From c50fdccc3b3e1aee9f51c576da5942bcc1732e14 Mon Sep 17 00:00:00 2001
From: Andres Freund <andres@anarazel.de>
Date: Fri, 12 Apr 2024 15:04:32 -0700
Subject: [PATCH v5 1/2] ci: Per-repo triggers for not automated tasks

We're not ready to trigger some tasks automatically by default, so you
normally have to trigger then manually via Cirrus if you want to run
them.  This avoids using too many credits by default.

With this commit, an individual repository can be configured to trigger
them automatically using an environment variable defined under
"Repository Settings", for example:

REPO_CI_AUTOMATIC_TRIGGER_TASKS="mingw netbsd openbsd"

This will enable cfbot to turn them on by default when running tests for
the Commitfest app.  It is not subject to free credit limits as it runs
on credits donated by Google.

Author: Andres Freund <andres@anarazel.de>
Co-authored-by: Thomas Munro <thomas.munro@gmail.com>
Reviewed-by: Nazir Bilal Yavuz <byavuz81@gmail.com>
Discussion: https://postgr.es/m/20240413021221.hg53rvqlvldqh57i%40awork3.anarazel.de
Backpatch: 16-, where first manual task was added
---
 .cirrus.star        | 50 +++++++++++++++++++++++++++++++++++++++++----
 .cirrus.tasks.yml   | 15 +++++++-------
 .cirrus.yml         | 12 +++++++++--
 src/tools/ci/README | 11 ++++++++++
 4 files changed, 75 insertions(+), 13 deletions(-)

diff --git a/.cirrus.star b/.cirrus.star
index 36233872d1e..218fce887b5 100644
--- a/.cirrus.star
+++ b/.cirrus.star
@@ -7,7 +7,7 @@ https://github.com/bazelbuild/starlark/blob/master/spec.md
 See also .cirrus.yml and src/tools/ci/README
 """
 
-load("cirrus", "env", "fs")
+load("cirrus", "env", "fs", "yaml")
 
 
 def main():
@@ -18,19 +18,36 @@ def main():
 
     1) the contents of .cirrus.yml
 
-    2) if defined, the contents of the file referenced by the, repository
+    2) computed environment variables
+
+    3) if defined, the contents of the file referenced by the, repository
        level, REPO_CI_CONFIG_GIT_URL variable (see
        https://cirrus-ci.org/guide/programming-tasks/#fs for the accepted
        format)
 
-    3) .cirrus.tasks.yml
+    4) .cirrus.tasks.yml
     """
 
     output = ""
 
     # 1) is evaluated implicitly
 
+
     # Add 2)
+    additional_env = compute_environment_vars()
+    env_fmt = """
+###
+# Computed environment variables start here
+###
+{0}
+###
+# Computed environment variables end here
+###
+"""
+    output += env_fmt.format(yaml.dumps({'env': additional_env}))
+
+
+    # Add 3)
     repo_config_url = env.get("REPO_CI_CONFIG_GIT_URL")
     if repo_config_url != None:
         print("loading additional configuration from \"{}\"".format(repo_config_url))
@@ -38,12 +55,37 @@ def main():
     else:
         output += "\n# REPO_CI_CONFIG_URL was not set\n"
 
-    # Add 3)
+
+    # Add 4)
     output += config_from(".cirrus.tasks.yml")
 
+
     return output
 
 
+def compute_environment_vars():
+    cenv = {}
+
+    # The following tasks are manually triggered by default because they
+    # might use too many resources for users of free Cirrus credits, but you can
+    # trigger them automatically by naming them in an environment variable eg
+    # REPO_CI_AUTOMATIC_TRIGGER_TASKS="mingw netbsd" under "Repository
+    # Settings" on Cirrus CI's website.
+
+    default_manual_trigger_tasks = ['mingw', 'netbsd', 'openbsd']
+
+    repo_ci_automatic_trigger_tasks = env.get('REPO_CI_AUTOMATIC_TRIGGER_TASKS', '')
+    for task in default_manual_trigger_tasks:
+        name = 'CI_TRIGGER_TYPE_' + task.upper()
+        if repo_ci_automatic_trigger_tasks.find(task) != -1:
+            value = 'automatic'
+        else:
+            value = 'manual'
+        cenv[name] = value
+
+    return cenv
+
+
 def config_from(config_src):
     """return contents of config file `config_src`, surrounded by markers
     indicating start / end of the included file
diff --git a/.cirrus.tasks.yml b/.cirrus.tasks.yml
index 86a1fa9bbdb..0cf6ea67ba5 100644
--- a/.cirrus.tasks.yml
+++ b/.cirrus.tasks.yml
@@ -239,7 +239,6 @@ task:
 
 task:
   depends_on: SanityCheck
-  trigger_type: manual
 
   env:
     # Below are experimentally derived to be a decent choice.
@@ -257,6 +256,8 @@ task:
 
   matrix:
     - name: NetBSD - Meson
+      # See REPO_CI_AUTOMATIC_TRIGGER_TASKS in .cirrus.star
+      trigger_type: $CI_TRIGGER_TYPE_NETBSD
       only_if: $CIRRUS_CHANGE_MESSAGE !=~ '.*\nci-os-only:.*' || $CIRRUS_CHANGE_MESSAGE =~ '.*\nci-os-only:[^\n]*netbsd.*'
       env:
         OS_NAME: netbsd
@@ -274,6 +275,8 @@ task:
       <<: *netbsd_task_template
 
     - name: OpenBSD - Meson
+      # See REPO_CI_AUTOMATIC_TRIGGER_TASKS in .cirrus.star
+      trigger_type: $CI_TRIGGER_TYPE_OPENBSD
       only_if: $CIRRUS_CHANGE_MESSAGE !=~ '.*\nci-os-only:.*' || $CIRRUS_CHANGE_MESSAGE =~ '.*\nci-os-only:[^\n]*openbsd.*'
       env:
         OS_NAME: openbsd
@@ -743,13 +746,11 @@ task:
   << : *WINDOWS_ENVIRONMENT_BASE
   name: Windows - Server 2019, MinGW64 - Meson
 
-  # due to resource constraints we don't run this task by default for now
-  trigger_type: manual
-  # worth using only_if despite being manual, otherwise this task will show up
-  # when e.g. ci-os-only: linux is used.
-  only_if: $CIRRUS_CHANGE_MESSAGE !=~ '.*\nci-os-only:.*' || $CIRRUS_CHANGE_MESSAGE =~ '.*\nci-os-only:[^\n]*mingw.*'
-  # otherwise it'll be sorted before other tasks
+  # See REPO_CI_AUTOMATIC_TRIGGER_TASKS in .cirrus.star.
+  trigger_type: $CI_TRIGGER_TYPE_MINGW
+
   depends_on: SanityCheck
+  only_if: $CIRRUS_CHANGE_MESSAGE !=~ '.*\nci-os-only:.*' || $CIRRUS_CHANGE_MESSAGE =~ '.*\nci-os-only:[^\n]*mingw.*'
 
   env:
     TEST_JOBS: 4 # higher concurrency causes occasional failures
diff --git a/.cirrus.yml b/.cirrus.yml
index 33c6e481d74..3f75852e84e 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -10,12 +10,20 @@
 #
 # 1) the contents of this file
 #
-# 2) if defined, the contents of the file referenced by the, repository
+# 2) computed environment variables
+#
+#    Used to enable/disable tasks based on the execution environment. See
+#    .cirrus.star: compute_environment_vars()
+#
+# 3) if defined, the contents of the file referenced by the, repository
 #    level, REPO_CI_CONFIG_GIT_URL variable (see
 #    https://cirrus-ci.org/guide/programming-tasks/#fs for the accepted
 #    format)
 #
-# 3) .cirrus.tasks.yml
+#    This allows running tasks in a different execution environment than the
+#    default, e.g. to have sufficient resources for cfbot.
+#
+# 4) .cirrus.tasks.yml
 #
 # This composition is done by .cirrus.star
 
diff --git a/src/tools/ci/README b/src/tools/ci/README
index 12c1e7c308f..d183648a8d0 100644
--- a/src/tools/ci/README
+++ b/src/tools/ci/README
@@ -82,3 +82,14 @@ defined in .cirrus.yml, by redefining the relevant yaml anchors.
 Custom compute resources can be provided using
 - https://cirrus-ci.org/guide/supported-computing-services/
 - https://cirrus-ci.org/guide/persistent-workers/
+
+
+Enabling manual tasks by default
+================================
+
+Some tasks are not triggered automatically by default, to avoid using up CI
+credits too quickly. This can be changed on the repository level, e.g. when
+custom compute resources are configured.
+
+The following repository level environment variables are recognized:
+- REPO_CI_AUTOMATIC_TRIGGER_TASKS - space-separated list of (mingw|netbsd|openbsd)
-- 
2.49.0

