Prep for multiple container image stores

For now, this is effectively a no-op as it only implements a store for
the current ostree container implementation.

Beyond some minor code movement and plumbing, this also only handles
the store implementation backing the `bootc status` command.
Additional image store functionality (check, pull, delete, etc.) will
be added in future changes in order to keep things smaller and more
manageable.

Author: jeckersb

lib/src/cli.rs

@@ -427,6 +427,12 @@ pub(crate) async fn get_locked_sysroot() -> Result<ostree_ext::sysroot::SysrootL
     Ok(sysroot)
 }
 
+#[context("Initializing storage")]
+pub(crate) async fn get_storage() -> Result<crate::store::Storage> {
+    let sysroot = get_locked_sysroot().await?;
+    Ok(crate::store::Storage::new(sysroot))
+}
+
 #[context("Querying root privilege")]
 pub(crate) fn require_root() -> Result<()> {
     let uid = rustix::process::getuid();
@@ -479,7 +485,7 @@ fn prepare_for_write() -> Result<()> {
 /// Implementation of the `bootc upgrade` CLI command.
 #[context("Upgrading")]
 async fn upgrade(opts: UpgradeOpts) -> Result<()> {
-    let sysroot = &get_locked_sysroot().await?;
+    let sysroot = &get_storage().await?;
     let repo = &sysroot.repo();
     let (booted_deployment, _deployments, host) =
         crate::status::get_status_require_booted(sysroot)?;
@@ -616,7 +622,7 @@ async fn switch(opts: SwitchOpts) -> Result<()> {
 
     let cancellable = gio::Cancellable::NONE;
 
-    let sysroot = &get_locked_sysroot().await?;
+    let sysroot = &get_storage().await?;
     let repo = &sysroot.repo();
     let (booted_deployment, _deployments, host) =
         crate::status::get_status_require_booted(sysroot)?;
@@ -655,14 +661,14 @@ async fn switch(opts: SwitchOpts) -> Result<()> {
 /// Implementation of the `bootc rollback` CLI command.
 #[context("Rollback")]
 async fn rollback(_opts: RollbackOpts) -> Result<()> {
-    let sysroot = &get_locked_sysroot().await?;
+    let sysroot = &get_storage().await?;
     crate::deploy::rollback(sysroot).await
 }
 
 /// Implementation of the `bootc edit` CLI command.
 #[context("Editing spec")]
 async fn edit(opts: EditOpts) -> Result<()> {
-    let sysroot = &get_locked_sysroot().await?;
+    let sysroot = &get_storage().await?;
     let repo = &sysroot.repo();
 
     let (booted_deployment, _deployments, host) =

lib/src/deploy.rs

@@ -22,6 +22,7 @@ use ostree_ext::sysroot::SysrootLock;
 use crate::spec::ImageReference;
 use crate::spec::{BootOrder, HostSpec};
 use crate::status::labels_of_config;
+use crate::store::Storage;
 
 // TODO use https://github.com/ostreedev/ostree-rs-ext/pull/493/commits/afc1837ff383681b947de30c0cefc70080a4f87a
 const BASE_IMAGE_PREFIX: &str = "ostree/container/baseimage/bootc";
@@ -405,7 +406,7 @@ pub(crate) async fn stage(
 }
 
 /// Implementation of rollback functionality
-pub(crate) async fn rollback(sysroot: &SysrootLock) -> Result<()> {
+pub(crate) async fn rollback(sysroot: &Storage) -> Result<()> {
     const ROLLBACK_JOURNAL_ID: &str = "26f3b1eb24464d12aa5e7b544a6b5468";
     let repo = &sysroot.repo();
     let (booted_deployment, deployments, host) = crate::status::get_status_require_booted(sysroot)?;

lib/src/image.rs

@@ -26,7 +26,7 @@ pub(crate) async fn list_entrypoint() -> Result<()> {
 #[context("Pushing image")]
 pub(crate) async fn push_entrypoint(source: Option<&str>, target: Option<&str>) -> Result<()> {
     let transport = Transport::ContainerStorage;
-    let sysroot = crate::cli::get_locked_sysroot().await?;
+    let sysroot = crate::cli::get_storage().await?;
 
     let repo = &sysroot.repo();
 

lib/src/lib.rs

@@ -26,6 +26,7 @@ pub(crate) mod metadata;
 mod reboot;
 mod reexec;
 mod status;
+mod store;
 mod task;
 mod utils;
 

lib/src/spec.rs

@@ -40,6 +40,17 @@ pub enum BootOrder {
     Rollback,
 }
 
+#[derive(
+    clap::ValueEnum, Serialize, Deserialize, Copy, Clone, Debug, PartialEq, Eq, JsonSchema, Default,
+)]
+#[serde(rename_all = "camelCase")]
+/// The container storage backend
+pub enum Store {
+    /// Use the ostree-container storage backend.
+    #[default]
+    OstreeContainer,
+}
+
 #[derive(Serialize, Deserialize, Default, Debug, Clone, PartialEq, Eq)]
 #[serde(rename_all = "camelCase")]
 /// The host specification
@@ -112,6 +123,9 @@ pub struct BootEntry {
     pub incompatible: bool,
     /// Whether this entry will be subject to garbage collection
     pub pinned: bool,
+    /// The container storage backend
+    #[serde(default)]
+    pub store: Option<Store>,
     /// If this boot entry is ostree based, the corresponding state
     pub ostree: Option<BootEntryOstree>,
 }

lib/src/status.rs

@@ -8,13 +8,12 @@ use ostree_container::OstreeImageReference;
 use ostree_ext::container as ostree_container;
 use ostree_ext::keyfileext::KeyFileExt;
 use ostree_ext::oci_spec;
-use ostree_ext::oci_spec::image::ImageConfiguration;
 use ostree_ext::ostree;
-use ostree_ext::sysroot::SysrootLock;
 
 use crate::cli::OutputFormat;
-use crate::spec::{BootEntry, BootOrder, Host, HostSpec, HostStatus, HostType, ImageStatus};
+use crate::spec::{BootEntry, BootOrder, Host, HostSpec, HostStatus, HostType};
 use crate::spec::{ImageReference, ImageSignature};
+use crate::store::{CachedImageStatus, ContainerImageStore, Storage};
 
 impl From<ostree_container::SignatureSource> for ImageSignature {
     fn from(sig: ostree_container::SignatureSource) -> Self {
@@ -115,65 +114,46 @@ pub(crate) fn labels_of_config(
     config.config().as_ref().and_then(|c| c.labels().as_ref())
 }
 
-/// Convert between a subset of ostree-ext metadata and the exposed spec API.
-pub(crate) fn create_imagestatus(
-    image: ImageReference,
-    manifest_digest: &str,
-    config: &ImageConfiguration,
-) -> ImageStatus {
-    let labels = labels_of_config(config);
-    let timestamp = labels
-        .and_then(|l| {
-            l.get(oci_spec::image::ANNOTATION_CREATED)
-                .map(|s| s.as_str())
-        })
-        .and_then(try_deserialize_timestamp);
-
-    let version = ostree_container::version_for_config(config).map(ToOwned::to_owned);
-    ImageStatus {
-        image,
-        version,
-        timestamp,
-        image_digest: manifest_digest.to_owned(),
-    }
-}
-
 /// Given an OSTree deployment, parse out metadata into our spec.
 #[context("Reading deployment metadata")]
 fn boot_entry_from_deployment(
-    sysroot: &SysrootLock,
+    sysroot: &Storage,
     deployment: &ostree::Deployment,
 ) -> Result<BootEntry> {
-    let repo = &sysroot.repo();
-    let (image, cached_update, incompatible) = if let Some(origin) = deployment.origin().as_ref() {
+    let (
+        store,
+        CachedImageStatus {
+            image,
+            cached_update,
+        },
+        incompatible,
+    ) = if let Some(origin) = deployment.origin().as_ref() {
         let incompatible = crate::utils::origin_has_rpmostree_stuff(origin);
-        let (image, cached) = if incompatible {
+        let (store, cached_imagestatus) = if incompatible {
             // If there are local changes, we can't represent it as a bootc compatible image.
-            (None, None)
+            (None, CachedImageStatus::default())
         } else if let Some(image) = get_image_origin(origin)? {
-            let image = ImageReference::from(image);
-            let csum = deployment.csum();
-            let imgstate = ostree_container::store::query_image_commit(repo, &csum)?;
-            let cached = imgstate.cached_update.map(|cached| {
-                create_imagestatus(image.clone(), &cached.manifest_digest, &cached.config)
-            });
-            let imagestatus =
-                create_imagestatus(image, &imgstate.manifest_digest, &imgstate.configuration);
-            // We found a container-image based deployment
-            (Some(imagestatus), cached)
+            let store = deployment.store()?;
+            let store = store.as_ref().unwrap_or(&sysroot.store);
+            let spec = Some(store.spec());
+            let status = store.imagestatus(sysroot, deployment, image)?;
+
+            (spec, status)
         } else {
             // The deployment isn't using a container image
-            (None, None)
+            (None, CachedImageStatus::default())
         };
-        (image, cached, incompatible)
+        (store, cached_imagestatus, incompatible)
     } else {
         // The deployment has no origin at all (this generally shouldn't happen)
-        (None, None, false)
+        (None, CachedImageStatus::default(), false)
     };
+
     let r = BootEntry {
         image,
         cached_update,
         incompatible,
+        store,
         pinned: deployment.is_pinned(),
         ostree: Some(crate::spec::BootEntryOstree {
             checksum: deployment.csum().into(),
@@ -203,7 +183,7 @@ impl BootEntry {
 
 /// A variant of [`get_status`] that requires a booted deployment.
 pub(crate) fn get_status_require_booted(
-    sysroot: &SysrootLock,
+    sysroot: &Storage,
 ) -> Result<(ostree::Deployment, Deployments, Host)> {
     let booted_deployment = sysroot.require_booted_deployment()?;
     let (deployments, host) = get_status(sysroot, Some(&booted_deployment))?;
@@ -214,7 +194,7 @@ pub(crate) fn get_status_require_booted(
 /// a more native Rust structure.
 #[context("Computing status")]
 pub(crate) fn get_status(
-    sysroot: &SysrootLock,
+    sysroot: &Storage,
     booted_deployment: Option<&ostree::Deployment>,
 ) -> Result<(Deployments, Host)> {
     let stateroot = booted_deployment.as_ref().map(|d| d.osname());
@@ -311,7 +291,7 @@ pub(crate) async fn status(opts: super::cli::StatusOpts) -> Result<()> {
     let host = if !Utf8Path::new("/run/ostree-booted").try_exists()? {
         Default::default()
     } else {
-        let sysroot = super::cli::get_locked_sysroot().await?;
+        let sysroot = super::cli::get_storage().await?;
         let booted_deployment = sysroot.booted_deployment();
         let (_deployments, host) = get_status(&sysroot, booted_deployment.as_ref())?;
         host

lib/src/store/mod.rs

@@ -0,0 +1,87 @@
+use std::env;
+use std::ops::Deref;
+
+use anyhow::Result;
+use clap::ValueEnum;
+
+use ostree_ext::container::OstreeImageReference;
+use ostree_ext::keyfileext::KeyFileExt;
+use ostree_ext::ostree;
+use ostree_ext::sysroot::SysrootLock;
+
+use crate::spec::ImageStatus;
+
+mod ostree_container;
+
+pub(crate) struct Storage {
+    pub sysroot: SysrootLock,
+    pub store: Box<dyn ContainerImageStoreImpl>,
+}
+
+#[derive(Default)]
+pub(crate) struct CachedImageStatus {
+    pub image: Option<ImageStatus>,
+    pub cached_update: Option<ImageStatus>,
+}
+
+pub(crate) trait ContainerImageStore {
+    fn store(&self) -> Result<Option<Box<dyn ContainerImageStoreImpl>>>;
+}
+
+pub(crate) trait ContainerImageStoreImpl {
+    fn spec(&self) -> crate::spec::Store;
+
+    fn imagestatus(
+        &self,
+        sysroot: &SysrootLock,
+        deployment: &ostree::Deployment,
+        image: OstreeImageReference,
+    ) -> Result<CachedImageStatus>;
+}
+
+impl Deref for Storage {
+    type Target = SysrootLock;
+
+    fn deref(&self) -> &Self::Target {
+        &self.sysroot
+    }
+}
+
+impl Storage {
+    pub fn new(sysroot: SysrootLock) -> Self {
+        let store = match env::var("BOOTC_STORAGE") {
+            Ok(val) => crate::spec::Store::from_str(&val, true).unwrap_or_else(|_| {
+                let default = crate::spec::Store::default();
+                tracing::warn!("Unknown BOOTC_STORAGE option {val}, falling back to {default:?}");
+                default
+            }),
+            Err(_) => crate::spec::Store::default(),
+        };
+
+        let store = load(store);
+
+        Self { sysroot, store }
+    }
+}
+
+impl ContainerImageStore for ostree::Deployment {
+    fn store<'a>(&self) -> Result<Option<Box<dyn ContainerImageStoreImpl>>> {
+        if let Some(origin) = self.origin().as_ref() {
+            if let Some(store) = origin.optional_string("bootc", "backend")? {
+                let store =
+                    crate::spec::Store::from_str(&store, true).map_err(anyhow::Error::msg)?;
+                Ok(Some(load(store)))
+            } else {
+                Ok(None)
+            }
+        } else {
+            Ok(None)
+        }
+    }
+}
+
+pub(crate) fn load(ty: crate::spec::Store) -> Box<dyn ContainerImageStoreImpl> {
+    match ty {
+        crate::spec::Store::OstreeContainer => Box::new(ostree_container::OstreeContainerStore),
+    }
+}