feat(codecs): Add lossy option to JSON deserializer (vectordotdev#17628)

Closes: vectordotdev#16406.

Adds a `decoding.json.lossy` option.

<!--
**Your PR title must conform to the conventional commit spec!**

  <type>(<scope>)!: <description>

  * `type` = chore, enhancement, feat, fix, docs
  * `!` = OPTIONAL: signals a breaking change
* `scope` = Optional when `type` is "chore" or "docs", available scopes
https://github.com/vectordotdev/vector/blob/master/.github/semantic.yml#L20
  * `description` = short description of the change

Examples:

  * enhancement(file source): Add `sort` option to sort discovered files
  * feat(new source): Initial `statsd` source
  * fix(file source): Fix a bug discovering new files
  * chore(external docs): Clarify `batch_size` option
-->

lib/codecs/src/decoding/format/json.rs

@@ -2,9 +2,11 @@ use std::convert::TryInto;
 
 use bytes::Bytes;
 use chrono::Utc;
+use derivative::Derivative;
 use lookup::PathPrefix;
 use serde::{Deserialize, Serialize};
 use smallvec::{smallvec, SmallVec};
+use vector_config::configurable_component;
 use vector_core::{
     config::{log_schema, DataType, LogNamespace},
     event::Event,
@@ -16,7 +18,36 @@ use super::Deserializer;
 
 /// Config used to build a `JsonDeserializer`.
 #[derive(Debug, Clone, Default, Deserialize, Serialize)]
-pub struct JsonDeserializerConfig;
+pub struct JsonDeserializerConfig {
+    #[serde(
+        default,
+        skip_serializing_if = "vector_core::serde::skip_serializing_if_default"
+    )]
+    /// Options for the JSON deserializer.
+    pub json: JsonDeserializerOptions,
+}
+
+/// JSON-specific decoding options.
+#[configurable_component]
+#[derive(Debug, Clone, PartialEq, Eq, Derivative)]
+#[derivative(Default)]
+pub struct JsonDeserializerOptions {
+    /// Determines whether or not to replace invalid UTF-8 sequences instead of returning an error.
+    ///
+    /// When true, invalid UTF-8 sequences are replaced with the [`U+FFFD REPLACEMENT CHARACTER`][U+FFFD].
+    ///
+    /// [U+FFFD]: https://en.wikipedia.org/wiki/Specials_(Unicode_block)#Replacement_character
+    #[serde(
+        default = "default_lossy",
+        skip_serializing_if = "vector_core::serde::skip_serializing_if_default"
+    )]
+    #[derivative(Default(value = "default_lossy()"))]
+    lossy: bool,
+}
+
+const fn default_lossy() -> bool {
+    true
+}
 
 impl JsonDeserializerConfig {
     /// Build the `JsonDeserializer` from this configuration.
@@ -56,19 +87,23 @@ impl JsonDeserializerConfig {
 
 impl JsonDeserializerConfig {
     /// Creates a new `JsonDeserializerConfig`.
-    pub fn new() -> Self {
-        Default::default()
+    pub fn new(options: JsonDeserializerOptions) -> Self {
+        Self { json: options }
     }
 }
 
 /// Deserializer that builds `Event`s from a byte frame containing JSON.
-#[derive(Debug, Clone, Default)]
-pub struct JsonDeserializer;
+#[derive(Debug, Clone, Derivative)]
+#[derivative(Default)]
+pub struct JsonDeserializer {
+    #[derivative(Default(value = "default_lossy()"))]
+    lossy: bool,
+}
 
 impl JsonDeserializer {
     /// Creates a new `JsonDeserializer`.
-    pub fn new() -> Self {
-        Default::default()
+    pub fn new(lossy: bool) -> Self {
+        Self { lossy }
     }
 }
 
@@ -84,8 +119,11 @@ impl Deserializer for JsonDeserializer {
             return Ok(smallvec![]);
         }
 
-        let json: serde_json::Value = serde_json::from_slice(&bytes)
-            .map_err(|error| format!("Error parsing JSON: {:?}", error))?;
+        let json: serde_json::Value = match self.lossy {
+            true => serde_json::from_str(&String::from_utf8_lossy(&bytes)),
+            false => serde_json::from_slice(&bytes),
+        }
+        .map_err(|error| format!("Error parsing JSON: {:?}", error))?;
 
         // If the root is an Array, split it into multiple events
         let mut events = match json {
@@ -119,8 +157,10 @@ impl Deserializer for JsonDeserializer {
 }
 
 impl From<&JsonDeserializerConfig> for JsonDeserializer {
-    fn from(_: &JsonDeserializerConfig) -> Self {
-        Self
+    fn from(config: &JsonDeserializerConfig) -> Self {
+        Self {
+            lossy: config.json.lossy,
+        }
     }
 }
 
@@ -133,7 +173,7 @@ mod tests {
     #[test]
     fn deserialize_json() {
         let input = Bytes::from(r#"{ "foo": 123 }"#);
-        let deserializer = JsonDeserializer::new();
+        let deserializer = JsonDeserializer::default();
 
         for namespace in [LogNamespace::Legacy, LogNamespace::Vector] {
             let events = deserializer.parse(input.clone(), namespace).unwrap();
@@ -160,7 +200,7 @@ mod tests {
     #[test]
     fn deserialize_json_array() {
         let input = Bytes::from(r#"[{ "foo": 123 }, { "bar": 456 }]"#);
-        let deserializer = JsonDeserializer::new();
+        let deserializer = JsonDeserializer::default();
         for namespace in [LogNamespace::Legacy, LogNamespace::Vector] {
             let events = deserializer.parse(input.clone(), namespace).unwrap();
             let mut events = events.into_iter();
@@ -197,7 +237,7 @@ mod tests {
     #[test]
     fn deserialize_skip_empty() {
         let input = Bytes::from("");
-        let deserializer = JsonDeserializer::new();
+        let deserializer = JsonDeserializer::default();
 
         for namespace in [LogNamespace::Legacy, LogNamespace::Vector] {
             let events = deserializer.parse(input.clone(), namespace).unwrap();
@@ -208,7 +248,44 @@ mod tests {
     #[test]
     fn deserialize_error_invalid_json() {
         let input = Bytes::from("{ foo");
-        let deserializer = JsonDeserializer::new();
+        let deserializer = JsonDeserializer::default();
+
+        for namespace in [LogNamespace::Legacy, LogNamespace::Vector] {
+            assert!(deserializer.parse(input.clone(), namespace).is_err());
+        }
+    }
+
+    #[test]
+    fn deserialize_lossy_replace_invalid_utf8() {
+        let input = Bytes::from(b"{ \"foo\": \"Hello \xF0\x90\x80World\" }".as_slice());
+        let deserializer = JsonDeserializer::new(true);
+
+        for namespace in [LogNamespace::Legacy, LogNamespace::Vector] {
+            let events = deserializer.parse(input.clone(), namespace).unwrap();
+            let mut events = events.into_iter();
+
+            {
+                let event = events.next().unwrap();
+                let log = event.as_log();
+                assert_eq!(log["foo"], b"Hello \xEF\xBF\xBDWorld".into());
+                assert_eq!(
+                    log.get((
+                        lookup::PathPrefix::Event,
+                        log_schema().timestamp_key().unwrap()
+                    ))
+                    .is_some(),
+                    namespace == LogNamespace::Legacy
+                );
+            }
+
+            assert_eq!(events.next(), None);
+        }
+    }
+
+    #[test]
+    fn deserialize_non_lossy_error_invalid_utf8() {
+        let input = Bytes::from(b"{ \"foo\": \"Hello \xF0\x90\x80World\" }".as_slice());
+        let deserializer = JsonDeserializer::new(false);
 
         for namespace in [LogNamespace::Legacy, LogNamespace::Vector] {
             assert!(deserializer.parse(input.clone(), namespace).is_err());

lib/codecs/src/decoding/format/mod.rs

@@ -14,7 +14,7 @@ mod syslog;
 use ::bytes::Bytes;
 use dyn_clone::DynClone;
 pub use gelf::{GelfDeserializer, GelfDeserializerConfig};
-pub use json::{JsonDeserializer, JsonDeserializerConfig};
+pub use json::{JsonDeserializer, JsonDeserializerConfig, JsonDeserializerOptions};
 pub use native::{NativeDeserializer, NativeDeserializerConfig};
 pub use native_json::{NativeJsonDeserializer, NativeJsonDeserializerConfig};
 use smallvec::SmallVec;

lib/codecs/src/decoding/mod.rs

@@ -9,8 +9,9 @@ use bytes::{Bytes, BytesMut};
 pub use error::StreamDecodingError;
 pub use format::{
     BoxedDeserializer, BytesDeserializer, BytesDeserializerConfig, GelfDeserializer,
-    GelfDeserializerConfig, JsonDeserializer, JsonDeserializerConfig, NativeDeserializer,
-    NativeDeserializerConfig, NativeJsonDeserializer, NativeJsonDeserializerConfig,
+    GelfDeserializerConfig, JsonDeserializer, JsonDeserializerConfig, JsonDeserializerOptions,
+    NativeDeserializer, NativeDeserializerConfig, NativeJsonDeserializer,
+    NativeJsonDeserializerConfig,
 };
 #[cfg(feature = "syslog")]
 pub use format::{SyslogDeserializer, SyslogDeserializerConfig};
@@ -243,7 +244,14 @@ pub enum DeserializerConfig {
     /// Decodes the raw bytes as [JSON][json].
     ///
     /// [json]: https://www.json.org/
-    Json,
+    Json {
+        /// Options for the JSON deserializer.
+        #[serde(
+            default,
+            skip_serializing_if = "vector_core::serde::skip_serializing_if_default"
+        )]
+        json: JsonDeserializerOptions,
+    },
 
     #[cfg(feature = "syslog")]
     /// Decodes the raw bytes as a Syslog message.
@@ -284,8 +292,8 @@ impl From<BytesDeserializerConfig> for DeserializerConfig {
 }
 
 impl From<JsonDeserializerConfig> for DeserializerConfig {
-    fn from(_: JsonDeserializerConfig) -> Self {
-        Self::Json
+    fn from(config: JsonDeserializerConfig) -> Self {
+        Self::Json { json: config.json }
     }
 }
 
@@ -307,7 +315,9 @@ impl DeserializerConfig {
     pub fn build(&self) -> Deserializer {
         match self {
             DeserializerConfig::Bytes => Deserializer::Bytes(BytesDeserializerConfig.build()),
-            DeserializerConfig::Json => Deserializer::Json(JsonDeserializerConfig.build()),
+            DeserializerConfig::Json { json } => {
+                Deserializer::Json(JsonDeserializerConfig::new(json.clone()).build())
+            }
             #[cfg(feature = "syslog")]
             DeserializerConfig::Syslog => {
                 Deserializer::Syslog(SyslogDeserializerConfig::default().build())
@@ -325,7 +335,7 @@ impl DeserializerConfig {
         match self {
             DeserializerConfig::Native => FramingConfig::LengthDelimited,
             DeserializerConfig::Bytes
-            | DeserializerConfig::Json
+            | DeserializerConfig::Json { .. }
             | DeserializerConfig::Gelf
             | DeserializerConfig::NativeJson => FramingConfig::NewlineDelimited {
                 newline_delimited: Default::default(),
@@ -341,7 +351,9 @@ impl DeserializerConfig {
     pub fn output_type(&self) -> DataType {
         match self {
             DeserializerConfig::Bytes => BytesDeserializerConfig.output_type(),
-            DeserializerConfig::Json => JsonDeserializerConfig.output_type(),
+            DeserializerConfig::Json { json } => {
+                JsonDeserializerConfig::new(json.clone()).output_type()
+            }
             #[cfg(feature = "syslog")]
             DeserializerConfig::Syslog => SyslogDeserializerConfig::default().output_type(),
             DeserializerConfig::Native => NativeDeserializerConfig.output_type(),
@@ -354,7 +366,9 @@ impl DeserializerConfig {
     pub fn schema_definition(&self, log_namespace: LogNamespace) -> schema::Definition {
         match self {
             DeserializerConfig::Bytes => BytesDeserializerConfig.schema_definition(log_namespace),
-            DeserializerConfig::Json => JsonDeserializerConfig.schema_definition(log_namespace),
+            DeserializerConfig::Json { json } => {
+                JsonDeserializerConfig::new(json.clone()).schema_definition(log_namespace)
+            }
             #[cfg(feature = "syslog")]
             DeserializerConfig::Syslog => {
                 SyslogDeserializerConfig::default().schema_definition(log_namespace)
@@ -371,12 +385,12 @@ impl DeserializerConfig {
     pub const fn content_type(&self, framer: &FramingConfig) -> &'static str {
         match (&self, framer) {
             (
-                DeserializerConfig::Json | DeserializerConfig::NativeJson,
+                DeserializerConfig::Json { .. } | DeserializerConfig::NativeJson,
                 FramingConfig::NewlineDelimited { .. },
             ) => "application/x-ndjson",
             (
                 DeserializerConfig::Gelf
-                | DeserializerConfig::Json
+                | DeserializerConfig::Json { .. }
                 | DeserializerConfig::NativeJson,
                 FramingConfig::CharacterDelimited {
                     character_delimited:
@@ -388,7 +402,7 @@ impl DeserializerConfig {
             ) => "application/json",
             (DeserializerConfig::Native, _) => "application/octet-stream",
             (
-                DeserializerConfig::Json
+                DeserializerConfig::Json { .. }
                 | DeserializerConfig::NativeJson
                 | DeserializerConfig::Bytes
                 | DeserializerConfig::Gelf,

src/codecs/decoding/decoder.rs

@@ -122,7 +122,7 @@ mod tests {
         let reader = StreamReader::new(stream);
         let decoder = Decoder::new(
             Framer::NewlineDelimited(NewlineDelimitedDecoder::new()),
-            Deserializer::Json(JsonDeserializer::new()),
+            Deserializer::Json(JsonDeserializer::default()),
         );
         let mut stream = FramedRead::new(reader, decoder);
 

src/components/validation/resources/mod.rs

@@ -141,7 +141,7 @@ fn deserializer_config_to_serializer(config: &DeserializerConfig) -> encoding::S
         // "bytes" can be a top-level field and we aren't implicitly decoding everything into the
         // `message` field... but it's close enough for now.
         DeserializerConfig::Bytes => SerializerConfig::Text(TextSerializerConfig::default()),
-        DeserializerConfig::Json => SerializerConfig::Json(JsonSerializerConfig::default()),
+        DeserializerConfig::Json { .. } => SerializerConfig::Json(JsonSerializerConfig::default()),
         // TODO: We need to create an Avro serializer because, certainly, for any source decoding
         // the data as Avro, we can't possibly send anything else without the source just
         // immediately barfing.
@@ -184,7 +184,9 @@ fn serializer_config_to_deserializer(config: &SerializerConfig) -> decoding::Des
         SerializerConfig::Avro { .. } => todo!(),
         SerializerConfig::Csv { .. } => todo!(),
         SerializerConfig::Gelf => DeserializerConfig::Gelf,
-        SerializerConfig::Json(_) => DeserializerConfig::Json,
+        SerializerConfig::Json(_) => DeserializerConfig::Json {
+            json: Default::default(),
+        },
         SerializerConfig::Logfmt => todo!(),
         SerializerConfig::Native => DeserializerConfig::Native,
         SerializerConfig::NativeJson => DeserializerConfig::NativeJson,

src/sources/datadog_agent/tests.rs

@@ -1595,7 +1595,9 @@ fn test_config_outputs() {
         (
             "json / single output",
             TestCase {
-                decoding: DeserializerConfig::Json,
+                decoding: DeserializerConfig::Json {
+                    json: Default::default(),
+                },
                 multiple_outputs: false,
                 want: HashMap::from([(
                     None,
@@ -1620,7 +1622,9 @@ fn test_config_outputs() {
         (
             "json / multiple output",
             TestCase {
-                decoding: DeserializerConfig::Json,
+                decoding: DeserializerConfig::Json {
+                    json: Default::default(),
+                },
                 multiple_outputs: true,
                 want: HashMap::from([
                     (

src/sources/http_client/client.rs

@@ -235,7 +235,9 @@ impl ValidatableComponent for HttpClientConfig {
         let config = Self {
             endpoint: uri.to_string(),
             interval: Duration::from_secs(1),
-            decoding: DeserializerConfig::Json,
+            decoding: DeserializerConfig::Json {
+                json: Default::default(),
+            },
             ..Default::default()
         };