fix: restore CI for Traefik v1.7

Co-authored-by: Michael <michael.matur@gmail.com>

script/docs-verify-docker-image/Dockerfile

@@ -1,16 +1,37 @@
-FROM alpine:3.8
+FROM alpine:3.14 as alpine
 
 RUN apk --no-cache --no-progress add \
-    ca-certificates \
-    curl \
-    findutils \
+    libcurl \
+    ruby \
     ruby-bigdecimal \
     ruby-etc \
     ruby-ffi \
     ruby-json \
-    ruby-nokogiri=1.8.3-r0 \
-    tini \
-  && gem install --no-document html-proofer -v 3.9.3
+    ruby-nokogiri \
+    ruby-dev \
+    build-base
+
+RUN gem install html-proofer --version 3.19.0 --no-document -- --use-system-libraries
+
+# After Ruby, some NodeJS YAY!
+RUN apk --no-cache --no-progress add \
+    git \
+    nodejs \
+    npm
+
+# To handle 'not get uid/gid'
+RUN npm config set unsafe-perm true
+
+RUN npm install --global \
+    markdownlint@0.22.0 \
+    markdownlint-cli@0.26.0
+
+# Finally the shell tools we need for later
+# tini helps to terminate properly all the parallelized tasks when sending CTRL-C
+RUN apk --no-cache --no-progress add \
+    ca-certificates \
+    curl \
+    tini
 
 COPY ./validate.sh /validate.sh
 

script/docs-verify-docker-image/validate.sh

@@ -1,13 +1,13 @@
 #!/bin/sh
 
+PATH_TO_SITE="${1:-/app/site}"
+
 set -eu
 
-PATH_TO_SITE="/app/site"
 [ -d "${PATH_TO_SITE}" ]
 
 NUMBER_OF_CPUS="$(grep -c processor /proc/cpuinfo)"
 
-
 echo "=== Checking HTML content..."
 
 # Search for all HTML files except the theme's partials
@@ -19,10 +19,12 @@ find "${PATH_TO_SITE}" -type f -not -path "/app/site/theme/*" \
   htmlproofer \
   --check-html \
   --check_external_hash \
+  --empty_alt_ignore \
   --alt_ignore="/traefikproxy-vertical-logo-color.svg/" \
   --http_status_ignore="0,500,501,503" \
-  --url-ignore "/https://groups.google.com/a/traefik.io/forum/#!forum/security/,/localhost:/,/127.0.0.1:/,/fonts.gstatic.com/,/.minikube/,/doc.traefik.io\/traefik/,/traefik.io/,/github.com\/traefik\/traefik\/*edit*/,/github.com\/traefik\/traefik\/$/" \
-  '{}'
+  --file_ignore="/404.html/" \
+  --url_ignore="/https://groups.google.com/a/traefik.io/forum/#!forum/security/,/localhost:/,/127.0.0.1:/,/fonts.gstatic.com/,/.minikube/,/github.com\/traefik\/traefik\/*edit*/,/github.com\/traefik\/traefik/,/doc.traefik.io/,/github\.com\/golang\/oauth2\/blob\/36a7019397c4c86cf59eeab3bc0d188bac444277\/.+/,/www.akamai.com/,/pilot.traefik.io\/profile/,/traefik.io/,/doc.traefik.io\/traefik-mesh/,/www.mkdocs.org/,/squidfunk.github.io/,/ietf.org/,/www.namesilo.com/,/www.youtube.com/,/www.linode.com/,/www.alibabacloud.com/" \
+  '{}' 1>/dev/null
 ## HTML-proofer options at https://github.com/gjtorikian/html-proofer#configuration
 
-echo "= Documentation checked successfuly."
+echo "= Documentation checked successfully."