Merge pull request #8 from bobrik/nobody

Drop privileges to nobody, make MESOS_HOST optional

collector/Dockerfile

@@ -6,7 +6,12 @@ RUN echo "APT::Install-Recommends false;" >> /etc/apt/apt.conf.d/recommends.conf
     apt-get update && \
     apt-get upgrade -y && \
     apt-get install -y collectd python-pip ca-certificates && \
-    pip install envtpl
+    pip install envtpl && \
+    apt-get install -y curl && \
+    curl -sL https://github.com/tianon/gosu/releases/download/1.4/gosu-amd64 > /usr/bin/gosu && \
+    chmod +x /usr/bin/gosu && \
+    apt-get remove -y curl && \
+    apt-get autoremove -y
 
 COPY ./docker/collectd.conf.tpl /etc/collectd/collectd.conf.tpl
 COPY ./docker/run.sh /run.sh

collector/docker/collectd.conf.tpl

@@ -1,4 +1,4 @@
-Hostname "{{ COLLECTD_HOST | default(MESOS_HOST) }}"
+Hostname "{{ COLLECTD_HOST }}"
 
 FQDNLookup false
 Interval {{ COLLECTD_INTERVAL | default(10) }}

collector/docker/run.sh

@@ -2,9 +2,15 @@
 
 set -e
 
+if [ -n "${MESOS_HOST}" ]; then
+    if [ -z "${COLLECTD_HOST}" ]; then
+        export COLLECTD_HOST="${MESOS_HOST}"
+    fi
+fi
+
 if [ ! -e "/.initialized" ]; then
     touch "/.initialized"
     envtpl /etc/collectd/collectd.conf.tpl
 fi
 
-collectd -f > /dev/null
+gosu nobody collectd -f > /dev/null