mariadb: Fixes incremental backup failure when full not created today

backup_full() saves the history name in $BACKUP_DIR/last_full_date.
backup_incremental() attempts to read from $BACKUP_DIR/last_full_date
into $LAST_FULL_DATE. After the read attempt; if $LAST_FULL_DATE is zero
length then $(date +%d-%m-%Y) is used.

Change-Id: I4172b814d5d95ae3debbc1cf3feaeee2e2bec9bd
Closes-bug: 1897948
(cherry picked from commit ccfe65b5f7)

docker/mariadb/mariadb-server/backup.sh

@@ -6,23 +6,31 @@ set -o pipefail
 # Execute a full backup
 backup_full() {
     echo "Taking a full backup"
+    LAST_FULL_DATE=$(date +%d-%m-%Y)
     mariabackup \
         --defaults-file=/etc/mysql/my.cnf \
         --backup \
         --stream=xbstream \
-        --history=$(date +%d-%m-%Y) | gzip > \
+        --history=$LAST_FULL_DATE | gzip > \
         $BACKUP_DIR/mysqlbackup-$(date +%d-%m-%Y-%s).qp.xbc.xbs.gz
+    echo $LAST_FULL_DATE > $BACKUP_DIR/last_full_date
 }
 
 # Execute an incremental backup
 backup_incremental() {
     echo "Taking an incremental backup"
+    if [ -r $BACKUP_DIR/last_full_date ]; then
+        LAST_FULL_DATE=$(cat $BACKUP_DIR/last_full_date)
+    fi
+    if [ -z $LAST_FULL_DATE ]; then
+        LAST_FULL_DATE=$(date +%d-%m-%Y)
+    fi
     mariabackup \
         --defaults-file=/etc/mysql/my.cnf \
         --backup \
         --stream=xbstream \
-        --incremental-history-name=$(date +%d-%m-%Y) \
-        --history=$(date +%d-%m-%Y) | gzip > \
+        --incremental-history-name=$LAST_FULL_DATE \
+        --history=$LAST_FULL_DATE | gzip > \
         $BACKUP_DIR/incremental-$(date +%H)-mysqlbackup-$(date +%d-%m-%Y-%s).qp.xbc.xbs.gz
 }
 

docker/mariadb/mariadb/backup.sh

@@ -6,23 +6,31 @@ set -o pipefail
 # Execute a full backup
 backup_full() {
     echo "Taking a full backup"
+    LAST_FULL_DATE=$(date +%d-%m-%Y)
     mariabackup \
         --defaults-file=/etc/mysql/my.cnf \
         --backup \
         --stream=xbstream \
-        --history=$(date +%d-%m-%Y) | gzip > \
+        --history=$LAST_FULL_DATE | gzip > \
         $BACKUP_DIR/mysqlbackup-$(date +%d-%m-%Y-%s).qp.xbc.xbs.gz
+    echo $LAST_FULL_DATE > $BACKUP_DIR/last_full_date
 }
 
 # Execute an incremental backup
 backup_incremental() {
     echo "Taking an incremental backup"
+    if [ -r $BACKUP_DIR/last_full_date ]; then
+        LAST_FULL_DATE=$(cat $BACKUP_DIR/last_full_date)
+    fi
+    if [ -z $LAST_FULL_DATE ]; then
+        LAST_FULL_DATE=$(date +%d-%m-%Y)
+    fi
     mariabackup \
         --defaults-file=/etc/mysql/my.cnf \
         --backup \
         --stream=xbstream \
-        --incremental-history-name=$(date +%d-%m-%Y) \
-        --history=$(date +%d-%m-%Y) | gzip > \
+        --incremental-history-name=$LAST_FULL_DATE \
+        --history=$LAST_FULL_DATE | gzip > \
         $BACKUP_DIR/incremental-$(date +%H)-mysqlbackup-$(date +%d-%m-%Y-%s).qp.xbc.xbs.gz
 }
 

releasenotes/notes/bug-1897948-a0eb6d890eea8061.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Fixes MariaDB incremental backup failure when full
+    backup was not created the same day.
+    `LP#1897948 <https://launchpad.net/bugs/1897948>`__