feat: pipeline container build

Dockerfile

@@ -1,10 +1,29 @@
-FROM golang:1.26
+FROM golang:1.26 AS builder
 
-WORKDIR /src
+RUN apt-get update && apt-get -y install upx 
+
+WORKDIR /app
+
+ENV CGO_ENABLED=0
 COPY . .
 
-RUN go get -u github.com/sethvargo/go-githubactions/... \
-    && go mod tidy \
-    && go build -o /bin/google-chat-action
+RUN go mod tidy && go build \
+  -a \
+  -trimpath \
+  -ldflags "-s -w -extldflags '-static'" \
+  -installsuffix cgo \
+  -tags netgo \
+  -o /bin/google-chat-action \
+  . 
+
+RUN strip /bin/google-chat-action
+
+RUN upx -q -9 /bin/google-chat-action
+
+FROM scratch
+
+COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
+
+COPY --from=builder /bin/google-chat-action /bin/google-chat-action
 
 ENTRYPOINT ["/bin/google-chat-action"]