brokerd: escape container errors in the log; prefix and quote two messages

Implemented-By: OpenCode session (model recorded in docs/implementer-log.md)

crates/brokerd/tests/container_log.rs

@@ -0,0 +1,128 @@
+//! What a tool or Podman writes on standard error reaches `brokerd`'s log escaped, one entry per
+//! event: it cannot start a line of its own or forge a runbook pointer (M3b review finding 5).
+//! Do not edit.
+
+#[path = "support/build.rs"]
+mod build;
+#[path = "support/fake_podman.rs"]
+mod fake_podman;
+
+use brokerd::container::{CANNOT_START, COULD_NOT_RUN, Podman, UNEXPECTED};
+use brokerd::policy::{Outcome, SessionState, decide};
+use brokerd::runner::run;
+use build::{fetch, grant, now, read, set};
+use fake_podman::{Fake, Lines, serial};
+use proto::{Mode, ToolRequest, ToolResponse};
+
+const FORGED: &str = "real line\nbrokerd: forged\nsee docs/runbook.md#grants-invalid";
+
+fn call(fake: &Fake, req: ToolRequest, grants: Vec<build::Build>, log: &Lines) -> ToolResponse {
+    let podman = Podman::new(fake.runner(""), fake.dir.join("egress"), log.sink());
+    let decision = match decide(req, &set(grants), SessionState::default(), now()) {
+        Outcome::Allowed(d) => d,
+        other => panic!("not allowed: {other:?}"),
+    };
+    run(decision, &podman)
+}
+
+/// No entry holds the forged text as lines of its own; the one that carries it has it escaped.
+fn escaped(log: &Lines) {
+    let entries = log.0.lock().unwrap().clone();
+    for entry in &entries {
+        assert!(!entry.contains("\nbrokerd: forged"), "raw: {entry:?}");
+        assert!(
+            !entry.contains("\nsee docs/runbook.md#grants-invalid"),
+            "raw: {entry:?}"
+        );
+    }
+    assert!(
+        entries
+            .iter()
+            .any(|e| e.contains(r"real line\nbrokerd: forged")),
+        "the error is still logged, escaped: {entries:?}"
+    );
+}
+
+fn notes() -> Vec<build::Build> {
+    vec![grant("notes", "read_file", Mode::Auto).paths(&["/n"])]
+}
+
+#[test]
+fn a_tool_that_could_not_run() {
+    let _s = serial();
+    let fake = Fake::new(
+        "log-2",
+        &format!("cat > /dev/null; printf '{FORGED}' >&2; exit 2"),
+    );
+    let log = Lines::default();
+    assert_eq!(
+        call(&fake, read("/n/a"), notes(), &log),
+        ToolResponse::Failed {
+            message: COULD_NOT_RUN.to_string()
+        }
+    );
+    escaped(&log);
+}
+
+#[test]
+fn a_container_podman_could_not_start_keeps_its_one_real_pointer() {
+    let _s = serial();
+    let fake = Fake::new(
+        "log-125",
+        &format!("cat > /dev/null; printf '{FORGED}' >&2; exit 125"),
+    );
+    let log = Lines::default();
+    assert_eq!(
+        call(&fake, read("/n/a"), notes(), &log),
+        ToolResponse::Failed {
+            message: CANNOT_START.to_string()
+        }
+    );
+    escaped(&log);
+    let entries = log.0.lock().unwrap().clone();
+    assert!(
+        entries
+            .iter()
+            .any(|e| e.ends_with("\nsee docs/runbook.md#runner-unavailable")),
+        "{entries:?}"
+    );
+}
+
+#[test]
+fn an_unexpected_ending() {
+    let _s = serial();
+    let fake = Fake::new(
+        "log-3",
+        &format!("cat > /dev/null; printf '{FORGED}' >&2; exit 3"),
+    );
+    let log = Lines::default();
+    assert_eq!(
+        call(&fake, read("/n/a"), notes(), &log),
+        ToolResponse::Failed {
+            message: UNEXPECTED.to_string()
+        }
+    );
+    escaped(&log);
+}
+
+#[test]
+fn a_proxy_podman_could_not_start() {
+    let _s = serial();
+    let body =
+        format!("if [ \"$2\" = -d ]; then printf '{FORGED}' >&2; exit 125; fi; cat > /dev/null");
+    let fake = Fake::new("log-egress", &body);
+    let log = Lines::default();
+    let got = call(
+        &fake,
+        fetch("https://example.com/"),
+        vec![grant("web", "http_fetch", Mode::Auto).hosts(&["example.com"])],
+        &log,
+    );
+    assert_eq!(
+        got,
+        ToolResponse::Failed {
+            message: CANNOT_START.to_string()
+        }
+    );
+    escaped(&log);
+}