feat: Add dig function

.github/workflows/build.yaml

@@ -29,15 +29,15 @@ jobs:
         run: >
           echo ::set-output name=repo_owner::$(echo ${{ github.repository_owner }} |
           tr '[:upper:]' '[:lower:]')
-      - name: Docker Login
-        run: > 
-          echo ${{secrets.DOCKER_PASSWORD}} | 
-          docker login ghcr.io --username 
-          ${{ steps.get_repo_owner.outputs.repo_owner }} 
-          --password-stdin
+      - name: Login to Docker Registry
+        uses: docker/login-action@v1
+        with:
+          username: ${{ steps.get_repo_owner.outputs.repo_owner }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
+          registry: ghcr.io
       - name: Publish functions
         run: >
-          OWNER="${{ steps.get_repo_owner.outputs.repo_owner }}" 
+          OWNER="${{ steps.get_repo_owner.outputs.repo_owner }}"
           TAG="latest"
           faas-cli publish
           --extra-tag ${{ github.sha }}

README.md

@@ -45,6 +45,7 @@ curl http://127.0.0.1:8080 -d "-c 5 -n 1000 https://your-service.com/"
 
 * `alpine` - a base for running built-in bash or busybox commands like `env` (use it to debug headers) or `wc -l` to count text within a body
 * `curl` - debug outgoing networking or internal services
+* `dig` - debug DNS resolution from inside your cluster
 * `figlet` - print ASCII logso
 * `hey` - run a load-test against a HTTP API, website, or function with [hey](https://github.com/rakyll/hey)
 * `nmap` - scan a network range

dig/Dockerfile

@@ -0,0 +1,40 @@
+FROM --platform=${TARGETPLATFORM:-linux/amd64} ghcr.io/openfaas/of-watchdog:0.8.4 as watchdog
+
+FROM --platform=${TARGETPLATFORM:-linux/amd64} alpine:3.13
+
+RUN mkdir -p /home/app
+
+RUN apk add --no-cache bind-tools
+
+COPY --from=watchdog /fwatchdog /usr/bin/fwatchdog
+RUN chmod +x /usr/bin/fwatchdog
+
+# Add non root user
+RUN addgroup -S app && adduser app -S -G app
+RUN chown app /home/app
+
+WORKDIR /home/app
+
+USER app
+
+COPY --chown=app:app dig.sh .
+RUN chmod +x dig.sh
+
+# customize the json key name for the success responses
+ENV response_key="ip_address"
+
+# configure of-watchdog
+# https://github.com/openfaas/of-watchdog#configuration
+ENV fprocess="/home/app/dig.sh"
+ENV mode="streaming"
+ENV content_type="application/json"
+ENV suppress_lock="false"
+ENV prefix_logs="false"
+# Set to true to see request in function logs
+ENV write_debug="false"
+
+EXPOSE 8080
+
+HEALTHCHECK --interval=3s CMD [ -e /tmp/.lock ] || exit 1
+
+CMD ["fwatchdog"]

dig/dig.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/env sh
+
+
+# write log message to stderr
+log() {
+    echo "$@" 1>&2;
+}
+
+IFS='' read -d '' -r request
+response=$(dig "$request" +short 2>&1)
+status=$?
+
+log "request=\"$request\" response=\"$response\" content_type=\"$content_type\""
+
+if [ "$content_type" = "application/json" ]; then
+    key="error"
+    if [ $status -eq 0 ]; then
+        key="${response_key:-response}"
+    fi
+
+    echo "{\"$key\": \"$response\"}"
+else
+    echo "$response"
+fi

stack.yml

@@ -12,6 +12,11 @@ functions:
     handler: ./curl
     image: ghcr.io/${OWNER:-openfaas}/curl:${TAG:-latest}
 
+  dig:
+    lang: dockerfile
+    handler: ./dig
+    image: ghcr.io/${OWNER:-openfaas}/dig:${TAG:-latest}
+
   shasum:
     lang: dockerfile
     handler: ./shasum