More robust shell script using getopts.

.gitignore

@@ -1,3 +1,4 @@
 data
 .idea
-*.bak
+*.bak
+deploy.sh

armv6-deploy.sh

@@ -1,26 +1,58 @@
 #!/bin/bash
+# shellcheck disable=SC2086
+# https://wiki.bash-hackers.org/howto/getopts_tutorial 🍻
+
+usage() {
+  echo "  -i install telelgraf on the remote machine"
+  echo "  -u username to use for ssh connection"
+  echo "  -t target host or ip address for ssh connection"
+  echo "  -r remote influx master node/hub ip address or hostname"
+}
+
+while getopts ":hiu:t:r:" opt; do
+  case $opt in
+    i ) INSTALL=1;;
+    t ) PI_HOST=$OPTARG;;
+    u ) PI_USER=$OPTARG;;
+    h ) usage; exit 0;;
+    r ) HUB_IP_OR_HOST=$OPTARG;;
+    \?)
+      echo "Invalid option: -$OPTARG" >&2
+      exit 1
+      ;;
+    :)
+      echo "Option -$OPTARG requires an argument. " >&2
+      exit 1
+      ;;
+  esac
+done
+
+if [ -z ${PI_HOST} ] && [ -z ${PI_USER} ]; then echo "neither host nor username is set" && exit 1; fi
+if [ -z ${PI_HOST} ] || [ -z ${PI_USER} ]; then echo "both host and username need to be set" && exit 1; fi
+if [ -z ${HUB_IP_OR_HOST} ]; then echo "you need to use the -r flag, see -h for more info" && exit 1; fi
+if [ -n "$INSTALL" ]; then echo "going to install telelgraf"; fi
 
-PI_USER=$1
-PI_HOST=$2
-HUB_IP_OR_HOST=$3
 PI_USER_AT_HOST="${PI_USER}@${PI_HOST}"
 
 scp armv6/telegraf.conf "${PI_USER_AT_HOST}:/home/${PI_USER}/telegraf.conf"
 
 ssh "${PI_USER_AT_HOST}" /bin/bash <<EOF
 
-#echo "initial install"
-#curl -sL https://repos.influxdata.com/influxdb.key | sudo apt-key add -
-#echo "deb https://repos.influxdata.com/debian buster stable" | sudo tee /etc/apt/sources.list.d/influxdb.list
-#sudo apt-get update && sudo apt-get install telegraf -y
-### comment out the next line if you do not run docker on this machine
-#sudo usermod -aG docker telegraf && echo 'usermod'
+if [ -n "$INSTALL" ];
+then
+  echo "initial install"
+  curl -sL https://repos.influxdata.com/influxdb.key | sudo apt-key add -
+  echo "deb https://repos.influxdata.com/debian buster stable" | sudo tee /etc/apt/sources.list.d/influxdb.list
+  sudo apt-get update && sudo apt-get install telegraf -y
+  ## comment out the next line if you do not run docker on this machine
+  sudo usermod -aG docker telegraf && echo 'usermod'
+fi
 
 echo "deployment"
 sudo systemctl stop telegraf && echo 'stop'
 cat /home/$PI_USER/telegraf.conf | sudo tee /etc/telegraf/telegraf.conf
 export INFLUX_URL="http://$HUB_IP_OR_HOST:8086"
-# remove variables are escaped, .e.g \$INFLUX_URL
+# remote variables are escaped, e.g. \$INFLUX_URL
 echo "INFLUX_URL=\"\$INFLUX_URL\"" | sudo tee /etc/default/telegraf
 
 sudo systemctl daemon-reload && echo 'reload'

configs/telegraf.conf

@@ -34,7 +34,6 @@
   # Configuration for sending metrics to InfluxDB
 [[outputs.influxdb]]
   ## The full HTTP or UDP URL for your InfluxDB instance.
-  #urls = ["http://192.168.0.28:8086"]
   urls = ["http://influxdb:8086"]
 
   ## The target database for metrics; will be created as needed.

readme.md

@@ -8,37 +8,44 @@ https://www.influxdata.com/time-series-platform/ for raspberry pi with docker.
   * running raspian
   * with [docker](https://docs.docker.com/engine/install/debian/#install-using-the-convenience-script) and [docker-compose](https://docs.docker.com/compose/install/) installed
 - (optional) some other Pi's to connect to the hub
-  * running raspian with ssh enables (to use automation scripts)
+  * running raspian with ssh enabled (to use automation scripts)
 
 ## Installing the Hub
 
 1. Log in to your Pi
 2. clone this repository and `cd` into it
 3. (optional) to have this Pi's hostname show up in metrics, run: `export TELEGRAF_HOST="$(hostname)"`
 4. (optional) `docker-compose config` to output the compose file with the actual env vars set.
-5. `docker-compose up`
+5. `docker-compose up` (to see logs) or `docker-compose up -d` to run detached/in background.
 
 Visit http://localhost:5000/sources/0/hosts if running locally, or 
-`http://<your-pi-hostname.local-or-ip>:5000/sources/0/hosts` to check your metrics are coming through.
+`http://<your-pi-hostname.local-or-ip>:5000/sources/0/hosts` to check your metrics are coming through for the "hub".
 
 ## Installing Telegraf on Nodes (Arm v6)
 
 The official telegraf image won't work on Arm v6 Pi's. 
 Instead, we need to install telegraf on the host with `apt`.
 
-There is a file ([armv6-deploy.sh](armv6/telegraf.conf)) included which can install telegraf on your pi and start it up with a
-config file, see [armv6/telegraf.conf](armv6/telegraf.conf). Run the file with three bits of info:
-* username
-* hostname or IP address of the pi you want to install telegraf on
-* the hostname or IP address of the pi (hub) which is running the TICK stack 
+There is a file ([armv6-deploy.sh](armv6-deploy.sh) included which can install telegraf on your pi and start it up with a
+config file, see [armv6/telegraf.conf](armv6/telegraf.conf).
 
-If you usually SSH into your pi like: `ssh pi@pi2.local` and the hub running the TICK stack is `192.168.0.2`, 
-then you'd run the script like this:
+```
+./armv6-deploy.sh -h
+  -i install telelgraf on the remote machine
+  -u username to use for ssh connection
+  -t target host or ip address for ssh connection
+  -r remote influx master node/hub ip address or hostname
+```
+
+If you usually SSH into your pi like: `ssh pi@pi2.local` and the hub running the TICK stack is `192.168.0.2`, **and** you
+want to install `telegraf`, then you'd run the script like this:
 
 ```
-./armv6-deploy.sh pi pi2.local 192.168.0.2
+./armv6-deploy.sh -i -u pi -t pi2.local -r 192.168.0.2
 ```
 
+Once you have installed telegraf on a given machine, you shouldn't use the `-i` flag again.
+
 Do look at the script and try to understand what it does before running it 😜
 
 ### TODO