From 1fd9771e9178f119cddc1e0b68e6dac42dff39b2 Mon Sep 17 00:00:00 2001
From: Patrick Stadler <patrick.stadler@gmail.com>
Date: Sun, 22 Mar 2015 13:22:41 +0100
Subject: [PATCH] load custom reporters. update README

---
 .gitignore                |  2 +
 README.md                 |  4 +-
 init.d/metrics.sh         |  7 +--
 lib/main.sh               | 91 ++++++++++++++++++++++-----------------
 lib/utils/loader.sh       | 54 ++++++++++++++++++++---
 metrics/custom/.gitkeep   |  0
 reporters/custom/.gitkeep |  0
 7 files changed, 108 insertions(+), 50 deletions(-)
 create mode 100644 .gitignore
 create mode 100644 metrics/custom/.gitkeep
 create mode 100644 reporters/custom/.gitkeep

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..b27d8d8
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+/metrics/custom/*.sh
+/reporters/custom/*.sh
\ No newline at end of file
diff --git a/README.md b/README.md
index 103ea2f..e39faf6 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # metrics.sh
 
-metrics.sh is a lightweight metrics collection and fowarding utility implemented in portable POSIX compliant shell scripts. A transparent interface based on hooks enables writing custom metric collectors and reporters in an elegant way.
+metrics.sh is a lightweight metrics collection and fowarding utility implemented in portable POSIX compliant shell scripts. A transparent interface based on hooks enables writing custom collectors and reporters in an elegant way.
 
 ## Usage
 
@@ -28,7 +28,7 @@ $ git clone git@github.com:pstadler/metrics.sh.git
 
 ### Requirements
 
-metrics.sh has been tested on Ubuntu 14.04 and Mac OS X but is supposed to run on most *NIX-like operating systems. Some of the provided metrics require [procfs](http://en.wikipedia.org/wiki/Procfs) to be available.
+metrics.sh has been tested on Ubuntu 14.04 and Mac OS X but is supposed to run on most *NIX-like operating systems. Some of the provided metrics require [procfs](http://en.wikipedia.org/wiki/Procfs) to be available when running on *NIX. POSIX compliancy means that metrics.sh works with minimalistic command interpreters such as [dash](http://manpages.ubuntu.com/manpages/trusty/en/man1/dash.1.html). Built-in metrics do **not** require root privileges.
 
 ## Metrics
 
diff --git a/init.d/metrics.sh b/init.d/metrics.sh
index 1606a1c..ac07194 100644
--- a/init.d/metrics.sh
+++ b/init.d/metrics.sh
@@ -11,7 +11,8 @@
 
 SCRIPT=<SCRIPT>
 RUNAS=<USER>
-ARGS=<ARGS>
+CONFIG_FILE=<CONFIG_FILE>
+ARGS="-c $CONFIG_FILE"
 NAME=metrics.sh
 
 PIDFILE=/var/run/$NAME.pid
@@ -25,7 +26,7 @@ start() {
     echo 'Service already running' >&2
     return 1
   fi
-  echo 'Starting service…' >&2
+  echo 'Starting service...' >&2
   local CMD="$SCRIPT &> \"$LOGFILE\" & echo \$!"
   su -c "$CMD $ARGS" $RUNAS > "$PIDFILE"
   echo 'Service started' >&2
@@ -36,7 +37,7 @@ stop() {
     echo 'Service not running' >&2
     return 1
   fi
-  echo 'Stopping service…' >&2
+  echo 'Stopping service...' >&2
   kill -15 $(cat "$PIDFILE") && rm -f "$PIDFILE"
   echo 'Service stopped' >&2
 }
diff --git a/lib/main.sh b/lib/main.sh
index 9c93851..7f93fe2 100644
--- a/lib/main.sh
+++ b/lib/main.sh
@@ -5,19 +5,21 @@ for util in ./lib/utils/*.sh; do
   . $util
 done
 
-# init
-__AVAILABLE_METRICS=
-__AVAILABLE_REPORTERS=
-
 main_defaults () {
   if [ -z $INTERVAL ]; then
     INTERVAL=2
   fi
-  if [ -z $METRICS ]; then
-    METRICS=cpu,disk_io,disk_usage,heartbeat,memory,network_io,swap
+  if [ -z $DEFAULT_METRICS ]; then
+    DEFAULT_METRICS=cpu,memory,swap,network_io,disk_io,disk_usage
   fi
-  if [ -z $REPORTER ]; then
-    REPORTER=stdout
+  if [ -z $DEFAULT_REPORTER ]; then
+    DEFAULT_REPORTER=stdout
+  fi
+  if [ -z $CUSTOM_REPORTERS_PATH ]; then
+    CUSTOM_REPORTERS_PATH=./reporters/custom
+  fi
+  if [ -z $CUSTOM_METRICS_PATH ]; then
+    CUSTOM_METRICS_PATH=./metrics/custom
   fi
 }
 
@@ -25,28 +27,23 @@ main_load () {
   # set defaults
   main_defaults
 
-  # load reporter
-  for file in ./reporters/*.sh; do
-    local filename=$(basename $file)
-    local reporter=${filename%.*}
-
-    __AVAILABLE_REPORTERS=$(trim "$__AVAILABLE_REPORTERS $reporter")
-  done
-
-  # load available metrics
-  for file in ./metrics/*.sh; do
-    local filename=$(basename $file)
-    local metric=${filename%.*}
-
-    # register metric
-    __AVAILABLE_METRICS=$(trim "$__AVAILABLE_METRICS $metric")
-  done
+  __AVAILABLE_REPORTERS=$(get_available_reporters)
+  __AVAILABLE_METRICS=$(get_available_metrics)
 }
 
 main_init () {
-  # handle args
-  __METRICS=$(echo $1 | sed 's/,/ /g')
-  __REPORTER=$2
+  local metrics="$1"
+  local reporter="$2"
+
+  if [ -z "$metrics" ]; then
+    metrics=$DEFAULT_METRICS
+  fi
+  if [ -z "$reporter" ]; then
+    reporter=$DEFAULT_REPORTER
+  fi
+
+  __METRICS=$(echo $metrics| sed 's/,/ /g')
+  __REPORTER=$reporter
 
   # create temp dir
   TEMP_DIR=$(make_temp_dir)
@@ -78,14 +75,17 @@ main_collect () {
   # init reporter
   local reporter_name=$(get_name_for_reporter $__REPORTER)
   local reporter_alias=$(get_alias $__REPORTER)
-  load_reporter_with_prefix __r_${reporter_alias}_ ./reporters/${reporter_name}.sh
+  load_reporter_with_prefix __r_${reporter_alias}_ ${reporter_name}
 
   if is_function __r_${reporter_alias}_defaults; then
     __r_${reporter_alias}_defaults
   fi
+
   if is_function __r_${reporter_alias}_config; then
     __r_${reporter_alias}_config
   fi
+
+  verbose "Starting reporter '${reporter_alias}'"
   if is_function __r_${reporter_alias}_start; then
     __r_${reporter_alias}_start
   fi
@@ -98,7 +98,7 @@ main_collect () {
       local metric_alias=$(get_alias $metric)
 
       # init metric
-      load_metric_with_prefix __m_${metric_alias}_ ./metrics/${metric_name}.sh
+      load_metric_with_prefix __m_${metric_alias}_ ${metric_name}
 
       if is_function __m_${metric_alias}_defaults; then
         __m_${metric_alias}_defaults
@@ -108,11 +108,13 @@ main_collect () {
         __m_${metric_alias}_config
       fi
 
+      verbose "Starting metric '${metric_alias}'"
       if is_function __m_${metric_alias}_start; then
         __m_${metric_alias}_start
       fi
 
       if ! is_function __m_${metric_alias}_collect; then
+        verbose "No collect() function found for '${metric_alias}'"
         continue
       fi
 
@@ -172,10 +174,19 @@ main_terminate () {
 }
 
 main_print_docs () {
+  echo "# GLOBAL"
+  echo
+  echo "INTERVAL=$INTERVAL"
+  echo "DEFAULT_REPORTER=$DEFAULT_REPORTER"
+  echo "DEFAULT_METRICS=$DEFAULT_METRICS"
+  echo "CUSTOM_REPORTERS_PATH=$CUSTOM_REPORTERS_PATH"
+  echo "CUSTOM_METRICS_PATH=$CUSTOM_METRICS_PATH"
+
+  echo
   echo "# METRICS"
 
   for metric in $__AVAILABLE_METRICS; do
-    load_metric_with_prefix __m_${metric}_ ./metrics/${metric}.sh
+    load_metric_with_prefix __m_${metric}_ ${metric}
 
     if ! is_function __m_${metric}_docs; then
       continue
@@ -193,7 +204,7 @@ main_print_docs () {
   echo
   echo "# REPORTERS"
   for reporter in $__AVAILABLE_REPORTERS; do
-    load_reporter_with_prefix __r_${reporter}_ ./reporters/${reporter}.sh
+    load_reporter_with_prefix __r_${reporter}_ ${reporter}
 
     if ! is_function __r_${reporter}_docs; then
       continue
@@ -212,11 +223,13 @@ main_print_docs () {
 main_print_config () {
   echo "[metrics.sh]"
   echo ";INTERVAL=$INTERVAL"
-  echo ";METRICS=$METRICS"
-  echo ";REPORTER=$REPORTER"
+  echo ";DEFAULT_REPORTER=$DEFAULT_REPORTER"
+  echo ";DEFAULT_METRICS=$DEFAULT_METRICS"
+  echo ";CUSTOM_REPORTERS_PATH=$CUSTOM_REPORTERS_PATH"
+  echo ";CUSTOM_METRICS_PATH=$CUSTOM_METRICS_PATH"
 
   for metric in $__AVAILABLE_METRICS; do
-    load_metric_with_prefix __m_${metric}_ ./metrics/${metric}.sh
+    load_metric_with_prefix __m_${metric}_ ${metric}
 
     if is_function __m_${metric}_defaults; then
       __m_${metric}_defaults
@@ -231,11 +244,7 @@ main_print_config () {
   done
 
   for reporter in $__AVAILABLE_REPORTERS; do
-    load_reporter_with_prefix __r_${reporter}_ ./reporters/${reporter}.sh
-
-    if ! is_function __r_${reporter}_docs; then
-      continue
-    fi
+    load_reporter_with_prefix __r_${reporter}_ ${reporter}
 
     if is_function __r_${reporter}_defaults; then
       __r_${reporter}_defaults
@@ -243,6 +252,8 @@ main_print_config () {
 
     echo
     echo ";[reporter $reporter]"
-    print_prefixed ";" "$(__r_${reporter}_docs)"
+    if is_function __r_${reporter}_docs; then
+      print_prefixed ";" "$(__r_${reporter}_docs)"
+    fi
   done
 }
\ No newline at end of file
diff --git a/lib/utils/loader.sh b/lib/utils/loader.sh
index 0264803..432cb52 100644
--- a/lib/utils/loader.sh
+++ b/lib/utils/loader.sh
@@ -1,10 +1,43 @@
 #!/bin/sh
 
+get_available_reporters () {
+  local result
+  for file in `ls ./reporters/*.sh $CUSTOM_REPORTERS_PATH/*.sh 2>/dev/null`; do
+    local filename=$(basename $file)
+    local reporter=${filename%.*}
+    result=$(echo "$result $reporter")
+  done
+  echo $result
+}
+
+get_available_metrics () {
+  local result
+  for file in `ls ./metrics/*.sh $CUSTOM_METRICS_PATH/*.sh  2>/dev/null`; do
+    local filename=$(basename $file)
+    local metric=${filename%.*}
+    # register metric
+    result=$(trim "$result $metric")
+  done
+  echo $result
+}
+
 load_reporter_with_prefix () {
   local prefix=$1
-  local file=$2
-  local content
+  local name=$2
 
+  local file
+  for dir in $CUSTOM_REPORTERS_PATH ./reporters; do
+    if [ -f $dir/$name.sh ]; then
+      file=$dir/$name.sh
+      break
+    fi
+  done
+
+  if [ -z $file ]; then
+    return 1
+  fi
+
+  local content
   content=$(sed \
           -e 's/^[[:space:]]*\(defaults[ ]*()[ ]*{\)/'"$prefix"'\1/' \
           -e 's/^[[:space:]]*\(start[ ]*()[ ]*{\)/'"$prefix"'\1/' \
@@ -17,10 +50,21 @@ load_reporter_with_prefix () {
 
 load_metric_with_prefix () {
   local prefix=$1
-  local file=$2
-  local content
+  local name=$2
 
-  # dash will error if this variable is defined as `local`
+  local file
+  for dir in $CUSTOM_METRICS_PATH ./metrics; do
+    if [ -f $dir/$name.sh ]; then
+      file=$dir/$name.sh
+      break
+    fi
+  done
+
+  if [ -z $file ]; then
+    return 1
+  fi
+
+  local content
   content=$(sed \
           -e 's/^[[:space:]]*\(defaults[ ]*()[ ]*{\)/'"$prefix"'\1/' \
           -e 's/^[[:space:]]*\(start[ ]*()[ ]*{\)/'"$prefix"'\1/' \
diff --git a/metrics/custom/.gitkeep b/metrics/custom/.gitkeep
new file mode 100644
index 0000000..e69de29
diff --git a/reporters/custom/.gitkeep b/reporters/custom/.gitkeep
new file mode 100644
index 0000000..e69de29