rpm-ostree: Use upstream Rust bindings

Depends: coreos/rpm-ostree#2636

Use the upstream client bindings for the status data.

An interesting note: In the upstream API, the commit
metadata is exposed as a generic `HashMap<>` because
that's how it's used by both ostree and rpm-ostree.  It'd
be a layering violation for us to hardcode `coreos-assembler.basearch`
in the rpm-ostree git for example, not to mention `fedora-coreos.stream`.
So those constants stay here in zincati.

I dropped the `_json` terminology from various functions
because that's weird - we parsed the data from JSON, but
that's not really very relevant except as an implementation
detail.  It's just a `Deployment`, not a `DeploymentJSON`.

Also I dropped for now the optimization of using `--booted`;
it's not a huge amount of data.  If we care we can re-add that
later.  Note it makes caching more complex because then we
need to carefully check the booted state too.

Cargo.toml

@@ -33,6 +33,8 @@ prometheus = { version = "0.11", default-features = false }
 rand = "0.8"
 regex = "1.4"
 reqwest = { version = "0.10", features = ["json"] }
+# Not published to crates.io right now
+rpmostree-client = { git = "https://github.com/coreos/rpm-ostree", rev = "3041d648bbce3beaef2d6b69c8461532e508329d" }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 tempfile = "^3.2"

src/identity/mod.rs

@@ -8,6 +8,7 @@ use libsystemd::id128;
 use ordered_float::NotNan;
 use prometheus::{Gauge, IntGaugeVec};
 use regex::Regex;
+use rpm_ostree::Release;
 use serde::Serialize;
 use std::collections::HashMap;
 
@@ -90,19 +91,28 @@ impl Identity {
     /// Try to build default agent identity.
     pub fn try_default() -> Fallible<Self> {
         // Invoke rpm-ostree to get the status of the currently booted deployment.
-        let status = rpm_ostree::invoke_cli_status(true)?;
-        let basearch = rpm_ostree::parse_basearch(&status)
-            .context("failed to introspect OS base architecture")?;
-        let current_os =
-            rpm_ostree::parse_booted(&status).context("failed to introspect booted OS image")?;
+        let status = rpmostree_client::query_status(&*rpm_ostree::CLI_CLIENT)
+            .map_err(failure::Error::from_boxed_compat)?;
+        let booted = status
+            .require_booted()
+            .map_err(failure::Error::from_boxed_compat)?;
+        let basearch = booted
+            .find_base_commitmeta_string(rpm_ostree::COSA_BASEARCH)
+            .map_err(failure::Error::from_boxed_compat)
+            .context("failed to introspect OS base architecture")?
+            .to_string();
         let node_uuid = {
             let app_id = id128::Id128::try_from_slice(APP_ID)
                 .map_err(|e| format_err!("failed to parse application ID: {}", e))?;
             compute_node_uuid(&app_id)?
         };
         let platform = platform::read_id("/proc/cmdline")?;
-        let stream = rpm_ostree::parse_updates_stream(&status)
-            .context("failed to introspect OS updates stream")?;
+        let stream = booted
+            .find_base_commitmeta_string(rpm_ostree::FCOS_STREAM)
+            .map_err(failure::Error::from_boxed_compat)
+            .context("failed to introspect OS updates stream")?
+            .to_string();
+        let current_os: Release = booted.into();
 
         let id = Self {
             basearch,

src/rpm_ostree/actor.rs

@@ -1,6 +1,5 @@
 //! rpm-ostree client actor.
 
-use super::cli_status::StatusJSON;
 use super::Release;
 use actix::prelude::*;
 use failure::Fallible;
@@ -12,7 +11,7 @@ use std::rc::Rc;
 /// Cache of local deployments.
 #[derive(Clone, Debug)]
 pub struct StatusCache {
-    pub status: Rc<StatusJSON>,
+    pub status: Rc<rpmostree_client::Status>,
     pub mtime: FileTime,
 }
 

src/rpm_ostree/cli_status.rs

@@ -2,15 +2,16 @@
 
 use super::actor::{RpmOstreeClient, StatusCache};
 use super::Release;
-use failure::{bail, ensure, format_err, Fallible, ResultExt};
+use failure::{format_err, Fallible, ResultExt};
 use filetime::FileTime;
 use log::trace;
 use prometheus::IntCounter;
-use serde::Deserialize;
 use std::collections::BTreeSet;
 use std::fs;
 use std::rc::Rc;
 
+use super::CLI_CLIENT;
+
 /// Path to local OSTree deployments. We use its mtime to check for modifications (e.g. new deployments)
 /// to local deployments that might warrant querying `rpm-ostree status` again to update our knowledge
 /// of the current state of deployments.
@@ -37,82 +38,31 @@ lazy_static::lazy_static! {
     )).unwrap();
 }
 
-/// JSON output from `rpm-ostree status --json`
-#[derive(Clone, Debug, Deserialize)]
-pub struct StatusJSON {
-    deployments: Vec<DeploymentJSON>,
-}
-
-/// Partial deployment object (only fields relevant to zincati).
-#[derive(Clone, Debug, Deserialize)]
-#[serde(rename_all = "kebab-case")]
-pub struct DeploymentJSON {
-    booted: bool,
-    base_checksum: Option<String>,
-    #[serde(rename = "base-commit-meta")]
-    base_metadata: BaseCommitMetaJSON,
-    checksum: String,
-    // NOTE(lucab): missing field means "not staged".
-    #[serde(default)]
-    staged: bool,
-    version: String,
-}
-
-/// Metadata from base commit (only fields relevant to zincati).
-#[derive(Clone, Debug, Deserialize)]
-struct BaseCommitMetaJSON {
-    #[serde(rename = "coreos-assembler.basearch")]
-    basearch: String,
-    #[serde(rename = "fedora-coreos.stream")]
-    stream: String,
-}
-
-impl DeploymentJSON {
-    /// Convert into `Release`.
-    pub fn into_release(self) -> Release {
+impl From<&rpmostree_client::Deployment> for Release {
+    fn from(d: &rpmostree_client::Deployment) -> Self {
         Release {
-            checksum: self.base_revision(),
-            version: self.version,
+            checksum: d
+                .base_checksum
+                .clone()
+                .unwrap_or_else(|| d.checksum.clone()),
+            version: d.version.clone().unwrap_or_default(),
             age_index: None,
         }
     }
-
-    /// Return the deployment base revision.
-    pub fn base_revision(&self) -> String {
-        self.base_checksum
-            .clone()
-            .unwrap_or_else(|| self.checksum.clone())
-    }
-}
-
-/// Parse base architecture for booted deployment from status object.
-pub fn parse_basearch(status: &StatusJSON) -> Fallible<String> {
-    let json = booted_json(status)?;
-    Ok(json.base_metadata.basearch)
-}
-
-/// Parse the booted deployment from status object.
-pub fn parse_booted(status: &StatusJSON) -> Fallible<Release> {
-    let json = booted_json(status)?;
-    Ok(json.into_release())
-}
-
-/// Parse updates stream for booted deployment from status object.
-pub fn parse_updates_stream(status: &StatusJSON) -> Fallible<String> {
-    let json = booted_json(status)?;
-    ensure!(!json.base_metadata.stream.is_empty(), "empty stream value");
-    Ok(json.base_metadata.stream)
 }
 
 /// Parse local deployments from a status object.
-fn parse_local_deployments(status: &StatusJSON, omit_staged: bool) -> Fallible<BTreeSet<Release>> {
+fn parse_local_deployments(
+    status: &rpmostree_client::Status,
+    omit_staged: bool,
+) -> Fallible<BTreeSet<Release>> {
     let mut deployments = BTreeSet::<Release>::new();
     for entry in &status.deployments {
-        if omit_staged && entry.staged {
+        if omit_staged && entry.staged.unwrap_or_default() {
             continue;
         }
 
-        let release = entry.clone().into_release();
+        let release = entry.clone().into();
         deployments.insert(release);
     }
     Ok(deployments)
@@ -123,29 +73,14 @@ pub fn local_deployments(
     client: &mut RpmOstreeClient,
     omit_staged: bool,
 ) -> Fallible<BTreeSet<Release>> {
-    let status = status_json(client)?;
+    let status = query_status(client)?;
     let local_depls = parse_local_deployments(&status, omit_staged)?;
 
     Ok(local_depls)
 }
 
-/// Return JSON object for booted deployment.
-fn booted_json(status: &StatusJSON) -> Fallible<DeploymentJSON> {
-    let booted = status
-        .clone()
-        .deployments
-        .into_iter()
-        .find(|d| d.booted)
-        .ok_or_else(|| format_err!("no booted deployment found"))?;
-
-    ensure!(!booted.base_revision().is_empty(), "empty base revision");
-    ensure!(!booted.version.is_empty(), "empty version");
-    ensure!(!booted.base_metadata.basearch.is_empty(), "empty basearch");
-    Ok(booted)
-}
-
 /// Ensure our status cache is up to date; if empty or out of date, run `rpm-ostree status` to populate it.
-fn status_json(client: &mut RpmOstreeClient) -> Fallible<Rc<StatusJSON>> {
+fn query_status_inner(client: &mut RpmOstreeClient) -> Fallible<Rc<rpmostree_client::Status>> {
     STATUS_CACHE_ATTEMPTS.inc();
     let ostree_depls_data = fs::metadata(OSTREE_DEPLS_PATH)
         .with_context(|e| format_err!("failed to query directory {}: {}", OSTREE_DEPLS_PATH, e))?;
@@ -160,7 +95,9 @@ fn status_json(client: &mut RpmOstreeClient) -> Fallible<Rc<StatusJSON>> {
 
     STATUS_CACHE_MISSES.inc();
     trace!("cache stale, invoking rpm-ostree to retrieve local deployments");
-    let status = Rc::new(invoke_cli_status(false)?);
+    let status = Rc::new(
+        rpmostree_client::query_status(&*CLI_CLIENT).map_err(failure::Error::from_boxed_compat)?,
+    );
     client.status_cache = Some(StatusCache {
         status: status.clone(),
         mtime: ostree_depls_data_mtime,
@@ -170,41 +107,26 @@ fn status_json(client: &mut RpmOstreeClient) -> Fallible<Rc<StatusJSON>> {
 }
 
 /// CLI executor for `rpm-ostree status --json`.
-pub fn invoke_cli_status(booted_only: bool) -> Fallible<StatusJSON> {
+pub fn query_status(client: &mut RpmOstreeClient) -> Fallible<Rc<rpmostree_client::Status>> {
     RPM_OSTREE_STATUS_ATTEMPTS.inc();
 
-    let mut cmd = std::process::Command::new("rpm-ostree");
-    cmd.arg("status").env("RPMOSTREE_CLIENT_ID", "zincati");
-
-    // Try to request the minimum scope we need.
-    if booted_only {
-        cmd.arg("--booted");
-    }
-
-    let cmdrun = cmd
-        .arg("--json")
-        .output()
-        .with_context(|_| "failed to run 'rpm-ostree' binary")?;
-
-    if !cmdrun.status.success() {
-        RPM_OSTREE_STATUS_FAILURES.inc();
-        bail!(
-            "rpm-ostree status failed:\n{}",
-            String::from_utf8_lossy(&cmdrun.stderr)
-        );
+    match query_status_inner(client) {
+        Ok(s) => Ok(s),
+        Err(e) => {
+            RPM_OSTREE_STATUS_FAILURES.inc();
+            Err(e)
+        }
     }
-    let status: StatusJSON = serde_json::from_slice(&cmdrun.stdout)?;
-    Ok(status)
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
 
-    fn mock_status(path: &str) -> Fallible<StatusJSON> {
+    fn mock_status(path: &str) -> Fallible<rpmostree_client::Status> {
         let fp = std::fs::File::open(path).unwrap();
         let bufrd = std::io::BufReader::new(fp);
-        let status: StatusJSON = serde_json::from_reader(bufrd)?;
+        let status = serde_json::from_reader(bufrd)?;
         Ok(status)
     }
 
@@ -226,18 +148,4 @@ mod tests {
             assert_eq!(deployments.len(), 1);
         }
     }
-
-    #[test]
-    fn mock_booted_basearch() {
-        let status = mock_status("tests/fixtures/rpm-ostree-status.json").unwrap();
-        let booted = booted_json(&status).unwrap();
-        assert_eq!(booted.base_metadata.basearch, "x86_64");
-    }
-
-    #[test]
-    fn mock_booted_updates_stream() {
-        let status = mock_status("tests/fixtures/rpm-ostree-status.json").unwrap();
-        let booted = booted_json(&status).unwrap();
-        assert_eq!(booted.base_metadata.stream, "testing-devel");
-    }
 }

src/rpm_ostree/mod.rs

@@ -1,7 +1,8 @@
 mod cli_deploy;
 mod cli_finalize;
 mod cli_status;
-pub use cli_status::{invoke_cli_status, parse_basearch, parse_booted, parse_updates_stream};
+pub use cli_status::query_status;
+use lazy_static::lazy_static;
 
 mod actor;
 pub use actor::{FinalizeDeployment, QueryLocalDeployments, RpmOstreeClient, StageDeployment};
@@ -14,6 +15,16 @@ use failure::{ensure, format_err, Fallible, ResultExt};
 use serde::Serialize;
 use std::cmp::Ordering;
 
+/// Metadata key the base (RPM) architecture; injected by coreos-assembler
+pub(crate) const COSA_BASEARCH: &str = "coreos-assembler.basearch";
+/// Metadata key for the Fedora CoreOS stream, injected by FCOS tooling via cosa.
+pub(crate) const FCOS_STREAM: &str = "fedora-coreos.stream";
+
+lazy_static! {
+    pub(crate) static ref CLI_CLIENT: rpmostree_client::CliClient =
+        rpmostree_client::CliClient::new("zincati");
+}
+
 /// An OS release.
 #[derive(Clone, Debug, PartialEq, Eq, Serialize)]
 pub struct Release {