chore(components): remove usages of facet (#2321)

## Summary

As stated in the PR title.

Our original intent for using `facet` was to get around the limitations of `serde` in the context of using it to deal with Agent configuration. Now that we have the full configuration schema for the Agent, however, we can do much more up front at build time, almost entirely obviating the need for a hypothetical and bespoke configuration loading system based on `facet`.

As such, we're removing the code. :)

## Change Type
- [ ] Bug fix
- [ ] New feature
- [x] Non-functional (chore, refactoring, docs)
- [ ] Performance

## How did you test this PR?

Existing tests, lints, etc etc.

## References

DADP-2

Co-authored-by: toby.lawrence <toby.lawrence@datadoghq.com>

Author: tobz

Cargo.lock

@@ -111,7 +111,6 @@ async-compression = { version = "0.4.42", default-features = false, features = [
 ] }
 zstd = { version = "0.13.3", default-features = false }
 bitmask-enum = { version = "2.2", default-features = false }
-facet = { version = "0.46.0", default-features = false, features = ["std"] }
 figment = { version = "0.10", default-features = false }
 foldhash = { version = "0.2", default-features = false, features = ["std"] }
 headers = { version = "0.4", default-features = false }

Cargo.toml

@@ -73,7 +73,6 @@ combine,https://github.com/Marwes/combine,MIT,Markus Westerlind <marwes91@gmail.
 comfy-table,https://github.com/nukesor/comfy-table,MIT,Arne Beer <contact@arne.beer>
 compression-codecs,https://github.com/Nullus157/async-compression,MIT OR Apache-2.0,"Wim Looman <wim@nemo157.com>, Allen Bui <fairingrey@gmail.com>"
 compression-core,https://github.com/Nullus157/async-compression,MIT OR Apache-2.0,"Wim Looman <wim@nemo157.com>, Allen Bui <fairingrey@gmail.com>"
-const-fnv1a-hash,https://github.com/HindrikStegenga/const-fnv1a-hash,MIT,The const-fnv1a-hash Authors
 const-hex,https://github.com/danipopes/const-hex,MIT OR Apache-2.0,DaniPopes <57450786+DaniPopes@users.noreply.github.com>
 const-oid,https://github.com/RustCrypto/formats,Apache-2.0 OR MIT,RustCrypto Developers
 const-oid,https://github.com/RustCrypto/formats/tree/master/const-oid,Apache-2.0 OR MIT,RustCrypto Developers
@@ -112,12 +111,6 @@ encoding_rs_io,https://github.com/BurntSushi/encoding_rs_io,MIT OR Apache-2.0,An
 enum_dispatch,https://gitlab.com/antonok/enum_dispatch,MIT OR Apache-2.0,Anton Lazarev <https://antonok.com>
 equivalent,https://github.com/indexmap-rs/equivalent,Apache-2.0 OR MIT,The equivalent Authors
 errno,https://github.com/lambda-fairy/rust-errno,MIT OR Apache-2.0,"Chris Wong <lambda.fairy@gmail.com>, Dan Gohman <dev@sunfishcode.online>"
-facet,https://github.com/facet-rs/facet,MIT OR Apache-2.0,The facet Authors
-facet-core,https://github.com/facet-rs/facet,MIT OR Apache-2.0,The facet-core Authors
-facet-macro-parse,https://github.com/facet-rs/facet,MIT OR Apache-2.0,The facet-macro-parse Authors
-facet-macro-types,https://github.com/facet-rs/facet,MIT OR Apache-2.0,The facet-macro-types Authors
-facet-macros,https://github.com/facet-rs/facet,MIT OR Apache-2.0,The facet-macros Authors
-facet-macros-impl,https://github.com/facet-rs/facet,MIT OR Apache-2.0,The facet-macros-impl Authors
 faster-hex,https://github.com/NervosFoundation/faster-hex,MIT,zhangsoledad <787953403@qq.com>
 fastrand,https://github.com/smol-rs/fastrand,Apache-2.0 OR MIT,Stjepan Glavina <stjepang@gmail.com>
 figment,https://github.com/SergioBenitez/Figment,MIT OR Apache-2.0,Sergio Benitez <sb@sergio.bz>
@@ -179,11 +172,9 @@ icu_properties,https://github.com/unicode-org/icu4x,Unicode-3.0,The ICU4X Projec
 icu_properties_data,https://github.com/unicode-org/icu4x,Unicode-3.0,The ICU4X Project Developers
 icu_provider,https://github.com/unicode-org/icu4x,Unicode-3.0,The ICU4X Project Developers
 id-arena,https://github.com/fitzgen/id-arena,MIT OR Apache-2.0,"Nick Fitzgerald <fitzgen@gmail.com>, Aleksey Kladov <aleksey.kladov@gmail.com>"
-iddqd,https://github.com/oxidecomputer/iddqd,MIT OR Apache-2.0,The iddqd Authors
 ident_case,https://github.com/TedDriggs/ident_case,MIT OR Apache-2.0,Ted Driggs <ted.driggs@outlook.com>
 idna,https://github.com/servo/rust-url,MIT OR Apache-2.0,The rust-url developers
 idna_adapter,https://github.com/hsivonen/idna_adapter,Apache-2.0 OR MIT,The rust-url developers
-impls,https://github.com/nvzqz/impls,MIT OR Apache-2.0,"Nikolai Vazquez, Nadrieril Feneanar"
 indexmap,https://github.com/indexmap-rs/indexmap,Apache-2.0 OR MIT,The indexmap Authors
 inlinable_string,https://github.com/fitzgen/inlinable_string,Apache-2.0 OR MIT,Nick Fitzgerald <fitzgen@gmail.com>
 ipnet,https://github.com/krisprice/ipnet,MIT OR Apache-2.0,Kris Price <kris@krisprice.nz>
@@ -235,7 +226,6 @@ miniz_oxide,https://github.com/Frommi/miniz_oxide/tree/master/miniz_oxide,MIT OR
 mintex,https://github.com/garypen/mintex,Apache-2.0,garypen <garypen@gmail.com>
 mio,https://github.com/tokio-rs/mio,MIT,"Carl Lerche <me@carllerche.com>, Thomas de Zeeuw <thomasdezeeuw@gmail.com>, Tokio Contributors <team@tokio.rs>"
 multimap,https://github.com/havarnov/multimap,MIT OR Apache-2.0,Håvar Nøvik <havar.novik@gmail.com>
-mutants,https://github.com/sourcefrog/cargo-mutants,MIT,The mutants Authors
 ndarray,https://github.com/rust-ndarray/ndarray,MIT OR Apache-2.0,"Ulrik Sverdrup ""bluss"", Jim Turner"
 nix,https://github.com/nix-rust/nix,MIT,The nix Authors
 nohash-hasher,https://github.com/paritytech/nohash-hasher,Apache-2.0 OR MIT,Parity Technologies <admin@parity.io>
@@ -460,7 +450,6 @@ unicode-segmentation,https://github.com/unicode-rs/unicode-segmentation,MIT OR A
 unicode-width,https://github.com/unicode-rs/unicode-width,MIT OR Apache-2.0,"kwantam <kwantam@gmail.com>, Manish Goregaokar <manishsmail@gmail.com>"
 unicode-xid,https://github.com/unicode-rs/unicode-xid,MIT OR Apache-2.0,"erick.tryzelaar <erick.tryzelaar@gmail.com>, kwantam <kwantam@gmail.com>, Manish Goregaokar <manishsmail@gmail.com>"
 unsafe-libyaml,https://github.com/dtolnay/unsafe-libyaml,MIT,David Tolnay <dtolnay@gmail.com>
-unsynn,https://seed.pipapo.org/nodes/seed.pipapo.org/rad:z39WbeupErKS8TwbDS5yU8eZSa3C,MIT OR Apache-2.0,Christian Thäter <ct@pipapo.org>
 untrusted,https://github.com/briansmith/untrusted,ISC,Brian Smith <brian@briansmith.org>
 url,https://github.com/servo/rust-url,MIT OR Apache-2.0,The rust-url developers
 utf8-width,https://github.com/magiclen/utf8-width,MIT,Magic Len <len@magiclen.org>

LICENSE-3rdparty.csv

@@ -29,7 +29,6 @@ datadog-agent-config = { workspace = true }
 datadog-agent-metrics-v3 = { workspace = true }
 datadog-protos = { workspace = true }
 ddsketch = { workspace = true }
-facet = { workspace = true }
 faster-hex = { workspace = true }
 figment = { workspace = true }
 float-cmp = { workspace = true, features = ["ratio"] }

lib/saluki-components/Cargo.toml

@@ -1,7 +1,6 @@
 use std::time::Duration;
 
 use agent_data_plane_config::shared::{Endpoints, MetricsEncoding};
-use facet::Facet;
 use saluki_config::{DurationString, GenericConfiguration};
 use saluki_error::GenericError;
 use saluki_io::net::client::http::{HttpProtocol, TlsMinimumVersion};
@@ -83,7 +82,7 @@ fn min_tls_version_from_config_value(value: &str) -> TlsMinimumVersion {
 
 /// HTTP protocol selection for the Datadog forwarder.
 #[repr(u8)]
-#[derive(Clone, Copy, Debug, Default, Deserialize, Eq, PartialEq, Facet)]
+#[derive(Clone, Copy, Debug, Default, Deserialize, Eq, PartialEq)]
 #[serde(rename_all = "lowercase")]
 #[cfg_attr(test, derive(serde::Serialize))]
 pub enum ForwarderHttpProtocol {
@@ -109,7 +108,7 @@ impl From<ForwarderHttpProtocol> for HttpProtocol {
 /// The Agent exposes this override under two top-level sections -- `observability_pipelines_worker`
 /// and its deprecated `vector` predecessor -- so this struct is flattened by its owner to read both
 /// from the same root.
-#[derive(Clone, Default, Deserialize, Facet)]
+#[derive(Clone, Default, Deserialize)]
 #[cfg_attr(test, derive(Debug, PartialEq, serde::Serialize))]
 pub(crate) struct OpwMetricsConfiguration {
     /// Observability Pipelines Worker routing settings.
@@ -124,7 +123,7 @@ pub(crate) struct OpwMetricsConfiguration {
 }
 
 /// One routing target's `metrics` section.
-#[derive(Clone, Default, Deserialize, Facet)]
+#[derive(Clone, Default, Deserialize)]
 #[cfg_attr(test, derive(Debug, PartialEq, serde::Serialize))]
 pub(crate) struct OpwMetricsSection {
     /// Metrics routing settings for this target.
@@ -133,7 +132,7 @@ pub(crate) struct OpwMetricsSection {
 }
 
 /// The routing settings themselves.
-#[derive(Clone, Default, Deserialize, Facet)]
+#[derive(Clone, Default, Deserialize)]
 #[cfg_attr(test, derive(Debug, PartialEq, serde::Serialize))]
 pub(crate) struct OpwMetricsSettings {
     /// Enables routing all metrics to this target.
@@ -154,7 +153,7 @@ pub(crate) struct OpwMetricsSettings {
 }
 
 /// The `use_v3_api` sub-section of a routing target's metrics settings.
-#[derive(Clone, Default, Deserialize, Facet)]
+#[derive(Clone, Default, Deserialize)]
 #[cfg_attr(test, derive(Debug, PartialEq, serde::Serialize))]
 pub(crate) struct OpwUseV3ApiSettings {
     /// Enables V3 series metrics when routing to this target.
@@ -235,7 +234,7 @@ impl OpwMetricsConfiguration {
 /// This adapter provides a simple way to utilize the existing configuration values that are passed to the Datadog
 /// Agent, which are used to control the behavior of its forwarder, such as retries and concurrency, in conjunction with
 /// with existing primitives, as such retry policies in [`saluki_io::util::retry`].
-#[derive(Clone, Deserialize, Facet)]
+#[derive(Clone, Deserialize)]
 #[cfg_attr(test, derive(Debug, PartialEq, serde::Serialize))]
 pub struct ForwarderConfiguration {
     /// Maximum number of concurrent requests for an individual endpoint.
@@ -351,7 +350,6 @@ pub struct ForwarderConfiguration {
 
     /// Parsed minimum TLS protocol version for Datadog intake forwarding.
     #[serde(skip)]
-    #[facet(opaque)]
     parsed_min_tls_version: TlsMinimumVersion,
 
     /// Timeout for completing the TLS handshake after a connection is established, for Datadog intake forwarding.
@@ -360,7 +358,6 @@ pub struct ForwarderConfiguration {
     /// bounds the entire request. A value of `0` disables the handshake deadline entirely, matching the core Agent
     /// convention for this setting.
     #[serde(default = "default_tls_handshake_timeout")]
-    #[facet(opaque)]
     tls_handshake_timeout: DurationString,
 
     /// Whether to signal that the backend should allow arbitrary tag values.

lib/saluki-components/src/common/datadog/config.rs

@@ -5,11 +5,10 @@
 //! actually reads: a struct that also accepted unrelated `data_plane` keys would silently change
 //! shape when one of them is set, which the configuration smoke tests treat as a defect.
 
-use facet::Facet;
 use serde::Deserialize;
 
 /// The `data_plane` keys read by a payload encoder.
-#[derive(Clone, Debug, Default, Deserialize, Facet)]
+#[derive(Clone, Debug, Default, Deserialize)]
 #[cfg_attr(test, derive(PartialEq, serde::Serialize))]
 pub(crate) struct EncoderDataPlaneConfiguration {
     /// ADP-specific zstd compression level, taking precedence over the Core Agent's

lib/saluki-components/src/common/datadog/data_plane.rs

@@ -4,7 +4,6 @@ use std::{
     sync::LazyLock,
 };
 
-use facet::Facet;
 use http::uri::Authority;
 use regex::Regex;
 use saluki_config::GenericConfiguration;
@@ -359,11 +358,11 @@ pub(crate) enum EndpointError {
 }
 
 #[serde_as]
-#[derive(Clone, Debug, Default, Deserialize, Facet)]
+#[derive(Clone, Debug, Default, Deserialize)]
 #[cfg_attr(test, derive(PartialEq, serde::Serialize))]
 struct APIKeys(#[serde_as(as = "OneOrMany<_>")] Vec<String>);
 
-#[derive(Clone, Debug, Default, Deserialize, Facet)]
+#[derive(Clone, Debug, Default, Deserialize)]
 #[cfg_attr(test, derive(PartialEq, serde::Serialize))]
 struct MappedAPIKeys(HashMap<String, APIKeys>);
 
@@ -397,7 +396,7 @@ impl std::fmt::Display for MappedAPIKeys {
 ///
 /// Each endpoint can be associated with multiple API keys. Requests will be forwarded to each unique endpoint/API key pair.
 #[serde_as]
-#[derive(Clone, Debug, Default, Deserialize, Facet)]
+#[derive(Clone, Debug, Default, Deserialize)]
 #[cfg_attr(test, derive(PartialEq, serde::Serialize))]
 pub(crate) struct AdditionalEndpoints(#[serde_as(as = "PickFirst<(DisplayFromStr, _)>")] MappedAPIKeys);
 
@@ -457,7 +456,7 @@ impl AdditionalEndpoints {
 }
 
 /// Endpoint configuration for sending payloads to the Datadog platform.
-#[derive(Clone, Deserialize, Facet)]
+#[derive(Clone, Deserialize)]
 #[cfg_attr(test, derive(Debug, PartialEq, serde::Serialize))]
 pub struct EndpointConfiguration {
     /// The API key to use.