docs: use bind mounts in Go Dockerfile examples

Signed-off-by: Eng Zer Jun <[email protected]>

Author: Juneezee

content/manuals/build/ci/github-actions/cache.md

@@ -139,13 +139,16 @@ Example Dockerfile in `build/package/Dockerfile`
 FROM golang:1.21.1-alpine as base-build
 
 WORKDIR /build
-RUN go env -w GOMODCACHE=/root/.cache/go-build
 
-COPY go.mod go.sum ./
-RUN --mount=type=cache,target=/root/.cache/go-build go mod download
+RUN --mount=type=cache,target=/go/pkg/mod \
+    --mount=type=bind,source=go.mod,target=go.mod \
+    --mount=type=bind,source=go.sum,target=go.sum \
+    go mod download
 
-COPY ./src ./
-RUN --mount=type=cache,target=/root/.cache/go-build go build -o /bin/app /build/src
+RUN --mount=type=cache,target=/go/pkg/mod \
+    --mount=type=cache,target=/root/.cache/go-build \
+    --mount=type=bind,target=. \
+    go build -o /bin/app /build/src
 ...
 ```
 

content/manuals/extensions/extensions-sdk/build/backend-extension-tutorial.md

@@ -190,13 +190,13 @@ FROM node:17.7-alpine3.14 AS client-builder
 FROM golang:1.17-alpine AS builder
 ENV CGO_ENABLED=0
 WORKDIR /backend
-COPY vm/go.* .
 RUN --mount=type=cache,target=/go/pkg/mod \
-    --mount=type=cache,target=/root/.cache/go-build \
+    --mount=type=bind,source=vm/go.mod,target=go.mod \
+    --mount=type=bind,source=vm/go.sum,target=go.sum \
     go mod download
-COPY vm/. .
 RUN --mount=type=cache,target=/go/pkg/mod \
     --mount=type=cache,target=/root/.cache/go-build \
+    --mount=type=bind,source=vm/.,target=. \
     go build -trimpath -ldflags="-s -w" -o bin/service
 
 FROM alpine:3.15

hack/releaser/Dockerfile

@@ -8,8 +8,9 @@ FROM golang:${GO_VERSION}-alpine AS base
 RUN apk add --no-cache openssl
 ENV CGO_ENABLED=0
 WORKDIR /src
-COPY go.mod go.sum ./
 RUN --mount=type=cache,target=/go/pkg/mod \
+  --mount=type=bind,source=go.mod,target=go.mod \
+  --mount=type=bind,source=go.sum,target=go.sum \
   go mod download
 
 FROM base AS releaser