style: Define error variants instead of using unwrap()

crates/bpf-common/src/containers/layers.rs

@@ -80,12 +80,27 @@ struct Rootfs {
 /// Returns a list of layer paths for the given Docker image ID.
 pub(crate) async fn docker_layers(image_id: &str) -> Result<Vec<PathBuf>, ContainerError> {
     let client = Client::unix();
-    let url = HyperlocalUri::new(DOCKER_SOCKET, &format!("/images/{}/json", image_id));
-
-    let response = client.get(url.into()).await.unwrap();
-    let body_bytes = body::to_bytes(response).await.unwrap();
-
-    let response: ImageInspect = serde_json::from_slice(&body_bytes).unwrap();
+    let uri = HyperlocalUri::new(DOCKER_SOCKET, &format!("/images/{}/json", image_id));
+    let uri: hyper::Uri = uri.into();
+
+    let response =
+        client
+            .get(uri.clone())
+            .await
+            .map_err(|source| ContainerError::HyperRequest {
+                source,
+                uri: uri.clone(),
+            })?;
+    let body_bytes =
+        body::to_bytes(response)
+            .await
+            .map_err(|source| ContainerError::HyperResponse {
+                source,
+                uri: uri.clone(),
+            })?;
+
+    let response: ImageInspect = serde_json::from_slice(&body_bytes)
+        .map_err(|source| ContainerError::ParseResponse { source, uri })?;
 
     match response.graph_driver.name {
         GraphDriverName::Btrfs => docker_btrfs_layers(image_id),
@@ -132,7 +147,10 @@ fn docker_btrfs_layers(image_id: &str) -> Result<Vec<PathBuf>, ContainerError> {
         .map_err(|source| ContainerError::ParseConfigFile { source, path })?;
 
     for layer_id in imagedb_entry.rootfs.diff_ids {
-        let layer_id = layer_id.split(':').last().unwrap();
+        let layer_id = layer_id
+            .split(':')
+            .last()
+            .ok_or(ContainerError::InvalidLayerID(layer_id.clone()))?;
 
         let path = PathBuf::from(DOCKER_LAYERDB_PATH).join(&layer_id);
         if path.exists() {
@@ -156,6 +174,7 @@ fn docker_overlayfs_layers(
     if let Some(graph_driver_data) = graph_driver_data {
         if let Some(lower_dirs) = graph_driver_data.lower_dir {
             for lower_dir in lower_dirs.split(':') {
+                // `PathBuf::from_str` is infallible.
                 layers.push(PathBuf::from_str(lower_dir).unwrap());
             }
         }

crates/bpf-common/src/containers/mod.rs

@@ -41,8 +41,26 @@ pub enum ContainerError {
         source: serde_json::error::Error,
         path: PathBuf,
     },
+    #[error("parsing response from `{uri:?}` failed")]
+    ParseResponse {
+        #[source]
+        source: serde_json::error::Error,
+        uri: hyper::Uri,
+    },
     #[error("path `{path}` is non-UTF-8")]
     PathNonUtf8 { path: PathBuf },
+    #[error("failed to make a request to the UNIX socket `{uri:?}`")]
+    HyperRequest {
+        #[source]
+        source: hyper::Error,
+        uri: hyper::Uri,
+    },
+    #[error("failed to parse a response from the UNIX socket `{uri:?}`")]
+    HyperResponse {
+        #[source]
+        source: hyper::Error,
+        uri: hyper::Uri,
+    },
     #[error("could not connect to the database `{path:?}`")]
     SqliteConnection {
         #[source]
@@ -79,6 +97,10 @@ pub enum ContainerError {
     BoltBucketNotFound(String),
     #[error("bolt key `{0}` not found")]
     BoltKeyNotFound(String),
+    #[error("Invalid layer ID: `{0}`")]
+    InvalidLayerID(String),
+    #[error("Invalid image digest: `{0}`")]
+    InvalidImageDigest(String),
 }
 
 /// A container ID.
@@ -204,7 +226,10 @@ impl ContainerInfo {
         // ```
         //
         // The unprefixed digest is used as an image ID.
-        let image_id = image_digest.split(':').last().unwrap();
+        let image_id = image_digest
+            .split(':')
+            .last()
+            .ok_or(ContainerError::InvalidImageDigest(image_digest.clone()))?;
 
         let layers = layers::docker_layers(image_id).await?;
         log::debug!("found layer filesystems for container {id}: {layers:?}");