Rework API to use a Kubernetes CRD

I was working on the configmap support slowly, but a big issue
it raised was how we expose the ability to mutate things.

Our current "API" is just an imperative CLI.  This would require
higher level tooling to manage Kubernetes style declarative system state.

Instead, let's use the really nice Rust `kube` crate to define a CRD;
this is what is output (in YAML form) via `bootc status` now.

We translate the imperative CLI verbs into changes to the `spec`
field.

However, things become more compelling when we offer a `bootc edit`
CLI verb that allows arbitrary changes to the spec.

I think this will become the *only* way to manage attached configmaps,
instead of having imperative CLI verbs like `bootc configmap add` etc.
At least to start.

Signed-off-by: Colin Walters <[email protected]>

lib/Cargo.toml

@@ -19,15 +19,19 @@ hex = "^0.4"
 fn-error-context = "0.2.0"
 gvariant = "0.4.0"
 indicatif = "0.17.0"
+k8s-openapi = { version = "0.18.0", features = ["v1_25"] }
+kube = { version = "0.83.0", features = ["runtime", "derive"] }
 libc = "^0.2"
 liboverdrop = "0.1.0"
 once_cell = "1.9"
 openssl = "^0.10"
 nix = ">= 0.24, < 0.26"
 regex = "1.7.1"
 rustix = { "version" = "0.37", features = ["thread", "process"] }
+schemars = "0.8.6"
 serde = { features = ["derive"], version = "1.0.125" }
 serde_json = "1.0.64"
+serde_yaml = "0.9.17"
 serde_with = ">= 1.9.4, < 2"
 tokio = { features = ["io-std", "time", "process", "rt", "net"], version = ">= 1.13.0" }
 tokio-util = { features = ["io-util"], version = "0.7" }

lib/src/cli.rs

@@ -19,6 +19,9 @@ use std::ffi::OsString;
 use std::os::unix::process::CommandExt;
 use std::process::Command;
 
+use crate::spec::HostSpec;
+use crate::spec::ImageReference;
+
 /// Perform an upgrade operation
 #[derive(Debug, Parser)]
 pub(crate) struct UpgradeOpts {
@@ -170,9 +173,10 @@ pub(crate) async fn get_locked_sysroot() -> Result<ostree_ext::sysroot::SysrootL
 #[context("Pulling")]
 async fn pull(
     repo: &ostree::Repo,
-    imgref: &OstreeImageReference,
+    imgref: &ImageReference,
     quiet: bool,
 ) -> Result<Box<LayeredImageState>> {
+    let imgref = &OstreeImageReference::from(imgref.clone());
     let config = Default::default();
     let mut imp = ostree_container::store::ImageImporter::new(repo, imgref, config).await?;
     let prep = match imp.prepare().await? {
@@ -211,22 +215,35 @@ async fn pull(
 async fn stage(
     sysroot: &SysrootLock,
     stateroot: &str,
-    imgref: &ostree_container::OstreeImageReference,
     image: Box<LayeredImageState>,
-    origin: &glib::KeyFile,
+    spec: &HostSpec,
 ) -> Result<()> {
     let cancellable = gio::Cancellable::NONE;
     let stateroot = Some(stateroot);
     let merge_deployment = sysroot.merge_deployment(stateroot);
+    let origin = glib::KeyFile::new();
+    let ostree_imgref = spec
+        .image
+        .as_ref()
+        .map(|imgref| OstreeImageReference::from(imgref.clone()));
+    if let Some(imgref) = ostree_imgref.as_ref() {
+        origin.set_string(
+            "origin",
+            ostree_container::deploy::ORIGIN_CONTAINER,
+            imgref.to_string().as_str(),
+        );
+    }
     let _new_deployment = sysroot.stage_tree_with_options(
         stateroot,
         image.merge_commit.as_str(),
-        Some(origin),
+        Some(&origin),
         merge_deployment.as_ref(),
         &Default::default(),
         cancellable,
     )?;
-    println!("Queued for next boot: {imgref}");
+    if let Some(imgref) = ostree_imgref.as_ref() {
+        println!("Queued for next boot: {imgref}");
+    }
     Ok(())
 }
 
@@ -262,33 +279,34 @@ async fn prepare_for_write() -> Result<()> {
 async fn upgrade(opts: UpgradeOpts) -> Result<()> {
     prepare_for_write().await?;
     let sysroot = &get_locked_sysroot().await?;
-    let repo = &sysroot.repo();
     let booted_deployment = &sysroot.require_booted_deployment()?;
-    let status = crate::status::DeploymentStatus::from_deployment(booted_deployment, true)?;
-    let osname = booted_deployment.osname();
-    let origin = booted_deployment
-        .origin()
-        .ok_or_else(|| anyhow::anyhow!("Deployment is missing an origin"))?;
-    let imgref = status
-        .image
-        .ok_or_else(|| anyhow::anyhow!("Booted deployment is not container image based"))?;
-    let imgref: OstreeImageReference = imgref.into();
-    if !status.supported {
+    let (_deployments, host) = crate::status::get_status(sysroot, Some(booted_deployment))?;
+    // SAFETY: There must be a status if we have a booted deployment
+    let status = host.status.unwrap();
+    let imgref = host.spec.image.as_ref();
+    // If there's no specified image, let's be nice and check if the booted system is using rpm-ostree
+    if imgref.is_none() && status.booted.map_or(false, |b| b.incompatible) {
         return Err(anyhow::anyhow!(
             "Booted deployment contains local rpm-ostree modifications; cannot upgrade via bootc"
         ));
     }
-    let commit = booted_deployment.csum();
-    let state = ostree_container::store::query_image_commit(repo, &commit)?;
-    let digest = state.manifest_digest.as_str();
-    let fetched = pull(repo, &imgref, opts.quiet).await?;
-
-    if fetched.merge_commit.as_str() == commit.as_str() {
-        println!("Already queued: {digest}");
-        return Ok(());
+    let imgref = imgref.ok_or_else(|| anyhow::anyhow!("No image source specified"))?;
+    // Find the currently queued digest, if any before we pull
+    let queued_digest = status
+        .staged
+        .as_ref()
+        .and_then(|e| e.image.as_ref())
+        .map(|img| img.image_digest.as_str());
+    let fetched = pull(&sysroot.repo(), &imgref, opts.quiet).await?;
+    if let Some(queued_digest) = queued_digest {
+        if fetched.merge_commit.as_str() == queued_digest {
+            println!("Already queued: {queued_digest}");
+            return Ok(());
+        }
     }
 
-    stage(sysroot, &osname, &imgref, fetched, &origin).await?;
+    let osname = booted_deployment.osname();
+    stage(sysroot, &osname, fetched, &host.spec).await?;
 
     if let Some(path) = opts.touch_if_changed {
         std::fs::write(&path, "").with_context(|| format!("Writing {path}"))?;
@@ -301,14 +319,14 @@ async fn upgrade(opts: UpgradeOpts) -> Result<()> {
 #[context("Switching")]
 async fn switch(opts: SwitchOpts) -> Result<()> {
     prepare_for_write().await?;
-
     let cancellable = gio::Cancellable::NONE;
-    let sysroot = get_locked_sysroot().await?;
-    let booted_deployment = &sysroot.require_booted_deployment()?;
-    let (origin, booted_image) = crate::utils::get_image_origin(booted_deployment)?;
-    let booted_refspec = origin.optional_string("origin", "refspec")?;
-    let osname = booted_deployment.osname();
+
+    let sysroot = &get_locked_sysroot().await?;
     let repo = &sysroot.repo();
+    let booted_deployment = &sysroot.require_booted_deployment()?;
+    let (_deployments, host) = crate::status::get_status(sysroot, Some(booted_deployment))?;
+    // SAFETY: There must be a status if we have a booted deployment
+    let status = host.status.unwrap();
 
     let transport = ostree_container::Transport::try_from(opts.transport.as_str())?;
     let imgref = ostree_container::ImageReference {
@@ -323,30 +341,38 @@ async fn switch(opts: SwitchOpts) -> Result<()> {
         SignatureSource::ContainerPolicy
     };
     let target = ostree_container::OstreeImageReference { sigverify, imgref };
+    let target = ImageReference::from(target);
+
+    let new_spec = {
+        let mut new_spec = host.spec.clone();
+        new_spec.image = Some(target.clone());
+        new_spec
+    };
+
+    if new_spec == host.spec {
+        anyhow::bail!("No changes in current host spec");
+    }
 
     let fetched = pull(repo, &target, opts.quiet).await?;
 
     if !opts.retain {
         // By default, we prune the previous ostree ref or container image
-        if let Some(ostree_ref) = booted_refspec {
-            let (remote, ostree_ref) =
-                ostree::parse_refspec(&ostree_ref).context("Failed to parse ostree ref")?;
-            repo.set_ref_immediate(remote.as_deref(), &ostree_ref, None, cancellable)?;
-            origin.remove_key("origin", "refspec")?;
-        } else if let Some(booted_image) = booted_image.as_ref() {
-            ostree_container::store::remove_image(repo, &booted_image.imgref)?;
-            let _nlayers: u32 = ostree_container::store::gc_image_layers(repo)?;
+        if let Some(booted_origin) = booted_deployment.origin() {
+            if let Some(ostree_ref) = booted_origin.optional_string("origin", "refspec")? {
+                let (remote, ostree_ref) =
+                    ostree::parse_refspec(&ostree_ref).context("Failed to parse ostree ref")?;
+                repo.set_ref_immediate(remote.as_deref(), &ostree_ref, None, cancellable)?;
+            } else if let Some(booted_image) = status.booted.as_ref().and_then(|b| b.image.as_ref())
+            {
+                let imgref = OstreeImageReference::from(booted_image.image.clone());
+                ostree_container::store::remove_image(repo, &imgref.imgref)?;
+                let _nlayers: u32 = ostree_container::store::gc_image_layers(repo)?;
+            }
         }
     }
 
-    // We always make a fresh origin to toss out old state.
-    let origin = glib::KeyFile::new();
-    origin.set_string(
-        "origin",
-        ostree_container::deploy::ORIGIN_CONTAINER,
-        target.to_string().as_str(),
-    );
-    stage(&sysroot, &osname, &target, fetched, &origin).await?;
+    let stateroot = booted_deployment.osname();
+    stage(&sysroot, &stateroot, fetched, &new_spec).await?;
 
     Ok(())
 }

lib/src/lib.rs

@@ -36,6 +36,7 @@ mod install;
 pub(crate) mod mount;
 #[cfg(feature = "install")]
 mod podman;
+pub mod spec;
 #[cfg(feature = "install")]
 mod task;
 

lib/src/spec.rs

@@ -0,0 +1,98 @@
+//! The definition for host system state.
+
+use kube::CustomResource;
+use schemars::JsonSchema;
+use serde::{Deserialize, Serialize};
+
+/// Representation of a bootc host system
+#[derive(
+    CustomResource, Serialize, Deserialize, Default, Debug, PartialEq, Eq, Clone, JsonSchema,
+)]
+#[kube(
+    group = "org.containers.bootc",
+    version = "v1alpha1",
+    kind = "BootcHost",
+    struct = "Host",
+    namespaced,
+    status = "HostStatus",
+    derive = "PartialEq",
+    derive = "Default"
+)]
+#[serde(rename_all = "camelCase")]
+pub struct HostSpec {
+    /// The host image
+    pub image: Option<ImageReference>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+/// An image signature
+#[serde(rename_all = "camelCase")]
+pub enum ImageSignature {
+    /// Fetches will use the named ostree remote for signature verification of the ostree commit.
+    OstreeRemote(String),
+    /// Fetches will defer to the `containers-policy.json`, but we make a best effort to reject `default: insecureAcceptAnything` policy.
+    ContainerPolicy,
+    /// No signature verification will be performed
+    Insecure,
+}
+
+/// A container image reference with attached transport and signature verification
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct ImageReference {
+    /// The container image reference
+    pub image: String,
+    /// The container image transport
+    pub transport: String,
+    /// Disable signature verification
+    pub signature: ImageSignature,
+}
+
+/// The status of the booted image
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, JsonSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct ImageStatus {
+    /// The currently booted image
+    pub image: ImageReference,
+    /// The digest of the fetched image (e.g. sha256:a0...);
+    pub image_digest: String,
+}
+
+/// A bootable entry
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, JsonSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct BootEntryOstree {
+    /// The ostree commit checksum
+    pub checksum: String,
+    /// The deployment serial
+    pub deploy_serial: u32,
+}
+
+/// A bootable entry
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, JsonSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct BootEntry {
+    /// The image reference
+    pub image: Option<ImageStatus>,
+    /// Whether this boot entry is not compatible (has origin changes bootc does not understand)
+    pub incompatible: bool,
+    /// Whether this entry will be subject to garbage collection
+    pub pinned: bool,
+    /// If this boot entry is ostree based, the corresponding state
+    pub ostree: Option<BootEntryOstree>,
+}
+
+/// The status of the host system
+#[derive(Debug, Clone, Serialize, Default, Deserialize, PartialEq, JsonSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct HostStatus {
+    /// The staged image for the next boot
+    pub staged: Option<BootEntry>,
+    /// The booted image; this will be unset if the host is not bootc compatible.
+    pub booted: Option<BootEntry>,
+    /// The previously booted image
+    pub rollback: Option<BootEntry>,
+
+    /// Whether or not the current system state is an ostree-based container
+    pub is_container: bool,
+}