lxc-create: Store template information in config

Change lxc-create to add the name of the template, checksum and any parameters
to the container's configuration.
This makes it easier to debug and figure out exactly how a container was built.

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

diff --git a/src/lxc/lxc-create.in b/src/lxc/lxc-create.in
index 30f0c22d90a0f7ec3e3aeb5a80f64c91fce71f71..7a50633fbcddaedd7516cf023fe81acca2eee5da 100644 (file)
--- a/src/lxc/lxc-create.in
+++ b/src/lxc/lxc-create.in
@@ -281,7 +281,29 @@ if [ ! -r "$lxc_config" ]; then
     exit 1
 fi
 
-cp $lxc_config $lxc_path/$lxc_name/config
+# Allow for a path to be provided as the template name
+if [ -x $lxc_template ]; then
+    template_path=$lxc_template
+else
+    template_path=${templatedir}/lxc-$lxc_template
+fi
+
+if ! [ -x "$template_path" ]; then
+    echo "$(basename $0): unknown template '$lxc_template'" >&2
+    cleanup
+fi
+
+if [ ! -z $lxc_template ]; then
+    sum=$(sha1sum $template_path | cut -d ' ' -f1)
+    echo "# Template used to create this container: $lxc_template" >> $lxc_path/$lxc_name/config
+    if [ -n "$*" ]; then
+        echo "# Parameters passed to the template: $*" >> $lxc_path/$lxc_name/config
+    fi
+    echo "# Checksum of the template script (SHA-1): $sum" >> $lxc_path/$lxc_name/config
+    echo "" >> $lxc_path/$lxc_name/config
+fi
+
+cat $lxc_config >> $lxc_path/$lxc_name/config
 
 if [ -n "$custom_rootfs" ]; then
        if grep -q "lxc.rootfs" $lxc_path/$lxc_name/config ; then
@@ -301,18 +323,6 @@ if [ $backingstore = "lvm" ]; then
 fi
 
 if [ ! -z $lxc_template ]; then
-    # Allow for a path to be provided as the template name
-    if [ -x $lxc_template ]; then
-        template_path=$lxc_template
-    else
-        template_path=${templatedir}/lxc-$lxc_template
-    fi
-
-    if ! [ -x "$template_path" ]; then
-        echo "$(basename $0): unknown template '$lxc_template'" >&2
-        cleanup
-    fi
-
     $template_path --path=$lxc_path/$lxc_name --name=$lxc_name $*
     if [ $? -ne 0 ]; then
         echo "$(basename $0): failed to execute template '$lxc_template'" >&2