added docker cron image build environment

README.md

@@ -1 +1,27 @@
-# cron
+# Docker Cron Image
+A docker-based cron image to handle periodic jobs with ease, everything included
+
+## Usage:
+```
+docker run -v $CRONTAB:/crontab/root -v $CRONJOBS:/jobs bryanpedini/cron:$VERSION-$DISTRO
+```
+
+## Example:
+`crontab`:
+```
+* * * * * /jobs/echo.sh
+```
+
+`jobs/echo.sh`:
+```
+#!/usr/bin/env sh
+echo "this is a custom cron job"
+```
+
+`docker` command:
+```
+docker run -it --rm -v $(pwd)/crontab:/crontab/root -v $(pwd)/jobs:/jobs bryanpedini/cron:1.0-alpine3.16
+```
+
+## WARNING:
+Pay attention to the `crontab` file permissions, ownership needs to be `0:0` for user `root`.

build.sh

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+
+# Copyright (c) 2023 · Bryan Joshua Pedini
+# LICENSE = gpl3
+# see the LICENSE file for more details
+
+while read -r LINE; do
+  VERSION=$(echo "${LINE}" | sed 's/-.*//')
+  DISTRO=$(echo "${LINE}" | sed 's/.*-//')
+  docker build \
+   --build-arg DISTRO="${DISTRO}" \
+   --build-arg VERSION="${VERSION}" \
+   -t bryanpedini/cron:"${VERSION}"-alpine"${DISTRO}" .
+done < versions

crontab

@@ -0,0 +1,8 @@
+# do daily/weekly/monthly maintenance
+# min   hour    day     month   weekday command
+
+# Copyright (c) 2023 · Bryan Joshua Pedini
+# LICENSE = gpl3
+# see the LICENSE file for more details
+
+*       *       *       *       *       echo "No cron job set, please set cron jobs, refer to the documentation"

docker-entrypoint.sh

@@ -0,0 +1,8 @@
+#!/usr/bin/env sh
+
+# Copyright (c) 2023 · Bryan Joshua Pedini
+# LICENSE = gpl3
+# see the LICENSE file for more details
+
+echo "Starting cron..."
+crond -f -l 9 -c /crontab

dockerfile

@@ -0,0 +1,15 @@
+# Copyright (c) 2023 · Bryan Joshua Pedini
+# LICENSE = gpl3
+# see the LICENSE file for more details
+
+ARG DISTRO
+FROM alpine:${DISTRO}
+
+ARG VERSION
+LABEL maintainer="Bryan Joshua Pedini <b.pedini@bjphoster.com>"
+LABEL version="${VERSION}"
+
+COPY crontab /crontab/root
+COPY docker-entrypoint.sh /docker-entrypoint.sh
+
+ENTRYPOINT [ "/docker-entrypoint.sh" ]

versions

@@ -0,0 +1,2 @@
+1.0-3.15
+1.0-3.16