Add image builders under tools section

README.md

@@ -181,6 +181,10 @@ Name | Description
   - [ ] Chef
   - [ ] Salt
 
+- [ ] Images
+  - [ ] [Packer](https://www.packer.io)
+  - [ ] [diskimage-builder](https://github.com/openstack/diskimage-builder)
+
 - [ ] Cloud
   - [ ] AWS
   - [ ] Azure
@@ -204,6 +208,10 @@ Name | Description
   - [ ] Grafana
   - [ ] Report Portal
 
+- [ ] Security
+  - [ ] [Vault](https://www.vaultproject.io) - "Secure, store and tightly control access to tokens, passwords, certificates, encryption keys for protecting secrets..."
+  - [ ] [Open Policy Agent](https://www.openpolicyagent.org) - "Flexible, fine-grained control for administrators across the stack"
+
 - [ ] Code review 
   - [ ] Gerrit - Code Review system
   - [ ] PullPanda - A collection of Tools such as reminder & analytics

resources/packer.md

@@ -0,0 +1,14 @@
+## Packer
+
+### Official Resources
+
+* Site: https://www.packer.io
+* Docs: https://www.packer.io/docs
+
+### Why Packer
+
+I recommend reading [this discussion](https://www.reddit.com/r/devops/comments/ko3cwq/why_packer) on Reddit
+
+### Blogs Posts
+
+* Getting started with Packer: https://codingshell.com/packer-getting-started

resources/vault.md

@@ -0,0 +1,16 @@
+## Cheat Sheet
+
+* Start Vault server in dev mode (NOT FOR PRODUCTION): `vault server -dev`
+* Set up vault client (dev mode):
+
+```
+export VAULT_ADDTR='http://<VAULT_ADDRESS>'
+echo <KEY> > unseal.key
+export VAULT_DEV_ROOT_TOKEN_ID=...
+vault status
+```
+
+* Write a secret using one pair of key, value: `vault kv put secret/hello foo=bar`
+* Write a secret using multiple pairs of key, value: `vault kv put secret/hello foo=bar y=x`
+
+* Get a secret: `vault kv get secret/hello`