instructions for upgrading elastic

CHANGELOG.md

@@ -1,9 +1,12 @@
 # Changelog Fab Manager
 
 ## next release
+
+- Upgraded ElasticSearch from 1.7 to 5.6
 - Updated OmniAuth to fix Hashie warnings [omniauth#872](https://github.com/omniauth/omniauth/issues/872)
 - Fix a security issue: dependency loofah has a vulnerability as described in [CVE-2018-8048](https://github.com/flavorjones/loofah/issues/144)
 - Ensure elasticSearch indices are started with green status on new installations
+- [TODO DEPLOY] **REQUIRED** Please read [elastic_upgrade.md](doc/elastic_upgrade.md) for instructions on upgrading ElasticSearch. 
 
 ## v2.6.4 2018 March 15
 

doc/elastic_upgrade.md

@@ -0,0 +1,20 @@
+# Instructions for upgrading ElasticSearch
+
+Fab-manager release 2.6.5 has upgraded its dependency to ElasticSearch from version 1.7 to version 5.6 as the previous was unsupported for months.
+To keep using fab-manager you need to upgrade your installation with the new version.
+We've wrote a script to automate the process while keeping your data integrity, but there's some requirements to understand before running it.
+
+- You need to install *curl*, *jq* and *sudo* on your system before running the script. 
+  Usually, `sudo apt update && sudo apt install curl jq sudo` will do the trick but this may change, depending upon your system.
+- You'll need at least 4GB of RAM for the data migration to complete successfully.
+  The script will try to add 4GB of swap memory if this requirement is detected as missing but this will consume you hard disk space (see below).
+- 1,17GB of free disk space are also required to perform the data migration.
+  Please ensure that you'll have enough space, considering the point above. The script won't run otherwise.
+- This script will run on any Debian compatible OS (like Ubuntu) and on MacOS X, on any other systems you'll need to perform the upgrade yourself manually. 
+
+Once you've understood all the points above, you can run the migration script with the following:
+
+```bash
+cd /apps/fabmanager
+# do not run as root, elevation will be prompted if needed
+```

scripts/elastic-upgrade.sh

@@ -24,6 +24,12 @@ config()
     echo "jq was not found, exiting..."
     exit 1
   fi
+  if ! command -v sudo
+  then
+    echo "Please install and configure sudo before running this script."
+    echo "sudo was not found, exiting..."
+    exit 1
+  fi
   echo "checking memory..."
   mem=$(free -mt | grep Total | awk '{print $2}')
   if [ "$mem" -lt 4000 ]