Azure App Service - Kudu deployment fails "Missing composer executable"

I'm having difficulties executing additional commands for my Azure App Service website. I've generated a basic PHP deployment script using kuduscript --php -y. The script gets executed whenever I push from my local git repository but fails at the first step, verifying if Composer is installed.

When I SSH into the server and execute composer --version it returns version 2.0.12 as that's what I installed globally. Also I have tried adding a composer.phar file to the root of my project but the error remains the same.

Something else I've noticed is that calling a php script such as php bin/console cache:clear returns a (php) command not found, but that's also working fine when I execute the same command directly on the server. The Yarn commands however work fine within the Kudu script.

My deploy.sh looks like this:

#!/bin/bash

# ----------------------
# KUDU Deployment Script
# Version: 1.0.17
# ----------------------

# Helpers
# -------

exitWithMessageOnError () {
  if [ ! $? -eq 0 ]; then
    echo "An error has occurred during web site deployment."
    echo $1
    exit 1
  fi
}

# Prerequisites
# -------------

# Verify node.js installed
hash node 2>/dev/null
exitWithMessageOnError "Missing node.js executable, please install node.js, if already installed make sure it can be reached from current environment."

# Setup
# -----

SCRIPT_DIR="${BASH_SOURCE[0]%\\*}"
SCRIPT_DIR="${SCRIPT_DIR%/*}"
ARTIFACTS=$SCRIPT_DIR/../artifacts
KUDU_SYNC_CMD=${KUDU_SYNC_CMD//\"}
DISABLE_HUGO_BUILD=true

if [[ ! -n "$DEPLOYMENT_SOURCE" ]]; then
  DEPLOYMENT_SOURCE=$SCRIPT_DIR
fi

if [[ ! -n "$NEXT_MANIFEST_PATH" ]]; then
  NEXT_MANIFEST_PATH=$ARTIFACTS/manifest

  if [[ ! -n "$PREVIOUS_MANIFEST_PATH" ]]; then
    PREVIOUS_MANIFEST_PATH=$NEXT_MANIFEST_PATH
  fi
fi

if [[ ! -n "$DEPLOYMENT_TARGET" ]]; then
  DEPLOYMENT_TARGET=$ARTIFACTS/wwwroot
else
  KUDU_SERVICE=true
fi

if [[ ! -n "$KUDU_SYNC_CMD" ]]; then
  # Install kudu sync
  echo Installing Kudu Sync
  npm install kudusync -g --silent
  exitWithMessageOnError "npm failed"

  if [[ ! -n "$KUDU_SERVICE" ]]; then
    # In case we are running locally this is the correct location of kuduSync
    KUDU_SYNC_CMD=kuduSync
  else
    # In case we are running on kudu service this is the correct location of kuduSync
    KUDU_SYNC_CMD=$APPDATA/npm/node_modules/kuduSync/bin/kuduSync
  fi
fi

# PHP Helpers
# -----------

initializeDeploymentConfig() {
    if [ ! -e "$COMPOSER_ARGS" ]; then
    COMPOSER_ARGS="--no-interaction --prefer-dist --optimize-autoloader --no-progress --no-dev --verbose"
    echo "No COMPOSER_ARGS variable declared in App Settings, using the default settings"
  else
    echo "Using COMPOSER_ARGS variable declared in App Setting"
  fi
  echo "Composer settings: $COMPOSER_ARGS"
}

##################################################################################################################################
# Deployment
# ----------

echo PHP deployment

# 1. KuduSync
if [[ "$IN_PLACE_DEPLOYMENT" -ne "1" ]]; then
  "$KUDU_SYNC_CMD" -v 50 -f "$DEPLOYMENT_SOURCE" -t "$DEPLOYMENT_TARGET" -n "$NEXT_MANIFEST_PATH" -p "$PREVIOUS_MANIFEST_PATH" -i ".git;.hg;.deployment;deploy.sh"
  exitWithMessageOnError "Kudu Sync failed"
fi

# 2. Verify composer installed
hash composer 2>/dev/null
exitWithMessageOnError "Missing composer executable"

# 3. Initialize Composer Config
initializeDeploymentConfig

# 4. Use composer
echo "$DEPLOYMENT_TARGET"
if [ -e "$DEPLOYMENT_TARGET/composer.json" ]; then
  php -v

  echo "Found composer.json"
  pushd "$DEPLOYMENT_TARGET"
  composer install $COMPOSER_ARGS
  exitWithMessageOnError "Composer install failed"
  popd
fi

# 5. Install and build yarn
if [ -e "$DEPLOYMENT_TARGET/package.json" ]; then
  echo "Found package.json"
  pushd "$DEPLOYMENT_TARGET"
  yarn install
  exitWithMessageOnError "Yarn install failed"
  yarn build
  exitWithMessageOnError "Yarn build failed"
  popd
fi

##################################################################################################################################
echo "Finished successfully."

After searching for hours without any success, I really hope anyone on here has a suggestion / solution for this.

Kind regards,

Kevin