Merge pull request #431 from victorcmoura/feature/430

Adds self-contained dev Dockerfile

CONTRIBUTING.md

@@ -25,4 +25,14 @@ go build                               # compiles and packages an executable bin
 go test ./... -v                       # runs tests with verbose output
 ./watchtower                           # runs the application (outside of a container)
 ```
+
 If you dont have it enabled, you'll either have to prefix each command with `GO111MODULE=on` or run `export GO111MODULE=on` before running the commands. [You can read more about modules here.](https://github.com/golang/go/wiki/Modules)
+
+To build a Watchtower image of your own, use the self-contained Dockerfiles. As the main Dockerfile, they can be found in `dockerfiles/`:
+- `dockerfiles/Dockerfile.dev-self-contained` will build an image based on your current local Watchtower files.
+- `dockerfiles/Dockerfile.self-contained` will build an image based on current Watchtower's repository on GitHub.
+
+e.g.:
+```bash
+sudo docker build . -f dockerfiles/Dockerfile.dev-self-contained -t containrrr/watchtower # to build an image from local files
+```

dockerfiles/Dockerfile.dev-self-contained

@@ -0,0 +1,38 @@
+#
+# Builder
+#
+
+FROM golang:alpine as builder
+
+# use version (for example "v0.3.3") or "master"
+ARG WATCHTOWER_VERSION=master
+
+RUN apk add --no-cache \
+    alpine-sdk \
+    ca-certificates \
+    git \
+    tzdata
+
+COPY . /watchtower
+
+RUN \
+  cd /watchtower && \
+  \
+  GO111MODULE=on CGO_ENABLED=0 GOOS=linux go build -a -ldflags '-extldflags "-static"' . && \
+  GO111MODULE=on go test ./... -v
+
+
+#
+# watchtower
+#
+
+FROM scratch
+
+LABEL "com.centurylinklabs.watchtower"="true"
+
+# copy files from other container
+COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
+COPY --from=builder /usr/share/zoneinfo /usr/share/zoneinfo
+COPY --from=builder /watchtower/watchtower /watchtower
+
+ENTRYPOINT ["/watchtower"]

goreleaser.yml

@@ -29,7 +29,7 @@ dockers:
     goos: linux
     goarch: amd64
     goarm: ''
-    dockerfile: Dockerfile
+    dockerfile: dockerfiles/Dockerfile
     image_templates:
       - containrrr/watchtower:amd64-{{ .Version }}
       - containrrr/watchtower:amd64-latest
@@ -39,7 +39,7 @@ dockers:
     goos: linux
     goarch: 386
     goarm: ''
-    dockerfile: Dockerfile
+    dockerfile: dockerfiles/Dockerfile
     image_templates:
       - containrrr/watchtower:i386-{{ .Version }}
       - containrrr/watchtower:i386-latest
@@ -49,7 +49,7 @@ dockers:
     goos: linux
     goarch: arm
     goarm: 6
-    dockerfile: Dockerfile
+    dockerfile: dockerfiles/Dockerfile
     image_templates:
       - containrrr/watchtower:armhf-{{ .Version }}
       - containrrr/watchtower:armhf-latest
@@ -59,7 +59,7 @@ dockers:
     goos: linux
     goarch: arm64
     goarm: ''
-    dockerfile: Dockerfile
+    dockerfile: dockerfiles/Dockerfile
     image_templates:
       - containrrr/watchtower:arm64v8-{{ .Version }}
       - containrrr/watchtower:arm64v8-latest