Wrapper Script for use with Unraid's User Scripts plugin

[Wigsinator]

Now I'm certainly no bash wizard, but I wanted a version of this which I could use with Unraid. I've done a bit of studying into how User Scripts run, and here is what I came up with. Unraid already has jq installed, so I only needed to grab the regctl binary. If the files don't exist, the script downloads them, then moves them into place. I don't have automatic downloading of notify.sh, you'll have to move that into place yourself. But, if dockcheck updates itself, it should automatically replace itself.

#!/bin/bash
#argumentDescription=Arguments passed to this script will be passed directly on to dockcheck.\nIf -i is used, notify.sh will be pulled from the script directory.\nIf -u is used, dockcheck will be sent back to the Script directory.
#argumentDefault=-aid7

# Static URLs and Paths
RawUrl="https://raw.githubusercontent.com/mag37/dockcheck/main/dockcheck.sh"
RegctlUrl="https://github.com/regclient/regclient/releases/latest/download/regctl-linux-amd64"
UserScripts="/boot/config/plugins/user.scripts/scripts/"

# Get Paths
TmpPath=$(readlink -f "$0")
TmpWorkDir=$(dirname "$TmpPath")
ScriptWorkDir="$UserScripts"$(basename "$TmpWorkDir")

ScriptArgs=( "$@" )

# Init Used Variables
AutoSelfUpdate=false
Notify=false

while getopts "iu" options; do
  case "${options}" in
    i)   Notify=true ;;
    u)   AutoSelfUpdate=true ;;
  esac
done

# Get dockcheck if it doesn't exist
if ! [[ -f "$ScriptWorkDir/dockcheck.sh" ]]; then
    curl -L "$RawUrl" > "$ScriptWorkDir/dockcheck.sh"
fi

# Get regctl if it doesn't exist
if ! [[ -f "$ScriptWorkDir/regctl" ]]; then
    curl -L "$RegctlUrl" > "$ScriptWorkDir/regctl"
fi

# Copy dockcheck, regctl, and notify into place
cp "$ScriptWorkDir/dockcheck.sh" "$TmpWorkDir"
chmod +x "$TmpWorkDir/dockcheck.sh"
cp "$ScriptWorkDir/regctl" "$TmpWorkDir"
chmod +x "$TmpWorkDir/regctl"
if [[ "$Notify" == true ]]; then
    cp "$ScriptWorkDir/notify.sh" "$TmpWorkDir"
    chmod +x "$TmpWorkDir/notify.sh"
fi

exec "$TmpWorkDir/dockcheck.sh" "${ScriptArgs[@]}"

# Replace held dockcheck if updates performed.
if [[ "$AutoSelfUpdate" == true ]]; then
    chmod -x "$TmpWorkDir/dockcheck.sh"
    cp $TmpWorkDir/dockcheck.sh $ScriptWorkDir
fi

I'd be happy to see if anyone has any improvements they'd like to suggest, as I said, Bash scripting is not my forte.

[mag37]

Sorry for not responding here!
Thank you so much for the contribution - I'll link to this from the Readme or add it to extras/ in the future.

I'll try to read through it and give some feedback asap!

[Wigsinator]

An update: I'm realizing I misunderstood its ability to update itself, and thought that -a would also upgrade dockcheck. I'll have to figure out some fixes.

[mag37]

I've just had a suggestion to have a variable parameter for auto updating dockcheck itself, I've been a bit hesitant to implement this due to security implications.

I'll consider making the variable option possible though with a warning :)

[Wigsinator]

That's a totally reasonable concern. I think having a way to run the auto update without needing interaction would be nice, and I would likely send it as an argument on the user script here. As it stands, because Unraid user scripts don't allow for interactivity, I have to effectively implement my own update, which feels redundant as your upgrade script is so good.

[mag37]

Yes, I will look into making it a variable or option (maybe -u) to allow selfupdating!

[mag37]

A few questions and suggestions on the script:

What's the goal of the variable expansion in this line? I mean in clear text what do you do with it :)

ScriptPath="${TmpPath/\/tmp\/user.scripts\/tmpScripts\//\/boot\/config\/plugins\/user.scripts\/scripts\/}"

When would there be a dockcheck.sh.bak file? for this line to check:

if [[ -f "$TmpWorkDir/dockcheck.sh.bak" ]]; then

I would probably be careful with double-quoting, eg: TmpWorkDir="$(dirname "$TmpPath")" in this case I would only quote the inner and not the outer -> TmpWorkDir=$(dirname "$TmpPath").

And quoting in general - I'd quote variables + paths in other places too like cp $ScriptWorkDir/dockcheck.sh $TmpWorkDir.

---

I'm gonna add a new option flag -u and a variable $AutoUpdateSelf (to be set in the dockcheck.conf) in the next update, if any of those are used it would allow automatic self update of the script.

And I'll add your User Script to extras + readme when you consider it done and working 😄 and if there's future changes you can make a PR or just message me / make an issue.

[Wigsinator]

What's the goal of the variable expansion in this line? I mean in clear text what do you do with it :)

That line exists because of how Unraid's User Scripts plugin works. The plugin stores the scripts in /boot/config/plugins/user.scripts/scripts without execute permissions for persistence, then moves them to a temp folder to be executed. That line undoes that conversion so that I can find the script folder without predefining the script name. Is it overkill? Almost certainly, I could probably just set up a variable for the script's name then just grab the folder with some string concatenation. A change I'll make in the next iteration.

When would there be a dockcheck.sh.bak file? for this line to check:

That was originally how I was checking for updates, when I thought -a would update automatically. self_update_curl() starts by creating that bak file. It's gonna be removed as I clean up the update system.

Quoting wise, I'll be honest, that's mostly just me not being great at bash scripting. Thank you for the advice!

[Wigsinator]

I just updated it. It's a bit bigger, but safer for sure, and also cleaner.

Changes:

• Rather than string replacement, I'm just doing basic string concatenation to get the location of the base script.
• I've cleaned up the quoting significantly
• The big one: argument passthrough. Whatever arguments are set for the unraid script now get passed through to dockcheck. This allows for changes in what arguments you want to send, while also letting me glean information from it. For example, notify.sh is now only copied if you set the -i flag. Default arguments can be set so that when it runs in the background (or scheduled), it runs how you want it to.

[mag37]

Great work!
Thank you for putting in the work and also describing the changes.