Tag: curl

  • Get OctoPrint Status via Bash

    Get OctoPrint Status via Bash

    I’m working on a module to add OctoPrint status to my zsh prompt, which I’ll probably write about in the future as a bigger post about my prompt customizations.

    To start with that though, I need to play around with accessing the API via curl.

    So here’s my super alpha version that will request the current status via HTTP and output it:

    #!/bin/bash
    
    OCTOPRINT_API="hunter2"
    BASE_URL="http://octoprint.example.com"
    JOB_ENDPOINT="${BASE_URL}/api/job"
    CURL_TIMEOUT="0.5"
    
    # Fetch the JSON from OctoPrint
    response="$(curl --max-time ${CURL_TIMEOUT} --silent --fail \
      --header "X-Api-Key: ${OCTOPRINT_API}" \
      "${JOB_ENDPOINT}")"
    
    # Extract fields with jq
    file_name=$(jq -r '.job.file.display' <<< "$response")
    completion=$(jq -r '.progress.completion' <<< "$response")
    state=$(jq -r '.state' <<< "$response")
    time_elapsed=$(jq -r '.progress.printTime' <<< "$response")
    time_left=$(jq -r '.progress.printTimeLeft' <<< "$response")
    
    # Round the completion percentage to two decimals
    completion_str=$(printf "%.2f" "$completion")
    
    # Convert seconds to H:MM:SS
    function fmt_time() {
      local total_seconds="$1"
      local hours=$((total_seconds / 3600))
      local minutes=$(((total_seconds % 3600) / 60))
      local seconds=$((total_seconds % 60))
      printf "%02d:%02d:%02d" "$hours" "$minutes" "$seconds"
    }
    
    # Convert the times
    time_elapsed_str=$(fmt_time "$time_elapsed")
    time_left_str=$(fmt_time "$time_left")
    
    # Print a readable summary
    echo "File: ${file_name}"
    echo "State: ${state}"
    echo "Completion: ${completion_str}%"
    echo "Time Elapsed: ${time_elapsed_str}"
    echo "Time Left: ${time_left_str}"
    Code language: Bash (bash)

    Do with this what you will.

  • Bash Script: Calculate before/after 2: Calculate Harder

    Bash Script: Calculate before/after 2: Calculate Harder

    As an update, or an evolution of my earlier script that did some simple math for me, I’ve made one that will full-on test a URL while I’m making changes to see what the impact performance is of my updates.

    $ abtesturl.sh --url=https://example.com/ --count=10
    Press any key to run initial tests...
    Initial average TTFB: 3.538 seconds
    Press any key to re-run tests...
    
    Running second test...
    Second average TTFB: 1.975 seconds
    Before TTFB: 3.538 seconds
    After TTFB: 1.975 seconds
    Change in TTFB: -1.563 seconds
    Percentage Change: -44.00%Code language: JavaScript (javascript)

    It makes it much simpler to gather data to write reports or figure out of a change is worth the effort.

    Well, that’s about it so here’s the script:

    #!/bin/bash
    
    function show_usage() {
    	echo "Usage: $0 --url=<URL> [--count=<number of requests>]"
    	echo "  --url        Specifies the URL to test."
    	echo "  --count      Optional. Specifies the number of requests to send. Default is 6."
    	echo
    	echo "Example: $0 --url=https://example.com/ --count=5"
    	exit
    }
    
    function average_ttfb() {
    	local URL=""
    	local COUNT=6 # Default COUNT to 6 if not supplied
    	local CURL_OPTS="-s"
    
    	# Parse arguments
    	for arg in "$@"; do
    		case $arg in
    			--url=*)
    			URL="${arg#*=}"
    			shift # Remove argument from processing
    			;;
    		--count=*)
    			COUNT="${arg#*=}"
    			shift # Remove argument from processing
    			;;
    		*)
    			# Unknown option
    			;;
    		esac
    	done
    
    	if [[ -z "$URL" ]]; then
    		exit 1
    	fi
    
    	local total_time=0
    	local count_success=0
    
    	for ((i=1; i<=COUNT; i++))
    	do
    		# Perform the curl command, extracting the time to first byte
    		ttfb=$(curl $CURL_OPTS -o /dev/null -w "%{time_starttransfer}\n" $URL)
    		
    		# Check if the curl command was successful
    		if [ $? -eq 0 ]; then
    			total_time=$(echo "$total_time + $ttfb" | bc)
    			((count_success++))
    		else
    			echo "Request $i failed." >&2
    		fi
    	done
    
    	if [ $count_success -eq 0 ]; then
    		echo "All requests failed." >&2
    		return 1
    	fi
    
    	# Calculate the average TTFB
    	average_time=$(echo "scale=3; $total_time / $count_success" | bc)
    	echo $average_time # This line now simply outputs the average time
    }
    
    function ab_test_ttfb() {
    	# Run initial test
    	read -p "Press any key to run initial tests..." -n 1 -r
    	initial_ttfb=$(set -e; average_ttfb "$@"; set +e)
    	echo "Initial average TTFB: $initial_ttfb seconds"
    	
    	# Wait for user input to proceed
    	read -p "Press any key to re-run tests..." -n 1 -r
    	echo # Move to a new line
    
    	# Run second test
    	echo "Running second test..."
    	second_ttfb=$(average_ttfb "$@")
    	echo "Second average TTFB: $second_ttfb seconds"
    
    	# Calculate and output the difference and percentage change
    	difference=$(echo "$second_ttfb - $initial_ttfb" | bc)
    	percent_change=$(echo "scale=2; ($difference / $initial_ttfb) * 100" | bc)
    
    	echo "Before TTFB: $initial_ttfb seconds"
    	echo "After TTFB: $second_ttfb seconds"
    	echo "Change in TTFB: $difference seconds"
    	echo "Percentage Change: $percent_change%"
    }
    
    # Check if help is requested or no arguments are provided
    if [[ " $* " == *" --help "* ]] || [[ "$#" -eq 0 ]]; then
    	show_usage
    fi
    
    # Check if --url is in the arguments
    url_present=false
    for arg in "$@"; do
    	if [[ $arg == --url=* ]]; then
    		url_present=true
    		break
    	fi
    done
    
    if [ "$url_present" = false ]; then
    	echo "Error: --url argument is required."
    	show_usage
    fi
    
    ab_test_ttfb "$@"Code language: Bash (bash)

    Don’t break anything!

  • Sending Prowl Alerts via Bash

    Sending Prowl Alerts via Bash

    I’m working on some server scripting and I wanted to find a way to make sure I get proper alerts. I tried hard getting Twilio working cheaply, but that failed. So I remembered that I use Prowl for other things on my phone–so why not just send more alerts that way?

    So, again with the help of ChatGPT I have made a terrible monstrosity:

    #!/bin/bash
    
    # Exit if any command fails, if an unset variable is used, or if a command in a pipeline fails
    set -euo pipefail
    
    # Default values
    application="Shell Notification"
    priority=0
    event="Event"
    message=""
    logfile="/var/log/send-prowl-alert.log"
    url=""
    
    # Usage information
    usage() {
        echo "Usage: $0 --message=<message> [--application=<application>] [--event=<event>] [--description=<description>] [--priority=<priority>] [--url=<url>]"
        echo "Required:"
        echo "  --message=<message>       A description of the event, generally terse"
        echo "                            Maximum of 10000 bytes"
        echo "Optional:"
        echo "  --application=<application>  The name of the application (default: 'Shell Notification')"
        echo "                               Maximum of 256 bytes"
        echo "  --event=<event>              The name of the event or subject of the notification (default: 'Event')"
        echo "                               Maximum of 1024 bytes"
        echo "  --priority=<priority>        The priority of the alert (default: 0)"
        echo "                               An integer value ranging [-2, 2] representing:"
        echo "                                   -2 Very Low"
        echo "                                   -1 Moderate"
        echo "                                    0 Normal"
        echo "                                    1 High"
        echo "                                    2 Emergency"
        echo "                               Emergency priority messages may bypass quiet hours according to the user's settings."
        echo "  --url=<url>                  The URL which should be attached to the notification"
        echo "                               Maximum of 512 bytes"
        echo "  --help                       Displays this help message"
    }
    
    # URL Encodes a string
    urlencode() {
      local string="$1"
      local length="${#string}"
      local i
    
      for ((i = 0; i < length; i++)); do
        local c="${string:i:1}"
        case $c in
          [a-zA-Z0-9.~_-])
            printf '%s' "$c"
            ;;
          *)
            printf '%%%02X' "'$c"
            ;;
        esac
      done
    }
    
    # Check if the script is being run manually or via cron
    if [[ -t 1 ]]; then
        # Output to console if being run manually
        log_message() { echo "[$(date '+%Y-%m-%d %H:%M:%S')] $*"; }
    else
        # Output to log file if being run via cron
        log_message() {
            echo "[$(date '+%Y-%m-%d %H:%M:%S')] $*" >> "${logfile}"
            # Truncate the log file to 1 megabyte
            if [[ $(wc -c <"${logfile}") -gt 1000000 ]]; then
                tail -c 1000000 "${logfile}" > "${logfile}.tmp" && mv "${logfile}.tmp" "${logfile}"
            fi
        }
    fi
    
    # Parse arguments
    for arg in "$@"; do
        case "${arg}" in
            --message=*)
                message=${arg#*=}
                ;;
            --application=*)
                application=${arg#*=}
                ;;
            --event=*)
                event=${arg#*=}
                ;;
            --priority=*)
                priority=${arg#*=}
                ;;
            --url=*)
                url=${arg#*=}
                ;;
            --help)
                usage
                exit 0
                ;;
            *)
                echo "Error: Unsupported argument ${arg}"
                usage
                exit 1
                ;;
        esac
    done
    
    
    # Create a variable to store error messages
    errors=""
    
    # Check if curl is installed
    if ! command -v curl &> /dev/null; then
        errors+="Error: curl is not installed. Please install curl and try again.\n"
    fi
    
    # Check that a message was provided
    if [[ -z "${message}" ]]; then
        errors+="Error: No message provided."
    fi
    
    # Check if the URL is valid
    if [[ -n $url && ! $url =~ ^(https?://)[^\s/$.?#].[^\s]*$ ]]; then
        errors+="Error: Invalid URL.\n"
    fi
    
    # Check byte size of the parameters and append error if they exceed the max limit
    if [[ "${#url}" -gt 512 ]]; then
        errors+="Error: URL exceeds maximum byte limit (512 bytes).\n"
    fi
    
    if [[ "${#application}" -gt 256 ]]; then
        errors+="Error: Application name exceeds maximum byte limit (256 bytes).\n"
    fi
    
    if [[ "${#event}" -gt 1024 ]]; then
        errors+="Error: Event name exceeds maximum byte limit (1024 bytes).\n"
    fi
    
    if [[ "${#message}" -gt 10000 ]]; then
        errors+="Error: Message exceeds maximum length (10000 bytes).\n"
    fi
    
    if [[ ! "${priority}" =~ ^-?[0-2]$ ]]; then
        errors+="Error: Invalid priority. Must be an integer between -2 and 2.\n"
    fi
    
    # Check if the API key file exists and is not empty
    if [[ ! -s ~/.prowl_api_key ]]; then
        errors+="Error: The Prowl API key file does not exist or is empty. Please create a file at ~/.prowl_api_key and add your API key to it.\nExample:\n  echo 'your_api_key' > ~/.prowl_api_key\n  chmod 600 ~/.prowl_api_key\n"
    fi
    
    # Check the permissions on the API key file, if it exists
    # We have to do it in a convoluted cross platform way because macos does not support `stat -c`
    if [[ -f ~/.prowl_api_key ]]; then
        # Retrieve the file permissions and remove any trailing '@' symbol (indicating extended attributes)
        permissions=$(ls -l -d ~/.prowl_api_key | awk '{print $1}' | tr -d '@')
    
        # Check if the permissions are not set to '-rw-------'
        if [[ "$permissions" != "-rw-------" ]]; then
            # Add an error message to the 'errors' variable
            errors+="Error: The permissions on the API key file are not set correctly. Please run 'chmod 600 ~/.prowl_api_key' and try again.\n"
        fi
    fi
    
    # If any errors were detected, print the error messages and exit
    if [[ -n $errors ]]; then
        echo -e "${errors}"  # -e enables interpretation of backslash escapes like \n
        exit 1
    fi
    
    # Get the Prowl API key
    prowl_api_key=$(cat ~/.prowl_api_key)
    
    # Save the alert data for logging before we encode it
    alert_log_string="$application : $event : $priority : $url : $message"
    
    # URL-encode the variables
    prowl_api_key=$(urlencode "$prowl_api_key")
    application=$(urlencode "$application")
    event=$(urlencode "$event")
    message=$(urlencode "$message")
    priority=$(urlencode "$priority")
    url=$(urlencode "$url")
    
    # Send the alert
    response=$(curl -s "https://api.prowlapp.com/publicapi/add?apikey=${prowl_api_key}&application=${application}&event=${event}&description=${message}&priority=${priority}&url=${url}")
    
    # Check if the alert was sent successfully
    if [[ "${response}" != *"success code=\"200\""* ]]; then
        log_message "Error sending alert: ${alert_log_string}"
        log_message "Response: ${response}"
        exit 1
    fi
    
    log_message "Alert sent successfully: $alert_log_string"
    exit 0
    Code language: PHP (php)

    Good luck!

  • Quick Tip: Viewing Headers With Curl

    Quick Tip: Viewing Headers With Curl

    Something that I do often at work is to check HTTP headers for random things such as redirects, cache headers, proxies, ssl, etc.

    A common way this is done is by using the -I (--header) switch:

    $ curl -I http://example.com/
    HTTP/1.1 200 OK
    Content-Encoding: gzip
    Accept-Ranges: bytes
    Cache-Control: max-age=604800
    Content-Type: text/html
    Date: Wed, 27 Jun 2018 22:03:57 GMT
    Etag: "1541025663+gzip"
    Expires: Wed, 04 Jul 2018 22:03:57 GMT
    Last-Modified: Fri, 09 Aug 2013 23:54:35 GMT
    Server: ECS (atl/FC94)
    X-Cache: HIT
    Content-Length: 606
    Code language: JavaScript (javascript)

    The downside to this is that it uses an HTTP HEAD request, which can sometimes return different headers or different information than a standard GET request. This can be fixed by using the -X (--request) switch. This overrides the default HEAD?request with whatever you choose:

    $ curl -I -XGET http://example.com/
    HTTP/1.1 200 OK
    Accept-Ranges: bytes
    Cache-Control: max-age=604800
    Content-Type: text/html
    Date: Wed, 27 Jun 2018 22:07:47 GMT
    Etag: "1541025663"
    Expires: Wed, 04 Jul 2018 22:07:47 GMT
    Last-Modified: Fri, 09 Aug 2013 23:54:35 GMT
    Server: ECS (atl/FC90)
    Vary: Accept-Encoding
    X-Cache: HIT
    Content-Length: 1270
    Code language: JavaScript (javascript)

    I like to just combine them into one quick command: curl -IXGET http://example.com/