structured main routines. implement file reporter

README.md

@@ -1,14 +1,12 @@
 ## TODO
 
-- [] README
-- [] option parsing
-- [] allow multiple reporters
-- [] implement log reporter
-- [] better docs, including reporters (--docs)
-- [] config file support
-- [] config file auto-generation
-- [] disk_io metric
-- [] load custom metrics
-- [] async metrics
-- [] extended metric labels?
-- [] same metric multiple times (e.g. disk_usage for multiple devices)
+- README
+- option parsing
+- allow multiple reporters
+- better docs, including reporters (--docs)
+- config file support
+- config file auto-generation
+- load custom metrics
+- async metrics
+- extended metric labels?
+- same metric multiple times (e.g. disk_usage for multiple devices)

lib/main.sh

@@ -0,0 +1,108 @@
+# load utils
+for util in ./lib/utils/*.sh; do source $util; done
+
+# init
+__METRICS=()
+__TEMP_DIR=$(make_temp_dir)
+
+# load reporter
+
+main_load () {
+  source ./reporters/${REPORTER}.sh
+  copy_function init      __r_${REPORTER}_init
+  copy_function report    __r_${REPORTER}_report
+  copy_function terminate __r_${REPORTER}_terminate
+  copy_function docs      __r_${REPORTER}_docs
+  unset -f init report terminate docs
+
+  # load metrics
+  for file in ./metrics/*.sh; do
+    filename=$(basename $file)
+    metric=${filename%.*}
+
+    # soruce file and copy functions
+    source $file
+    copy_function init      __m_${metric}_init
+    copy_function collect   __m_${metric}_collect
+    copy_function terminate __m_${metric}_terminate
+    copy_function docs      __m_${metric}_docs
+    unset -f init collect terminate docs
+
+    # register metric
+    __METRICS+=($metric)
+  done
+}
+
+main_init () {
+  # init reporter
+  if is_function __r_${REPORTER}_init; then
+    __r_${REPORTER}_init
+  fi
+
+  # init metrics
+  for metric in ${__METRICS[@]}; do
+    if ! is_function __m_${metric}_init; then
+      continue
+    fi
+
+    __m_${metric}_init
+  done
+}
+
+main_docs () {
+  echo "Available metrics:"
+  for metric in ${__METRICS[@]}; do
+    if ! is_function __m_${metric}_docs; then
+      continue
+    fi
+
+    echo "[$metric]"
+    __m_${metric}_docs
+    echo
+  done
+}
+
+main_collect () {
+  # used by metrics to return results
+  report () {
+    local _r_result
+    if [ -z $2 ]; then
+      _r_label=$metric
+      _r_result="$1"
+    else
+      _r_label="$metric.$1"
+      _r_result="$2"
+    fi
+    if is_number $_r_result; then
+      __r_${REPORTER}_report $_r_label $_r_result
+    fi
+  }
+
+  # collect metrics
+  while true; do
+    for metric in ${__METRICS[@]}; do
+      if ! is_function __m_${metric}_collect; then
+        continue
+      fi
+
+      __m_${metric}_collect
+    done
+
+    sleep $INTERVAL
+  done
+}
+
+main_terminate () {
+  # terminate metrics
+  for metric in ${__METRICS[@]}; do
+    if ! is_function __m_${metric}_terminate; then
+      continue
+    fi
+    __m_${metric}_terminate
+  done
+
+  # terminate reporter
+  if is_function __r_${REPORTER}_terminate; then
+    __r_${REPORTER}_terminate
+  fi
+}

lib/utils/helpers.sh

@@ -0,0 +1,7 @@
+is_number () {
+  [ ! -z "$1" ] && printf '%f' "$1" &>/dev/null
+}
+
+iso_date () {
+  date -u +"%Y-%m-%dT%H:%M:%SZ"
+}

lib/utils/os.sh

@@ -14,11 +14,13 @@ is_linux ()   { [ $OS_TYPE == 'solaris' ]; }
 is_bsd ()     { [ $OS_TYPE == 'bsd']; }
 is_unknown () { [ $OS_TYPE == 'unknown' ]; }
 
-
-make_temp_dir () {
-  if is_osx; then
+# http://unix.stackexchange.com/a/84980/50905
+if is_osx; then
+  make_temp_dir () {
     mktemp -d -t 'sysmetrics'
-  else
+  }
+else
+  make_temp_dir () {
     mktemp -d
-  fi
-}
+  }
+fi

metrics/disk_io.sh

@@ -1,12 +1,17 @@
 #!/bin/sh
 
-if [ -z $DISK_IO_MOUNTPOINT ]; then
-  if is_osx; then
-    DISK_IO_MOUNTPOINT="disk0"
-  else
-    DISK_IO_MOUNTPOINT="/dev/vda"
+init () {
+  if [ -z $DISK_IO_MOUNTPOINT ]; then
+    if is_osx; then
+      DISK_IO_MOUNTPOINT="disk0"
+    else
+      DISK_IO_MOUNTPOINT="/dev/vda"
+    fi
   fi
-fi
+  readonly __disk_io_fifo=$__TEMP_DIR/disk_io
+  mkfifo $__disk_io_fifo
+  __disk_io_bgproc &
+}
 
 if is_osx; then
   __disk_io_bgproc () {
@@ -20,19 +25,14 @@ else
   }
 fi
 
-__disk_io_fifo=$__TEMP_DIR/disk_io
-
-init () {
-  __disk_io_bgproc &
-  mkfifo $__disk_io_fifo
-}
-
 collect () {
   report $(cat $__disk_io_fifo)
 }
 
 terminate () {
-  rm $__disk_io_fifo
+  if [ ! -z $__disk_io_fifo ] && [ -f $__disk_io_fifo ]; then
+    rm $__disk_io_fifo
+  fi
 }
 
 docs () {

metrics/disk_usage.sh

@@ -1,12 +1,14 @@
 #!/bin/sh
 
-if [ -z $DISK_USAGE_MOUNTPOINT ]; then
-  if is_osx; then
-    DISK_USAGE_MOUNTPOINT="/dev/disk1"
-  else
-    DISK_USAGE_MOUNTPOINT="/dev/vda"
+init () {
+  if [ -z $DISK_USAGE_MOUNTPOINT ]; then
+    if is_osx; then
+      DISK_USAGE_MOUNTPOINT="/dev/disk1"
+    else
+      DISK_USAGE_MOUNTPOINT="/dev/vda"
+    fi
   fi
-fi
+}
 
 collect () {
   report $(df | awk -v disk_regexp="^$DISK_USAGE_MOUNTPOINT" \

metrics/memory.sh

@@ -1,7 +1,9 @@
 #!/bin/sh
 
 if is_osx; then
-  declare -r __memory_os_memsize=$(sysctl -n hw.memsize)
+  init () {
+    readonly __memory_os_memsize=$(sysctl -n hw.memsize)
+  }
 
   collect () {
     report $(vm_stat | awk -v total_memory=$__memory_os_memsize \

metrics/network_io.sh

@@ -1,19 +1,14 @@
 #!/bin/sh
 
-if [ -z $NETWORK_IO_INTERFACE ]; then
-  if is_osx; then
-    NETWORK_IO_INTERFACE="en0"
-  else
-    NETWORK_IO_INTERFACE="eth0"
+init () {
+  if [ -z $NETWORK_IO_INTERFACE ]; then
+    if is_osx; then
+      NETWORK_IO_INTERFACE="en0"
+    else
+      NETWORK_IO_INTERFACE="eth0"
+    fi
   fi
-fi
-
-declare -r __network_io_divisor=$[$INTERVAL * 1024]
-__network_io_sample=(0 0)
-
-__network_io_calc_kBps() {
-  echo $1 $2 | awk -v divisor=$__network_io_divisor \
-                '{printf "%.2f", ($1 - $2) / divisor}'
+  readonly __network_io_divisor=$[$INTERVAL * 1024]
 }
 
 if is_osx; then
@@ -28,9 +23,14 @@ else
   }
 fi
 
+__network_io_calc_kBps() {
+  echo $1 $2 | awk -v divisor=$__network_io_divisor \
+                '{printf "%.2f", ($1 - $2) / divisor}'
+}
+
 collect () {
   local sample=( $(__network_io_collect) )
-  if [ ${__network_io_sample[0]} -ne 0 ]; then
+  if [ ! -z $__network_io_sample ]; then
     report "in" $(__network_io_calc_kBps ${sample[0]} ${__network_io_sample[0]})
     report "out" $(__network_io_calc_kBps ${sample[1]} ${__network_io_sample[1]})
   fi

metrics/ping.sh

@@ -0,0 +1,9 @@
+#!/bin/sh
+
+collect () {
+  report 1
+}
+
+docs () {
+  echo "Send a simple ping in form of an integer '1'."
+}

reporters/file.sh

@@ -0,0 +1,24 @@
+#!/bin/sh
+
+report () {
+  local METRIC=$1
+  local VALUE=$2
+  local DATE=$(iso_date)
+  echo $DATE $METRIC: $VALUE >> $FILE_LOCATION
+}
+
+init () {
+  if [ -z $FILE_LOCATION ]; then
+    echo "Missing configuration: \$FILE_LOCATION"
+    return 1
+  fi
+
+  if [ ! -f $FILE_LOCATION ]; then
+    touch $FILE_LOCATION
+  fi
+}
+
+docs () {
+  echo "Write to a file or named pipe."
+  echo "\$FILE_LOCATION=$FILE_LOCATION"
+}

reporters/stathat.sh

@@ -3,7 +3,7 @@
 report () {
   METRIC=$1
   VALUE=$2
-  curl -d "stat=$METRIC&ezkey=$API_KEY&value=$VALUE" http://api.stathat.com/ez
+  curl -d "stat=$METRIC&ezkey=$STATHAT_API_KEY&value=$VALUE" http://api.stathat.com/ez
 }
 
 docs () {

sysmetricsd.sh

@@ -2,93 +2,16 @@
 
 # config
 INTERVAL=1
-REPORTER=stdout
-
-# load utils
-for util in ./lib/utils/*.sh; do source $util; done
-
-# init
-__METRICS=()
-__TEMP_DIR=$(make_temp_dir)
+REPORTER=file
 
 # register trap
 trap '
-  for metric in ${__METRICS[@]}; do
-    if ! is_function __m_${metric}_terminate; then
-      continue
-    fi
-    __m_${metric}_terminate
-  done
+  main_terminate
   trap - SIGTERM && kill -- -$$ SIGINT SIGTERM EXIT
 ' SIGINT SIGTERM EXIT
 
-# load reporter
-source ./reporters/${REPORTER}.sh
-copy_function init      __r_${REPORTER}_init
-copy_function report    __r_${REPORTER}_report
-copy_function terminate __r_${REPORTER}_terminate
-copy_function docs      __r_${REPORTER}_docs
-unset -f init report terminate docs
-
-# load metrics
-for file in ./metrics/*.sh; do
-  filename=$(basename $file)
-  metric=${filename%.*}
-
-  # soruce file and copy functions
-  source $file
-  copy_function init      __m_${metric}_init
-  copy_function collect   __m_${metric}_collect
-  copy_function terminate __m_${metric}_terminate
-  copy_function docs      __m_${metric}_docs
-  unset -f init collect terminate docs
-
-  # register metric
-  __METRICS+=($metric)
-done
-
-# init metrics
-for metric in ${__METRICS[@]}; do
-  if ! is_function __m_${metric}_init; then
-    continue
-  fi
-
-  __m_${metric}_init
-done
-
-# print docs for metrics
-echo "Available metrics:"
-for metric in ${__METRICS[@]}; do
-  if ! is_function __m_${metric}_docs; then
-    continue
-  fi
-
-  echo "[$metric]"
-  __m_${metric}_docs
-  echo
-done
-
-report () {
-  local result
-  if [ -z $2 ]; then
-    label=$metric
-    result="$1"
-  else
-    label="$metric.$1"
-    result="$2"
-  fi
-  __r_${REPORTER}_report $label $result
-}
-
-# collect metrics
-while true; do
-  for metric in ${__METRICS[@]}; do
-    if ! is_function __m_${metric}_collect; then
-      continue
-    fi
-
-    __m_${metric}_collect
-  done
-
-  sleep $INTERVAL
-done
+# load and start main routine
+source ./lib/main.sh
+main_load
+main_init
+main_collect