feat: probe endpoint /status

.gitlab-ci.yml

@@ -0,0 +1,34 @@
+variables:
+  WKHTMLTOPDF_VERSION: "0.12.6"
+
+  # explicit tag to be used within pipeline
+  BUILD_IMAGE_NAME: "$CI_REGISTRY_IMAGE/$CI_COMMIT_REF_SLUG:$CI_COMMIT_SHA"
+
+  # we also publish a floating tag to simplify manual testing
+  BUILD_IMAGE_NAME_LATEST: "$CI_REGISTRY_IMAGE/$CI_COMMIT_REF_SLUG:latest"
+
+build:
+  image: docker:20.10.6
+  stage: build
+  services:
+  - name: docker:20.10.6-dind
+
+  before_script:
+    - |
+      for i in $(seq 1 30); do
+          if ! docker info &> /dev/null; then
+              echo "Docker not responding yet. Sleeping for 2s..." && sleep 2s
+          else
+              echo "Docker ready. Continuing build..."
+              break
+          fi
+      done
+    - docker login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" "$CI_REGISTRY"
+  script:
+    - docker build
+      -f Dockerfile-${WKHTMLTOPDF_VERSION} 
+      --tag "$BUILD_IMAGE_NAME"
+      --tag "$BUILD_IMAGE_NAME_LATEST"
+      .
+    - docker push "$BUILD_IMAGE_NAME"
+    - docker push "$BUILD_IMAGE_NAME_LATEST"

Dockerfile-0.12.6

@@ -0,0 +1,30 @@
+# first stage: build kwkhtmltopdf_server
+
+FROM golang:1.11
+WORKDIR /tmp
+COPY server/kwkhtmltopdf_server.go .
+RUN go build kwkhtmltopdf_server.go
+
+# second stage: server with wkhtmltopdf
+
+FROM ubuntu:18.04
+
+RUN set -x \
+  && apt update \
+  && apt -y install --no-install-recommends curl ca-certificates fonts-liberation2 \
+  && curl -o /tmp/wkhtmltox.deb -SL https://github.com/wkhtmltopdf/packaging/releases/download/0.12.6-1/wkhtmltox_0.12.6-1.bionic_amd64.deb \
+  && echo "3a9a5619d9b423103cabd316ed9634e1c71d4504 /tmp/wkhtmltox.deb" | sha1sum -c - \
+  && apt -y install /tmp/wkhtmltox.deb \
+  && apt -y purge wget --autoremove \
+  && apt -y clean \
+  && rm -rf /var/lib/apt/lists/*
+
+COPY --from=0 /tmp/kwkhtmltopdf_server /usr/local/bin/
+
+RUN adduser --disabled-password --gecos '' kwkhtmltopdf
+USER kwkhtmltopdf
+ENV LANG C.UTF-8
+ENV LC_ALL C.UTF-8
+
+EXPOSE 8080
+CMD /usr/local/bin/kwkhtmltopdf_server

server/kwkhtmltopdf_server.go

@@ -70,6 +70,10 @@ func httpAbort(w http.ResponseWriter, err error) {
 
 func handler(w http.ResponseWriter, r *http.Request) {
 	log.Printf("%s %s", r.Method, r.URL.Path)
+	if r.URL.Path == "/status" {
+		w.WriteHeader(http.StatusOK)
+		return
+	}
 	if r.Method != http.MethodPost {
 		httpError(w, errors.New("http method not allowed: "+r.Method), http.StatusMethodNotAllowed)
 		return