diff --git a/README.md b/README.md
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@@ -1,2 +1,96 @@
 # ansible-target-practice
 
+## EC2 credentials
+Make sure you have a profile that can access the necessary AWS resources.
+Configure your AWS cli as described here
+[](https://docs.aws.amazon.com/cli/latest/userguide/cli-configure-files.html)
+
+You can use Environment Variables to specify configuration options of the AWS cli.
+More info here: [](https://docs.aws.amazon.com/cli/latest/userguide/cli-configure-envvars.html)
+
+Minimal example:
+
+`~/.aws/credentials`
+
+```
+[zoolite/vincent]
+aws_access_key_id=AKIAWNB2RT65DGTW
+aws_secret_access_key=Yhdg280zGg3U7CQVcyLAqLEs9/Wv6cYb7UYB6L0
+```
+
+
+
+`~/.aws/config`
+
+```
+[profile zoolite/vincent]
+region=eu-west-1
+output=text
+```
+
+You can use this profile by setting the `AWS_PROFILE` environment variable
+
+```
+export AWS_PROFILE=zoolite/vincent
+```
+
+Run `aws sts get-caller-identity` to test authentication
+
+
+## Ansible EC2 inventory plugin
+The Ansible EC2 inventory plugin allows you to create groups based on tags
+defined on resources. The configuration of this inventory plugin can be done
+through a configuration file.
+
+In this example we wan to create a group `dev` and should contain all
+instance that have a tag `env=dev`. We also create a group `tag_dev_env` which
+contains the same hosts.
+
+Create a file `aws_ec2.yml` with the following content
+
+```
+plugin: aws_ec2
+regions:
+  - eu-west-1
+filters:
+  tag:env:
+    - dev
+    - prod
+hostnames:
+  - private-dns-name
+  - ip-address
+  - network-interface.addresses.private-ip-address
+keyed_groups:
+  - key: tags.env
+    separator: ""
+  - prefix: tag
+    key: tags
+```
+
+### Filters
+In the example we apply a filter so we only end up with resources who have a tag
+`env` with a value of either `dev` or `prod`
+
+
+### Hostnames
+In this example we only want to use the private ip addresses, private dns record
+or the public ip address in our inventory. This can be defined in the `hostnames` section.  
+
+This list uses the order as preference. Example: If you prefer to use the prive
+dns records you need to put the `private-dns-name` option above all alse in the
+list.
+
+You can use the options defined in the AWS CLI `--filter` section.
+[](https://docs.aws.amazon.com/cli/latest/reference/ec2/describe-instances.html#options)
+
+
+
+## Run Ansible
+Testing the inventory can be done using `ansible-inventory`
+
+```
+ansible-inventory -i aws_ec2.yml --list
+```
+
+
+
diff --git a/aws_ec2.yml b/aws_ec2.yml
new file mode 100644
index 0000000..dd90357
--- /dev/null
+++ b/aws_ec2.yml
@@ -0,0 +1,20 @@
+plugin: aws_ec2
+regions:
+  - eu-west-1
+filters:
+  tag:env:
+    - dev
+    - prod
+hostnames:
+  - ip-address
+  - network-interface.addresses.private-ip-address
+  - private-dns-name
+keyed_groups:
+  - key: tags.env
+    separator: ""
+    #prefix: MyGroupPrefix
+  - prefix: tag
+    key: tags
+
+fact_caching_timeout: 10
+caching_timeout: 10