 1h
    ```

    Set the new values accordingly.

 *  The objects within the `filtering_groups` array have a new property,
    `block_adult`.  So replace this:

    ```yaml
    filtering_groups:
    -
        id: default
        filters:
        - adguard_dns_filter
        parental: false
        safe_browsing: true
        safe_search: false
        youtube_safe_search: false
    # …
    ```

    with this:

    ```yaml
    filtering_groups:
    -
        id: default
        filters:
        - adguard_dns_filter
        parental: false
        block_adult: false
        safe_browsing: true
        safe_search: false
        youtube_safe_search: false
    # …
    ```

    Set the new value accordingly.

 *  The objects within the `filters.lists` array have a new property,
    `refresh_interval`.  The property is only required when the property `url`
    is also set.  So replace this:

    ```yaml
    filters:
        # …
        lists:
        -
            id: adguard_dns_filter
            url: 'https://example.com/adguard_dns_filter.txt'
            path: ./test/filters/adguard_dns_filter.txt
        -
            id: peter_lowe_list
            path: ./test/filters/peter_lowe_list.txt
    ```

    with this:

    ```yaml
    filters:
        # …
        lists:
        -
            id: adguard_dns_filter
            url: 'https://example.com/adguard_dns_filter.txt'
            path: ./test/filters/adguard_dns_filter.txt
            refresh_interval: 1h
        -
            id: peter_lowe_list
            path: ./test/filters/peter_lowe_list.txt
    ```

    Set the new value accordingly.



##  Build 45

 *  The property `youtube_restricted` was renamed to `youtube_safe_search`.
    So replace this:

    ```yaml
    filtering_groups:
    -
        id: default
        # …
        youtube_restricted: false
    -
        id: strict
        # …
        youtube_restricted: true
    ```

    with this:

    ```yaml
    filtering_groups:
    -
        id: default
        # …
        youtube_safe_search: false
    -
        id: strict
        # …
        youtube_safe_search: true
    ```



##  AGDNS-152 / Build 43

 *  The blocked response TTL parameter has been moved and renamed.  From this:

    ```yaml
    dns:
        blocked_response_ttl: 10s
    ```

    to this:

    ```yaml
    filters:
        response_ttl: 10s
    ```

    The `dns` object has been completely removed.



##  AGDNS-177 / Build 40

 *  The TLS configuration for a server has changed from this:

    ```yaml
    tls:
        certificates:
        -
            certificate: /test/cert.crt
            key: /test/cert.key
        domains:
        - dns.adguard.com
    ```

    to this:

    ```yaml
    tls:
        certificates:
        -
            certificate: /test/cert.crt
            key: /test/cert.key
    ```

    The domains to be used in device ID detection are now expected to be
    contained in the certificate's DNS Names section of SAN.



##  AGDNS-167 / Build 39

 *  The filtering configuration has changed from this:

    ```yaml
    filters:
    -
        id: adguard_dns_filter
        path: ./tmp.dir/filter.txt
    ```

    to this:

    ```yaml
    filters:
        custom_filter_cache_size: 1024
        lists:
        -
            id: adguard_dns_filter
            path: ./tmp.dir/filter.txt
    ```