fix(demo gcp_pubsub internal_metrics source throttle transform): Fix …

…`interval` fractional second parsing (vectordotdev#17917)

The demo logs source `interval` parameter examples imply that demo logs
faster than 1/sec are possible by specifying a fractional value.
However, the demo logs source incorrectly parses this value using
serde's
[DurationSeconds](https://docs.rs/serde_with/latest/serde_with/struct.DurationSeconds.html).
This is incorrect - fractional second parts are coerced into a
full-integer value based on rounding rules. So currently, `interval`
values of >= 0.5 to 1 behave the same as `interval = 1`, while
`interval` values of < 0.5 behave the same as `interval = 0`. The
correct serde struct to use is
[DurationSecondsWithFrac](https://docs.rs/serde_with/latest/serde_with/struct.DurationSecondsWithFrac.html).

(edit): This has since expanded to complete replacement of all usages of
`DurationSeconds<f64, Strict>` with `DurationSecondsWithFrac<f64,
Strict>`. This now also affects `gcp_pubsub` and `internal_metrics`
sources, as well as the `throttle` transform.

lib/vector-config/src/external/serde_with.rs

@@ -50,7 +50,7 @@ where
 impl Configurable for serde_with::DurationSeconds<u64, serde_with::formats::Strict> {
     fn referenceable_name() -> Option<&'static str> {
         // We're masking the type parameters here because we only deal with whole seconds via this
-        // version, and handle fractional seconds with `DurationSeconds<f64, Strict>`, which we
+        // version, and handle fractional seconds with `DurationSecondsWithFrac<f64, Strict>`, which we
         // expose as `serde_with::DurationFractionalSeconds`.
         Some("serde_with::DurationSeconds")
     }
@@ -76,7 +76,7 @@ impl Configurable for serde_with::DurationSeconds<u64, serde_with::formats::Stri
     }
 }
 
-impl Configurable for serde_with::DurationSeconds<f64, serde_with::formats::Strict> {
+impl Configurable for serde_with::DurationSecondsWithFrac<f64, serde_with::formats::Strict> {
     fn referenceable_name() -> Option<&'static str> {
         // We're masking the type parameters here because we only deal with fractional seconds via this
         // version, and handle whole seconds with `DurationSeconds<u64, Strict>`, which we

src/sources/demo_logs.rs

@@ -48,7 +48,7 @@ pub struct DemoLogsConfig {
     #[derivative(Default(value = "default_interval()"))]
     #[serde(default = "default_interval")]
     #[configurable(metadata(docs::examples = 1.0, docs::examples = 0.1, docs::examples = 0.01,))]
-    #[serde_as(as = "serde_with::DurationSeconds<f64>")]
+    #[serde_as(as = "serde_with::DurationSecondsWithFrac<f64>")]
     pub interval: Duration,
 
     /// The total number of lines to output.

src/sources/gcp_pubsub.rs

@@ -162,7 +162,7 @@ pub struct PubsubConfig {
     /// How often to poll the currently active streams to see if they
     /// are all busy and so open a new stream.
     #[serde(default = "default_poll_time")]
-    #[serde_as(as = "serde_with::DurationSeconds<f64>")]
+    #[serde_as(as = "serde_with::DurationSecondsWithFrac<f64>")]
     #[configurable(metadata(docs::human_name = "Poll Time"))]
     pub poll_time_seconds: Duration,
 
@@ -184,7 +184,7 @@ pub struct PubsubConfig {
 
     /// The amount of time, in seconds, to wait between retry attempts after an error.
     #[serde(default = "default_retry_delay")]
-    #[serde_as(as = "serde_with::DurationSeconds<f64>")]
+    #[serde_as(as = "serde_with::DurationSecondsWithFrac<f64>")]
     #[configurable(metadata(docs::human_name = "Retry Delay"))]
     pub retry_delay_secs: Duration,
 
@@ -198,7 +198,7 @@ pub struct PubsubConfig {
     /// before sending a keepalive request. If this is set larger than
     /// `60`, you may see periodic errors sent from the server.
     #[serde(default = "default_keepalive")]
-    #[serde_as(as = "serde_with::DurationSeconds<f64>")]
+    #[serde_as(as = "serde_with::DurationSecondsWithFrac<f64>")]
     #[configurable(metadata(docs::human_name = "Keepalive"))]
     pub keepalive_secs: Duration,
 

src/sources/internal_metrics.rs

@@ -27,7 +27,7 @@ use crate::{
 #[serde(deny_unknown_fields, default)]
 pub struct InternalMetricsConfig {
     /// The interval between metric gathering, in seconds.
-    #[serde_as(as = "serde_with::DurationSeconds<f64>")]
+    #[serde_as(as = "serde_with::DurationSecondsWithFrac<f64>")]
     #[serde(default = "default_scrape_interval")]
     #[configurable(metadata(docs::human_name = "Scrape Interval"))]
     pub scrape_interval_secs: Duration,

src/transforms/throttle.rs

@@ -30,7 +30,7 @@ pub struct ThrottleConfig {
     threshold: u32,
 
     /// The time window in which the configured `threshold` is applied, in seconds.
-    #[serde_as(as = "serde_with::DurationSeconds<f64>")]
+    #[serde_as(as = "serde_with::DurationSecondsWithFrac<f64>")]
     #[configurable(metadata(docs::human_name = "Time Window"))]
     window_secs: Duration,