update-resin-supervisor-cache

#!/bin/bash
set -o pipefail

# Help function
function update-resin-supervisor-help {
    cat << EOF
Wrapper to run supervisor agent updates on resin distributions.
$0 <OPTION>

Options:
  -h, --help
        Display this help and exit.

  -i <SUPERVISOR IMAGE>, --supervisor-image <SUPERVISOR IMAGE>
        Set supervisor image to update to.

  -t <SUPERVISOR TAG>, --supervisor-tag <SUPERVISOR TAG>
        Set supervisor tag to update to.
EOF
}

# Parse arguments
while [[ $# > 0 ]]; do
    arg="$1"

    case $arg in
        -h|--help)
            update-resin-supervisor-help
            exit 0
            ;;
        -i|--supervisor-image)
            if [ -z "$2" ]; then
                log ERROR "\"$1\" argument needs a value."
            fi
            UPDATER_SUPERVISOR_IMAGE=$2
            shift
            ;;
        -t|--supervisor-tag)
            if [ -z "$2" ]; then
                log ERROR "\"$1\" argument needs a value."
            fi
            UPDATER_SUPERVISOR_TAG=$2
            shift
            ;;
        --cache)
            CACHE=yes
            ;;
        *)
            log ERROR "Unrecognized option $1."
            ;;
    esac
    shift
done

# Don't souce before parsing args - resin-vars parses args too
source /usr/sbin/resin-vars

# A temporary file used until next reboot
UPDATECONF=/tmp/update-supervisor.conf

if [ -z "$API_ENDPOINT" -o -z "$CONFIG_PATH" ]; then
    echo "Environment variables API_ENDPOINT and CONFIG_PATH must be set."
    exit 1
fi

# If the user api key exists we use it instead of the deviceApiKey as it means we haven't done the key exchange yet
read DEVICE_API_KEY DEVICE_ID <<<$(jq -r '.apiKey // .deviceApiKey,.deviceId' $CONFIG_PATH)
if [ -z "$DEVICE_API_KEY" -o -z "$DEVICE_ID" ]; then
    echo "JSON in config file $CONFIG_PATH must have apiKey or deviceApiKey, and deviceId attributes."
    exit 1
fi

function error_handler {
    # If docker pull fails, start the old supervisor again and exit
    rm -rf $UPDATECONF
    systemctl start resin-supervisor
    exit 1
}

trap 'error_handler $LINENO' ERR

# Detect containers engine
if which docker &>/dev/null; then
    DOCKER=docker
elif which rce &>/dev/null; then
    DOCKER=rce
else
    error_handler $LINENO "no container engine detected"
fi

# Get target supervisor tag from API.
# The script will exit if curl does not get a valid response.
# Getting data separately before reading it fixes error handling.
echo "Getting image name and tag..."
if data=$(curl --silent --header "User-Agent:" --compressed "$API_ENDPOINT/v1/supervisor_release?\$select=supervisor_version,image_name&\$filter=device/any(d:d/id%20eq%20$DEVICE_ID)&apikey=$DEVICE_API_KEY" | jq -e -r '.d[0].supervisor_version,.d[0].image_name'); then
    echo "Supervisor configuration found from API."

    if [ -n "$UPDATER_SUPERVISOR_TAG" ] || [ -n "$UPDATER_SUPERVISOR_IMAGE" ]; then
        echo "WARN: Ignore image/tag arguments as API overrides them."
    fi

    read tag image_name <<<$data

    # Check that we didn't somehow get an empty tag version.
    if [ -z "$tag" ]; then
        error_handler $LINENO "no tag received"
    fi
else
    echo "No supervisor configuration found from API. Using arguments for image and tag."
    source /etc/resin-supervisor/supervisor.conf
    if [ -z "$UPDATER_SUPERVISOR_TAG" ]; then
        # Try to get the tag from supervisor.conf
        if [ -n "$SUPERVISOR_TAG" ]; then
            UPDATER_SUPERVISOR_TAG=$SUPERVISOR_TAG
        else
            echo "ERROR: No tag argument provided."
            error_handler $LINENO "no tag argument provided"
        fi
    fi
    if [ -z "$UPDATER_SUPERVISOR_IMAGE" ]; then
        UPDATER_SUPERVISOR_IMAGE=$SUPERVISOR_IMAGE
    fi
    echo "Set based on arguments image=$UPDATER_SUPERVISOR_IMAGE and tag=$UPDATER_SUPERVISOR_TAG."
    image_name=$UPDATER_SUPERVISOR_IMAGE
    tag=$UPDATER_SUPERVISOR_TAG
fi

# Get image id of tag. This will be non-empty only in case it's already downloaded.
echo "Getting image id..."
imageid=$($DOCKER inspect -f '{{.Id}}' "$image_name:$tag") || imageid=""

if [ -n "$imageid" ]; then
    echo "Supervisor $image_name:$tag already downloaded."
    exit 0
fi

# Try to stop old supervisor to prevent it deleting the intermediate images while downloading the new one
echo "Stop supervisor..."
systemctl stop resin-supervisor

# Pull target version.
echo "Pulling supervisor $image_name:$tag..."
if [ "${CACHE-no}" == "yes"  ]; then
  SUPERVISOR_CACHE_FILE="/mnt/data/resinhup/cache/resin_supervisor_4_2_4_raspberry_pi.tar.gz"
  if [ -f "${SUPERVISOR_CACHE_FILE}" ]; then
    echo "==> found cache, loading"
    $DOCKER load -i ${SUPERVISOR_CACHE_FILE}
  else
    echo "No cached supervisor found at ${SUPERVISOR_CACHE_FILE}"
    exit 3
  fi
else
  $DOCKER pull "$image_name:$tag"
fi

$DOCKER rm --force resin_supervisor || true

# Store the tagged image string so resin-supervisor.service can pick it up
echo "SUPERVISOR_IMAGE=$image_name:$tag" > $UPDATECONF

# Run supervisor with the device-type-specific options.
# We give a specific name to the container to guarantee only one running.
echo "Start supervisor..."
systemctl start resin-supervisor

# Mark supervisor as working. This version will run when the device reboots.
echo "Mark pulled tag as latest..."
$DOCKER tag -f "$image_name:$tag" "$image_name:latest"
sed --in-place "s|SUPERVISOR_IMAGE=.*|SUPERVISOR_IMAGE=$image_name|" /etc/resin-supervisor/supervisor.conf
sed --in-place "s|SUPERVISOR_TAG=.*|SUPERVISOR_TAG=$tag|" /etc/resin-supervisor/supervisor.conf