src/sys/pkg/lib/isolated-swd/src/resolver.rs

// Copyright 2020 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#[cfg(test)]
pub(crate) mod for_tests {
    use crate::cache::for_tests::CacheForTest;
    use anyhow::{anyhow, Context, Error};
    use blobfs_ramdisk::BlobfsRamdisk;
    use fidl_fuchsia_pkg_ext::RepositoryConfigs;
    use fuchsia_component_test::{
        Capability, ChildOptions, ChildRef, DirectoryContents, RealmBuilder, RealmInstance, Ref,
        Route,
    };
    use fuchsia_pkg_testing::serve::ServedRepository;
    use fuchsia_url::RepositoryUrl;
    use futures::{FutureExt as _, StreamExt as _};
    use std::sync::Arc;
    use {
        fidl_fuchsia_io as fio, fidl_fuchsia_metrics as fmetrics, fidl_fuchsia_pkg as fpkg,
        fidl_fuchsia_pkg_ext as pkg, fuchsia_async as fasync,
    };

    const SSL_TEST_CERTS_PATH: &str = "/pkg/data/ssl/cert.pem";
    const SSL_CERT_FILE_NAME: &str = "cert.pem";
    pub const EMPTY_REPO_PATH: &str = "/pkg/empty-repo";

    /// Represents the sandboxed package resolver.
    pub struct Resolver {
        proxy: fpkg::PackageResolverProxy,
    }

    impl Resolver {
        fn new_with_proxy(pkg_resolver_proxy: fpkg::PackageResolverProxy) -> Result<Self, Error> {
            Ok(Self { proxy: pkg_resolver_proxy })
        }
    }

    /// This wraps the `Resolver` in order to reduce test boilerplate.
    pub struct ResolverForTest {
        pub cache: CacheForTest,
        pub resolver: Arc<Resolver>,
        _served_repo: Arc<ServedRepository>,
    }

    pub struct ResolverRealm {
        pub resolver: ChildRef,
        pub cache: ChildRef,
    }

    impl ResolverForTest {
        pub async fn realm_setup(
            realm_builder: &RealmBuilder,
            served_repo: Arc<ServedRepository>,
            repo_url: RepositoryUrl,
            blobfs: &BlobfsRamdisk,
        ) -> Result<ResolverRealm, Error> {
            let cache_ref =
                CacheForTest::realm_setup(realm_builder, blobfs).await.expect("setting up cache");

            let repo_config =
                RepositoryConfigs::Version1(vec![served_repo.make_repo_config(repo_url)]);

            let cert_bytes = std::fs::read(std::path::Path::new(SSL_TEST_CERTS_PATH)).unwrap();

            let service_reflector = realm_builder
                .add_local_child(
                    "pkg_resolver_service_reflector",
                    move |handles| {
                        let mut fs = fuchsia_component::server::ServiceFs::new();
                        // Not necessary for updates, but prevents spam of irrelevant error logs.
                        fs.dir("svc").add_fidl_service(move |stream| {
                            fasync::Task::spawn(
                                Arc::new(mock_metrics::MockMetricEventLoggerFactory::new())
                                    .run_logger_factory(stream),
                            )
                            .detach()
                        });
                        async move {
                            fs.serve_connection(handles.outgoing_dir).unwrap();
                            let () = fs.collect().await;
                            Ok(())
                        }
                        .boxed()
                    },
                    ChildOptions::new(),
                )
                .await
                .unwrap();

            let pkg_resolver = realm_builder
                .add_child("pkg-resolver", "#meta/pkg-resolver.cm", ChildOptions::new())
                .await
                .unwrap();

            realm_builder
                .read_only_directory(
                    "config-data",
                    vec![&pkg_resolver],
                    DirectoryContents::new().add_file(
                        "repositories/test.json",
                        serde_json::to_string(&repo_config).unwrap(),
                    ),
                )
                .await
                .unwrap();

            realm_builder
                .read_only_directory(
                    "root-ssl-certificates",
                    vec![&pkg_resolver],
                    DirectoryContents::new().add_file(SSL_CERT_FILE_NAME, cert_bytes),
                )
                .await
                .unwrap();

            realm_builder
                .add_route(
                    Route::new()
                        .capability(Capability::protocol_by_name("fuchsia.logger.LogSink"))
                        .from(Ref::parent())
                        .to(&pkg_resolver),
                )
                .await
                .unwrap();

            realm_builder
                .add_route(
                    Route::new()
                        .capability(Capability::protocol_by_name("fuchsia.net.name.Lookup"))
                        .capability(Capability::protocol_by_name("fuchsia.posix.socket.Provider"))
                        .from(Ref::parent())
                        .to(&pkg_resolver),
                )
                .await
                .unwrap();

            realm_builder
                .add_route(
                    Route::new()
                        .capability(Capability::protocol_by_name("fuchsia.pkg.PackageResolver-ota"))
                        .from(&pkg_resolver)
                        .to(Ref::parent()),
                )
                .await
                .unwrap();

            realm_builder
                .add_route(
                    Route::new()
                        .capability(Capability::protocol_by_name("fuchsia.pkg.PackageCache"))
                        .capability(Capability::protocol_by_name("fuchsia.space.Manager"))
                        .from(&cache_ref)
                        .to(&pkg_resolver),
                )
                .await
                .unwrap();

            realm_builder
                .add_route(
                    Route::new()
                        .capability(
                            Capability::protocol::<fmetrics::MetricEventLoggerFactoryMarker>(),
                        )
                        .from(&service_reflector)
                        .to(&pkg_resolver),
                )
                .await
                .unwrap();

            Ok(ResolverRealm { resolver: pkg_resolver, cache: cache_ref })
        }

        pub async fn new(
            realm_instance: &RealmInstance,
            blobfs: BlobfsRamdisk,
            served_repo: Arc<ServedRepository>,
        ) -> Result<Self, Error> {
            let cache = CacheForTest::new(realm_instance, blobfs).await.unwrap();

            let resolver_proxy = realm_instance
                .root
                .connect_to_named_protocol_at_exposed_dir::<fpkg::PackageResolverMarker>(
                    "fuchsia.pkg.PackageResolver-ota",
                )
                .expect("connect to pkg resolver");

            let resolver = Resolver::new_with_proxy(resolver_proxy).unwrap();

            let cache_proxy = cache.cache.package_cache_proxy().unwrap();

            assert_eq!(cache_proxy.sync().await.unwrap(), Ok(()));

            Ok(ResolverForTest { cache, resolver: Arc::new(resolver), _served_repo: served_repo })
        }

        /// Resolve a package using the resolver, returning the root directory of the package,
        /// and the context for resolving relative package URLs.
        pub async fn resolve_package(
            &self,
            url: &str,
        ) -> Result<(fio::DirectoryProxy, pkg::ResolutionContext), Error> {
            let proxy = &self.resolver.proxy;
            let (package, package_remote) =
                fidl::endpoints::create_proxy().context("creating package directory endpoints")?;
            let resolved_context = proxy
                .resolve(url, package_remote)
                .await
                .unwrap()
                .map_err(|e| anyhow!("Package resolver error: {:?}", e))?;
            Ok((package, (&resolved_context).try_into().expect("resolver returns valid context")))
        }
    }
}

#[cfg(test)]
pub mod tests {
    use super::for_tests::{ResolverForTest, EMPTY_REPO_PATH};
    use anyhow::{Context, Error};
    use fuchsia_async as fasync;
    use fuchsia_component_test::RealmBuilder;
    use fuchsia_pkg_testing::{PackageBuilder, RepositoryBuilder};
    use std::sync::Arc;

    const TEST_REPO_URL: &str = "fuchsia-pkg://test";

    #[fasync::run_singlethreaded(test)]
    pub async fn test_resolver() -> Result<(), Error> {
        let name = "test-resolver";
        let package = PackageBuilder::new(name)
            .add_resource_at("data/file1", "hello".as_bytes())
            .add_resource_at("data/file2", "hello two".as_bytes())
            .build()
            .await
            .unwrap();
        let repo = Arc::new(
            RepositoryBuilder::from_template_dir(EMPTY_REPO_PATH)
                .add_package(&package)
                .build()
                .await
                .context("Building repo")
                .unwrap(),
        );

        let realm_builder = RealmBuilder::new().await.unwrap();
        let served_repo = Arc::new(Arc::clone(&repo).server().start().unwrap());
        let blobfs =
            blobfs_ramdisk::BlobfsRamdisk::start().await.context("starting blobfs").unwrap();
        let _resolver_realm = ResolverForTest::realm_setup(
            &realm_builder,
            Arc::clone(&served_repo),
            TEST_REPO_URL.parse().unwrap(),
            &blobfs,
        )
        .await
        .unwrap();

        let realm_instance = realm_builder.build().await.unwrap();

        let resolver = ResolverForTest::new(&realm_instance, blobfs, served_repo)
            .await
            .context("launching resolver")?;
        let (root_dir, _resolved_context) =
            resolver.resolve_package(&format!("{TEST_REPO_URL}/{name}")).await.unwrap();

        package.verify_contents(&root_dir).await.unwrap();
        Ok(())
    }
}