优化springboot的wait-for-mysql镜像

springboot/image-build/wait-for-mysql/Dockerfile

@@ -6,4 +6,7 @@ RUN apk --no-cache update && \
     apk --no-cache add mysql-client && \
     rm -fr /tmp/* /var/cache/apk/*
 
-ENTRYPOINT "/entrypoint.sh"
+COPY wait-for-mysql.sh /wait-for-mysql.sh
+RUN chmod +x /wait-for-mysql.sh
+
+ENTRYPOINT ["/wait-for-mysql.sh"]

springboot/image-build/wait-for-mysql/wait-for-mysql.sh

@@ -0,0 +1,45 @@
+#!/bin/bash
+# wait until MySQL is really available
+max_counter=45
+
+port=3306
+host=localhost
+username=root
+password=
+
+cmd="$@"
+
+if [[ -n "${MYSQL_PORT}" ]]; then
+    port="${MYSQL_PORT}"
+fi
+if [[ -n "${MYSQL_HOST}" ]]; then
+    host="${MYSQL_HOST}"
+fi
+if [[ -n "${MYSQL_USER}" ]]; then
+    username="${MYSQL_USER}"
+fi
+if [[ -n "${MYSQL_PASSWORD}" ]]; then
+    password="${MYSQL_PASSWORD}"
+fi
+
+password_arg=
+if [[ -n ${password} ]]; then
+    password_arg="-p${password}"
+fi
+
+counter=1
+waiting_dot='.'
+while ! mysql --protocol TCP -h"${host}" -P"${port}" -u"${username}" ${password_arg} -e "show databases;" > /dev/null 2>&1; do
+    sleep 1
+    ehco "${waiting_dot}"
+    waiting_dot+='.'
+    counter=`expr ${counter} + 1`
+    if [[ ${counter} -gt ${max_counter} ]]; then
+        >&2 echo "We have been waiting for MySQL too long already; failing."
+        exit 1
+    fi;
+done
+
+echo "MySQL is up - executing command"
+exec ${cmd}
+