Simplify Golang images

golang/go-cloud-run-hello-world/Dockerfile

@@ -1,8 +1,5 @@
 # Use base golang image from Docker Hub
-FROM golang:1.15
-
-# Download the dlv (delve) debugger for go (you can comment this out if unused)
-RUN go get -u -v github.com/go-delve/delve/cmd/dlv
+FROM golang:1.15 AS build
 
 WORKDIR /src/hello-world
 
@@ -14,20 +11,23 @@ RUN go mod download
 COPY . ./
 
 # Compile the application to /app.
-RUN go build -mod=readonly -v -o /app
+# Skaffold passes in debug-oriented compiler flags
+ARG SKAFFOLD_GO_GCFLAGS
+RUN echo "Go gcflags: ${SKAFFOLD_GO_GCFLAGS}"
+RUN go build -gcflags="${SKAFFOLD_GO_GCFLAGS}" -mod=readonly -v -o /app
+
+# Now create separate deployment image
+FROM gcr.io/distroless/base
+
+# Definition of this variable is used by 'skaffold debug' to identify a golang binary.
+# Default behavior - a failure prints a stack trace for the current goroutine.
+# See https://golang.org/pkg/runtime/
+ENV GOTRACEBACK=single
 
 # Copy template & assets
-COPY index.html /index.html
-COPY assets ./assets/
-
-# If you want to use the debugger, you need to modify the entrypoint to the
-# container and point it to the "dlv debug" command:
-#   * UNCOMMENT the following ENTRYPOINT statement,
-#   * COMMENT OUT the last ENTRYPOINT statement
-# Start the "dlv debug" server on port 3000 of the container.
-ENTRYPOINT ["dlv", "exec", "/app", "--continue", "--accept-multiclient", "--api-version=2", "--headless", "--listen=:3000", "--log"]
-
-# If you want to run WITHOUT the debugging server:
-#   * COMMENT OUT the previous ENTRYPOINT statements,
-#   * UNCOMMENT the following ENTRYPOINT statement.
-# ENTRYPOINT ["/app"]
+WORKDIR /hello-world
+COPY --from=build /app ./app
+COPY index.html index.html
+COPY assets assets/
+
+ENTRYPOINT ["./app"]

golang/go-guestbook/src/backend/Dockerfile

@@ -1,8 +1,5 @@
 # Use base golang image from Docker Hub
-FROM golang:1.15
-
-# Download the dlv (delve) debugger for go (you can comment this out if unused)
-RUN go get -u -v github.com/go-delve/delve/cmd/dlv
+FROM golang:1.15 as build
 
 WORKDIR /src/backend
 
@@ -14,16 +11,19 @@ RUN go mod download
 COPY . ./
 
 # Compile the application to /app/backend.
-RUN go build -o /app/backend .
+# Skaffold passes in debug-oriented compiler flags
+ARG SKAFFOLD_GO_GCFLAGS
+RUN echo "Go gcflags: ${SKAFFOLD_GO_GCFLAGS}"
+RUN go build -gcflags="${SKAFFOLD_GO_GCFLAGS}" -mod=readonly -v -o /app/backend .
+
+# Now create separate deployment image
+FROM gcr.io/distroless/base
 
-# If you want to use the debugger, you need to modify the entrypoint to the
-# container and point it to the "dlv debug" command:
-#   * UNCOMMENT the following ENTRYPOINT statement,
-#   * COMMENT OUT the last ENTRYPOINT statement
-# Start the "dlv debug" server on port 3000 of the container.
-ENTRYPOINT ["dlv", "exec", "/app/backend", "--continue", "--accept-multiclient", "--api-version=2", "--headless", "--listen=:3000", "--log"]
+# Definition of this variable is used by 'skaffold debug' to identify a golang binary.
+# Default behavior - a failure prints a stack trace for the current goroutine.
+# See https://golang.org/pkg/runtime/
+ENV GOTRACEBACK=single
 
-# If you want to run WITHOUT the debugging server:
-#   * COMMENT OUT the previous ENTRYPOINT statements,
-#   * UNCOMMENT the following ENTRYPOINT statement.
-# ENTRYPOINT ["/app/backend"]
+WORKDIR /app
+COPY --from=build /app/backend /app/backend
+ENTRYPOINT ["/app/backend"]

golang/go-guestbook/src/frontend/Dockerfile

@@ -1,8 +1,5 @@
 # Use base golang image from Docker Hub
-FROM golang:1.15
-
-# Download the dlv (delve) debugger for go (you can comment this out if unused)
-RUN go get -u -v github.com/go-delve/delve/cmd/dlv
+FROM golang:1.15 as build
 
 WORKDIR /src/frontend
 
@@ -14,16 +11,21 @@ RUN go mod download
 COPY . ./
 
 # Compile the application to /app/frontend.
-RUN go build -o /app/frontend .
+# Skaffold passes in debug-oriented compiler flags
+ARG SKAFFOLD_GO_GCFLAGS
+RUN echo "Go gcflags: ${SKAFFOLD_GO_GCFLAGS}"
+RUN go build -gcflags="${SKAFFOLD_GO_GCFLAGS}" -mod=readonly -v -o /app/frontend .
+
+# Now create separate deployment image
+FROM gcr.io/distroless/base
 
-# If you want to use the debugger, you need to modify the entrypoint to the
-# container and point it to the "dlv debug" command:
-#   * UNCOMMENT the following ENTRYPOINT statement,
-#   * COMMENT OUT the last ENTRYPOINT statement
-# Start the "dlv debug" server on port 3000 of the container.
-ENTRYPOINT ["dlv", "exec", "/app/frontend", "--continue", "--accept-multiclient", "--api-version=2", "--headless", "--listen=:3000", "--log"]
+# Definition of this variable is used by 'skaffold debug' to identify a golang binary.
+# Default behavior - a failure prints a stack trace for the current goroutine.
+# See https://golang.org/pkg/runtime/
+ENV GOTRACEBACK=single
 
-# If you want to run WITHOUT the debugging server:
-#   * COMMENT OUT the previous ENTRYPOINT statements,
-#   * UNCOMMENT the following ENTRYPOINT statement.
-# ENTRYPOINT ["/app/frontend"]
+WORKDIR /app
+COPY static /app/static
+COPY templates /app/templates
+COPY --from=build /app/frontend /app/frontend
+ENTRYPOINT ["/app/frontend"]

golang/go-hello-world/Dockerfile

@@ -1,8 +1,7 @@
-# Use base golang image from Docker Hub
-FROM golang:1.15
+# Go binaries are standalone, so use a multi-stage build to produce smaller images.
 
-# Download the dlv (delve) debugger for go (you can comment this out if unused)
-RUN go get -u -v github.com/go-delve/delve/cmd/dlv
+# Use base golang image from Docker Hub
+FROM golang:1.15 as build
 
 WORKDIR /src/hello-world
 
@@ -14,16 +13,20 @@ RUN go mod download
 COPY . ./
 
 # Compile the application to /app.
-RUN go build -v -o /app
-
-# If you want to use the debugger, you need to modify the entrypoint to the
-# container and point it to the "dlv debug" command:
-#   * UNCOMMENT the following ENTRYPOINT statement,
-#   * COMMENT OUT the last ENTRYPOINT statement
-# Start the "dlv debug" server on port 3000 of the container.
-ENTRYPOINT ["dlv", "exec", "/app", "--continue", "--accept-multiclient", "--api-version=2", "--headless", "--listen=:3000", "--log"]
-
-# If you want to run WITHOUT the debugging server:
-#   * COMMENT OUT the previous ENTRYPOINT statements,
-#   * UNCOMMENT the following ENTRYPOINT statement.
-# ENTRYPOINT ["/app"]
+# Skaffold passes in debug-oriented compiler flags
+ARG SKAFFOLD_GO_GCFLAGS
+RUN echo "Go gcflags: ${SKAFFOLD_GO_GCFLAGS}"
+RUN go build -gcflags="${SKAFFOLD_GO_GCFLAGS}" -mod=readonly -v -o /app
+
+# Now create separate deployment image
+FROM gcr.io/distroless/base
+
+# Definition of this variable is used by 'skaffold debug' to identify a golang binary.
+# Default behavior - a failure prints a stack trace for the current goroutine.
+# See https://golang.org/pkg/runtime/
+ENV GOTRACEBACK=single
+
+WORKDIR /hello-world
+COPY --from=build /app .
+COPY template ./template
+ENTRYPOINT ["./app"]