migrate Dockerfiles

Author: andriisoldatenko

Dockerfile-debug

@@ -1,28 +1,29 @@
 # Compile stage
-FROM golang:1.10.1-alpine3.7 AS build-env
-ENV CGO_ENABLED 0
-ADD . /go/src/hello
- 
-# The -gcflags "all=-N -l" flag helps us get a better debug experience
-RUN go build -gcflags "all=-N -l" -o /server hello
- 
-# Compile Delve
-RUN apk add --no-cache git
-RUN go get github.com/go-delve/delve/cmd/dlv
- 
+FROM golang:1.21.1-alpine3.18 AS build-env
+#ENV CGO_ENABLED 0
+WORKDIR /usr/src/app
+
+# Download and install the Delve debugger.
+RUN go install github.com/go-delve/delve/cmd/dlv@latest
+
+# pre-copy/cache go.mod for pre-downloading dependencies and only redownloading them in subsequent builds if they change
+COPY ./sample_app/go.mod ./sample_app/go.sum ./
+RUN go mod download && go mod verify
+
+COPY ./sample_app .
+## The -gcflags "all=-N -l" flag helps us get a better debug experience
+RUN go build -gcflags "all=-N -l" -v -o /usr/local/bin/app ./...
+
 # Final stage
-FROM alpine:3.7
- 
+FROM alpine:3.18
 # Port 8080 belongs to our application, 40000 belongs to Delve
 EXPOSE 8080 40000
- 
-# Allow delve to run on Alpine based containers.
-RUN apk add --no-cache libc6-compat
- 
 WORKDIR /
- 
-COPY --from=build-env /server /
-COPY --from=build-env /go/bin/dlv /
- 
+
+COPY --from=build-env /go/bin/dlv /bin/dlv
+COPY --from=build-env /usr/local/bin/app /
+
+# TODO: use env var and conditional run.sh
+# https://github.com/ccampo133/go-docker-alpine-remote-debug/blob/main/Dockerfile
 # Run delve
-CMD ["/dlv", "--listen=0.0.0.0:40000", "--headless=true", "--api-version=2", "debug", "go/src/hello", "--log"]
+CMD ["dlv", "--listen=0.0.0.0:40000", "--headless=true", "--api-version=2", "debug", "/app", "--log"]

Dockerfile-dlv-debug

@@ -0,0 +1,16 @@
+# Compile stage
+FROM golang:1.21.1-alpine3.18 AS build-env
+ENV CGO_ENABLED 0
+WORKDIR /usr/src/app
+
+# Download and install the Delve debugger.
+RUN go install github.com/go-delve/delve/cmd/dlv@latest
+
+# pre-copy/cache go.mod for pre-downloading dependencies and only redownloading them in subsequent builds if they change
+COPY ./sample_app/go.mod ./sample_app/go.sum ./
+RUN go mod download && go mod verify
+
+COPY ./sample_app .
+
+CMD ["/bin/sh"]
+ENTRYPOINT ["/bin/sh"]

Dockerfile-dlv-exec

@@ -0,0 +1,23 @@
+# Compile stage
+FROM golang:1.21.1-alpine3.18 AS build-env
+ENV CGO_ENABLED 0
+WORKDIR /usr/src/app
+
+# Download and install the Delve debugger.
+RUN go install github.com/go-delve/delve/cmd/dlv@latest
+
+# pre-copy/cache go.mod for pre-downloading dependencies and only redownloading them in subsequent builds if they change
+COPY ./sample_app/go.mod ./sample_app/go.sum ./
+RUN go mod download && go mod verify
+
+COPY ./sample_app .
+RUN go build -gcflags "all=-N -l" -v -o /usr/local/bin/app ./...
+
+# Final stage
+FROM alpine:3.18
+EXPOSE 8080
+WORKDIR /
+
+COPY --from=build-env /go/bin/dlv /bin/dlv
+COPY --from=build-env /usr/local/bin/app /
+CMD ["/app"]

Makefile

@@ -2,6 +2,12 @@
 build-sample-app: ## Build docker image for sample-app
 	docker build -f Dockerfile -t asoldatenko/sample-app .
 
-.PHONY: build-sample-app
-build-sample-app: ## Download goimports locally if necessary.
-	docker build -f Dockerfile -t asoldatenko/sample-app .
+kind-setup:
+	kind create cluster --name=debug-kind
+	kubectl namespace create demo
+
+kind-dlv-debug:
+	docker build -f Dockerfile-dlv-debug -t asoldatenko/my-golang-app:new-tag .
+	kind load docker-image asoldatenko/my-golang-app:new-tag --name=debug-kind
+	kubectl apply -f ./config/samples/sample.yaml
+	kubectl exec -n demo sample-app -it -- /bin/sh

config/samples/sample.yaml

@@ -0,0 +1,12 @@
+apiVersion: v1
+kind: Pod
+metadata:
+  name: sample-app
+  namespace: demo
+spec:
+  containers:
+    - name: sample-debug
+      image: asoldatenko/my-golang-app:new-tag
+      command: [ "/bin/sh", "-c", "--" ]
+      args: [ "while true; do sleep 300; done;" ]
+

start.sh

@@ -3,4 +3,4 @@ docker run \
   -p 8080:8080 \
   -p 40000:40000 \
   --security-opt="apparmor=unconfined" \
-  --cap-add=SYS_PTRACE hello-debug
+  --cap-add=SYS_PTRACE t