Initial commit

2 files changed, 84 insertions, 0 deletions

diff --git a/pkgs/rdsdump/default.nix b/pkgs/rdsdump/default.nix
new file mode 100644
index 0000000..0efe033
--- /dev/null
+++ b/pkgs/rdsdump/default.nix
@@ -0,0 +1,14 @@
+{ stdenv, bash, ... }:
+
+stdenv.mkDerivation {
+  name = "rdsdump";
+  buildInputs = [ bash ];
+  phases = [ "installPhase" ];
+  installPhase = ''
+    mkdir -p $out/bin
+    cp -a ${./rdsdump.bash} $out/bin/rdsdump
+    chmod +x $out/bin/rdsdump
+    patchShebangs $out/bin/rdsdump
+  '';
+}
+
diff --git a/pkgs/rdsdump/rdsdump.bash b/pkgs/rdsdump/rdsdump.bash
new file mode 100644
index 0000000..6b8cbf1
--- /dev/null
+++ b/pkgs/rdsdump/rdsdump.bash
@@ -0,0 +1,70 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+mysql_args=
+mysqldump_args=
+master_data=0
+while [ $# -gt 0 ]; do
+  case $1 in
+    --host=*|--password=*|--user=*|\
+    --defaults-file=*|--defaults-extra-file=*|\
+    --ssl=*|--ssl-ca=*|--ssl-key=*|--ssl-cert=*|\
+    -h?*|-u?*|-p?*)
+      mysql_args="$mysql_args $1"
+      mysqldump_args="$mysqldump_args $1"
+      shift 1;;
+    --host|--user|\
+    --defaults-file|--defaults-extra-file|\
+    --ssl-ca|--ssl-key|--ssl-cert|\
+    -h|-u)
+      mysql_args="$mysql_args $1 $2"
+      mysqldump_args="$mysqldump_args $1 $2"
+      shift 2;;
+    --master-data=*)
+      master_data=$(echo "$1" | cut -d= -f2)
+      shift;;
+    --master-data)
+      master_data=$2
+      shift 2;;
+    *)
+      mysqldump_args="$mysqldump_args $1"
+      shift;;
+  esac
+done
+
+replica () {
+  mysql $mysql_args "$@"
+}
+
+start_replication () {
+  replica -N -e "CALL mysql.rds_start_replication;" >&2
+}
+
+stop_replication () {
+  replica -N -e "CALL mysql.rds_stop_replication;" >&2
+}
+
+trap 'start_replication' EXIT
+stop_replication
+
+if [ "$master_data" -gt 0 ]; then
+if [ "$master_data" -eq 2 ]; then
+  printf '-- '
+fi
+replica -e 'SHOW SLAVE STATUS\G' | awk -f <(cat - <<- 'AWK'
+  /\<Exec_Master_Log_Pos\>/    { log_pos = $2 };
+  /\<Relay_Master_Log_File\>/  { log_file = $2 };
+  END {
+    printf "CHANGE MASTER TO MASTER_LOG_FILE='%s', MASTER_LOG_POS=%d;\n", log_file, log_pos
+  }
+AWK
+)
+fi
+
+mysqldump $mysqldump_args &
+sleep 30
+
+start_replication
+trap - EXIT
+
+wait