Merge pull request #6 from cuchi/env-vars

Enable the usage of environment variables

Author: cuchi

.github/workflows/ci.yml

@@ -55,3 +55,49 @@ jobs:
             bar= \nthis\nvariable\nhas\nmany\n    \nlines\n    and trailing whitespace    
       - name: '[test] many variables with messy whitespace'
         run: diff test/whitespace/result test/whitespace/expected
+
+      - name: '[run] yaml data file'
+        uses: ./
+        with:
+          template: test/many-variables/template
+          output_file: test/data-files/yaml-result
+          data_file: test/data-files/data.yml
+      - name: '[test] yaml data file'
+        run: diff test/data-files/yaml-result test/many-variables/expected
+
+      - name: '[run] ini data file'
+        uses: ./
+        with:
+          template: test/many-variables/template
+          output_file: test/data-files/ini-result
+          data_file: test/data-files/data.yml
+      - name: '[test] ini data file'
+        run: diff test/data-files/ini-result test/many-variables/expected
+
+      - name: '[run] json data file'
+        uses: ./
+        with:
+          template: test/many-variables/template
+          output_file: test/data-files/json-result
+          data_file: test/data-files/data.yml
+      - name: '[test] json data file'
+        run: diff test/data-files/json-result test/many-variables/expected
+
+      - name: '[run] env data file'
+        uses: ./
+        with:
+          template: test/many-variables/template
+          output_file: test/data-files/env-result
+          data_file: test/data-files/data.yml
+      - name: '[test] env data file'
+        run: diff test/data-files/env-result test/many-variables/expected
+
+      - name: '[run] env variables'
+        uses: ./
+        with:
+          template: test/env-variables/template
+          output_file: test/env-variables/result
+        env:
+          FOO: bar
+      - name: '[test] env variables'
+        run: diff test/env-variables/result test/env-variables/expected

Dockerfile

@@ -1,5 +1,9 @@
 FROM dinutac/jinja2docker:2.1.3
 
+RUN pip install \
+    j2cli==0.3.10 \
+    pyyaml==5.3.1
+
 COPY entrypoint.py /entrypoint.py
 
 ENTRYPOINT ["/entrypoint.py"]

README.md

@@ -1,15 +1,14 @@
 [![release](https://img.shields.io/github/v/release/cuchi/jinja2-action?style=flat-square)](https://github.com/cuchi/jinja2-action/releases/latest)
 [![marketplace](https://img.shields.io/badge/marketplace-jinja2--action-blue?logo=github&style=flat-square)](https://github.com/marketplace/actions/jinja2-action)
 
-Jinja2 is a fast and straightforward templating engine.
+Jinja2 is a fast and straightforward templating engine. You can use this action
+to easily run it in your GitHub workflows.
 
-You can use this action to easily run the [Jinja2 CLI](https://github.com/mattrobenolt/jinja2-cli) inside your repository.
 
-
-# Example
+# Using input variables
 ```yml
 - name: Setup nginx
-  uses: cuchi/jinja2-action@v1.1.0
+  uses: cuchi/jinja2-action@v1.2.0
   with:
     template: infra/nginx.conf.j2
     output_file: infra/nginx.conf
@@ -19,5 +18,35 @@ You can use this action to easily run the [Jinja2 CLI](https://github.com/mattro
       timeout=30s
 ```
 
+# Using data files
+```yml
+- name: Setup nginx
+  uses: cuchi/jinja2-action@v1.2.0
+  with:
+    template: infra/nginx.conf.j2
+    output_file: infra/nginx.conf
+    data_file: staging_config.json
+    data_format: json # Will try to guess from the extension instead (unnecessary in this case)
+```
+
+# Using environment variables
+```yml
+- name: Setup nginx
+  uses: cuchi/jinja2-action@v1.2.0
+  with:
+    template: infra/nginx.conf.j2
+    output_file: infra/nginx.conf
+  env:
+    SERVER_HOST: staging.example.com
+```
+
+Environment variables are used this way in the template file:
+```
+{{ env['SERVER_HOST'] }} <-- This is always strict
+```
+```
+{{ env.get('SERVER_HOST') }} <-- This is never strict, and displays `None` if you don't specify a default value
+```
+
 # See also
 - [Jinja2 docs](https://jinja.palletsprojects.com/)

action.yml

@@ -1,17 +1,23 @@
 name: 'Jinja2 Action'
-description: 'Use the Jinja2 templating engine'
+description: 'Use the Jinja2 templating engine on your workflow'
 inputs:
   template:
     required: true
   output_file:
     required: true
   strict:
+    description: 'Fails on missing values'
     required: false
     default: false
   variables:
     required: false
   data_file:
+    description: 'See "data_format" for supported formats'
     required: false
+  data_format:
+    description: 'To be used with the "data_file" input, can be one of: env, ini, yaml or json'
+    required: false
+    default: yaml
 runs:
   using: 'docker'
   image: 'Dockerfile'

entrypoint.py

@@ -1,21 +1,39 @@
 #!/usr/bin/env python3
 
 import os
-import re
-import subprocess
+from jinja2 import Template, StrictUndefined
+from j2cli.context import read_context_data
 
-params = [os.environ['INPUT_TEMPLATE']]
+def guess_format(file_name):
+    _, extension = os.path.splitext(file_name)
+    print(extension)
+    formats = {
+        '.yaml': 'yaml',
+        '.yml': 'yaml',
+        '.json': 'json',
+        '.ini': 'ini',
+        '.env': 'env',
+    }
+    return formats.get(extension, 'env')
 
+variables = {'env': os.environ}
 for variable in os.environ.get('INPUT_VARIABLES', '').split('\n'):
     clean_variable = bytes(variable.strip(), 'utf-8').decode('unicode_escape')
     if clean_variable != '':
-        params.extend(['-D', clean_variable])
+        name, value = clean_variable.split('=', 1)
+        variables.update({name: value})
 
-if os.environ.get('INPUT_STRICT') == 'true':
-    params.append('--strict')
+data_file = os.environ.get('INPUT_DATA_FILE')
+if data_file:
+    format = os.environ.get('INPUT_DATA_FORMAT', guess_format(data_file))
+    with open(data_file, 'r') as file:
+        variables.update(read_context_data(format, file, None))
 
-params.extend(['-o', os.environ['INPUT_OUTPUT_FILE']])
+with open(os.environ['INPUT_TEMPLATE'], 'r') as file:
+    template_kwargs = {}
+    if os.environ.get('INPUT_STRICT') == 'true':
+        template_kwargs.update({'undefined': StrictUndefined})
+    template = Template(str(file.read()), **template_kwargs)
 
-params.extend([os.environ.get('INPUT_DATA_FILE','')])
-
-subprocess.run(['jinja2'] + params, check = True)
+with open(os.environ['INPUT_OUTPUT_FILE'], 'w') as file:
+    file.write(template.render(**variables) + '\n')

test/data-files/data.env

@@ -0,0 +1,2 @@
+foo=bar
+baz=cux

test/data-files/data.ini

@@ -0,0 +1,5 @@
+foo=bar
+baz=cux
+
+[someting_else]
+foo=bar2

test/data-files/data.json

@@ -0,0 +1,4 @@
+{
+    "foo": "bar",
+    "baz": "cux"
+}

test/data-files/data.yml

@@ -0,0 +1,2 @@
+foo: bar
+baz: cux

test/env-variables/expected

@@ -0,0 +1,5 @@
+bar
+
+None
+
+hello