Add a version check for bubblewrap in the server. Fixes crossbeam-rs#316

Cargo.toml

@@ -89,6 +89,7 @@ nix = { version = "0.11.0", optional = true }
 rouille = { version = "2.2", optional = true, default-features = false, features = ["ssl"] }
 syslog = { version = "4.0.1", optional = true }
 void = { version = "1", optional = true }
+version-compare = { version = "0.0.8", optional = true }
 
 [patch.crates-io]
 # Waiting for https://github.com/tiny-http/tiny-http/pull/151
@@ -134,7 +135,7 @@ unstable = []
 # Enables distributed support in the sccache client
 dist-client = ["ar", "flate2", "hyper", "hyperx", "reqwest", "rust-crypto", "url"]
 # Enables the sccache-dist binary
-dist-server = ["arraydeque", "crossbeam-utils", "jsonwebtoken", "flate2", "libmount", "nix", "openssl", "reqwest", "rouille", "syslog", "void"]
+dist-server = ["arraydeque", "crossbeam-utils", "jsonwebtoken", "flate2", "libmount", "nix", "openssl", "reqwest", "rouille", "syslog", "void", "version-compare"]
 # Enables dist tests with external requirements
 dist-tests = []
 

src/bin/sccache-dist/build.rs

@@ -26,6 +26,7 @@ use std::iter;
 use std::path::{self, Path, PathBuf};
 use std::process::{ChildStdin, Command, Output, Stdio};
 use std::sync::{Mutex};
+use version_compare::Version;
 
 use crate::errors::*;
 
@@ -95,6 +96,26 @@ impl OverlayBuilder {
             bail!("not running as root")
         }
 
+        let out = Command::new(&bubblewrap).arg("--version").check_stdout_trim()
+            .chain_err(|| "Failed to execute bwrap for version check")?;
+        if let Some(s) = out.split_whitespace().nth(1) {
+            match (Version::from("0.3.0"), Version::from(s)) {
+                (Some(min), Some(seen)) => {
+                    if seen < min {
+                        bail!("bubblewrap 0.3.0 or later is required, got {:?} for {:?}",
+                              out, bubblewrap);
+                    }
+                },
+                (_, _) => {
+                    bail!("Unexpected version format running {:?}: got {:?}, expected \"bubblewrap x.x.x\"",
+                          bubblewrap, out);
+                }
+            }
+        } else {
+            bail!("Unexpected version format running {:?}: got {:?}, expected \"bubblewrap x.x.x\"",
+                  bubblewrap, out);
+        }
+
         // TODO: pidfile
         let ret = Self {
             bubblewrap,