fix:dockerfile (#144)

Dockerfile

@@ -1,17 +1,40 @@
-FROM golang:1.17.10 AS builder
+FROM golang:1.17.13-alpine3.15  AS builder
 
 # ENV GOPROXY      https://goproxy.io
 
-RUN mkdir /app
+RUN mkdir /app && apk add --no-cache --virtual .build-deps \
+    ca-certificates \
+    gcc \
+    g++
+
 ADD . /app/
+
 WORKDIR /app
+
 RUN sed -i 's@localhost:389@openldap:389@g' /app/config.yml \
     && sed -i 's@host: localhost@host: mysql@g'  /app/config.yml && go build -o go-ldap-admin .
 
-FROM centos:centos7
+### build final image
+FROM alpine:3.15
+
+# we set the timezone `Asia/Shanghai` by default, you can be modified
+# by `docker build --build-arg="TZ=Other_Timezone ..."`
+ARG TZ="Asia/Shanghai"
+
+ENV TZ ${TZ}
+
 RUN mkdir /app
+
 WORKDIR /app
+
 COPY --from=builder /app/ .
-RUN chmod +x wait go-ldap-admin && yum -y install vim net-tools telnet wget curl && yum clean all
+
+
+RUN apk upgrade \
+    && apk add bash tzdata \
+    && ln -sf /usr/share/zoneinfo/${TZ} /etc/localtime \
+    && echo ${TZ} > /etc/timezone
+
+RUN chmod +x wait go-ldap-admin
 
 CMD ./wait && ./go-ldap-admin