use gh actions for testing, releasing

.github/workflows/build.yaml

@@ -0,0 +1,19 @@
+name: build
+on: [
+  push,
+  pull_request
+]
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Install Go
+        uses: actions/setup-go@v2
+      - name: Checkout code
+        uses: actions/checkout@v2
+      - name: build
+        run: |
+          make build
+          make test
+          make vet
+          make lint

.github/workflows/release.yaml

@@ -0,0 +1,24 @@
+name: GoReleaser
+on:
+  workflow_run:
+    workflows: ["Bump Git/Docker Version"]
+    branches: [master]
+    types:
+      - completed
+jobs:
+  goreleaser:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Unshallow
+        run: git fetch --prune --unshallow
+      - name: Install Go
+        uses: actions/setup-go@v2
+      - name: Run GoReleaser
+        uses: goreleaser/goreleaser-action@v2
+        with:
+          version: latest
+          args: release --rm-dist
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/tag.yaml

@@ -0,0 +1,44 @@
+name: Bump Git/Docker Version
+on:
+  push:
+    branches:
+      - master
+
+jobs:
+  semver:
+    runs-on: ubuntu-latest
+    outputs:
+      tag: ${{ steps.tagging.outputs.new_tag }}
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: '0'
+    - name: Bump version and push tag
+      uses: anothrNick/github-tag-action@1.39.0
+      id: tagging
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        WITH_V: true
+        RELEASE_BRANCHES: master
+        DEFAULT_BUMP: minor
+  docker:
+    runs-on: ubuntu-latest
+    needs: semver
+    steps:
+      - name: Login to DockerHub
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.docker_username }}
+          password: ${{ secrets.docker_password }}
+      - name: Build and push latest
+        id: docker_build_latest
+        uses: docker/build-push-action@v2
+        with:
+          push: true
+          tags: ${{ github.repository }}:latest
+      - name: Build and push versioned
+        id: docker_build_versioned
+        uses: docker/build-push-action@v2
+        with:
+          push: true
+          tags: ${{ github.repository }}:${{ needs.semver.outputs.tag }}

.goreleaser.yaml

@@ -0,0 +1,27 @@
+# Visit https://goreleaser.com for documentation on how to customize this
+# behavior.
+before:
+  hooks:
+    - go mod tidy
+builds:
+- env:
+    # goreleaser does not work with CGO, it could also complicate
+    # usage by users in CI/CD systems like Terraform Cloud where
+    # they are unable to install libraries.
+    - CGO_ENABLED=0
+  mod_timestamp: '{{ .CommitTimestamp }}'
+  flags:
+    - -trimpath
+  ldflags:
+    - '-s -w -X main.Version={{.Version}} -X main.Commit={{.Commit}}'
+  goos:
+    - linux
+  goarch:
+    - amd64
+  binary: '{{ .ProjectName }}_v{{ .Version }}'
+archives:
+  - format: binary
+    name_template: '{{ .ProjectName }}_{{ .Version }}_{{ .Os }}_{{ .Arch }}'
+changelog:
+  skip: false
+  sort: asc

README.md

@@ -16,15 +16,14 @@ To deploy directly onto digitalocean, click the button below.
 #### Docker
 
 ```bash
-docker pull metalmatze/digitalocean_exporter:0.6.1
-docker run --rm -p 9212:9212 -e DIGITALOCEAN_TOKEN=XXX metalmatze/digitalocean_exporter:0.6.1
+docker run --rm -p 9212:9212 -e DIGITALOCEAN_TOKEN=XXX metalmatze/digitalocean_exporter
 ```
 
 Example `docker-compose.yml` with Transmission also running in docker.
 
 ```yaml
 digitalocean_exporter:
-    image: metalmatze/digitalocean_exporter:0.6.1
+    image: metalmatze/digitalocean_exporter
     environment:
     - '-do.token=XXX'
     restart: always