Add cron-bkp-blockchain.sh; Update README

.gitignore

@@ -2,3 +2,5 @@ files/*.pub
 *.retry
 group_vars/all
 hosts
+out.txt
+err.txt

README.md

@@ -1,5 +1,61 @@
-# poa-devops
-DevOps scripts
+## DevOps scripts
 
-Prepare for run: Change variables in group_vars/all.
-How run: ansible-playbook -i hosts site.yml
+### Setup blockchain backup from a node:
+1. connect to the node as `root`.
+
+2. clone this repository to `root`'s home folder:
+```
+git clone https://github.com/poanetwork/poa-devops.git
+```
+
+3. make sure `python` (v2.6+ or v3.5+) is installed on the node.
+
+4. install `pip` and/or upgrade it to the newest version:
+```
+apt-get install python-pip
+pip install --upgrade pip
+```
+
+5. upgrade `setuptools` to the newest version:
+```
+pip install --upgrade setuptools
+```
+
+6. install `ansible`:
+```
+pip install ansible
+```
+
+7. create `group_vars/all` file:
+```
+cp group_vars/all.example group_vars/all
+```
+and set the following variables:
+* `poa_role` - node's role (one of `bootnode`, `validator`, `moc`, `explorer`, `netstat`)
+* `access_key` - s3 access key
+* `secret_key` - s3 secret key
+* `s3_bucket` - s3 bucket name 
+
+8. create `hosts` file:
+```
+cp hosts.example hosts
+```
+and set it to run on localhost:
+```
+[backup]
+localhost
+```
+
+9. run playbook (still, do this on the node)
+```
+ansible-playbook -i hosts -c local site.yml
+```
+
+19. if all is well, setup a cronjob to run every hour:
+```
+crontab -e
+```
+append the following line:
+```
+30 * * * * /bin/bash /root/poa-devops/cron-bkp-blockchain.sh
+```

cron-bkp-blockchain.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+
+#### line to add to crontab (remove leading '#')
+# 30 * * * * /bin/bash /root/poa-devops/cron-bkp-blockchain.sh
+####
+
+set -e
+set -u
+set -o
+
+cd /root/poa-devops
+/usr/local/bin/ansible-playbook -i hosts -c local site.yml > out.txt 2> err.txt