build proper dockerized example

docker/Dockerfile

@@ -1,15 +0,0 @@
-FROM golang:1.9-stretch
-
-RUN apt-get update && apt-get -y install cron sudo
-COPY docker/etc/cron.d /etc/cron.d
-COPY docker/scripts /scripts
-
-RUN useradd -ms /bin/bash myuser && \
-    adduser myuser sudo && \
-    echo 'myuser ALL=(ALL) NOPASSWD:ALL' >> /etc/sudoers
-USER myuser
-
-
-WORKDIR /go/src/github.com/dominicbreuker
-
-

docker/Dockerfile.development

@@ -0,0 +1,20 @@
+FROM golang:1.10-stretch
+
+RUN apt-get update && apt-get -y install cron python3 sudo procps
+
+# install root cronjob
+COPY docker/var/spool/cron/crontabs /var/spool/cron/crontabs
+RUN chmod 600 /var/spool/cron/crontabs/root
+COPY docker/root/scripts /root/scripts
+
+# set up unpriviledged user
+# allows passwordless sudo to start cron as root on startup
+RUN useradd -ms /bin/bash myuser && \
+    adduser myuser sudo && \
+    echo 'myuser ALL=(ALL) NOPASSWD:ALL' >> /etc/sudoers
+USER myuser
+
+# drop into bash shell
+COPY docker/entrypoint-development.sh /entrypoint.sh
+RUN sudo chmod +x /entrypoint.sh
+CMD ["/entrypoint.sh"]

docker/Dockerfile.example

@@ -0,0 +1,25 @@
+FROM debian:stretch
+
+RUN apt-get update && apt-get -y install cron python3 sudo procps
+
+# install root cronjob
+COPY docker/var/spool/cron/crontabs /var/spool/cron/crontabs
+RUN chmod 600 /var/spool/cron/crontabs/root
+COPY docker/root/scripts /root/scripts
+
+# install pspy
+COPY bin/pspy64 /usr/bin/pspy
+
+# set up unpriviledged user
+# allows passwordless sudo to start cron as root on startup
+RUN useradd -ms /bin/bash myuser && \
+    adduser myuser sudo && \
+    echo 'myuser ALL=(ALL) NOPASSWD:ALL' >> /etc/sudoers
+USER myuser
+
+# deploy startup script
+COPY docker/entrypoint-example.sh /entrypoint.sh
+RUN sudo chmod +x /entrypoint.sh
+CMD ["/entrypoint.sh"]
+
+

docker/entrypoint-development.sh

@@ -0,0 +1,13 @@
+#!/bin/bash
+
+set -e 
+
+sudo cron -f &
+sleep 1
+sudo ps | grep cron 1>/dev/null
+echo "[+] cron started"
+
+echo "[+] Running as user `id`"
+
+echo "[+] Dropping into shell..."
+exec /bin/bash

docker/entrypoint-example.sh

@@ -0,0 +1,13 @@
+#!/bin/bash
+
+set -e 
+
+sudo cron -f &
+sleep 1
+sudo ps | grep cron 1>/dev/null
+echo "[+] cron started"
+
+echo "[+] Running as user `id`"
+
+echo "[+] Starting pspy now..."
+pspy 2>/dev/null

docker/etc/cron.d/changepwds

@@ -0,0 +1 @@
+* * * * * root python /root/scripts/password_reset.py

docker/etc/cron.d/myjob

@@ -1 +0,0 @@
-* * * * * root echo 'this is some text' >> /tmp/myjob.log

docker/etc/cron.d/print

@@ -1 +0,0 @@
-* * * * * root python /scripts/print_stuff.py >> /tmp/print.log

docker/root/scripts/password_reset.py

@@ -0,0 +1,12 @@
+#!/usr/bin/python
+import string
+import random
+from subprocess import call
+
+new_password = ''.join(random.SystemRandom()
+                       .choice(string.ascii_uppercase + string.digits)
+                       for _ in range(16))
+
+call("/bin/echo -e \"{}\\n{}\" | passwd myuser"
+     .format(new_password, new_password), shell=True)
+

docker/scripts/print_stuff.py

@@ -1,9 +0,0 @@
-#!/usr/bin/python
-
-user = "myusername"
-password = "thepw"
-
-for i in range(100):
-    print("a"*i)
-
-print("done")

docker/var/spool/cron/crontabs/root

@@ -0,0 +1 @@
+* * * * * python3 /root/scripts/password_reset.py