Move to Alpine linux

Based on https://github.com/sanjeevan/baseimage

Image size reduced from 232MB to 90MB

Also make the change monitors more like services that restart if they crash

60_create_monitors.sh

@@ -0,0 +1,42 @@
+#!/bin/bash
+
+function ts {
+  echo [`date '+%Y-%m-%d %H:%M:%S'`] MASTER:
+}
+
+echo "$(ts) Starting master controller"
+
+if [ -f /config/sample.conf ]; then
+  echo "$(ts) /config/sample.conf exists. Rename it to <monitor name>.conf, check the settings, then rerun the container. Exiting."
+  exit 1
+fi
+
+readarray -t CONFIG_FILES < <(ls /config/*.conf)
+
+# If there is no config file copy the default one
+if [[ "$CONFIG_FILES" == "" ]]
+then
+  echo "$(ts) Creating sample config file. Rename it to <monitor name>.conf, check the settings, then rerun the container. Exiting."
+  cp /files/sample.conf /config/sample.conf
+  chmod a+w /config/sample.conf
+  exit 1
+fi
+
+for CONFIG_FILE in "${CONFIG_FILES[@]}" 
+do 
+  FILENAME=$(basename "$CONFIG_FILE")
+
+  echo "$(ts) Creating monitor for $FILENAME"
+
+  FILEBASE="${FILENAME%.*}"
+  
+  mkdir -p /etc/service/$FILEBASE
+
+  cat > /etc/service/$FILEBASE/run <<EOF
+#!/bin/bash
+
+/files/monitor.py "$CONFIG_FILE"
+EOF
+
+  chmod a+x /etc/service/$FILEBASE/run
+done

Dockerfile

@@ -1,43 +1,40 @@
-FROM phusion/baseimage:0.9.19
+FROM alpine:3.7
 
 MAINTAINER David Coppit <david@coppit.org>
 
-
+ENV TERM=xterm-256color
-# Use baseimage-docker's init system
-CMD ["/sbin/my_init"]
-
-ENV DEBIAN_FRONTEND noninteractive
-ADD dpkg-excludes /etc/dpkg/dpkg.cfg.d/excludes
 
 RUN true && \
+\
+echo "http://dl-cdn.alpinelinux.org/alpine/v3.7/community" >> /etc/apk/repositories && \
+apk --update upgrade && \
+\
+# Basics, including runit
+apk add bash curl htop runit && \
+\
+# Needed by our code
+apk add --no-cache python3 icu-libs shadow && \
+pip3 install watchdog && \
+wget https://raw.githubusercontent.com/phusion/baseimage-docker/9f998e1a09bdcb228af03595092dbc462f1062d0/image/bin/setuser -O /sbin/setuser && \
+chmod +x /sbin/setuser && \
+\
+rm -rf /var/cache/apk/* && \
+\
+# RunIt stuff
+adduser -h /home/user-service -s /bin/sh -D user-service -u 2000 && \
+chown user-service:user-service /home/user-service && \
+mkdir -p /etc/run_once /etc/service
 
-set -x && \
+# Boilerplate startup code
-
+COPY ./boot.sh /sbin/boot.sh
-# Create dir to keep things tidy. Make sure it's readable by $UID
+RUN chmod +x /sbin/boot.sh
-mkdir /files && \
+CMD [ "/sbin/boot.sh" ]
-chmod a+rwX /files && \
-
-# Speed up APT
-echo "force-unsafe-io" > /etc/dpkg/dpkg.cfg.d/02apt-speedup && \
-echo "Acquire::http {No-Cache=True;};" > /etc/apt/apt.conf.d/no-cache && \
-
-apt-get update && \
-apt-get install -qy python3-watchdog wget && \
-
-# clean up
-apt-get clean && \
-rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* \
-/usr/share/man /usr/share/groff /usr/share/info \
-/usr/share/lintian /usr/share/linda /var/cache/man && \
-(( find /usr/share/doc -depth -type f ! -name copyright|xargs rm || true )) && \
-(( find /usr/share/doc -empty|xargs rmdir || true ))
 
 VOLUME ["/config", \
   "/dir1", "/dir2", "/dir3", "/dir4", "/dir5", "/dir6", "/dir7", "/dir8", "/dir9", "/dir10", \
   "/dir11", "/dir12", "/dir13", "/dir14", "/dir15", "/dir16", "/dir17", "/dir18", "/dir19", "/dir20"]
 
 # Set the locale, to help Python and the user's applications deal with files that have non-ASCII characters
-RUN locale-gen en_US.UTF-8
 ENV LANG en_US.UTF-8
 ENV LANGUAGE en_US:en
 ENV LC_ALL en_US.UTF-8
@@ -45,11 +42,11 @@ ENV LC_ALL en_US.UTF-8
 ENV UMAP ""
 ENV GMAP ""
 
-# Add local files
 COPY sample.conf monitor.py runas.sh /files/
+# Make sure it's readable by $UID
+RUN chmod a+rwX /files
 
-ADD 50_remap_ids.sh /etc/my_init.d/
+# run-parts ignores files with "." in them
-
+ADD 50_remap_ids.sh /etc/run_once/50_remap_ids
-RUN mkdir /etc/service/monitor
+ADD 60_create_monitors.sh /etc/run_once/60_create_monitors
-ADD monitor.sh /etc/service/monitor/run
+RUN chmod +x /etc/run_once/*
-RUN chmod +x /etc/service/monitor/run

boot.sh

@@ -0,0 +1,56 @@
+#!/bin/sh
+
+# Based on https://github.com/sanjeevan/baseimage
+
+shutdown() {
+  echo
+  echo "Shutting down container..."
+
+  # first shutdown any service started by runit
+  for _srv in $(ls -1 /etc/service); do
+    sv force-stop $_srv
+  done
+
+  # shutdown runsvdir command
+  kill -HUP $RUNSVDIR
+  wait $RUNSVDIR
+
+  # give processes time to stop
+  sleep 0.5
+
+  # kill any other processes still running in the container
+  for _pid  in $(ps -eo pid | grep -v PID  | tr -d ' ' | grep -v '^1$' | head -n -6); do
+    timeout -t 5 /bin/sh -c "kill $_pid && wait $_pid || kill -9 $_pid"
+  done
+
+  exit
+}
+
+# catch shutdown signals
+trap shutdown SIGTERM SIGHUP SIGQUIT SIGINT
+
+# store environment variables
+export > /etc/envvars
+
+PATH=/bin:/sbin:/usr/bin
+
+# run all scripts in the run_once folder
+if ! /bin/run-parts /etc/run_once
+then
+  echo "Run-once scripts failed. Stopping container"
+  shutdown
+fi
+
+exec env - PATH=$PATH runsvdir -P /etc/service &
+
+RUNSVDIR=$!
+echo "Started runsvdir, PID is $RUNSVDIR. Waiting for processes to start...."
+
+sleep 5
+for _srv in $(ls -1 /etc/service); do
+    sv status $_srv
+done
+
+wait $RUNSVDIR
+
+shutdown

dpkg-excludes

@@ -1,16 +0,0 @@
-path-exclude /usr/share/doc/*
-# we need to keep copyright files for legal reasons
-path-include /usr/share/doc/*/copyright
-path-exclude /usr/share/man/*
-path-exclude /usr/share/groff/*
-path-exclude /usr/share/info/*
-# lintian stuff is small, but really unnecessary
-path-exclude /usr/share/lintian/*
-path-exclude /usr/share/linda/*
-# Drop locales except English
-path-exclude=/usr/share/locale/*
-path-include=/usr/share/locale/en/*
-path-include=/usr/share/locale/locale.alias
-
-
-

monitor.sh

@@ -1,57 +0,0 @@
-#!/bin/bash
-
-function ts {
-  echo [`date '+%Y-%m-%d %H:%M:%S'`] MASTER:
-}
-
-echo "$(ts) Starting master controller"
-
-if [ -f /config/sample.conf ]; then
-  echo "$(ts) /config/sample.conf exists. Rename it, check the settings, then rerun the container. Exiting."
-  exit 1
-fi
-
-readarray -t CONFIG_FILES < <(ls /config/*.conf)
-
-# If there is no config file copy the default one
-if [[ "$CONFIG_FILES" == "" ]]
-then
-  echo "$(ts) Creating sample config file. Rename it, check the settings, then rerun the container. Exiting."
-  cp /files/sample.conf /config/sample.conf
-  chmod a+w /config/sample.conf
-  exit 1
-fi
-
-PIDS=()
-
-for CONFIG_FILE in "${CONFIG_FILES[@]}" 
-do 
-  echo "$(ts) Launching monitor for $CONFIG_FILE"
-  /files/monitor.py $CONFIG_FILE &
-  PIDS+=($!)
-done
-
-# Sleep for a second to allow the monitors to check their config files
-sleep 1
-
-while true
-do
-  for ((i = 0; i < ${#PIDS[@]}; i++))
-  do
-    if ps -p ${PIDS[$i]} > /dev/null
-    then
-      continue
-    fi
-
-    echo "$(ts) Monitor for ${CONFIG_FILES[$i]} has died (PID ${PIDS[$i]}). Killing other monitors and exiting."
-
-    for PID in "${PIDS[@]}" 
-    do 
-      kill -9 $PID >/dev/null 2>&1
-    done
-
-    exit 2
-  done
-
-  sleep 60
-done