feat: add json output to stderr of upgrade and switch

Author: antheas

lib/src/cli.rs

@@ -52,6 +52,10 @@ pub(crate) struct UpgradeOpts {
     /// a userspace-only restart.
     #[clap(long, conflicts_with = "check")]
     pub(crate) apply: bool,
+
+    /// Pipe download progress to stderr in a jsonl format.
+    #[clap(long)]
+    pub(crate) json: bool,
 }
 
 /// Perform an switch operation
@@ -101,6 +105,10 @@ pub(crate) struct SwitchOpts {
 
     /// Target image to use for the next boot.
     pub(crate) target: String,
+
+    /// Pipe download progress to stderr in a jsonl format.
+    #[clap(long)]
+    pub(crate) json: bool,
 }
 
 /// Options controlling rollback
@@ -670,7 +678,7 @@ async fn upgrade(opts: UpgradeOpts) -> Result<()> {
             }
         }
     } else {
-        let fetched = crate::deploy::pull(repo, imgref, None, opts.quiet).await?;
+        let fetched = crate::deploy::pull(repo, imgref, None, opts.quiet, opts.json).await?;
         let staged_digest = staged_image.map(|s| s.digest().expect("valid digest in status"));
         let fetched_digest = &fetched.manifest_digest;
         tracing::debug!("staged: {staged_digest:?}");
@@ -764,7 +772,7 @@ async fn switch(opts: SwitchOpts) -> Result<()> {
     }
     let new_spec = RequiredHostSpec::from_spec(&new_spec)?;
 
-    let fetched = crate::deploy::pull(repo, &target, None, opts.quiet).await?;
+    let fetched = crate::deploy::pull(repo, &target, None, opts.quiet, opts.json).await?;
 
     if !opts.retain {
         // By default, we prune the previous ostree ref so it will go away after later upgrades
@@ -826,7 +834,7 @@ async fn edit(opts: EditOpts) -> Result<()> {
         return crate::deploy::rollback(sysroot).await;
     }
 
-    let fetched = crate::deploy::pull(repo, new_spec.image, None, opts.quiet).await?;
+    let fetched = crate::deploy::pull(repo, new_spec.image, None, opts.quiet, false).await?;
 
     // TODO gc old layers here
 

lib/src/deploy.rs

@@ -45,6 +45,16 @@ pub(crate) struct ImageState {
     pub(crate) ostree_commit: String,
 }
 
+/// Download information
+#[derive(Debug,serde::Serialize)]
+pub struct JsonProgress {
+    pub done_bytes: u64,
+    pub download_bytes: u64,
+    pub image_bytes: u64,
+    pub n_layers: usize,
+    pub n_layers_done: usize,
+}
+
 impl<'a> RequiredHostSpec<'a> {
     /// Given a (borrowed) host specification, "unwrap" its internal
     /// options, giving a spec that is required to have a base container image.
@@ -234,13 +244,73 @@ async fn handle_layer_progress_print(
     }
 }
 
+/// Write container fetch progress to standard output.
+async fn handle_layer_progress_print_jsonl(
+    mut layers: tokio::sync::mpsc::Receiver<ostree_container::store::ImportProgress>,
+    mut layer_bytes: tokio::sync::watch::Receiver<Option<ostree_container::store::LayerProgress>>,
+    n_layers_to_fetch: usize,
+    download_bytes: u64,
+    image_bytes: u64,
+) {
+    let mut total_read = 0u64;
+    let mut layers_done: usize = 0;
+    let mut last_json_written = std::time::Instant::now();
+    loop {
+        tokio::select! {
+            // Always handle layer changes first.
+            biased;
+            layer = layers.recv() => {
+                if let Some(l) = layer {
+                    if !l.is_starting() {
+                        let layer = descriptor_of_progress(&l);
+                        layers_done += 1;
+                        total_read += total_read.saturating_add(layer.size());
+                    }
+                } else {
+                    // If the receiver is disconnected, then we're done
+                    break
+                };
+            },
+            r = layer_bytes.changed() => {
+                if r.is_err() {
+                    // If the receiver is disconnected, then we're done
+                    break
+                }
+                let bytes = layer_bytes.borrow();
+                if let Some(bytes) = &*bytes {
+                    let done_bytes = total_read + bytes.fetched;
+
+                    // Lets update the json output only on bytes fetched
+                    // They are common enough, anyhow. Debounce on time.
+                    let curr = std::time::Instant::now();
+                    if curr.duration_since(last_json_written).as_secs_f64() > 0.2 {
+                        let json = JsonProgress {
+                            done_bytes,
+                            download_bytes,
+                            image_bytes,
+                            n_layers: n_layers_to_fetch,
+                            n_layers_done: layers_done,
+                        };
+                        let json = serde_json::to_string(&json).unwrap();
+                        // Write to stderr so that consumer can filter this
+                        eprintln!("{}", json);
+                        last_json_written = curr;
+                    }
+                }
+            }
+        }
+    }
+}
+
+
 /// Wrapper for pulling a container image, wiring up status output.
 #[context("Pulling")]
 pub(crate) async fn pull(
     repo: &ostree::Repo,
     imgref: &ImageReference,
     target_imgref: Option<&OstreeImageReference>,
     quiet: bool,
+    json: bool,
 ) -> Result<Box<ImageState>> {
     let ostree_imgref = &OstreeImageReference::from(imgref.clone());
     let mut imp = new_importer(repo, ostree_imgref).await?;
@@ -262,14 +332,22 @@ pub(crate) async fn pull(
     let layers_to_fetch = prep.layers_to_fetch().collect::<Result<Vec<_>>>()?;
     let n_layers_to_fetch = layers_to_fetch.len();
     let download_bytes: u64 = layers_to_fetch.iter().map(|(l, _)| l.layer.size()).sum();
+    let image_bytes: u64 = prep.all_layers().map(|l| l.layer.size()).sum();
 
-    let printer = (!quiet).then(|| {
+    let printer = (!quiet || json).then(|| {
         let layer_progress = imp.request_progress();
         let layer_byte_progress = imp.request_layer_progress();
-        tokio::task::spawn(async move {
-            handle_layer_progress_print(layer_progress, layer_byte_progress, n_layers_to_fetch, download_bytes)
-                .await
-        })
+        if json {
+            tokio::task::spawn(async move {
+                handle_layer_progress_print_jsonl(layer_progress, layer_byte_progress, n_layers_to_fetch, download_bytes, image_bytes)
+                    .await
+            })
+        } else {
+            tokio::task::spawn(async move {
+                handle_layer_progress_print(layer_progress, layer_byte_progress, n_layers_to_fetch, download_bytes)
+                    .await
+            })
+        }
     });
     let import = imp.import(prep).await;
     if let Some(printer) = printer {

lib/src/install.rs

@@ -744,7 +744,7 @@ async fn install_container(
         let spec_imgref = ImageReference::from(src_imageref.clone());
         let repo = &sysroot.repo();
         repo.set_disable_fsync(true);
-        let r = crate::deploy::pull(repo, &spec_imgref, Some(&state.target_imgref), false).await?;
+        let r = crate::deploy::pull(repo, &spec_imgref, Some(&state.target_imgref), false, false).await?;
         repo.set_disable_fsync(false);
         r
     };