change ci config

.drone.yml

@@ -4,35 +4,21 @@ type: docker
 name: default
 
 steps:
-  - name: build docker image (alpine)
+  - name: build docker image
     image: plugins/docker
     environment:
       DOCKER_BUILDKIT: '1'
     settings:
       purge: true
       repo: otakukaze/golang-base-image
+      tags:
+        - "${DRONE_BRANCH}"
       username: otakukaze
       password:
         from_secret: password
-      tags:
+      build_args:
-        - "${DRONE_BRANCH}"
+        - "IMG_TAG=${DRONE_BRANCH}"
     when:
       ref:
         - refs/heads/1-alpine
 
-  - name: build docker image (debian)
-    image: plugins/docker
-    environment:
-      DOCKER_BUILDKIT: '1'
-    settings:
-      purge: true
-      repo: otakukaze/golang-base-image
-      username: otakukaze
-      password:
-        from_secret: password
-      tags:
-        - "1"
-        - "latest"
-    when:
-      ref:
-        - refs/heads/master

Dockerfile

@@ -1,11 +1,5 @@
-ARG IMG_TAG=1
+ARG IMG_TAG=1-alpine
-FROM golang:${IMG_TAG} as builder
-RUN go get -u -v github.com/go-bindata/go-bindata/... \
-  && dir=$(mktemp -d) \
-  && git clone https://github.com/go-swagger/go-swagger "$dir" \
-  && cd "$dir" \
-  && go install ./cmd/swagger
-
 FROM golang:${IMG_TAG}
-COPY --from=builder /go/bin/swagger /usr/bin
+RUN apk add --no-cache git make gcc libc-dev \
-COPY --from=builder /go/bin/go-bindata /usr/bin
+  && go get -u github.com/go-bindata/go-bindata/... \
+  && go get -u github.com/go-swagger/go-swagger/...