Changes that are expected to cause an incompatibility if applicable; deployment changes are likely required
- config: v2 is now fatal-by-default. This may be overridden by setting :option:`--bootstrap-version` 2 on the CLI for a v2 bootstrap file and also enabling the runtime envoy.reloadable_features.enable_deprecated_v2_api feature. See the :ref:`FAQ entry <faq_api_version_transition>` for further details.
Changes that may cause incompatibilities for some users, but should not for most
- build: the Alpine based debug images are no longer built in CI, use Ubuntu based images instead.
- decompressor: set the default value of window_bits of the decompressor to 15 to be able to decompress responses compressed by a compressor with any window size.
- expr filter: added connection.termination_details property support.
- formatter: the :ref:`text_format <envoy_v3_api_field_config.core.v3.SubstitutionFormatString.text_format>` field no longer requires at least one byte, and may now be the empty string. It has also become :ref:`deprecated <1_17_deprecated>`.
- grpc_web filter: if a grpc-accept-encoding header is present it's passed as-is to the upstream and if it isn't grpc-accept-encoding:identity is sent instead. The header was always overwriten with grpc-accept-encoding:identity,deflate,gzip before.
- http: upstream protocol will now only be logged if an upstream stream was established.
- jwt_authn filter: added support of JWT time constraint verification with a clock skew (default to 60 seconds) and added a filter config field :ref:`clock_skew_seconds <envoy_v3_api_field_extensions.filters.http.jwt_authn.v3.JwtProvider.clock_skew_seconds>` to configure it.
- listener: injection of the :ref:`TLS inspector <config_listener_filters_tls_inspector>` has been disabled by default. This feature is controlled by the runtime guard envoy.reloadable_features.disable_tls_inspector_injection.
- lua: added always_wrap_body argument to body() API to always return a :ref:`buffer object <config_http_filters_lua_buffer_wrapper>` even if the body is empty.
- memory: enabled new tcmalloc with restartable sequences for aarch64 builds.
- mongo proxy metrics: swapped network connection remote and local closed counters previously set reversed (cx_destroy_local_with_active_rq and cx_destroy_remote_with_active_rq).
- outlier detection: added :ref:`max_ejection_time <envoy_v3_api_field_config.cluster.v3.OutlierDetection.max_ejection_time>` to limit ejection time growth when a node stays unhealthy for extended period of time. By default :ref:`max_ejection_time <envoy_v3_api_field_config.cluster.v3.OutlierDetection.max_ejection_time>` limits ejection time to 5 minutes. Additionally, when the node stays healthy, ejection time decreases. See :ref:`ejection algorithm<arch_overview_outlier_detection_algorithm>` for more info. Previously, ejection time could grow without limit and never decreased.
- performance: improved performance when handling large HTTP/1 bodies.
- tcp_proxy: now waits for HTTP tunnel to be established before start streaming the downstream data, the runtime guard envoy.reloadable_features.http_upstream_wait_connect_response can be set to "false" to disable this behavior.
- tls: removed RSA key transport and SHA-1 cipher suites from the client-side defaults.
- watchdog: the watchdog action :ref:`abort_action <envoy_v3_api_msg_watchdog.v3alpha.AbortActionConfig>` is now the default action to terminate the process if watchdog kill / multikill is enabled.
- xds: to support TTLs, heartbeating has been added to xDS. As a result, responses that contain empty resources without updating the version will no longer be propagated to the subscribers. To undo this for VHDS (which is the only subscriber that wants empty resources), the envoy.reloadable_features.vhds_heartbeats can be set to "false".
Changes expected to improve the state of the world and are unlikely to have negative effects
- config: validate that upgrade configs have a non-empty :ref:`upgrade_type <envoy_v3_api_field_extensions.filters.network.http_connection_manager.v3.HttpConnectionManager.UpgradeConfig.upgrade_type>`, fixing a bug where an errant "-" could result in unexpected behavior.
- dns: fixed a bug where custom resolvers provided in configuration were not preserved after network issues.
- dns_filter: correctly associate DNS response IDs when multiple queries are received.
- grpc mux: fixed sending node again after stream is reset when :ref:`set_node_on_first_message_only <envoy_api_field_core.ApiConfigSource.set_node_on_first_message_only>` is set.
- http: fixed URL parsing for HTTP/1.1 fully qualified URLs and connect requests containing IPv6 addresses.
- http: reject requests with missing required headers after filter chain processing.
- http: sending CONNECT_ERROR for HTTP/2 where appropriate during CONNECT requests.
- proxy_proto: fixed a bug where the wrong downstream address got sent to upstream connections.
- proxy_proto: fixed a bug where network filters would not have the correct downstreamRemoteAddress() when accessed from the StreamInfo. This could result in incorrect enforcement of RBAC rules in the RBAC network filter (but not in the RBAC HTTP filter), or incorrect access log addresses from tcp_proxy.
- sds: fixed a bug that clusters sharing same sds target are marked active immediately.
- tls: fixed detection of the upstream connection close event.
- tls: fixed read resumption after triggering buffer high-watermark and all remaining request/response bytes are stored in the SSL connection's internal buffers.
- udp: fixed issue in which receiving truncated UDP datagrams would cause Envoy to crash.
- watchdog: touch the watchdog before most event loop operations to avoid misses when handling bursts of callbacks.
Normally occurs at the end of the :ref:`deprecation period <deprecated>`
- dispatcher: removed legacy socket read/write resumption code path and runtime guard envoy.reloadable_features.activate_fds_next_event_loop.
- ext_authz: removed auto ignore case in HTTP-based ext_authz header matching and the runtime guard envoy.reloadable_features.ext_authz_http_service_enable_case_sensitive_string_matcher. To ignore case, set the :ref:`ignore_case <envoy_api_field_type.matcher.StringMatcher.ignore_case>` field to true.
- ext_authz: the deprecated field use_alpha is no longer supported and cannot be set anymore.
- http: removed envoy.reloadable_features.http1_flood_protection and legacy code path for turning flood protection off.
- http: removed envoy.reloadable_features.new_codec_behavior and legacy codecs.
- compression: the :ref:`compressor <envoy_v3_api_msg_extensions.filters.http.compressor.v3.Compressor>` filter added support for compressing request payloads. Its configuration is unified with the :ref:`decompressor <envoy_v3_api_msg_extensions.filters.http.decompressor.v3.Decompressor>` filter with two new fields for different directions - :ref:`requests <envoy_v3_api_field_extensions.filters.http.compressor.v3.Compressor.request_direction_config>` and :ref:`responses <envoy_v3_api_field_extensions.filters.http.compressor.v3.Compressor.response_direction_config>`. The latter deprecates the old response-specific fields and, if used, roots the response-specific stats in <stat_prefix>.compressor.<compressor_library.name>.<compressor_library_stat_prefix>.response.* instead of <stat_prefix>.compressor.<compressor_library.name>.<compressor_library_stat_prefix>.*.
- config: added ability to flush stats when the admin's :ref:`/stats endpoint <operations_admin_interface_stats>` is hit instead of on a timer via :ref:`stats_flush_on_admin <envoy_v3_api_field_config.bootstrap.v3.Bootstrap.stats_flush_on_admin>`.
- config: added new runtime feature envoy.features.enable_all_deprecated_features that allows the use of all deprecated features.
- crash support: added the ability to dump L4 connection data on crash.
- formatter: added new :ref:`text_format_source <envoy_v3_api_field_config.core.v3.SubstitutionFormatString.text_format_source>` field to support format strings both inline and from a file.
- formatter: added support for custom date formatting to :ref:`%DOWNSTREAM_PEER_CERT_V_START% <config_access_log_format_downstream_peer_cert_v_start>` and :ref:`%DOWNSTREAM_PEER_CERT_V_END% <config_access_log_format_downstream_peer_cert_v_end>`, similar to :ref:`%START_TIME% <config_access_log_format_start_time>`.
- grpc: implemented header value syntax support when defining :ref:`initial metadata <envoy_v3_api_field_config.core.v3.GrpcService.initial_metadata>` for gRPC-based ext_authz :ref:`HTTP <envoy_v3_api_field_extensions.filters.http.ext_authz.v3.ExtAuthz.grpc_service>` and :ref:`network <envoy_v3_api_field_extensions.filters.network.ext_authz.v3.ExtAuthz.grpc_service>` filters, and :ref:`ratelimit <envoy_v3_api_field_config.ratelimit.v3.RateLimitServiceConfig.grpc_service>` filters.
- grpc-json: added support for configuring :ref:`unescaping behavior <envoy_v3_api_field_extensions.filters.http.grpc_json_transcoder.v3.GrpcJsonTranscoder.url_unescape_spec>` for path components.
- hds: added support for delta updates in the :ref:`HealthCheckSpecifier <envoy_v3_api_msg_service.health.v3.HealthCheckSpecifier>`, making only the Endpoints and Health Checkers that changed be reconstructed on receiving a new message, rather than the entire HDS.
- health_check: added option to use :ref:`no_traffic_healthy_interval <envoy_v3_api_field_config.core.v3.HealthCheck.no_traffic_healthy_interval>` which allows a different no traffic interval when the host is healthy.
- http: added HCM :ref:`request_headers_timeout config field <envoy_v3_api_field_extensions.filters.network.http_connection_manager.v3.HttpConnectionManager.request_headers_timeout>` to control how long a downstream has to finish sending headers before the stream is cancelled.
- http: added frame flood and abuse checks to the upstream HTTP/2 codec. This check is off by default and can be enabled by setting the envoy.reloadable_features.upstream_http2_flood_checks runtime key to true.
- http: added :ref:`stripping any port from host header <envoy_v3_api_field_extensions.filters.network.http_connection_manager.v3.HttpConnectionManager.strip_any_host_port>` support.
- http: clusters added support for selecting HTTP/1 or HTTP/2 based on ALPN, configurable via :ref:`alpn_config <envoy_v3_api_field_extensions.upstreams.http.v3.HttpProtocolOptions.auto_config>` in the :ref:`http_protocol_options <envoy_v3_api_msg_extensions.upstreams.http.v3.HttpProtocolOptions>` message.
- jwt_authn: added support for :ref:`per-route config <envoy_v3_api_msg_extensions.filters.http.jwt_authn.v3.PerRouteConfig>`.
- jwt_authn: changed config field :ref:`issuer <envoy_v3_api_field_extensions.filters.http.jwt_authn.v3.JwtProvider.issuer>` to be optional to comply with JWT RFC requirements.
- kill_request: added new :ref:`HTTP kill request filter <config_http_filters_kill_request>`.
- listener: added an optional :ref:`default filter chain <envoy_v3_api_field_config.listener.v3.Listener.default_filter_chain>`. If this field is supplied, and none of the :ref:`filter_chains <envoy_v3_api_field_config.listener.v3.Listener.filter_chains>` matches, this default filter chain is used to serve the connection.
- listener: added back the :ref:`use_original_dst field <envoy_v3_api_field_config.listener.v3.Listener.use_original_dst>`.
- listener: added the :ref:`Listener.bind_to_port field <envoy_v3_api_field_config.listener.v3.Listener.bind_to_port>`.
- log: added a new custom flag
%_to the log pattern to print the actual message to log, but with escaped newlines. - lua: added downstreamDirectRemoteAddress() and downstreamLocalAddress() APIs to :ref:`streamInfo() <config_http_filters_lua_stream_info_wrapper>`.
- mongo_proxy: the list of commands to produce metrics for is now :ref:`configurable <envoy_v3_api_field_extensions.filters.network.mongo_proxy.v3.MongoProxy.commands>`.
- network: added a :ref:`transport_socket_connect_timeout config field <envoy_v3_api_field_config.listener.v3.FilterChain.transport_socket_connect_timeout>` for incoming connections completing transport-level negotiation, including TLS and ALTS hanshakes.
- overload: added :ref:`envoy.overload_actions.reduce_timeouts <config_overload_manager_overload_actions>` overload action to enable scaling timeouts down with load. Scaling support :ref:`is limited <envoy_v3_api_enum_config.overload.v3.ScaleTimersOverloadActionConfig.TimerType>` to the HTTP connection and stream idle timeouts.
- ratelimit: added support for use of various :ref:`metadata <envoy_v3_api_field_config.route.v3.RateLimit.Action.metadata>` as a ratelimit action.
- ratelimit: added :ref:`disable_x_envoy_ratelimited_header <envoy_v3_api_msg_extensions.filters.http.ratelimit.v3.RateLimit>` option to disable X-Envoy-RateLimited header.
- ratelimit: added :ref:`body <envoy_v3_api_field_service.ratelimit.v3.RateLimitResponse.raw_body>` field to support custom response bodies for non-OK responses from the external ratelimit service.
- ratelimit: added :ref:`descriptor extensions <envoy_v3_api_field_config.route.v3.RateLimit.Action.extension>`.
- ratelimit: added :ref:`computed descriptors <envoy_v3_api_msg_extensions.rate_limit_descriptors.expr.v3.Descriptor>`.
- ratelimit: added :ref:`dynamic_metadata <envoy_v3_api_field_service.ratelimit.v3.RateLimitResponse.dynamic_metadata>` field to support setting dynamic metadata from the ratelimit service.
- router: added support for regex rewrites during HTTP redirects using :ref:`regex_rewrite <envoy_v3_api_field_config.route.v3.RedirectAction.regex_rewrite>`.
- sds: improved support for atomic :ref:`key rotations <xds_certificate_rotation>` and added configurable rotation triggers for :ref:`TlsCertificate <envoy_v3_api_field_extensions.transport_sockets.tls.v3.TlsCertificate.watched_directory>` and :ref:`CertificateValidationContext <envoy_v3_api_field_extensions.transport_sockets.tls.v3.CertificateValidationContext.watched_directory>`.
- signal: added an extension point for custom actions to run on the thread that has encountered a fatal error. Actions are configurable via :ref:`fatal_actions <envoy_v3_api_field_config.bootstrap.v3.Bootstrap.fatal_actions>`.
- start_tls: added new :ref:`transport socket<envoy_v3_api_msg_extensions.transport_sockets.starttls.v3.StartTlsConfig>` which starts in clear-text but may programatically be converted to use tls.
- tcp: added a new :ref:`envoy.overload_actions.reject_incoming_connections <config_overload_manager_overload_actions>` action to reject incoming TCP connections.
- thrift_proxy: added a new :ref:`payload_passthrough <envoy_v3_api_field_extensions.filters.network.thrift_proxy.v3.ThriftProxy.payload_passthrough>` option to skip decoding body in the Thrift message.
- tls: added support for RSA certificates with 4096-bit keys in FIPS mode.
- tracing: added :ref:`SkyWalking tracer <envoy_v3_api_msg_config.trace.v3.SkyWalkingConfig>`.
- tracing: added support for setting the hostname used when sending spans to a Zipkin collector using the :ref:`collector_hostname <envoy_v3_api_field_config.trace.v3.ZipkinConfig.collector_hostname>` field.
- xds: added support for resource TTLs. A TTL is specified on the :ref:`Resource <envoy_api_msg_Resource>`. For SotW, a :ref:`Resource <envoy_api_msg_Resource>` can be embedded in the list of resources to specify the TTL.
- cluster: HTTP configuration for upstream clusters has been reworked. HTTP-specific configuration is now done in the new :ref:`http_protocol_options <envoy_v3_api_msg_extensions.upstreams.http.v3.HttpProtocolOptions>` message, configured via the cluster's :ref:`extension_protocol_options<envoy_v3_api_field_config.cluster.v3.Cluster.typed_extension_protocol_options>`. This replaces explicit HTTP configuration in cluster config, including :ref:`upstream_http_protocol_options<envoy_v3_api_field_config.cluster.v3.Cluster.upstream_http_protocol_options>` :ref:`common_http_protocol_options<envoy_v3_api_field_config.cluster.v3.Cluster.common_http_protocol_options>` :ref:`http_protocol_options<envoy_v3_api_field_config.cluster.v3.Cluster.http_protocol_options>` :ref:`http2_protocol_options<envoy_v3_api_field_config.cluster.v3.Cluster.http2_protocol_options>` and :ref:`protocol_selection<envoy_v3_api_field_config.cluster.v3.Cluster.protocol_selection>`. Examples of before-and-after configuration can be found in the :ref:`http_protocol_options docs <envoy_v3_api_msg_extensions.upstreams.http.v3.HttpProtocolOptions>` and all of Envoy's example configurations have been updated to the new style of config.
- compression: the fields :ref:`content_length <envoy_v3_api_field_extensions.filters.http.compressor.v3.Compressor.content_length>`, :ref:`content_type <envoy_v3_api_field_extensions.filters.http.compressor.v3.Compressor.content_type>`, :ref:`disable_on_etag_header <envoy_v3_api_field_extensions.filters.http.compressor.v3.Compressor.disable_on_etag_header>`, :ref:`remove_accept_encoding_header <envoy_v3_api_field_extensions.filters.http.compressor.v3.Compressor.remove_accept_encoding_header>` and :ref:`runtime_enabled <envoy_v3_api_field_extensions.filters.http.compressor.v3.Compressor.runtime_enabled>` of the :ref:`Compressor <envoy_v3_api_msg_extensions.filters.http.compressor.v3.Compressor>` message have been deprecated in favor of :ref:`response_direction_config <envoy_v3_api_field_extensions.filters.http.compressor.v3.Compressor.response_direction_config>`.
- formatter: :ref:`text_format <envoy_v3_api_field_config.core.v3.SubstitutionFormatString.text_format>` is now deprecated in favor of :ref:`text_format_source <envoy_v3_api_field_config.core.v3.SubstitutionFormatString.text_format_source>`. To migrate existing text format strings, use the :ref:`inline_string <envoy_v3_api_field_config.core.v3.DataSource.inline_string>` field.
- gzip: :ref:`HTTP Gzip filter <config_http_filters_gzip>` is rejected now unless explicitly allowed with :ref:`runtime override <config_runtime_deprecation>` envoy.deprecated_features.allow_deprecated_gzip_http_filter set to true. Use the :ref:`compressor filter <config_http_filters_compressor>`.
- listener: :ref:`use_proxy_proto <envoy_v3_api_field_config.listener.v3.FilterChain.use_proxy_proto>` has been deprecated in favor of adding a :ref:`PROXY protocol listener filter <config_listener_filters_proxy_protocol>` explicitly.
- logging: the --log-format-prefix-with-location option is removed.
- ratelimit: the :ref:`dynamic metadata <envoy_v3_api_field_config.route.v3.RateLimit.Action.dynamic_metadata>` action is deprecated in favor of the more generic :ref:`metadata <envoy_v3_api_field_config.route.v3.RateLimit.Action.metadata>` action.
- stats: the --use-fake-symbol-table option is removed.
- tracing: OpenCensus :ref:`Zipkin configuration <envoy_api_field_config.trace.v2.OpenCensusConfig.zipkin_exporter_enabled>` is now deprecated, the preferred Zipkin export is via Envoy's :ref:`native Zipkin tracer <envoy_v3_api_msg_config.trace.v3.ZipkinConfig>`.