add defaults() fn. add --print-config. config loader now fails on error

README.md

@@ -55,6 +55,6 @@ TODO: how to write custom reporters
 
 - README
 - config file docs
-- config file auto-generation
 - load custom/contrib metrics and reporters
+- enable -m <alias> / -r <alias>
 - allow multiple reporters?

lib/main.sh

@@ -9,7 +9,22 @@ done
 __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
+  fi
+  if [ -z $REPORTER ]; then
+    REPORTER=stdout
+  fi
+}
+
 main_load () {
+  # set defaults
+  main_defaults
+
   # load reporter
   for file in ./reporters/*.sh; do
     local filename=$(basename $file)
@@ -54,11 +69,14 @@ main_init () {
   done
 
   # init reporter
+  if is_function __r_${__REPORTER}_defaults; then
+    __r_${__REPORTER}_defaults
+  fi
   if is_function __r_${__REPORTER}_config; then
     __r_${__REPORTER}_config
   fi
-  if is_function __r_${__REPORTER}_init; then
+  if is_function __r_${__REPORTER}_start; then
-    __r_${__REPORTER}_init
+    __r_${__REPORTER}_start
   fi
 }
 
@@ -77,6 +95,35 @@ main_collect () {
     (
       local metric_name=$(get_name $metric)
       local metric_alias=$(get_alias $metric)
+
+      # init metric
+      load_metric_with_prefix __m_${metric_alias}_ ./metrics/${metric_name}.sh
+
+      if is_function __m_${metric_alias}_defaults; then
+        __m_${metric_alias}_defaults
+      fi
+
+      if is_function __m_${metric_alias}_config; then
+        __m_${metric_alias}_config
+      fi
+
+      if is_function __m_${metric_alias}_start; then
+        __m_${metric_alias}_start
+      fi
+
+      if ! is_function __m_${metric_alias}_collect; then
+        continue
+      fi
+
+      # collect metrics
+      trap "
+        verbose \"Stopping metric '${metric_alias}'\"
+        if is_function __m_${metric_alias}_stop; then
+          __m_${metric_alias}_stop
+        fi
+        exit 0
+      " 13
+
       # used by metrics to return results
       report () {
         local _r_label _r_result
@@ -92,30 +139,6 @@ main_collect () {
         fi
       }
 
-      # init metric
-      if is_function __m_${metric_alias}_config; then
-        __m_${metric_alias}_config
-      fi
-
-      load_metric_with_prefix __m_${metric_alias}_ ./metrics/${metric_name}.sh
-
-      if is_function __m_${metric_alias}_init; then
-        __m_${metric_alias}_init
-      fi
-
-      if ! is_function __m_${metric_alias}_collect; then
-        continue
-      fi
-
-      # collect metrics
-      trap "
-        if is_function __m_${metric_alias}_terminate; then
-          verbose 'Stopping metric ${metric_alias}'
-          __m_${metric_alias}_terminate
-        fi
-        exit 0
-      " 13
-
       while true; do
         __m_${metric_alias}_collect
         sleep $INTERVAL
@@ -132,13 +155,13 @@ main_collect () {
 }
 
 main_terminate () {
-  # terminate reporter
+  # stop reporter
-  if is_function __r_${__REPORTER}_terminate; then
+  verbose "Stopping reporter '${__REPORTER}'"
-    verbose "Stopping reporter ${__REPORTER}"
+  if is_function __r_${__REPORTER}_stop; then
-    __r_${__REPORTER}_terminate
+    __r_${__REPORTER}_stop
   fi
 
-  verbose -n "Cleaning up..."
+  verbose "Cleaning up..."
   # delete temporary directory
   if [ -d $TEMP_DIR ]; then
     rmdir $TEMP_DIR
@@ -146,8 +169,8 @@ main_terminate () {
   verbose "done"
 }
 
-main_docs () {
+main_print_docs () {
-  echo "# Metrics"
+  echo "# METRICS"
 
   for metric in $__AVAILABLE_METRICS; do
     load_metric_with_prefix __m_${metric}_ ./metrics/${metric}.sh
@@ -156,6 +179,10 @@ main_docs () {
       continue
     fi
 
+    if is_function __m_${metric}_defaults; then
+      __m_${metric}_defaults
+    fi
+
     echo
     echo "[$metric]"
     __m_${metric}_docs
@@ -168,8 +195,48 @@ main_docs () {
       continue
     fi
 
+    if is_function __r_${reporter}_defaults; then
+      __r_${reporter}_defaults
+    fi
+
     echo
     echo "[$reporter]"
     __r_${reporter}_docs
   done
 }
+
+main_print_config () {
+  echo "[metrics.sh]"
+  echo ";INTERVAL=$INTERVAL"
+  echo ";METRICS=$METRICS"
+  echo ";REPORTER=$REPORTER"
+
+  for metric in $__AVAILABLE_METRICS; do
+    load_metric_with_prefix __m_${metric}_ ./metrics/${metric}.sh
+
+    if is_function __m_${metric}_defaults; then
+      __m_${metric}_defaults
+    fi
+
+    echo
+    echo ";[metric $metric]"
+    if ! is_function __m_${metric}_docs; then
+      continue
+    fi
+    print_prefixed ";" "$(__m_${metric}_docs)"
+  done
+
+  for reporter in $__AVAILABLE_REPORTERS; do
+    if ! is_function __r_${reporter}_docs; then
+      continue
+    fi
+
+    if is_function __r_${reporter}_defaults; then
+      __r_${reporter}_defaults
+    fi
+
+    echo
+    echo ";[reporter $reporter]"
+    print_prefixed ";" "$(__r_${reporter}_docs)"
+  done
+}

lib/utils/config.sh

@@ -48,8 +48,13 @@ parse_config () {
       return
     fi
 
-    #echo "${fn_name}_config () { ${_body}; }"
+    if ! eval "$_body" > /dev/null 2>&1; then
-    eval "${fn_name}_config () { ${_body}; }"
+      echo "Error parsing config section: $_name: $_body"
+      exit 1
+    fi
+
+    #echo "${fn_name}_config () { $_body; }"
+    eval "${fn_name}_config () { $_body; }"
   }
 
   for line in $(cat $1); do

lib/utils/helpers.sh

@@ -9,8 +9,6 @@ iso_date () {
 }
 
 in_array () {
-  local item=$1
-  local arr=$2
   echo " $2 " | grep -q " $1 "
 }
 
@@ -24,3 +22,7 @@ unique_id () {
   echo __u_$(cat /dev/urandom | tr -dc 'A-Za-z0-9' | head -c 10)
   LC_ALL=$RESTORE_LC_ALL
 }
+
+print_prefixed () {
+  printf "$2" | sed -e "s/^/$1/g"
+}

lib/utils/loader.sh

@@ -6,9 +6,10 @@ load_reporter_with_prefix () {
   local content
 
   content=$(sed \
-          -e 's/^[[:space:]]*\(init[ ]*()[ ]*{\)/'"$prefix"'\1/' \
+          -e 's/^[[:space:]]*\(defaults[ ]*()[ ]*{\)/'"$prefix"'\1/' \
+          -e 's/^[[:space:]]*\(start[ ]*()[ ]*{\)/'"$prefix"'\1/' \
           -e 's/^[[:space:]]*\(report[ ]*()[ ]*{\)/'"$prefix"'\1/' \
-          -e 's/^[[:space:]]*\(terminate[ ]*()[ ]*{\)/'"$prefix"'\1/' \
+          -e 's/^[[:space:]]*\(stop[ ]*()[ ]*{\)/'"$prefix"'\1/' \
           -e 's/^[[:space:]]*\(docs[ ]*()[ ]*{\)/'"$prefix"'\1/' $file)
 
   eval "$content"
@@ -21,9 +22,10 @@ load_metric_with_prefix () {
 
   # dash will error if this variable is defined as `local`
   content=$(sed \
-          -e 's/^[[:space:]]*\(init[ ]*()[ ]*{\)/'"$prefix"'\1/' \
+          -e 's/^[[:space:]]*\(defaults[ ]*()[ ]*{\)/'"$prefix"'\1/' \
+          -e 's/^[[:space:]]*\(start[ ]*()[ ]*{\)/'"$prefix"'\1/' \
           -e 's/^[[:space:]]*\(collect[ ]*()[ ]*{\)/'"$prefix"'\1/' \
-          -e 's/^[[:space:]]*\(terminate[ ]*()[ ]*{\)/'"$prefix"'\1/' \
+          -e 's/^[[:space:]]*\(stop[ ]*()[ ]*{\)/'"$prefix"'\1/' \
           -e 's/^[[:space:]]*\(docs[ ]*()[ ]*{\)/'"$prefix"'\1/' $file)
 
   eval "$content"

metrics.sh

@@ -1,18 +1,12 @@
 #!/bin/sh
 
-# config
-INTERVAL=2
-REPORTER=stdout
-METRICS=cpu,disk_io,disk_usage,heartbeat,memory,network_io,swap
-CONFIG_FILE=
-
 # env
 LC_ALL=en_US.UTF-8
 LANG=en_US.UTF-8
 LANGUAGE=en_US.UTF-8
 
 usage () {
-  echo "  Usage: $0 [-d] [-h] [-v] [-c] [-m] [-r] [-i]"
+  echo "  Usage: $0 [-d] [-h] [-v] [-c] [-m] [-r] [-i] [-C]"
 }
 
 help () {
@@ -27,34 +21,40 @@ help () {
   echo "    -i, --interval <seconds>   collect metrics every n seconds (default: 2)"
   echo "    -v, --verbose              enable verbose mode"
   echo "    -d, --docs                 show documentation"
+  echo "    -C, --print-config         print output to be used in a config file"
   echo "    -h, --help                 show this text"
   echo
 }
 
 # handle opts
+opt_config_file=
+opt_metrics=
+opt_reporter=
+opt_interval=
 opt_docs=false
 opt_verbose=false
+opt_print_config=false
 
 while [ $# -gt 0 ]; do
   case $1 in
     -c|--config)
       shift
-      CONFIG_FILE=$1
+      opt_config_file=$1
       ;;
 
     -m|--metrics)
       shift
-      METRICS=$1
+      opt_metrics=$1
       ;;
 
     -r|--reporter)
       shift
-      REPORTER=$1
+      opt_reporter=$1
       ;;
 
     -i|--interval)
       shift
-      INTERVAL=$1
+      opt_interval=$1
       ;;
 
     -v|-verbose)
@@ -65,6 +65,10 @@ while [ $# -gt 0 ]; do
       opt_docs=true
       ;;
 
+    -C|--print-config)
+      opt_print_config=true
+      ;;
+
     -h|--help)
       help
       exit
@@ -85,29 +89,30 @@ done
 if [ $opt_verbose = true ]; then
   verbose_on
   verbose "Started in verbose mode"
-fi
   verbose "PID: $$"
   verbose "OS detected: $OS_TYPE"
+fi
 
 main_load
 verbose "Available metrics: $__AVAILABLE_METRICS"
 verbose "Available reporters: $__AVAILABLE_REPORTERS"
 
 if [ $opt_docs = true ]; then
-  main_docs
+  main_print_docs
   exit
 fi
 
-if [ -n "$CONFIG_FILE" ]; then
+if [ $opt_print_config = true ]; then
-  verbose "Loading configuration file: $CONFIG_FILE"
+  main_print_config
-
+  exit
-  parse_config $CONFIG_FILE
-  if [ $? -ne 0 ]; then
-    exit 1
 fi
 
-  if is_function main_config; then
+if [ -n "$opt_config_file" ]; then
-    main_config
+  verbose "Loading configuration file: $opt_config_file"
+
+  parse_config $opt_config_file
+  if [ $? -ne 0 ]; then
+    exit 1
   fi
 
   configured_reporters=$(get_configured_reporters)
@@ -121,6 +126,21 @@ if [ -n "$CONFIG_FILE" ]; then
   fi
 fi
 
+# --reporter always wins
+if [ -n "$opt_reporter" ]; then
+  REPORTER=$opt_reporter
+fi
+
+# --metrics always wins
+if [ -n "$opt_metrics" ]; then
+  METRICS=$opt_metrics
+fi
+
+# --interval always wins
+if [ -n "$opt_interval" ]; then
+  INTERVAL=$opt_interval
+fi
+
 main_init "$METRICS" "$REPORTER"
 verbose "Using metrics: $__METRICS"
 verbose "Using reporter: $__REPORTER"

metrics/disk_io.sh

@@ -1,6 +1,6 @@
 #!/bin/sh
 
-init () {
+defaults () {
   if [ -z $DISK_IO_MOUNTPOINT ]; then
     if is_osx; then
       DISK_IO_MOUNTPOINT="disk0"
@@ -8,10 +8,11 @@ init () {
       DISK_IO_MOUNTPOINT="/dev/vda"
     fi
   fi
+}
+
+start () {
   readonly __disk_io_fifo=$TEMP_DIR/$(unique_id)
   mkfifo $__disk_io_fifo
-  __disk_io_bgproc &
-}
 
   if is_osx; then
     __disk_io_bgproc () {
@@ -27,11 +28,14 @@ else
     }
   fi
 
+  __disk_io_bgproc &
+}
+
 collect () {
   report $(cat $__disk_io_fifo)
 }
 
-terminate () {
+stop () {
   if [ ! -z $__disk_io_fifo ] && [ -p $__disk_io_fifo ]; then
     rm $__disk_io_fifo
   fi
@@ -39,5 +43,5 @@ terminate () {
 
 docs () {
   echo "Disk I/O in MB/s."
-  echo "\$DISK_IO_MOUNTPOINT="
+  echo "DISK_IO_MOUNTPOINT=$DISK_IO_MOUNTPOINT"
 }

metrics/disk_usage.sh

@@ -1,6 +1,6 @@
 #!/bin/sh
 
-init () {
+defaults () {
   if [ -z $DISK_USAGE_MOUNTPOINT ]; then
     if is_osx; then
       DISK_USAGE_MOUNTPOINT="/dev/disk1"
@@ -17,5 +17,5 @@ collect () {
 
 docs () {
   echo "Disk usage percentage for a file system at a given mount point."
-  echo "\$DISK_USAGE_MOUNTPOINT="
+  echo "DISK_USAGE_MOUNTPOINT=$DISK_USAGE_MOUNTPOINT"
 }

metrics/memory.sh

@@ -1,7 +1,7 @@
 #!/bin/sh
 
 if is_osx; then
-  init () {
+  start () {
     readonly __memory_os_memsize=$(sysctl -n hw.memsize)
   }
 

metrics/network_io.sh

@@ -1,6 +1,6 @@
 #!/bin/sh
 
-init () {
+defaults () {
   if [ -z $NETWORK_IO_INTERFACE ]; then
     if is_osx; then
       NETWORK_IO_INTERFACE="en0"
@@ -8,32 +8,35 @@ init () {
       NETWORK_IO_INTERFACE="eth0"
     fi
   fi
-  readonly __network_io_divisor=$(($INTERVAL * 1024))
 }
 
+start () {
+  readonly __network_io_divisor=$(($INTERVAL * 1024))
+
   if is_osx; then
-  __network_io_collect () {
+    get_netstat () {
       netstat -b -I $NETWORK_IO_INTERFACE | awk '{ print $7" "$10 }' | tail -n 1
     }
   else
-  __network_io_collect () {
+    get_netstat () {
       cat /proc/net/dev | awk -v iface_regex="$NETWORK_IO_INTERFACE:" \
                                       '$0 ~ iface_regex { print $2" "$10 }'
     }
   fi
 
-__network_io_calc_kBps() {
+  calc_kBps() {
     echo $1 $2 | awk -v divisor=$__network_io_divisor \
                 '{ printf "%.2f", ($1 - $2) / divisor }'
   }
+}
 
 collect () {
   local sample
-  sample=$(__network_io_collect)
+  sample=$(get_netstat)
   if [ ! -z "$__network_io_sample" ]; then
-    report "in" $(__network_io_calc_kBps $(echo $sample | awk '{print $1}') \
+    report "in" $(calc_kBps $(echo $sample | awk '{print $1}') \
                                 $(echo $__network_io_sample | awk '{print $1}'))
-    report "out" $(__network_io_calc_kBps $(echo $sample | awk '{print $2}') \
+    report "out" $(calc_kBps $(echo $sample | awk '{print $2}') \
                                 $(echo $__network_io_sample | awk '{print $2}'))
   fi
   __network_io_sample="$sample"
@@ -41,5 +44,5 @@ collect () {
 
 docs () {
   echo "Network traffic in kB/s."
-  echo "\$NETWORK_IO_INTERFACE="
+  echo "NETWORK_IO_INTERFACE=$NETWORK_IO_INTERFACE"
 }

metrics/ping.sh

@@ -1,6 +1,6 @@
 #!/bin/sh
 
-init () {
+start () {
   if [ -z $PING_REMOTE_HOST ]; then
     echo "Error: ping metric requires \$PING_REMOTE_HOST to be specified"
     exit 1
@@ -19,5 +19,5 @@ collect () {
 docs () {
   echo "Check if remote host is reachable by sending a single ping."
   echo "Reports '1' if ping was successful, '0' if not."
-  echo "\$PING_REMOTE_HOST="
+  echo "PING_REMOTE_HOST=$PING_REMOTE_HOST"
 }

reporters/file.sh

@@ -1,6 +1,6 @@
 #!/bin/sh
 
-init () {
+start () {
   if [ -z $FILE_LOCATION ]; then
     echo "Error: file reporter requires \$FILE_LOCATION to be specified"
     exit 1
@@ -20,5 +20,5 @@ report () {
 
 docs () {
   echo "Write to a file or named pipe."
-  echo "\$FILE_LOCATION="
+  echo "FILE_LOCATION=$FILE_LOCATION"
 }

reporters/influxdb.sh

@@ -1,15 +1,17 @@
 #!/bin/sh
 
-init () {
+defaults () {
+  if [ -z $INFLUXDB_SEND_HOSTNAME ]; then
+    INFLUXDB_SEND_HOSTNAME=true
+  fi
+}
+
+start () {
   if [ -z $INFLUXDB_API_ENDPOINT ]; then
     echo "Error: influxdb requires \$INFLUXDB_API_ENDPOINT to be specified"
     exit 1
   fi
 
-  if [ -z $INFLUXDB_SEND_HOSTNAME ]; then
-    INFLUXDB_SEND_HOSTNAME=true
-  fi
-
   if [ "$INFLUXDB_SEND_HOSTNAME" = true ]; then
     __influxdb_columns="[\"value\",\"host\"]"
     __influxdb_hostname=$(hostname)
@@ -34,6 +36,6 @@ report () {
 
 docs () {
   echo "Send data to InfluxDB."
-  echo "\$INFLUXDB_API_ENDPOINT="
+  echo "INFLUXDB_API_ENDPOINT=$INFLUXDB_API_ENDPOINT"
-  echo "\$INFLUXDB_SEND_HOSTNAME=true"
+  echo "INFLUXDB_SEND_HOSTNAME=$INFLUXDB_SEND_HOSTNAME"
 }

reporters/keen_io.sh

@@ -1,6 +1,12 @@
 #!/bin/sh
 
-init() {
+defaults () {
+  if [ -z $KEEN_IO_EVENT_COLLECTION ]; then
+    KEEN_IO_EVENT_COLLECTION=$(hostname)
+  fi
+}
+
+start() {
   if [ -z $KEEN_IO_PROJECT_ID ]; then
     echo "Error: keen_io requires \$KEEN_IO_PROJECT_ID to be specified"
     exit 1
@@ -11,10 +17,6 @@ init() {
     exit 1
   fi
 
-  if [ -z $KEEN_IO_EVENT_COLLECTION ]; then
-    KEEN_IO_EVENT_COLLECTION=$(hostname)
-  fi
-
   __keen_io_api_url="https://api.keen.io/3.0"
   __keen_io_api_url="$__keen_io_api_url/projects/$KEEN_IO_PROJECT_ID"
   __keen_io_api_url="$__keen_io_api_url/events/$KEEN_IO_EVENT_COLLECTION"
@@ -31,7 +33,7 @@ report () {
 
 docs () {
   echo "Send data to Keen IO (https://keen.io)."
-  echo "\$KEEN_IO_WRITE_KEY=<write_key>"
+  echo "KEEN_IO_WRITE_KEY=$KEEN_IO_WRITE_KEY"
-  echo "\$KEEN_IO_PROJECT_ID=<project_id>"
+  echo "KEEN_IO_PROJECT_ID=$KEEN_IO_PROJECT_ID"
-  echo "\$KEEN_IO_EVENT_COLLECTION=$(hostname)"
+  echo "KEEN_IO_EVENT_COLLECTION=$KEEN_IO_EVENT_COLLECTION"
 }

reporters/stathat.sh

@@ -1,6 +1,6 @@
 #!/bin/sh
 
-init () {
+start () {
   if [ -z $STATHAT_API_KEY ]; then
     echo "Error: stathat requires \$STATHAT_API_KEY to be specified"
     exit 1
@@ -17,5 +17,5 @@ report () {
 
 docs () {
   echo "Send data to StatHat (https://www.stathat.com)."
-  echo "\$STATHAT_API_KEY=<ez_key>"
+  echo "STATHAT_API_KEY=$STATHAT_API_KEY"
 }

reporters/stdout.sh

@@ -8,5 +8,5 @@ report () {
 }
 
 docs () {
-  echo "Print to standard output (e.g. the TTY you're running the script in)"
+  echo "Print to standard output, e.g. the TTY you're running the script in."
 }