varlink: Add experimental IPC interface for status, update, and install

Cargo.toml

@@ -71,6 +71,7 @@ tracing-subscriber = { version = "0.3.18", features = ["env-filter"] }
 tracing-journald = "0.3.1"
 uzers = "0.12"
 xshell = "0.2.6"
+zlink = "0.4"
 
 # See https://github.com/coreos/cargo-vendor-filterer
 [workspace.metadata.vendor-filter]
@@ -98,7 +99,9 @@ bins = ["skopeo", "podman", "ostree", "zstd", "setpriv", "systemctl", "chcon"]
 # Require an extra opt-in for unsafe
 unsafe_code = "deny"
 # Absolutely must handle errors
-unused_must_use = "forbid"
+# "deny" rather than "forbid" so that proc-macro expansions (e.g. zlink)
+# can locally #[allow(unused)] without conflicting.
+unused_must_use = "deny"
 missing_docs = "deny"
 missing_debug_implementations = "deny"
 # Feel free to comment this one out locally during development of a patch.

crates/lib/Cargo.toml

@@ -70,6 +70,7 @@ tar = "0.4.43"
 tini = "1.3.0"
 uuid = { version = "1.8.0", features = ["v4"] }
 uapi-version = "0.4.0"
+zlink = { workspace = true }
 
 [dev-dependencies]
 similar-asserts = { workspace = true }

crates/lib/src/cli.rs

@@ -272,6 +272,13 @@ pub(crate) struct StatusOpts {
     /// Include additional fields in human readable format.
     #[clap(long, short = 'v')]
     pub(crate) verbose: bool,
+
+    /// Query a sysroot at an arbitrary path instead of the booted system.
+    ///
+    /// Useful for inspecting a freshly installed (not yet booted) system,
+    /// e.g. `bootc status --json --sysroot /mnt`.
+    #[clap(long)]
+    pub(crate) sysroot: Option<camino::Utf8PathBuf>,
 }
 
 /// Add a transient overlayfs on /usr
@@ -1598,6 +1605,11 @@ where
     I: IntoIterator,
     I::Item: Into<OsString> + Clone,
 {
+    // If we were socket-activated (e.g. via `varlinkctl exec:`), serve
+    // varlink and exit without parsing CLI arguments.
+    if crate::varlink::try_serve_varlink().await? {
+        return Ok(());
+    }
     run_from_opt(Opt::parse_including_static(args)).await
 }
 
@@ -2228,7 +2240,8 @@ mod tests {
                 format: None,
                 format_version: None,
                 booted: false,
-                verbose: false
+                verbose: false,
+                sysroot: None,
             })
         ));
         assert!(matches!(

crates/lib/src/install.rs

@@ -353,7 +353,7 @@ pub(crate) struct InstallConfigOpts {
     /// is to allow mounting the whole `/root` home directory as a `tmpfs`, while still
     /// getting the SSH key replaced on boot.
     #[clap(long)]
-    root_ssh_authorized_keys: Option<Utf8PathBuf>,
+    pub(crate) root_ssh_authorized_keys: Option<Utf8PathBuf>,
 
     /// Perform configuration changes suitable for a "generic" disk image.
     /// At the moment:

crates/lib/src/lib.rs

@@ -95,6 +95,7 @@ mod store;
 mod task;
 mod ukify;
 mod utils;
+pub(crate) mod varlink;
 
 #[cfg(feature = "docgen")]
 mod cli_json;