CI: check Dockerfiles via Dependabot (see #3)

Based on original pull request #1 by @reneleonhardt. Thanks!

.github/dependabot.yml

@@ -0,0 +1,140 @@
+
+version: 2
+
+# Multiple directories not working properly
+# See https://github.com/dependabot/dependabot-core/issues/2178
+
+updates:
+
+
+  - package-ecosystem: docker
+    directory: /buildenv-openjdk8
+    schedule:
+      interval: weekly
+
+
+  - package-ecosystem: docker
+    directory: /buildenv-openjdk8-with-ant-gcc
+    schedule:
+      interval: weekly
+
+
+  - package-ecosystem: docker
+    directory: /buildenv-openjdk9
+    schedule:
+      interval: weekly
+
+
+  - package-ecosystem: docker
+    directory: /buildenv-openjdk10
+    schedule:
+      interval: weekly
+
+
+  - package-ecosystem: docker
+    directory: /buildenv-openjdk11
+    schedule:
+      interval: weekly
+
+
+  - package-ecosystem: docker
+    directory: /buildenv-openjdk11-with-ant-gcc
+    schedule:
+      interval: weekly
+
+
+  - package-ecosystem: docker
+    directory: /buildenv-openjdk12
+    schedule:
+      interval: weekly
+
+
+  - package-ecosystem: docker
+    directory: /buildenv-openjdk13
+    schedule:
+      interval: weekly
+
+
+  - package-ecosystem: docker
+    directory: /buildenv-openjdk14
+    schedule:
+      interval: weekly
+
+
+  - package-ecosystem: docker
+    directory: /buildenv-openjdk15
+    schedule:
+      interval: weekly
+
+
+  - package-ecosystem: docker
+    directory: /buildenv-openjdk16
+    schedule:
+      interval: weekly
+
+
+  - package-ecosystem: docker
+    directory: /buildenv-openjdk17
+    schedule:
+      interval: weekly
+
+
+  - package-ecosystem: docker
+    directory: /buildenv-openjdk18
+    schedule:
+      interval: weekly
+
+
+  - package-ecosystem: docker
+    directory: /buildenv-openjdk19
+    schedule:
+      interval: weekly
+
+
+  - package-ecosystem: docker
+    directory: /buildenv-openjdk20
+    schedule:
+      interval: weekly
+
+
+  - package-ecosystem: docker
+    directory: /buildenv-openjdk21
+    schedule:
+      interval: weekly
+
+
+  - package-ecosystem: docker
+    directory: /buildenv-openjdk22
+    schedule:
+      interval: weekly
+
+
+  - package-ecosystem: docker
+    directory: /buildenv-openjdk23-ea
+    schedule:
+      interval: weekly
+
+
+  - package-ecosystem: docker
+    directory: /buildenv-openj9-openjdk8
+    schedule:
+      interval: weekly
+
+
+  - package-ecosystem: docker
+    directory: /buildenv-openj9-openjdk11
+    schedule:
+      interval: weekly
+
+
+  - package-ecosystem: docker
+    directory: /buildenv-openj9-openjdk17
+    schedule:
+      interval: weekly
+
+
+  - package-ecosystem: docker
+    directory: /buildenv-openj9-openjdk21
+    schedule:
+      interval: weekly
+

update.py

@@ -247,6 +247,22 @@
 
 '''
 
+GITHUB_DEPENDABOT_FILENAME = '.github/dependabot.yml'
+GITHUB_DEPENDABOT_HEADER = '''
+version: 2
+
+# Multiple directories not working properly
+# See https://github.com/dependabot/dependabot-core/issues/2178
+
+updates:
+'''
+GITHUB_DEPENDABOT_TEMPLATE = '''
+  - package-ecosystem: docker
+    directory: /buildenv-{name}
+    schedule:
+      interval: weekly
+'''
+
 
 def replace_shell_pseudo_variables(where, variables):
     if not variables:
@@ -318,5 +334,10 @@ def main():
         for version_config in VERSIONS:
             print(GITHUB_WORKFLOW_TEMPLATE.format(**version_config), file=f)
 
+    with open(GITHUB_DEPENDABOT_FILENAME, 'w') as f:
+        print(GITHUB_DEPENDABOT_HEADER, file=f)
+        for version_config in VERSIONS:
+            print(GITHUB_DEPENDABOT_TEMPLATE.format(**version_config), file=f)
+
 if __name__ == '__main__':
     main()