feat: [#428] upgrade default Grafana image to 12.4.2

- update domain config and code references

- align source examples and tests

- mark Grafana remediation subtask complete

Author: josecelano

docs/issues/428-docker-vulnerability-analysis-apr8-2026.md

@@ -113,7 +113,7 @@ For each image, execute these steps in order:
 #### 7. Grafana (`grafana/grafana:12.3.1`)
 
 - [x] Analysis and triage completed
-- [ ] Easy remediation implemented (if available)
+- [x] Easy remediation implemented (if available)
 - [ ] Image rebuilt and validated
 - [ ] Trivy re-scan completed and compared
 - [ ] Scan docs updated

src/application/command_handlers/show/info/docker_images.rs

@@ -15,7 +15,7 @@ pub struct DockerImagesInfo {
     /// Prometheus Docker image reference (e.g. `prom/prometheus:v3.5.1`), present when configured
     pub prometheus: Option<String>,
 
-    /// Grafana Docker image reference (e.g. `grafana/grafana:12.3.1`), present when configured
+    /// Grafana Docker image reference (e.g. `grafana/grafana:12.4.2`), present when configured
     pub grafana: Option<String>,
 }
 

src/domain/grafana/config.rs

@@ -13,7 +13,7 @@ use crate::shared::secrets::Password;
 pub const GRAFANA_DOCKER_IMAGE_REPOSITORY: &str = "grafana/grafana";
 
 /// Docker image tag for the Grafana container
-pub const GRAFANA_DOCKER_IMAGE_TAG: &str = "12.3.1";
+pub const GRAFANA_DOCKER_IMAGE_TAG: &str = "12.4.2";
 
 /// Grafana metrics visualization configuration
 ///
@@ -124,7 +124,7 @@ impl GrafanaConfig {
     /// use torrust_tracker_deployer_lib::domain::grafana::GrafanaConfig;
     ///
     /// let image = GrafanaConfig::docker_image();
-    /// assert_eq!(image.full_reference(), "grafana/grafana:12.3.1");
+    /// assert_eq!(image.full_reference(), "grafana/grafana:12.4.2");
     /// ```
     #[must_use]
     pub fn docker_image() -> DockerImage {

src/infrastructure/templating/docker_compose/template/wrappers/docker_compose/context/grafana.rs

@@ -18,7 +18,7 @@ use super::service_topology::ServiceTopology;
 /// Uses `ServiceTopology` to share the common topology structure with other services.
 #[derive(Serialize, Debug, Clone)]
 pub struct GrafanaServiceContext {
-    /// Docker image reference (e.g. `grafana/grafana:12.3.1`)
+    /// Docker image reference (e.g. `grafana/grafana:12.4.2`)
     pub image: String,
 
     /// Service topology (ports and networks)

src/shared/docker_image.rs

@@ -135,8 +135,8 @@ mod tests {
 
     #[test]
     fn it_should_implement_equality() {
-        let a = DockerImage::new("grafana/grafana", "12.3.1");
-        let b = DockerImage::new("grafana/grafana", "12.3.1");
+        let a = DockerImage::new("grafana/grafana", "12.4.2");
+        let b = DockerImage::new("grafana/grafana", "12.4.2");
         let c = DockerImage::new("grafana/grafana", "11.4.0");
 
         assert_eq!(a, b);