make maria db replication idempotent

also use primary/replica terminology

1 files changed, 66 insertions, 75 deletions

diff --git a/wip/mariadb-push-replica.sh b/wip/mariadb-push-replica.sh
index dcbabc1..495873e 100755
--- a/wip/mariadb-push-replica.sh
+++ b/wip/mariadb-push-replica.sh
@@ -3,12 +3,12 @@ set -e
 PATH=./src:$PATH
 source rpc.bash
 
-default_slave_remote_file=data/default-slave-remote
-master_password_file=data/mysql-master-password
+default_replica_host_file=data/default-replica-host
+replication_password_file=data/replication-password
 
-if [ -r "$default_slave_remote_file" ]
+if [ -r "$default_replica_host_file" ]
 then
-        read default_remote_host < "$default_slave_remote_file"
+        read default_replica_host < "$default_replica_host_file"
 fi
 
 gen_password()
@@ -19,51 +19,40 @@ gen_password()
         printf '%s\n' "$generated_password"
 }
 
-if ! [ -e "$master_password_file" ]
+if ! [ -e "$replication_password_file" ]
 then
-        gen_password > "$master_password_file"
+        gen_password > "$replication_password_file"
 fi
 
-if [ -r "$master_password_file" ]
+if [ -r "$replication_password_file" ]
 then
-        read master_password < "$master_password_file" 
-        [ "${#master_password}" -ge 30 ]
+        read replication_password < "$replication_password_file" 
+        [ "${#replication_password}" -ge 30 ]
 fi
 
-our_host=$(hostname --fqdn)
-remote_host=${1:-$default_remote_host}
-
-[ "$our_host" ]
-[ "$remote_host" ]
-[ "$master_password" ]
-
-primarydb_host=$our_host
-replicadb_host=$remote_host
-
+primary_host=$(hostname --fqdn)
+replica_host=${1:-$default_replica_host}
 replication_user=replication
-replication_password=$master_password
+
+[ "$primary_host" ]
+[ "$replica_host" ]
+[ "$replication_password" ]
 
 run_primary()
 {
-        BASH_RPC_REMOTE_DEST=$primarydb_host remote_run_function "$@"
+        (set -x
+        : primary : $1 $2 ${3:+ ...})
+        BASH_RPC_REMOTE_DEST=$primary_host remote_run_function "$@"
 }
 
 run_replica()
 {
-        BASH_RPC_REMOTE_DEST=$replicadb_host remote_run_function "$@"
-}
-
-primarydb()
-{
-        run_primary mariadb -t
-}
-
-replicadb()
-{
-        run_replica mariadb -t
+        (set -x
+        : replica : $1 $2 ${3:+ ...})
+        BASH_RPC_REMOTE_DEST=$replica_host remote_run_function "$@"
 }
 
-syscheck()
+show_hostnames()
 {
         printf \
                 "==> %s %s <==\n    %s\n" \
@@ -72,9 +61,9 @@ syscheck()
                 "$(uptime)"
 }
 
-dbcheck()
+check_db()
 {
-        syscheck
+        show_hostnames
         mariadb -t <<END | sed 's/^/   /'
 select @@hostname, @@server_id, @@gtid_slave_pos, @@sql_log_bin;
 END
@@ -82,78 +71,80 @@ END
 
 create_backup()
 {
+        set -e
         mariabackup_target_dir=/var/mariadb/backup
+        binlog_info_file=$mariabackup_target_dir/xtrabackup_binlog_info 
+        [ -e "$binlog_info_file" ] && return
         mkdir -p "$mariabackup_target_dir"
-        mariabackup -u root --backup  --target-dir="$mariabackup_target_dir"
-        mariabackup -u root --prepare --target-dir="$mariabackup_target_dir"
+        set -- -u root --target-dir="$mariabackup_target_dir"
+        mariabackup --backup --rsync "$@"
+        mariabackup --prepare "$@"
+        [ -e "$binlog_info_file" ]
 }
 
 send_backup()
 {
         mariabackup_target_dir=/var/mariadb/backup
-        rsync -zRaP -- /./"$mariabackup_target_dir" "$1":/
+        rsync -zaR -- /./"$mariabackup_target_dir" "$1":/
 }
 
 enable_replication()
 {
-        our_host=$1
+        replica_host=$1
         replication_user=$2
         replication_password=$3
         mariabackup_target_dir=/var/mariadb/backup
         binlog_info_file=$mariabackup_target_dir/xtrabackup_binlog_info 
-        read  master_log_file master_log_pos gtid_slave_pos < $binlog_info_file || return
+        set -x
+        [ -e "$binlog_info_file" ] || return 0
+        read master_log_file master_log_pos gtid_slave_pos < $binlog_info_file
         mariadb -t <<END
-        SET GLOBAL gtid_slave_pos = "$gtid_slave_pos";
-        CHANGE MASTER TO
-          MASTER_HOST='$our_host',
-          MASTER_USER='$replication_user',
-          MASTER_PASSWORD='$replication_password',
-          MASTER_USE_GTID=slave_pos;
-        START SLAVE;
+STOP SLAVE;
+SET GLOBAL gtid_slave_pos = "$gtid_slave_pos";
+CHANGE MASTER TO
+  MASTER_HOST='$replica_host',
+  MASTER_USER='$replication_user',
+  MASTER_PASSWORD='$replication_password',
+  MASTER_USE_GTID=slave_pos;
+START SLAVE;
 END
+        rm -r /var/mariadb/backup
 }
 
 create_replication_user()
 {
         mariadb -t <<END
-        CREATE OR REPLACE USER '$1' IDENTIFIED BY '$2';
-        GRANT REPLICATION SLAVE ON *.*  TO '$1';
+CREATE OR REPLACE USER '$2'@'$1' IDENTIFIED BY '$3';
+GRANT REPLICATION SLAVE ON *.*  TO '$2'@'$1';
 END
 }
 
 showvars()
 {
-        for db in primarydb replicadb
+        for h in "$@"
         do
-                $db <<END
-                        select VARIABLE_NAME,SESSION_VALUE,GLOBAL_VALUE 
-                        from INFORMATION_SCHEMA.SYSTEM_VARIABLES
-                        where VARIABLE_NAME='sql_log_bin' or VARIABLE_NAME='HOSTNAME' \G
+                run_$h mariadb -t <<END
+select VARIABLE_NAME,SESSION_VALUE,GLOBAL_VALUE 
+from INFORMATION_SCHEMA.SYSTEM_VARIABLES
+where VARIABLE_NAME LIKE '%SLAVE%' \G
 END
         done
 }
 
-checkboth()
-{
-        for h in primary replica
-        do
-                run_$h dbcheck
-        done
-}
-
+run_primary check_db
+run_replica check_db
 if false
 then
-        checkboth
-        showvars
-fi
-mariabackup_target_dir=/var/mariadb/backup
-if [ ! -d "$mariabackup_target_dir" ]
-then
-        run_primary create_replication_user \
-                "$replication_user'@'$replicadb_host" \
-                "$replication_password"
-        run_primary create_backup "$replicadb_host"
+        showvars replica
+        exit
 fi
-run_primary send_backup "$replicadb_host"
-run_replica enable_replication "$our_host" "$replication_user" "$replication_password"
-
+run_primary create_replication_user \
+        "$replica_host" \
+        "$replication_user" \
+        "$replication_password"
+run_primary create_backup
+
+run_primary send_backup "$replica_host"
+run_replica enable_replication "$replica_host" "$replication_user" "$replication_password"
+set -x
+rm -r /var/mariadb/backup