From fb6ffbf4f482382094d17dcb48d10ab0826f2147 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nicolas=20Mass=C3=A9?= <nicolas.masse@itix.fr>
Date: Thu, 3 May 2018 08:55:16 +0200
Subject: [PATCH] check requirements before playbook is run

---
 README.md                    |  8 ++++----
 tasks/check_requirements.yml | 27 +++++++++++++++++++++++++++
 tasks/main.yml               |  2 ++
 3 files changed, 33 insertions(+), 4 deletions(-)
 create mode 100644 tasks/check_requirements.yml

diff --git a/README.md b/README.md
index 581311d..d67f0bd 100644
--- a/README.md
+++ b/README.md
@@ -20,14 +20,14 @@ you can install it with:
 pip install jmespath
 ```
 
-A recent version of Jinja (2.8) is also required. You can install it with:
+A recent version of Jinja (2.8) is also required. You can upgrade your Jinja version with:
 ```
-pip install jinja2
+pip install -U Jinja2
 ```
 
-If your control node runs on RHEL7, you can run 
+If your control node runs on RHEL7, you can run
 [this playbook](https://github.com/nmasse-itix/OpenShift-Lab/blob/master/common/verify-local-requirements.yml)
-to install the missing dependencies. 
+to install the missing dependencies.
 
 ## Example: Deploy an API on 3scale SaaS with hosted APIcast gateways
 
diff --git a/tasks/check_requirements.yml b/tasks/check_requirements.yml
new file mode 100644
index 0000000..9584460
--- /dev/null
+++ b/tasks/check_requirements.yml
@@ -0,0 +1,27 @@
+---
+
+- name: Check if jmespath is installed locally
+  debug: msg={{dummy|json_query('@')}}
+  register: check_jmespath
+  ignore_errors: yes
+  vars:
+    dummy: Hello World
+
+- name: Check if jinja 2.8 is installed locally
+  debug: msg={{(dummy|selectattr("id", "equalto", "hello")|first)['value']}}
+  vars:
+    dummy:
+    - id: hello
+      value: Hello World
+  register: check_jinja28
+  ignore_errors: yes
+
+- assert:
+    that:
+    - 'check_jmespath is success'
+    msg: "The JMESPath library is required by this role. Please install the JMESPath library with 'pip install jmespath'."
+
+- assert:
+    that:
+    - 'check_jinja28 is success'
+    msg: "At least Jinja v2.8 is required by this role. Please update Jinja with 'pip install -U Jinja2'."
diff --git a/tasks/main.yml b/tasks/main.yml
index 6578025..54cdf72 100644
--- a/tasks/main.yml
+++ b/tasks/main.yml
@@ -1,5 +1,7 @@
 ---
 
+- import_tasks: check_requirements.yml
+
 - name: Ensure pre-requisites are met
   assert:
     that: