teach Propolis a -v flag with Git metadata

Cargo.toml

@@ -190,9 +190,9 @@ tracing-bunyan-formatter = "0.3.3"
 tracing-subscriber = "0.3.14"
 usdt = { version = "0.6", default-features = false }
 uuid = "1.3.2"
+vergen-git2 = { version = "10.0.0" }
 zerocopy = "0.8.25"
 
-
 #
 # It's common during development to use a local copy of various complex
 # dependencies.  If you want to use those, uncomment one of these blocks.

bin/propolis-server/src/main.rs

@@ -73,7 +73,7 @@ fn parse_log_level(s: &str) -> anyhow::Result<slog::Level> {
 }
 
 #[derive(Debug, Parser)]
-#[clap(about, version)]
+#[clap(about, version = propolis::version())]
 /// An HTTP server providing access to Propolis
 enum Args {
     /// Runs the Propolis server.
@@ -122,6 +122,8 @@ fn run_server(
 ) -> anyhow::Result<()> {
     use propolis::api_version;
 
+    slog::info!(log, "Running {}", propolis::version());
+
     // Check that devices conform to expected API version
     if let Err(e) = api_version::check() {
         use api_version::{Error, VersionCheckError};

bin/propolis-standalone/src/main.rs

@@ -1591,6 +1591,7 @@ fn api_version_checks(log: &slog::Logger) -> std::io::Result<()> {
 }
 
 #[derive(clap::Parser)]
+#[clap(version = propolis::version())]
 /// Propolis command-line frontend for running a VM.
 struct Args {
     /// Either the VM config file or a previously captured snapshot image.
@@ -1624,6 +1625,8 @@ fn main() -> anyhow::Result<ExitCode> {
 
     let log = build_log(log_level);
 
+    slog::info!(log, "Running {}", propolis::version());
+
     // Check that vmm and viona device version match what we expect
     api_version_checks(&log).context("API version checks")?;
 

lib/propolis/Cargo.toml

@@ -57,6 +57,10 @@ softnpu = { workspace = true, optional = true }
 dlpi = { workspace = true, optional = true }
 static_assertions = "1.1.0"
 
+[build-dependencies]
+anyhow.workspace = true
+vergen-git2.workspace = true
+
 [dev-dependencies]
 crossbeam-channel.workspace = true
 tempfile.workspace = true

lib/propolis/build.rs

@@ -0,0 +1,18 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
+fn main() -> anyhow::Result<()> {
+    let git2 = vergen_git2::Git2::builder()
+        .branch(true)
+        .commit_count(true)
+        .dirty(true)
+        .sha(true)
+        .build();
+    vergen_git2::Emitter::default()
+        .idempotent()
+        .add_instructions(&git2)?
+        .emit()?;
+
+    Ok(())
+}

lib/propolis/src/lib.rs

@@ -39,3 +39,76 @@ pub mod vsock;
 
 pub use exits::{VmEntry, VmExit};
 pub use vmm::Machine;
+
+pub fn version() -> &'static str {
+    lazy_static::lazy_static! {
+        static ref VERSION: String = {
+            use std::fmt::Write;
+
+            let git = match (
+                option_env!("VERGEN_GIT_BRANCH"),
+                option_env!("VERGEN_GIT_SHA"),
+                option_env!("VERGEN_GIT_COMMIT_COUNT"),
+                option_env!("VERGEN_GIT_DIRTY"),
+            ) {
+                (Some(branch), Some(sha), Some(commit), Some(dirty)) => {
+                    Some((branch, sha, commit, dirty))
+                },
+                _ => {
+                    None
+                }
+            };
+
+            let mut version = format!("v{}", env!("CARGO_PKG_VERSION"));
+            if let Some((branch, sha, commit, dirty)) = git {
+                write!(version, "-{commit} ").unwrap();
+                let sha_prefix = sha.get(..9).unwrap_or(sha);
+                if dirty == "true" {
+                    write!(version, "(DIRTY {sha_prefix}) ").unwrap();
+                } else {
+                    write!(version, "({sha_prefix}) ").unwrap();
+                }
+                write!(version, "{branch}").unwrap();
+            } else {
+                version.push_str(" <unknown git commit>");
+            }
+
+            version.push_str(", ");
+            match bhyve_api::api_version() {
+                Ok(v) => {
+                    write!(version, "bhyve API v{v}").unwrap();
+                }
+                Err(_) => {
+                    version.push_str("<unknown bhyve API version>");
+                }
+            }
+
+            version.push_str(", ");
+            match viona_api::api_version() {
+                Ok(v) => {
+                    write!(version, "viona API v{v}").unwrap();
+                }
+                Err(_) => {
+                    version.push_str("<unknown viona API version>");
+                }
+            }
+
+            version
+        };
+    };
+    &VERSION
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn print_version() {
+        let v = version();
+        eprintln!("propolis {v}");
+        assert!(v.contains(env!("CARGO_PKG_VERSION")));
+        assert!(v.contains("bhyve API"));
+        assert!(v.contains("viona API"));
+    }
+}