copr-dist-git: run the cleanup cron twice per month

https://github.com/fedora-copr/copr/issues/3020

roles/copr/dist_git/files/copr-dist-git.weekly

@@ -4,6 +4,11 @@
 # When you uncomment this, all the sources from the dist-git lookaside cache
 # will be periodically unlinked, except for those sources mentioned in the
 # last commits of the git repo branches.
+
+# We run this on Sunday 4.22 every week (default cron weekly timing).  To run
+# this bi-weekly, we have to skip every second run.
+/usr/local/bin/test-too-soon "cleaning-dist-git-data-volume" 10 && exit 0
+
 runuser -c 'dist-git-clear-tarballs.py' - copr-dist-git
 
 # From time to time assure that the CGIT caches are consistent, and that the

roles/copr/dist_git/files/test-too-soon

@@ -0,0 +1,38 @@
+#! /bin/bash
+
+# Return non-zero exit status if this script has been run before more than N
+# days (or never).  Arguments are $ID (word or description) and number of days.
+# Use like 'test-not-before last-dist-git-cleanup-run 10 || do_something'
+
+id=$1
+days=$2
+file=/var/tmp/
+umask 0077
+dir="/var/tmp/test-too-soon-script-$(id -u -n)"
+file=$dir/$id
+lock=$file.lock
+coeficient="24*3600"
+log() { echo >&2 "LOG: $id: $*"; }
+mkdir -p "$dir"
+(
+    flock 9
+    stamp=$(date +%s)
+    if test ! -e "$file"; then
+        log "running for the first time"
+        echo "$stamp" > "$file"
+        exit 1
+    fi
+
+    old_stamp=$(cat "$file")
+
+    last=$(( (stamp - old_stamp) / ("$coeficient") ))
+    if test $(( stamp - old_stamp )) -ge $(( days * ("$coeficient") )); then
+        log "Last run $old_stamp, before $last days, running."
+        echo "$stamp" > "$file"
+        exit 1
+    else
+        log "Last run $old_stamp, before $last days, skipping."
+        exit 0
+    fi
+) 9>"$lock"
+# no more tasks, exit status inherited from sub-shell

roles/copr/dist_git/tasks/main.yml

@@ -133,12 +133,33 @@
 - name: install .config/copr for copr-dist-git user (required for pruning)
   template: src="copr.conf" dest="/home/copr-dist-git/.config/copr" owner=copr-dist-git group=copr-dist-git
 
+- name: install the helper cron scripts
+  copy:
+    src: "{{ item }}"
+    dest: "/usr/local/bin/{{ item }}"
+    mode: '0755'
+  tags:
+    - config
+    - cron
+  loop:
+    - test-too-soon
+
 - name: install copr-dist-git.daily cron file
   copy: src="copr-dist-git.daily" dest="/etc/cron.daily/copr-dist-git" mode=755
   tags:
-  - config
+    - config
+    - cron
 
-- name: install copr-dist-git.monthly cron file
-  copy: src="copr-dist-git.monthly" dest="/etc/cron.monthly/copr-dist-git" mode=755
+- name: install copr-dist-git.weekly cron file
+  copy: src="copr-dist-git.weekly" dest="/etc/cron.weekly/copr-dist-git" mode=755
   tags:
-  - config
+    - config
+    - cron
+
+- name: drop monthly cron job
+  file:
+    path: /etc/cron.weekly/copr-dist-git
+    state: absent
+  tags:
+    - config
+    - cron