d/cloud-init-base.{config,postinst}: handle migration of debconf values

debian/cloud-init-base.config

@@ -44,6 +44,28 @@ get_yaml_list() {
     [ -n "$RET" ] || RET="$default"
 }
 
+# Migrate a debconf value from cloud-init/* to cloud-init-base/*
+# cleaning up the old value.
+#
+# Arguments:
+#   Name of the debconf question
+migrate_debconf_to_cloud_init_base() {
+    local old="cloud-init/$1" new="cloud-init-base/$1"
+    if db_get "$new"; then
+       # cloud-init-base/* win against cloud-init/* values
+       if db_get "$old"; then
+          echo "Removing ${old} in favor of ${new}" 1>&2 || :
+          db_unregister "$old" || :
+       fi
+       return 0
+    fi
+    if db_get "$old"; then
+       echo "Migrating debconf value: ${old} -> ${new}" 1>&2 || :
+       db_set "$new" "$RET"
+       db_unregister "$old" || :
+    fi
+}
+
 # old_dpkg_cfg is very old file that is no longer read by cloud-init.
 # it gets re-named to cloud.cfg.d/90_dpkg.cfg in the preinst.
 dpkg_cfg="/etc/cloud/cloud.cfg.d/90_dpkg.cfg"
@@ -52,10 +74,13 @@ if [ -f "${old_dpkg_cfg}" -a ! -f "$dpkg_cfg" ]; then
     dpkg_cfg="${old_dpkg_cfg}"
    echo "WARN: reading value from ${old_dpkg_cfg}" 1>&2
 fi
+
+migrate_debconf_to_cloud_init_base datasources
+
 if [ -f "$dpkg_cfg" ]; then
     if get_yaml_list "$dpkg_cfg" datasource_list NOTFOUND &&
         val="$RET" && [ "$val" != "NOTFOUND" ]; then
-        db_set cloud-init-base/datasources $val
+        db_set cloud-init-base/datasources "$val"
     else
         echo "WARN: failed to read datasource_list from $dpkg_cfg" 1>&2
     fi
@@ -64,7 +89,7 @@ elif { db_fget cloud-init-base/datasources seen || : ; } &&
     # this is the first time this we've run (installation or re-install after
     # purge). try to determine if the Ec2 datasource is there.
     # if it is, and Ec2 was not in the default list, then add it.
-    db_get cloud-init/datasources
+    db_get cloud-init-base/datasources
     def="${RET}"
     case " ${def}," in
         *\ Ec2,*) :;;

debian/cloud-init-base.postinst

@@ -55,8 +55,8 @@ handle_preseed_maas() {
    local cfg_file="/etc/cloud/cloud.cfg.d/90_dpkg_maas.cfg"
    local md_url="" creds_all="" c_key="" t_key="" t_sec="" c_sec="";
 
-   db_get "cloud-init/maas-metadata-url" && md_url="$RET" || :
-   db_get "cloud-init/maas-metadata-credentials" && creds_all="$RET" || :
+   db_get "cloud-init-base/maas-metadata-url" && md_url="$RET" || :
+   db_get "cloud-init-base/maas-metadata-credentials" && creds_all="$RET" || :
 
    # nothing to do
    [ -n "$md_url" -o -n "$creds_all" ] || return 0
@@ -86,7 +86,7 @@ for k in sys.argv[2:]:
       rm -f "$cfg_file"
    else
       local header="# written by cloud-init debian package per preseed entries
-# cloud-init/{maas-metadata-url,/maas-metadata-credentials}"
+# cloud-init-base/{maas-metadata-url,/maas-metadata-credentials}"
 
       local pair="" k="" v="" pload="" orig_umask=""
       for pair in "metadata_url:$md_url" "consumer_key:${c_key}" \
@@ -105,12 +105,12 @@ for k in sys.argv[2:]:
    fi
 
    # now clear the database of the values, as they've been consumed
-   db_unregister "cloud-init/maas-metadata-url" || :
-   db_unregister "cloud-init/maas-metadata-credentials" || :
+   db_unregister "cloud-init-base/maas-metadata-url" || :
+   db_unregister "cloud-init-base/maas-metadata-credentials" || :
 }
 
 handle_preseed_local_cloud_config() {
-   local ccfg="" debconf_name="cloud-init/local-cloud-config"
+   local ccfg="" debconf_name="cloud-init-base/local-cloud-config"
    local cfg_file="/etc/cloud/cloud.cfg.d/90_dpkg_local_cloud_config.cfg"
    local header="# written by cloud-init debian package per preseed entry
 # $debconf_name"
@@ -250,14 +250,48 @@ rename_hook_hotplug_udev_rule() {
     fi
 }
 
+# Migrate a debconf value from cloud-init/* to cloud-init-base/*
+# cleaning up the old value.
+#
+# Arguments:
+#   Name of the debconf question
+migrate_debconf_to_cloud_init_base() {
+    local old="cloud-init/$1" new="cloud-init-base/$1"
+    if db_get "$new"; then
+       # cloud-init-base/* win against cloud-init/* values
+       if db_get "$old"; then
+          echo "Removing ${old} in favor of ${new}" 1>&2 || :
+          db_unregister "$old" || :
+       fi
+       return 0
+    fi
+    if db_get "$old"; then
+       echo "Migrating debconf value: ${old} -> ${new}" 1>&2 || :
+       db_set "$new" "$RET"
+       db_unregister "$old" || :
+    fi
+}
+
+upgrade_to_cloud_init_base() {
+    migrate_debconf_to_cloud_init_base local-cloud-config
+    migrate_debconf_to_cloud_init_base maas-metadata-credentials
+    migrate_debconf_to_cloud_init_base maas-metadata-url
+
+    local oldver="$1" last_ver="24.4~3+really24.3.1-0ubuntu4"
+    dpkg --compare-versions "$oldver" le-nl "$last_ver" || return 0
+
+    migrate_debconf_to_cloud_init_base datasources
+}
 
 if [ "$1" = "configure" ]; then
-   if db_get cloud-init/datasources; then
+   upgrade_to_cloud_init_base "$2"
+
+   if db_get cloud-init-base/datasources; then
       values="$RET"
       if [ "${values#*MaaS}" != "${values}" ]; then
          # if db had old MAAS spelling, fix it.
          values=$(echo "$values" | sed 's,MaaS,MAAS,g')
-         db_set cloud-init/datasources "$values"
+         db_set cloud-init-base/datasources "$values"
       fi
       cat > /etc/cloud/cloud.cfg.d/90_dpkg.cfg <<EOF
 # to update this file, run dpkg-reconfigure cloud-init