feat: custom error types.

Add custom error types for all errors generated in the library.

Signed-off-by: José Guilherme Vanz <[email protected]>

Cargo.toml

@@ -11,7 +11,6 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-anyhow = "1.0"
 async-std = "1.9"
 async-stream = "0.3"
 async-trait = "0.1"
@@ -36,6 +35,7 @@ sigstore = { version = "0.7.2", default-features = false, features = [
   "tuf",
   "cached-client",
 ] }
+thiserror = "1.0"
 tracing = "0.1"
 url = { version = "2.2", features = ["serde"] }
 walkdir = "2"

src/errors.rs

@@ -0,0 +1,41 @@
+use thiserror::Error;
+
+pub type FetcherResult<T> = std::result::Result<T, FetcherError>;
+
+#[derive(Error, Debug)]
+pub enum FetcherError {
+    #[error("cannot retrieve path from uri: {0}")]
+    InvalidFilePathError(String),
+    #[error("invalid wasm file")]
+    InvalidWasmFileError,
+    #[error("wasm module cannot be save to {0:?}: {1}")]
+    CannotWriteWasmModuleFile(String, #[source] std::io::Error),
+    #[error(transparent)]
+    PolicyError(#[from] crate::policy::DigestError),
+    #[error(transparent)]
+    VerifyError(#[from] crate::verify::errors::VerifyError),
+    #[error(transparent)]
+    RegistryError(#[from] crate::registry::errors::RegistryError),
+    #[error(transparent)]
+    UrlParserError(#[from] url::ParseError),
+    #[error(transparent)]
+    SourceError(#[from] crate::sources::SourceError),
+    #[error(transparent)]
+    StoreError(#[from] crate::store::errors::StoreError),
+    #[error(transparent)]
+    InvalidURLError(#[from] InvalidURLError),
+    #[error(transparent)]
+    CannotCreateStoragePathError(#[from] CannotCreateStoragePathError),
+}
+
+#[derive(thiserror::Error, Debug)]
+#[error("{0}")]
+pub struct FailedToParseYamlDataError(#[from] pub serde_yaml::Error);
+
+#[derive(thiserror::Error, Debug)]
+#[error("invalid URL: {0}")]
+pub struct CannotCreateStoragePathError(#[from] pub std::io::Error);
+
+#[derive(thiserror::Error, Debug)]
+#[error("invalid URL: {0}")]
+pub struct InvalidURLError(pub String);

src/fetcher.rs

@@ -1,8 +1,7 @@
-use anyhow::Result;
 use async_trait::async_trait;
 use url::Url;
 
-use crate::sources::Certificate;
+use crate::{sources::Certificate, sources::SourceResult};
 
 #[derive(Clone, Debug, PartialEq)]
 pub(crate) enum ClientProtocol {
@@ -22,5 +21,5 @@ pub(crate) enum TlsVerificationMode {
 #[async_trait]
 pub(crate) trait PolicyFetcher {
     // Download and return the bytes of the WASM module
-    async fn fetch(&self, url: &Url, client_protocol: ClientProtocol) -> Result<Vec<u8>>;
+    async fn fetch(&self, url: &Url, client_protocol: ClientProtocol) -> SourceResult<Vec<u8>>;
 }

src/https.rs

@@ -1,6 +1,5 @@
 #![allow(clippy::upper_case_acronyms)]
 
-use anyhow::{anyhow, Result};
 use async_trait::async_trait;
 use std::{
     boxed::Box,
@@ -10,27 +9,39 @@ use url::Url;
 
 use crate::fetcher::{ClientProtocol, PolicyFetcher, TlsVerificationMode};
 use crate::sources::Certificate;
+use crate::sources::SourceError;
+use crate::sources::SourceResult;
 
 // Struct used to reference a WASM module that is hosted on a HTTP(s) server
 #[derive(Default)]
 pub(crate) struct Https {}
 
 impl TryFrom<&Certificate> for reqwest::Certificate {
-    type Error = anyhow::Error;
+    type Error = SourceError;
 
-    fn try_from(certificate: &Certificate) -> Result<Self> {
+    fn try_from(certificate: &Certificate) -> SourceResult<Self> {
         match certificate {
-            Certificate::Der(certificate) => reqwest::Certificate::from_der(certificate)
-                .map_err(|err| anyhow!("could not load certificate as DER encoded: {}", err)),
-            Certificate::Pem(certificate) => reqwest::Certificate::from_pem(certificate)
-                .map_err(|err| anyhow!("could not load certificate as PEM encoded: {}", err)),
+            Certificate::Der(certificate) => {
+                reqwest::Certificate::from_der(certificate).map_err(|err| {
+                    SourceError::InvalidCertificateError(format!(
+                        "could not load certificate as DER encoded: {err}"
+                    ))
+                })
+            }
+            Certificate::Pem(certificate) => {
+                reqwest::Certificate::from_pem(certificate).map_err(|err| {
+                    SourceError::InvalidCertificateError(format!(
+                        "could not load certificate as PEM encoded: {err}"
+                    ))
+                })
+            }
         }
     }
 }
 
 #[async_trait]
 impl PolicyFetcher for Https {
-    async fn fetch(&self, url: &Url, client_protocol: ClientProtocol) -> Result<Vec<u8>> {
+    async fn fetch(&self, url: &Url, client_protocol: ClientProtocol) -> SourceResult<Vec<u8>> {
         let mut client_builder = reqwest::Client::builder();
         match client_protocol {
             ClientProtocol::Http => {}

src/lib.rs

@@ -3,11 +3,13 @@ extern crate reqwest;
 extern crate rustls;
 extern crate walkdir;
 
-use anyhow::{anyhow, Result};
+use errors::FetcherResult;
 use std::boxed::Box;
 use std::fs;
+use store::errors::{StoreError, StoreResult};
 use url::Url;
 
+pub mod errors;
 pub mod fetcher;
 mod https;
 pub mod policy;
@@ -16,6 +18,7 @@ pub mod sources;
 pub mod store;
 pub mod verify;
 
+use crate::errors::{CannotCreateStoragePathError, FetcherError};
 use crate::fetcher::{ClientProtocol, PolicyFetcher, TlsVerificationMode};
 use crate::https::Https;
 use crate::policy::Policy;
@@ -78,7 +81,7 @@ pub async fn fetch_policy(
     url: &str,
     destination: PullDestination,
     sources: Option<&Sources>,
-) -> Result<Policy> {
+) -> FetcherResult<Policy> {
     let url = parse_url(url)?;
     match url.scheme() {
         "file" => {
@@ -87,15 +90,17 @@ pub async fn fetch_policy(
                 uri: url.to_string(),
                 local_path: url
                     .to_file_path()
-                    .map_err(|err| anyhow!("cannot retrieve path from uri {}: {:?}", url, err))?,
+                    .map_err(|_| FetcherError::InvalidFilePathError(url.to_string()))?,
             });
         }
         "registry" | "http" | "https" => Ok(()),
-        _ => Err(anyhow!("unknown scheme: {}", url.scheme())),
+        _ => Err(StoreError::UnknownSchemeError(url.scheme().to_owned())),
     }?;
     let (store, mut destination) = pull_destination(&url, &destination)?;
     if let Some(store) = store {
-        store.ensure(&store.policy_full_path(url.as_str(), store::PolicyPath::PrefixOnly)?)?;
+        store
+            .ensure(&store.policy_full_path(url.as_str(), store::PolicyPath::PrefixOnly)?)
+            .map_err(CannotCreateStoragePathError)?;
     }
     match url.scheme() {
         "registry" => {
@@ -134,11 +139,7 @@ pub async fn fetch_policy(
     {
         Err(err) => {
             if !sources.is_insecure_source(&host_and_port(&url)?) {
-                return Err(anyhow!(
-                    "the policy {} could not be downloaded due to error: {}",
-                    url,
-                    err
-                ));
+                return Err(FetcherError::SourceError(err));
             }
         }
         Ok(bytes) => return create_file_if_valid(&bytes, &destination, url.to_string()),
@@ -155,11 +156,14 @@ pub async fn fetch_policy(
 
     match policy_fetcher.fetch(&url, ClientProtocol::Http).await {
         Ok(bytes) => create_file_if_valid(&bytes, &destination, url.to_string()),
-        Err(e) => Err(anyhow!("could not pull policy {}: {}", url, e)),
+        Err(e) => Err(FetcherError::SourceError(e)),
     }
 }
 
-fn client_protocol(url: &Url, sources: &Sources) -> Result<ClientProtocol> {
+fn client_protocol(
+    url: &Url,
+    sources: &Sources,
+) -> std::result::Result<ClientProtocol, errors::InvalidURLError> {
     if let Some(certificates) = sources.source_authority(&host_and_port(url)?) {
         return Ok(ClientProtocol::Https(
             TlsVerificationMode::CustomCaCertificates(certificates),
@@ -168,7 +172,10 @@ fn client_protocol(url: &Url, sources: &Sources) -> Result<ClientProtocol> {
     Ok(ClientProtocol::Https(TlsVerificationMode::SystemCa))
 }
 
-fn pull_destination(url: &Url, destination: &PullDestination) -> Result<(Option<Store>, PathBuf)> {
+fn pull_destination(
+    url: &Url,
+    destination: &PullDestination,
+) -> FetcherResult<(Option<Store>, PathBuf)> {
     Ok(match destination {
         PullDestination::MainStore => {
             let store = Store::default();
@@ -196,19 +203,19 @@ fn pull_destination(url: &Url, destination: &PullDestination) -> Result<(Option<
 // Helper function, takes the URL of the policy and allocates the
 // right struct to interact with it
 #[allow(clippy::box_default)]
-fn url_fetcher(scheme: &str) -> Result<Box<dyn PolicyFetcher>> {
+fn url_fetcher(scheme: &str) -> StoreResult<Box<dyn PolicyFetcher>> {
     match scheme {
         "http" | "https" => Ok(Box::new(Https::default())),
         "registry" => Ok(Box::new(Registry::new())),
-        _ => Err(anyhow!("unknown scheme: {}", scheme)),
+        _ => Err(StoreError::UnknownSchemeError(scheme.to_owned())),
     }
 }
 
-pub(crate) fn host_and_port(url: &Url) -> Result<String> {
+pub(crate) fn host_and_port(url: &Url) -> std::result::Result<String, errors::InvalidURLError> {
     Ok(format!(
         "{}{}",
         url.host_str()
-            .ok_or_else(|| anyhow!("invalid URL {}", url))?,
+            .ok_or_else(|| errors::InvalidURLError(url.to_string()))?,
         url.port()
             .map(|port| format!(":{}", port))
             .unwrap_or_default(),
@@ -222,12 +229,13 @@ pub(crate) fn host_and_port(url: &Url) -> Result<String> {
 // https://webassembly.github.io/spec/core/bikeshed/#binary-magic
 const WASM_MAGIC_NUMBER: [u8; 4] = [0x00, 0x61, 0x73, 0x6D];
 
-fn create_file_if_valid(bytes: &[u8], destination: &Path, url: String) -> Result<Policy> {
+fn create_file_if_valid(bytes: &[u8], destination: &Path, url: String) -> FetcherResult<Policy> {
     if !bytes.starts_with(&WASM_MAGIC_NUMBER) {
-        return Err(anyhow!("invalid wasm file"));
+        return Err(FetcherError::InvalidWasmFileError);
     };
-    fs::write(destination, bytes)
-        .map_err(|e| anyhow!("wasm module cannot be save to {:?}: {}", destination, e))?;
+    fs::write(destination, bytes).map_err(|e| {
+        FetcherError::CannotWriteWasmModuleFile(destination.to_string_lossy().to_string(), e)
+    })?;
 
     Ok(Policy {
         uri: url,
@@ -359,7 +367,7 @@ mod tests {
         port: Some(5000),
         path: "/kubewarden/policies/test".to_string(),
     }))]
-    fn url_parsing(#[case] url: &str, #[case] expected: anyhow::Result<UrlParseDetails>) {
+    fn url_parsing(#[case] url: &str, #[case] expected: FetcherResult<UrlParseDetails>) {
         let res = parse_url(url);
         println!("{} -> {:?}", url, res);
         assert_eq!(res.is_ok(), expected.is_ok());

src/policy.rs

@@ -9,8 +9,15 @@ pub struct Policy {
     pub local_path: PathBuf,
 }
 
+#[derive(thiserror::Error, Debug)]
+#[error("cannot retrieve path from uri: {err}")]
+pub struct DigestError {
+    #[from]
+    err: std::io::Error,
+}
+
 impl Policy {
-    pub fn digest(&self) -> Result<String, std::io::Error> {
+    pub fn digest(&self) -> std::result::Result<String, DigestError> {
         let d = Sha256::digest(std::fs::read(&self.local_path)?);
         Ok(format!("{:x}", d))
     }

src/registry/errors.rs

@@ -0,0 +1,23 @@
+use thiserror::Error;
+
+use crate::errors::InvalidURLError;
+
+pub type RegistryResult<T> = std::result::Result<T, RegistryError>;
+
+#[derive(Error, Debug)]
+pub enum RegistryError {
+    #[error("Fail to interact with OCI registry: {0}")]
+    OCIRegistryError(#[from] oci_distribution::errors::OciDistributionError),
+    #[error("Invalid OCI image reference: {0}")]
+    InvalidOCIImageReferenceError(#[from] oci_distribution::ParseError),
+    #[error("{0}")]
+    BuildImmutableReferenceError(String),
+    #[error("Invalid destination format")]
+    InvalidDestinationError,
+    #[error("{0}")]
+    OtherError(String),
+    #[error(transparent)]
+    UrlParserError(#[from] url::ParseError),
+    #[error(transparent)]
+    InvalidURLError(#[from] InvalidURLError),
+}