identity: introspect basearch

This introspects node basearch from rpm-ostree, instead of using
build-time configuration and the internal mapping table.

src/identity/mod.rs

@@ -1,4 +1,3 @@
-mod basearch;
 mod platform;
 
 use crate::config::inputs;
@@ -58,7 +57,7 @@ impl Identity {
 
     /// Try to build default agent identity.
     pub fn try_default() -> Fallible<Self> {
-        let basearch = basearch::read_basearch()?;
+        let basearch = rpm_ostree::basearch()?;
         let current_os = rpm_ostree::booted().context("failed to introspect booted OS image")?;
         let node_uuid = {
             let app_id = id128::Id128::try_from_slice(APP_ID)

src/rpm_ostree/cli_status.rs

@@ -18,10 +18,19 @@ pub struct DeploymentJSON {
     booted: bool,
     #[serde(rename = "base-checksum")]
     base_checksum: Option<String>,
+    #[serde(rename = "base-commit-meta")]
+    base_metadata: BaseCommitMetaJSON,
     checksum: String,
     version: String,
 }
 
+/// Metadata from base commit (only fields relevant to zincati).
+#[derive(Debug, Deserialize)]
+struct BaseCommitMetaJSON {
+    #[serde(rename = "coreos-assembler.basearch")]
+    basearch: String,
+}
+
 impl DeploymentJSON {
     /// Convert into `Release`.
     pub fn into_release(self) -> Release {
@@ -39,30 +48,74 @@ impl DeploymentJSON {
     }
 }
 
+/// Return base architecture for booted deployment.
+pub fn basearch() -> Fallible<String> {
+    let status = status_json(true)?;
+    let json = booted_json(status)?;
+    Ok(json.base_metadata.basearch)
+}
+
 /// Find the booted deployment.
 pub fn booted() -> Fallible<Release> {
-    let cmd = std::process::Command::new("rpm-ostree")
-        .arg("status")
+    let status = status_json(true)?;
+    let json = booted_json(status)?;
+    Ok(json.into_release())
+}
+
+/// Return JSON object for booted deployment.
+fn booted_json(status: StatusJSON) -> Fallible<DeploymentJSON> {
+    let booted = status
+        .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)
+}
+
+/// Introspect deployments (rpm-ostree status).
+fn status_json(booted_only: bool) -> Fallible<StatusJSON> {
+    let mut cmd = std::process::Command::new("rpm-ostree");
+    cmd.arg("status");
+
+    // Try to request the minimum scope we need.
+    if booted_only {
+        cmd.arg("--booted");
+    }
+
+    let cmdrun = cmd
         .arg("--json")
-        .arg("--booted")
         .output()
         .with_context(|e| format_err!("failed to run rpm-ostree: {}", e))?;
 
-    if !cmd.status.success() {
+    if !cmdrun.status.success() {
         bail!(
             "rpm-ostree status failed:\n{}",
-            String::from_utf8_lossy(&cmd.stderr)
+            String::from_utf8_lossy(&cmdrun.stderr)
         );
     }
-    let status: StatusJSON = serde_json::from_slice(&cmd.stdout)?;
+    let status: StatusJSON = serde_json::from_slice(&cmdrun.stdout)?;
+    Ok(status)
+}
 
-    let booted = status
-        .deployments
-        .into_iter()
-        .find(|d| d.booted)
-        .ok_or_else(|| format_err!("no booted deployment found"))?;
+#[cfg(test)]
+mod tests {
+    use super::*;
 
-    ensure!(!booted.base_revision().is_empty(), "empty base revision");
-    ensure!(!booted.version.is_empty(), "empty version");
-    Ok(booted.into_release())
+    fn mock_status() -> Fallible<StatusJSON> {
+        let fp = std::fs::File::open("tests/fixtures/rpm-ostree-status.json").unwrap();
+        let mut bufrd = std::io::BufReader::new(fp);
+        let status: StatusJSON = serde_json::from_reader(bufrd)?;
+        Ok(status)
+    }
+
+    #[test]
+    fn mock_booted_basearch() {
+        let status = mock_status().unwrap();
+        let booted = booted_json(status).unwrap();
+        assert_eq!(booted.base_metadata.basearch, "x86_64");
+    }
 }

src/rpm_ostree/mod.rs

@@ -1,7 +1,7 @@
 mod cli_deploy;
 mod cli_finalize;
 mod cli_status;
-pub use cli_status::booted;
+pub use cli_status::{basearch, booted};
 
 mod actor;
 pub use actor::{FinalizeDeployment, RpmOstreeClient, StageDeployment};

tests/fixtures/rpm-ostree-status.json

@@ -0,0 +1,60 @@
+{
+  "deployments" : [
+    {
+      "unlocked" : "none",
+      "requested-local-packages" : [
+      ],
+      "base-commit-meta" : {
+        "coreos-assembler.config-dirty" : "true",
+        "coreos-assembler.config-gitrev" : "e5ffda727170e124c7f7d8782e256b0462bf9869",
+        "coreos-assembler.basearch" : "x86_64",
+        "rpmostree.inputhash" : "0e2ba98bac847c8a8cc5ffd42822a41d53ef6719ccaf6a0094559768aa24da33",
+        "version" : "30.1",
+        "rpmostree.rpmmd-repos" : [
+          {
+            "id" : "fedora-coreos-pool",
+            "timestamp" : 7435743550895030272
+          },
+          {
+            "id" : "fedora",
+            "timestamp" : -7689964138319052800
+          },
+          {
+            "id" : "fedora-updates",
+            "timestamp" : -1292510703390818304
+          },
+          {
+            "id" : "coreos-assembler-local-overrides",
+            "timestamp" : 1402332922660257792
+          }
+        ]
+      },
+      "base-removals" : [
+      ],
+      "gpg-enabled" : false,
+      "origin" : "fedora/x86_64/coreos/testing-devel",
+      "osname" : "fedora-coreos",
+      "pinned" : false,
+      "requested-base-local-replacements" : [
+      ],
+      "checksum" : "ce718b90ce19c2cac07fa45efdce91aad208a508c98e9f7f572f5aaba76f569a",
+      "regenerate-initramfs" : false,
+      "id" : "fedora-coreos-ce718b90ce19c2cac07fa45efdce91aad208a508c98e9f7f572f5aaba76f569a.0",
+      "version" : "30.1",
+      "requested-packages" : [
+      ],
+      "requested-base-removals" : [
+      ],
+      "serial" : 0,
+      "base-local-replacements" : [
+      ],
+      "timestamp" : 1561753297,
+      "booted" : true,
+      "packages" : [
+      ]
+    }
+  ],
+  "transaction" : null,
+  "cached-update" : null
+}
+