Merge pull request #34 from cgwalters/arch-api

Add a `this_architecture()` API, drop nix dependency

Author: cgwalters

Cargo.toml

@@ -6,7 +6,6 @@ edition = "2018"
 license = "Apache-2.0"
 
 [dependencies]
-nix = { version = ">= 0.24, < 0.26", default-features = false, features = ["feature"] }
 serde = { version = "^1.0", features = ["derive"] }
 strum = ">= 0.20, < 0.25"
 strum_macros = ">= 0.20, < 0.25"

src/lib.rs

@@ -164,14 +164,7 @@ pub struct Images {
 impl Stream {
     /// Returns the data for the CPU architecture matching the running process.
     pub fn this_architecture(&self) -> Option<&Arch> {
-        self.architectures.get(
-            // uname() shouldn't fail, and our return type assumes it won't.
-            nix::sys::utsname::uname()
-                .expect("couldn't get utsname")
-                .machine()
-                .to_str()
-                .expect("utsname machine isn't UTF-8"),
-        )
+        self.architectures.get(this_architecture())
     }
 
     /// Find a `disk` artifact.
@@ -192,3 +185,16 @@ impl Stream {
             .and_then(|(_fmt, v)| v.get("disk"))
     }
 }
+
+/// Return the RPM/GNU architecture identifier for the current binary.
+///
+/// See also https://github.com/coreos/stream-metadata-go/blob/c5fe1b98ac1b1e6ab62a606b7580dc1f30703f83/arch/arch.go
+pub fn this_architecture() -> &'static str {
+    match std::env::consts::ARCH {
+        // Funny enough, PowerPC is so far the only weird case here.
+        // For everything else, the Rust architecture is the same as RPM/GNU/Linux.
+        "powerpc64" if cfg!(target_endian = "big") => "ppc64",
+        "powerpc64" if cfg!(target_endian = "little") => "ppc64le",
+        o => o,
+    }
+}

tests/it/main.rs

@@ -10,8 +10,7 @@ fn test_basic() {
         "https://builds.coreos.fedoraproject.org/streams/stable.json"
     );
 
-    let un = nix::sys::utsname::uname().unwrap();
-    let myarch = un.machine().to_str().unwrap();
+    let myarch = coreos_stream_metadata::this_architecture();
 
     let st: Stream = serde_json::from_slice(STREAM_DATA).unwrap();
     assert_eq!(st.stream, "stable");