gitlab-ci: automatically hash build scripts into tag for ci-templates container

ci-templates builds and caches the test containers. When the build
scripts, the ci-template or "config.yml" changes, we need to bump
the tag so that the containers get rebuild.

Partly automate this. The tag now gets generated by the template and
contains a checksum of certain build files. Thus, if you change
any build files, then `ci-fairy generate-template` would generate a
different tag. You can not miss that, because we have tests that ensure
that our ".gitlab-ci.yml" is up to date. Also, you no longer need to
manually bump the tag when a build script changes, just regenerate
".gitlab-ci.yml" with `ci-fairy generate-template`.

See also: https://gitlab.freedesktop.org/freedesktop/ci-templates/-/merge_requests/54

.gitlab-ci.yml

@@ -7,7 +7,7 @@
 ########################################
 
 
-.templates_sha: &template_sha d303fafa66bbca44cc5bdb337d5773b5f019b70d # see https://docs.gitlab.com/ee/ci/yaml/#includefile
+.templates_sha: &template_sha 766e3d77c647e404b349e398427e8965a1769b64 # see https://docs.gitlab.com/ee/ci/yaml/#includefile
 
 include:
   # Centos container builder template
@@ -41,10 +41,10 @@ variables:
   # changing these will force rebuilding the associated image
   # Note: these tags have no meaning and are not tied to a particular
   # libinput version
-  FEDORA_TAG:  '2020-11-10.0'
+  FEDORA_TAG:  '2020-11-17.0-13e145ea4f89'
-  UBUNTU_TAG:  '2020-11-10.0'
+  UBUNTU_TAG:  '2020-11-17.0-a7a0eae3a046'
-  DEBIAN_TAG:  '2020-11-10.0'
+  DEBIAN_TAG:  '2020-11-17.0-f3fdbff29bf1'
-  CENTOS_TAG:  '2020-11-10.0'
+  CENTOS_TAG:  '2020-11-17.0-5ab38b9bd66e'
 
   FEDORA_EXEC: 'bash .gitlab-ci/fedora-install.sh'
   UBUNTU_EXEC: 'bash .gitlab-ci/ubuntu-install.sh'

.gitlab-ci/ci.template

@@ -9,7 +9,7 @@
 ########################################
 
 
-.templates_sha: &template_sha d303fafa66bbca44cc5bdb337d5773b5f019b70d # see https://docs.gitlab.com/ee/ci/yaml/#includefile
+.templates_sha: &template_sha 766e3d77c647e404b349e398427e8965a1769b64 # see https://docs.gitlab.com/ee/ci/yaml/#includefile
 
 include:
 {% for distro in distributions|sort(attribute="name") %}
@@ -34,7 +34,12 @@ variables:
   # Note: these tags have no meaning and are not tied to a particular
   # libinput version
 {% for distro in distributions %}
-  {{"%-13s"| format(distro.name.upper() + '_TAG:')}}'{{distro.tag}}'
+  {{"%-13s"| format(distro.name.upper() + '_TAG:')}}'{{distro.tag}}-{{
+    (ci_fairy.hashfiles('./.gitlab-ci/config.yml',
+                        './.gitlab-ci/ci.template',
+                        './.gitlab-ci/' + distro.name + '-install.sh',
+                        './contrib/' + distro.base_type + '/REQUIRED_PACKAGES'))[0:12]
+  }}'
 {% endfor %}
 
 {% for distro in distributions %}

.gitlab-ci/config.yml

@@ -8,7 +8,7 @@
 #
 
 # We're happy to rebuild all containers when one changes.
-.default_tag: &default_tag '2020-11-10.0'
+.default_tag: &default_tag '2020-11-17.0'
 
 
 # The list of all distributions we want to create job for.
@@ -16,6 +16,7 @@
 distributions:
   - name: fedora
     tag: *default_tag
+    base_type: fedora
     versions:
       - '28'
       - '29'
@@ -28,6 +29,7 @@ distributions:
       - '33'
   - name: ubuntu
     tag: *default_tag
+    base_type: debian
     versions:
       - '16.04'
       - '18.04'
@@ -36,6 +38,7 @@ distributions:
       - 'rolling'
   - name: debian
     tag: *default_tag
+    base_type: debian
     versions:
       - '9'
       - '10'
@@ -43,6 +46,7 @@ distributions:
       - 'sid'
   - name: centos
     tag: *default_tag
+    base_type: fedora
     versions:
       - '7.5.1804'
       - '7.6.1810'