Add option to create database dump from sql script

Loosely copied from the domjudge-scripts repo.

Remove side effect

Rewording remove prefix of "snapshot-"

Move to output location

Add warning on overwriting old database content

Remove cli flag in favor of adding name as parameter

Handle the comments

Makefile

@@ -196,6 +196,7 @@ inplace-conf-common: dist
 	            --with-domserver_tmpdir=$(CURDIR)/output/tmp \
 	            --with-judgehost_tmpdir=$(CURDIR)/output/tmp \
 	            --with-judgehost_judgedir=$(CURDIR)/output/judgings \
+	            --with-domserver_databasedumpdir=$(CURDIR)/output/db-dumps \
 	            --with-baseurl='http://localhost/domjudge/' \
 	            CFLAGS='$(MAINT_CXFLAGS) -std=c11' \
 	            CXXFLAGS='$(MAINT_CXFLAGS) -std=c++11' \

configure.ac

@@ -156,6 +156,7 @@ if test "x$FHS_ENABLED" = xyes ; then
 	AC_SUBST(domserver_rundir,          $localstatedir/run/${PACKAGE_TARNAME})
 	AC_SUBST(domserver_tmpdir,          /tmp)
 	AC_SUBST(domserver_exampleprobdir,  $datadir/${PACKAGE_TARNAME}/example_problems)
+	AC_SUBST(domserver_databasedumpdir, $localstatedir/lib/${PACKAGE_TARNAME}/db-dumps)
 
 	AC_SUBST(judgehost_root,            '')
 	AC_SUBST(judgehost_bindir,          $bindir)
@@ -200,6 +201,7 @@ AX_PATH(domserver_logdir,          [$domserver_root/log])
 AX_PATH(domserver_rundir,          [$domserver_root/run])
 AX_PATH(domserver_tmpdir,          [$domserver_root/tmp])
 AX_PATH(domserver_exampleprobdir,  [$domserver_root/example_problems])
+AX_PATH(domserver_databasedumpdir, [$domserver_root/db-dumps])
 AX_WITH_COMMENT(6,[     ])
 AX_PATH(judgehost_bindir,          [$judgehost_root/bin])
 AX_PATH(judgehost_etcdir,          [$judgehost_root/etc])
@@ -348,6 +350,7 @@ echo "    - sql..............: AX_VAR_EXPAND($domserver_sqldir)"
 echo "    - tmp..............: AX_VAR_EXPAND($domserver_tmpdir)"
 echo "    - webapp...........: AX_VAR_EXPAND($domserver_webappdir)"
 echo "    - example_problems.: AX_VAR_EXPAND($domserver_exampleprobdir)"
+echo "    - database_dumps...: AX_VAR_EXPAND($domserver_databasedumpdir)"
 echo ""
 echo " * judgehost...........: AX_VAR_EXPAND($judgehost_root)"
 echo "    - bin..............: AX_VAR_EXPAND($judgehost_bindir)"

paths.mk.in

@@ -85,6 +85,7 @@ domserver_logdir          = @domserver_logdir@
 domserver_rundir          = @domserver_rundir@
 domserver_tmpdir          = @domserver_tmpdir@
 domserver_exampleprobdir  = @domserver_exampleprobdir@
+domserver_databasedumpdir = @domserver_databasedumpdir@
 PHPVERSION                = @PHPVERSION@
 
 judgehost_bindir          = @judgehost_bindir@
@@ -108,7 +109,7 @@ domserver_dirs = $(domserver_bindir) $(domserver_etcdir) \
                  $(domserver_libdir) $(domserver_libvendordir) \
                  $(domserver_logdir) $(domserver_rundir) \
                  $(addprefix $(domserver_webappdir)/public/images/,affiliations countries teams) \
-                 $(domserver_exampleprobdir)
+                 $(domserver_exampleprobdir) $(domserver_databasedumpdir)
 
 judgehost_dirs = $(judgehost_bindir) $(judgehost_etcdir) $(judgehost_libdir) \
                  $(judgehost_libjudgedir) $(judgehost_logdir) \
@@ -136,6 +137,7 @@ define substconfigvars
 	-e 's,@domserver_rundir[@],@domserver_rundir@,g' \
 	-e 's,@domserver_tmpdir[@],@domserver_tmpdir@,g' \
 	-e 's,@domserver_exampleprobdir[@],@domserver_exampleprobdir@,g' \
+	-e 's,@domserver_databasedumpdir[@],@domserver_databasedumpdir@,g' \
 	-e 's,@judgehost_bindir[@],@judgehost_bindir@,g' \
 	-e 's,@judgehost_etcdir[@],@judgehost_etcdir@,g' \
 	-e 's,@judgehost_libdir[@],@judgehost_libdir@,g' \

sql/dj_setup_database.in

@@ -10,6 +10,7 @@ BINDIR="@domserver_bindir@"
 ETCDIR="@domserver_etcdir@"
 WEBAPPDIR="@domserver_webappdir@"
 EXAMPLEPROBDIR="@domserver_exampleprobdir@"
+DATABASEDUMPDIR="@domserver_databasedumpdir@"
 
 PASSWDFILE="$ETCDIR/dbpasswords.secret"
 
@@ -22,7 +23,7 @@ verbose()
 
 usage() {
 	cat <<EOF
-Usage: $0 [option]... <command>
+Usage: $0 [option]... <command> [argument]
 
 Commands:
   status           check database installation status
@@ -34,6 +35,7 @@ Commands:
   install-examples install examples only
   install-loadtest configure for load testing. WARNING: CREATES A LOT OF EXTRA ITEMS!
   upgrade          upgrade MySQL database schema to current version
+  dump [filename]  backup the current database to file (without .tar.gz suffix)
 
 Options:
   -u <user>  connect to MySQL with DB admin <user>
@@ -48,8 +50,7 @@ not have to pass any of the options above.
 EOF
 }
 
-# Wrapper around mysql command to allow setting options, user, etc.
-mysql()
+mysql_options()
 {
 	local user pass
 
@@ -68,7 +69,13 @@ mysql()
 	fi
 
 	[ -z "$USE_SOCKET" ] && port="-P$DBPORT"
-	command mysql $user ${pass:+"$pass"} -h "$DBHOST" ${port:+"$port"} --silent --skip-column-names "$@"
+	echo $user ${pass:+"$pass"} -h "$DBHOST" ${port:+"$port"}
+}
+
+# Wrapper around mysql command to allow setting options, user, etc.
+mysql()
+{
+	command mysql $(mysql_options) --silent --skip-column-names "$@"
 }
 
 # Quick shell hack to get a key from an INI file.
@@ -234,6 +241,10 @@ install_examples()
 	( cd "$EXAMPLEPROBDIR" && yes y | "$BINDIR"/import-contest )
 }
 
+create_database_dump () {
+	sudo mysqldump $(mysql_options) --opt --skip-lock-tables domjudge | pv | gzip > "$DATABASEDUMPDIR/${1}.sql.gz"
+}
+
 ### Script starts here ###
 
 # Parse command-line options:
@@ -354,6 +365,33 @@ upgrade)
 	verbose "DOMjudge database upgrade completed."
 	;;
 
+dump)
+	read_dbpasswords
+	DUMPNAME="$2"
+	if [ -z "$DUMPNAME" ]; then
+		usage
+		exit 1
+	fi
+
+	if [ -f "${DATABASEDUMPDIR}/${DUMPNAME}.sql.gz" ]; then
+		while true; do
+			read -p "Overwrite existing database dump (y/N)? " yn
+			case $yn in
+				[Yy]* ) create_database_dump $DUMPNAME; exit 0 ;;
+				''|[Nn]* ) break;;
+			esac
+		done
+	else
+		create_database_dump $DUMPNAME; exit 0
+	fi
+
+	read -p "Provide prefix or say 'no' to abort. Format: [prefix]-$1 " prefix
+	case $prefix in
+		''|[Nn]o|[Nn] ) exit 2; break;;
+		* ) create_database_dump ${prefix}-${DUMPNAME}; break;;
+	esac
+	;;
+
 *)
 	echo "Error: Unknown subcommand '$1'"
 	usage