1 files changed, 29 insertions, 0 deletions
diff --git a/worker/fs.ts b/worker/fs.ts
new file mode 100644
index 0000000..2c02b34
--- /dev/null
+++ b/worker/fs.ts
@@ -0,0 +1,29 @@
+import { Either, getStdout, IEither, LogMetricTraceable } from '@emprespresso/pengueno';
+import { readFileSync } from 'node:fs';
+
+// the container which runs the pipeline synthesizer (A) might be spawned by another container
+// (B) ((which should be the one running this job)) by talking to the host's docker daemon
+// (mounting /var/run/docker.sock) and executing the {@link getPipelineGenerationCommand}.
+//
+// so mounting {@link getSrcDirectoryForCiJob} has no meaning as it doesn't exist on the host;
+// here we replace the path in (B) with the actual volume source on the host, where the src
+// exists.
+export async function getPathOnHost(path: string, home = '/var/lib/laminar'): Promise<IEither<Error, string>> {
+    const container = await Either.fromFailable<Error, string>(() =>
+        readFileSync('/etc/hostname', 'utf-8'),
+    ).flatMapAsync((hostname) =>
+        LogMetricTraceable.of(`docker inspect ${hostname}`.split(' '))
+            .map((tCmd) => getStdout(tCmd))
+            .get(),
+    );
+    if (container.left().present()) {
+        return Either.right(path);
+    }
+    return container
+        .flatMap((inspect) => Either.fromFailable(() => JSON.parse(inspect)))
+        .mapRight(
+            ([container]) =>
+                container.Mounts.find(({ Destination }: { Destination: string }) => Destination === home).Source,
+        )
+        .mapRight((source) => path.replace(home, source));
+}