polkadot_node_update.sh

#!/bin/bash
#
# > make a file executable
# chmod +x ./polkadot_node_update.sh

DIRNAME="/polkadot/bin"
FILENAME="$DIRNAME/polkadot"
ARTIFACTS="./artifacts"

if [ ! -d "$ARTIFACTS" ]
then
        mkdir -p $ARTIFACTS
fi

# read the polkadot binary version to update (e.g.: 0.9.14) from the first positional 
# argument (e.g. ./polkadot_node_update.sh 0.9.14)
INPUT_VERSION = $1
if [ "$INPUT_VERSION" = "" ]; then
    INPUT_VERSION="0.9.12"
fi
URI="https://github.com/paritytech/polkadot/releases/download/v$INPUT_VERSION/polkadot"
URI_SHA256="https://github.com/paritytech/polkadot/releases/download/v$INPUT_VERSION/polkadot.sha256"
wget $URI -P $ARTIFACTS && wget $URI_SHA256 -P $ARTIFACTS

if sha256sum -c $ARTIFACTS/polkadot.sha256 2>&1 | grep -q 'OK'
then
        if [ ! -d "$DIRNAME" ]
        then
                mkdir -p $DIRNAME
        fi
        if [[ -f "$FILENAME" ]]
        then
                mv "$FILENAME" "$FILENAME.backup"
        fi
        rm $ARTIFACTS/polkadot.sha256
        chmod +x $ARTIFACTS/polkadot
        mv $ARTIFACTS/polkadot "$FILENAME"
        echo "** polkadot v$INPUT_VERSION successfully downloaded and verified $FILENAME **"
        sudo systemctl restart polkadot-node.service
        echo "** polkadot-node.service restarted **"
else
        echo "Error: SHA256 doesn't match!"
        rm "$ARTIFACTS/*"
fi