Update readme to explain where to get files from and how to set permissions
Change-Id: I59f863c94b9b32e6d2f86c5a13fe28c422fa9a35
(cherry picked from commit f741da1daaddbf37b196b6f06ff525c065979c19)
diff --git a/launcher/README.md b/launcher/README.md
index 278de81..956826f 100644
--- a/launcher/README.md
+++ b/launcher/README.md
@@ -61,6 +61,56 @@
sudo service libvirt-bin restart
```
+### What files should i populate (and where)?
+
+Create a directory to host your files. This directory will need to be accessible
+not only by you, but by libvirt, too, and libvirt will likely update ownership
+of your files. My recommendation is to use either `/srv/cf` or `/run/cf` folder.
+
+```
+mkdir /srv/cf
+sudo chown -R libvirt-qemu:root /srv/cf
+sudo setfacl -m u:${USER}:rwx /srv/cf
+sudo chmod 0770 /srv/cf
+```
+
+If you've done the above right, you should be able to create files there, even
+if you're not working on behalf of libvirt-qemu user or root group.
+
+You will need to copy (or link) the following files from your build directory:
+
+ * system.img
+ * ramdisk.img
+ * kernel
+
+This artifact needs to be built and copied from this repo:
+
+ * gce_ramdisk.img
+
+ build: `bazel build //guest:gce_ramdisk`, copy or link file from workspace
+ root's bazel-bin folder.
+
+These files need to be manually created:
+
+ * data.img and
+ * cache.img
+
+ ```
+ truncate -s 10G data.img
+ mkfs.ext4 data.img
+ truncate -s 2G cache.img
+ mkfs.ext4 cache.img
+ ```
+
+After you're done linking/copying/creating files, set posix acls on these files
+so that you don't lose access to them:
+
+```
+setfacl -m u:${USER}:rw /srv/cf/*
+```
+
+Done.
+
### I'm seeing `permission denied` errors
libvirt is not executing virtual machines on behalf of the calling user.
@@ -73,7 +123,7 @@
folder proper permissions.
```sh
-➜ ls -l /run/cf
+➜ ls -l /srv/cf
total 1569216
drwxr-x--- 2 libvirt-qemu eng 180 Jun 28 14:27 .
drwxr-xr-x 45 root root 2080 Jun 28 14:27 ..
@@ -85,9 +135,7 @@
-rwxr-x--- 1 root root 3221225472 Jun 28 14:27 system.img
```
-**Note**: the `/run/cf` folder's owner is `libvirt-qemu:eng`. This allows QEmu
+**Note**: the `/run/cf` folder's owner is `libvirt-qemu`. This allows QEmu
to access images - and me to poke in the folder.
Now don't worry about the `root` ownership. Libvirt manages permissions dynamically.
-You may want to give yourself write permissions to these files during development,
-though.
