add blockchain install scripts

lib/blockchain/do-volume.js

@@ -0,0 +1,67 @@
+const fs = require('fs')
+
+const common = require('./common')
+
+const MOUNT_POINT = '/mnt/blockchains'
+
+module.exports = {prepareVolume}
+
+const logger = common.logger
+
+function isMounted () {
+  return fs.existsSync(MOUNT_POINT)
+}
+
+function isFormatted (volumePath) {
+  const res = common.es(`file --dereference -s ${volumePath}`)
+  return res !== `${volumePath}: data`
+}
+
+function formatVolume (volumePath) {
+  if (isFormatted(volumePath)) {
+    logger.info('Volume is already formatted.')
+    return
+  }
+
+  logger.info('Formatting...')
+  common.es(`sudo mkfs.ext4 ${volumePath}`)
+}
+
+function mountVolume (volumePath) {
+  if (isMounted()) {
+    logger.info('Volume is already mounted.')
+    return
+  }
+
+  logger.info('Mounting...')
+  common.es(`sudo mkdir -p ${MOUNT_POINT}`)
+  common.es(`sudo mount -o discard,defaults ${volumePath} ${MOUNT_POINT}`)
+  common.es(`echo ${volumePath} ${MOUNT_POINT} ext4 defaults,nofail,discard 0 0 | sudo tee -a /etc/fstab`)
+}
+
+function locateVolume () {
+  const res = common.es('ls /dev/disk/by-id/*')
+  const lines = res.trim().split('\n')
+
+  if (lines.length > 1) {
+    logger.error('More than one volume present, cannot prepare.')
+    return null
+  }
+
+  if (lines.length === 0) {
+    logger.error('No available volumes. You might need to attach one.')
+    return null
+  }
+
+  return lines[0].trim()
+}
+
+function prepareVolume () {
+  const volumePath = locateVolume()
+  if (!volumePath) return false
+
+  formatVolume(volumePath)
+  mountVolume(volumePath)
+
+  return true
+}