build: add Docker cache mound for Go modules (#21)

* build: add cache mount for go modules

* doc(docker): update TZ description

* build: use entrypoint instead cmd exec

* build: add dockerignore

* build: add modules dir to image for migration command

* build: update dockerignore

* doc: fix typo

Co-authored-by: gazenw <163862510+gazenw@users.noreply.github.com>

---------

Co-authored-by: gazenw <163862510+gazenw@users.noreply.github.com>

Dockerfile

@@ -3,15 +3,15 @@ FROM golang:1.22 as builder
 WORKDIR /app
 
 COPY go.mod go.sum ./
-RUN go mod download
+RUN --mount=type=cache,target=/go/pkg/mod/ go mod download
 
 COPY ./ ./
 
 ENV GOOS=linux
 ENV CGO_ENABLED=0
 
-RUN go build \
-          -o main ./main.go
+RUN --mount=type=cache,target=/go/pkg/mod/ \
+    go build -o main ./main.go
 
 FROM alpine:latest
 
@@ -19,9 +19,10 @@ WORKDIR /app
 
 RUN apk --no-cache add ca-certificates tzdata
 
-
 COPY --from=builder /app/main .
+COPY --from=builder /app/modules ./modules
 
-# You can set `TZ` environment variable to change the timezone
+# You can set TZ identifier to change the timezone, See https://en.wikipedia.org/wiki/List_of_tz_database_time_zones#List
+# ENV TZ=US/Central
 
-CMD ["/app/main", "run"]
+ENTRYPOINT ["/app/main"]