Add showcase plugin

Signed-off-by: Matthias Beyer <matthias.beyer@ifm.com>

4 files changed, 170 insertions, 2 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 5cb6c7e4..de11f667 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1183,7 +1183,7 @@ dependencies = [
  "proc-macro-error",
  "proc-macro2 1.0.32",
  "quote 1.0.10",
- "syn 1.0.82",
+ "syn 1.0.91",
 ]
 
 [[package]]
@@ -2392,7 +2392,7 @@ dependencies = [
  "tedge_lib",
  "thiserror",
  "tokio",
- "tokio-util 0.7.0",
+ "tokio-util 0.7.1",
  "tracing",
 ]
 
@@ -2437,6 +2437,22 @@ dependencies = [
 ]
 
 [[package]]
+name = "plugin_random_measurements"
+version = "0.1.0"
+dependencies = [
+ "async-trait",
+ "humantime 2.1.0",
+ "humantime-serde",
+ "miette",
+ "rand",
+ "serde",
+ "tedge_api",
+ "tedge_lib",
+ "tokio",
+ "tracing",
+]
+
+[[package]]
 name = "plugin_sm"
 version = "0.5.2"
 dependencies = [
diff --git a/Cargo.toml b/Cargo.toml
index 0abe6314..735b96e2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -13,6 +13,7 @@ members = [
     "plugins/plugin_moneo_mapper",
     "plugins/plugin_mqtt",
     "plugins/plugin_mqtt_measurement_bridge",
+    "plugins/plugin_random_measurements",
     "plugins/plugin_sysstat",
     "plugins/tedge_apt_plugin",
     "plugins/tedge_dummy_plugin",
diff --git a/plugins/plugin_random_measurements/Cargo.toml b/plugins/plugin_random_measurements/Cargo.toml
new file mode 100644
index 00000000..399564be
--- /dev/null
+++ b/plugins/plugin_random_measurements/Cargo.toml
@@ -0,0 +1,19 @@
+[package]
+name = "plugin_random_measurements"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+async-trait = "0.1"
+humantime = "2.1"
+humantime-serde = "1.1"
+miette = "4.4"
+rand = "0.8"
+serde = { version = "1", features = ["derive"] }
+tokio = { version = "1", features = ["rt"] }
+tracing = "0.1"
+
+tedge_api = { path = "../../crates/core/tedge_api" }
+tedge_lib = { path = "../../crates/core/tedge_lib" }
diff --git a/plugins/plugin_random_measurements/src/lib.rs b/plugins/plugin_random_measurements/src/lib.rs
new file mode 100644
index 00000000..168e1db7
--- /dev/null
+++ b/plugins/plugin_random_measurements/src/lib.rs
@@ -0,0 +1,132 @@
+use std::sync::Arc;
+
+use async_trait::async_trait;
+use miette::Context;
+use miette::IntoDiagnostic;
+use tedge_api::plugin::PluginExt;
+use tedge_api::CancellationToken;
+
+use tedge_api::Address;
+use tedge_api::Plugin;
+use tedge_api::PluginBuilder;
+use tedge_api::PluginConfiguration;
+use tedge_api::PluginDirectory;
+use tedge_api::PluginError;
+use tedge_lib::mainloop::MainloopStopper;
+use tedge_lib::measurement::Measurement;
+use tedge_lib::measurement::MeasurementValue;
+
+pub struct RandomMeasurementsPluginBuilder;
+
+#[derive(serde::Deserialize, Debug)]
+struct RandomMeasurementsPluginConfig {
+    #[serde(with = "humantime_serde")]
+    interval: std::time::Duration,
+    target: String,
+}
+
+#[async_trait]
+impl<PD: PluginDirectory> PluginBuilder<PD> for RandomMeasurementsPluginBuilder {
+    fn kind_name() -> &'static str {
+        "random_measurements"
+    }
+
+    async fn verify_configuration(
+        &self,
+        config: &PluginConfiguration,
+    ) -> Result<(), tedge_api::error::PluginError> {
+        config
+            .clone()
+            .try_into()
+            .map(|_: RandomMeasurementsPluginConfig| ())
+            .into_diagnostic()
+            .context("Failed to parse random-measurements-plugin configuration")
+            .map_err(PluginError::from)
+    }
+
+    async fn instantiate(
+        &self,
+        config: PluginConfiguration,
+        _cancellation_token: CancellationToken,
+        plugin_dir: &PD,
+    ) -> Result<tedge_api::plugin::BuiltPlugin, PluginError> {
+        let config = config
+            .try_into::<RandomMeasurementsPluginConfig>()
+            .into_diagnostic()
+            .context("Failed to parse random-measurements-plugin configuration")?;
+
+        let address = plugin_dir.get_address_for::<MeasurementReceiver>(&config.target)?;
+        Ok(RandomMeasurementsPlugin::new(address, config.interval).finish())
+    }
+
+    fn kind_message_types() -> tedge_api::plugin::HandleTypes
+    where
+        Self: Sized,
+    {
+        RandomMeasurementsPlugin::get_handled_types()
+    }
+}
+
+tedge_api::make_receiver_bundle!(struct MeasurementReceiver(Measurement));
+
+struct RandomMeasurementsPlugin {
+    addr: Address<MeasurementReceiver>,
+    interval: std::time::Duration,
+
+    stopper: Option<MainloopStopper>,
+}
+
+impl tedge_api::plugin::PluginDeclaration for RandomMeasurementsPlugin {
+    type HandledMessages = ();
+}
+
+impl RandomMeasurementsPlugin {
+    fn new(addr: Address<MeasurementReceiver>, interval: std::time::Duration) -> Self {
+        Self {
+            addr,
+            interval,
+
+            stopper: None,
+        }
+    }
+}
+
+struct State {
+    target: Address<MeasurementReceiver>,
+}
+
+#[async_trait]
+impl Plugin for RandomMeasurementsPlugin {
+    async fn start(&mut self) -> Result<(), PluginError> {
+        let state = State {
+            target: self.addr.clone(),
+        };
+        let (stopper, mainloop) =
+            tedge_lib::mainloop::Mainloop::ticking_every(self.interval, state);
+
+        self.stopper = Some(stopper);
+
+        let _ = tokio::spawn(mainloop.run(main_random_measurements));
+        Ok(())
+    }
+
+    async fn shutdown(&mut self) -> Result<(), PluginError> {
+        if let Some(stopper) = self.stopper.take() {
+            stopper
+                .stop()
+                .map_err(|()| miette::miette!("Failed to stop mainloop"))?
+        }
+        Ok(())
+    }
+}
+
+async fn main_random_measurements(state: Arc<State>) -> Result<(), PluginError> {
+    let f: f64 = rand::random(); // value in [0, 1)
+    let msmt = Measurement::new("random".to_string(), MeasurementValue::Float(f));
+    state
+        .target
+        .send(msmt)
+        .await
+        .map_err(|_| miette::miette!("Failed to send random measurement"))?;
+    Ok(())
+}