Mac – Generic DMG Installer – JumpCloud

Purpose

Install macOS applications distributed as .dmg files using a single reusable script executed from JumpCloud → Commands. This is ideal for Chrome, Firefox, Slack, and similar DMG-based apps.

Prerequisites

• Admin access to the JumpCloud Admin Portal
• Target macOS devices enrolled in JumpCloud
• A direct DMG download URL or a URL that redirects to a DMG (validated via headers)
• Network egress allowed to the app vendor’s CDN

Tip: If you’re setting up new Macs, see our SOP on Automated macOS Device Enrollment via JumpCloud MDM (ADE + ABM + ZTE)

to make this part of your zero-touch flow.

Step-by-Step Instructions

Step 1 — Create the command

1. Log in to JumpCloud Admin Portal.
2. Go to Devices → Commands.
3. Click + to add a new command.
4. Select macOS (Shell).
5. Give the command a clear name (for example, Install – Chrome (DMG)).

Step 2 — Configure the script

• In the script, set DownloadUrl="DOWNLOAD_URL" to the app’s DMG link.
• The URL must either:
• End with .dmg, or
• Return a Location header that points to a DMG (the script checks this).

You can quickly verify with:

curl -s --head "<your URL>"

Look for a Location header ending in .dmg.

Step 3 — Scope and run

1. Assign the command to the target device(s) or device group.
2. Click Save, then Run (or schedule as needed).
3. Monitor the command logs for “Copied … to /Applications” and cleanup messages.

Command (use as-is; set the DownloadUrl)

#!/bin/bash
# *** USAGE *** Version: 1.2
# NOTE: Designed for DMG files only (not .pkg, .zip, or DMGs containing .pkg).
# Set the DMG download URL below.

DownloadUrl="DOWNLOAD_URL"

### Modify below this line at your own risk!
# Locate DMG Download Link From URL
regex='^https.*.dmg$'
if [[ $DownloadUrl =~ $regex ]]; then
    echo "URL points to direct DMG download"
    validLink="True"
else
    echo "Searching headers for download links"
    urlHead=$(curl -s --head "$DownloadUrl")
    locationSearch=$(echo "$urlHead" | grep https:)
    if [ -n "$locationSearch" ]; then
        locationRaw=$(echo "$locationSearch" | awk '{print $2}')
        locationFormatted="$(echo "${locationRaw}" | tr -d '[:space:]')"
        regex='^https.*'
        if [[ $locationFormatted =~ $regex ]]; then
            echo "Download link found"
            DownloadUrl="$locationFormatted"
        else
            echo "No https location download link found in headers"
            exit 1
        fi
    else
        echo "No location download link found in headers"
        exit 1
    fi
fi
# Create Temp Folder
DATE=$(date '+%Y-%m-%d-%H-%M-%S')
TempFolder="Download-$DATE"
mkdir -p "/tmp/$TempFolder"
# Navigate to Temp Folder
cd "/tmp/$TempFolder" || exit
# Download File into Temp Folder
curl -s -O "$DownloadUrl"
# Capture name of Download File
DownloadFile="$(ls)"
echo "Downloaded $DownloadFile to /tmp/$TempFolder"
# Verify DMG File
regex='\.dmg$'
if [[ $DownloadFile =~ $regex ]]; then
    DMGFile="$DownloadFile"
    echo "DMG File Found: $DMGFile"
else
    echo "File: $DownloadFile is not a DMG"
    rm -r "/tmp/$TempFolder"
    echo "Deleted /tmp/$TempFolder"
    exit 1
fi
# Mount DMG File (-nobrowse prevents the volume from popping up in Finder)
hdiutilAttach=$(hdiutil attach "/tmp/$TempFolder/$DMGFile" -nobrowse)
echo "Used hdiutil to mount $DMGFile"
err=$?
if [ ${err} -ne 0 ]; then
    echo "Could not mount $DMGFile Error: ${err}"
    rm -r "/tmp/$TempFolder"
    echo "Deleted /tmp/$TempFolder"
    exit 1
fi
regex='\/Volumes\/.*'
if [[ $hdiutilAttach =~ $regex ]]; then
    DMGVolume="${BASH_REMATCH[0]}"
    echo "Located DMG Volume: $DMGVolume"
else
    echo "DMG Volume not found"
    rm -r "/tmp/$TempFolder"
    echo "Deleted /tmp/$TempFolder"
    exit 1
fi
# Identify the mount point for the DMG file
DMGMountPoint=$(hdiutil info | grep "$DMGVolume" | awk '{ print $1 }')
echo "Located DMG Mount Point: $DMGMountPoint"
# Capture name of App file
cd "$DMGVolume" || exit
AppName=$(ls | grep '.app')
cd ~ || exit
echo "Located App: $AppName"
# Test to ensure App is not already installed
ExistingSearch=$(find "/Applications/" -name "$AppName" -depth 1)
if [ -n "$ExistingSearch" ]; then
    echo "$AppName already present in /Applications folder"
    hdiutil detach "$DMGMountPoint"
    echo "Used hdiutil to detach $DMGFile from $DMGMountPoint"
    rm -r "/tmp/$TempFolder"
    echo "Deleted /tmp/$TempFolder"
    exit 1
else
    echo "$AppName not present in /Applications folder"
fi
DMGAppPath=$(find "$DMGVolume" -name "*.app" -depth 1)
# Copy the contents of the DMG file to /Applications/
# Preserves all file attributes and ACLs
cp -pPR "$DMGAppPath" /Applications/
err=$?
if [ ${err} -ne 0 ]; then
    echo "Could not copy $DMGAppPath Error: ${err}"
    hdiutil detach "$DMGMountPoint"
    echo "Used hdiutil to detach $DMGFile from $DMGMountPoint"
    rm -r "/tmp/$TempFolder"
    echo "Deleted /tmp/$TempFolder"
    exit 1
fi
echo "Copied $DMGAppPath to /Applications"
# Unmount the DMG file
hdiutil detach "$DMGMountPoint"
echo "Used hdiutil to detach $DMGFile from $DMGMountPoint"
err=$?
if [ ${err} -ne 0 ]; then
    echo "Could not detach DMG: $DMGMountPoint Error: ${err}"
fi
# Remove Temp Folder and download
rm -r "/tmp/$TempFolder"
echo "Deleted /tmp/$TempFolder"

Validated DMG download URLs (examples)

1. https://dl.google.com/chrome/mac/universal/stable/GGRO/googlechrome.dmg
2. https://download.mozilla.org/?product=firefox-latest-ssl&os=osx&lang=en-US
3. https://go.microsoft.com/fwlink/p/?linkid=525133
4. https://slack.com/ssb/download-osx

Note: Some vendor links redirect; the script resolves the final DMG URL automatically.

Expected result / validation

• Command output shows URL detection, DMG mount, copy to /Applications, detach, and temp cleanup.
• The application appears in /Applications on target Macs and is ready to launch.
• Re-running the command will safely exit if the app already exists.

FAQs

1) Does this support .pkg or .zip?

No. This template is DMG-only. For PKG deployments, use a dedicated PKG installer workflow in JumpCloud.

2) How do I ensure the URL is correct?

Run:

curl -s --head "<URL>"

Confirm the Location header ends in .dmg, or the original URL ends with .dmg.

3) What if the DMG contains a .pkg instead of an .app?

This script expects a top-level .app. If the DMG contains a .pkg, use a PKG install command.

4) Can I scope this per team or department?

Yes. Assign the command to specific device groups to align with your app catalog strategy.