Custom py script for jinja2 rendering

As alternative to currently j2cli or such feature-full/heavy tool,
small custom python script is enough for rendering jinja2 templates.

Closes #77

generate-docker-compose.sh

@@ -12,7 +12,7 @@ while read line; do
   export distro=$(echo "$line" | awk -F, '{ print $4 }')
   touch "docker-compose/docker-compose-${shortname}.yml"
   echo "Generating docker-compose-${shortname}.yml (${gamename})"
-  j2 -f env docker-compose.yml.j2 >"docker-compose/docker-compose-${shortname}.yml"
+  ./j2render.py docker-compose.yml.j2 >"docker-compose/docker-compose-${shortname}.yml"
   echo -n "{" >>"shortnamearray.json"
   echo -n "\"shortname\":" >>"shortnamearray.json"
   echo -n "\"${shortname}\"" >>"shortnamearray.json"

generate-dockerfiles.sh

@@ -12,7 +12,7 @@ while read line; do
   export distro=$(echo "$line" | awk -F, '{ print $4 }')
   touch "dockerfiles/Dockerfile.${shortname}"
   echo "Generating Dockerfile.${shortname} (${gamename})"
-  j2 -f env Dockerfile.j2 >"dockerfiles/Dockerfile.${shortname}"
+  ./j2render.py Dockerfile.j2 >"dockerfiles/Dockerfile.${shortname}"
   echo -n "{" >>"shortnamearray.json"
   echo -n "\"shortname\":" >>"shortnamearray.json"
   echo -n "\"${shortname}\"" >>"shortnamearray.json"

j2render.py

@@ -0,0 +1,21 @@
+#!/usr/bin/env python
+
+import os
+import sys
+
+from jinja2 import Environment, FileSystemLoader, StrictUndefined
+
+env = Environment(
+        loader=FileSystemLoader('./'),
+        undefined=StrictUndefined)
+
+variables = dict(os.environ)
+
+try:
+    template_path = sys.argv[1]
+except IndexError:
+    print("ERROR: provide path to the template file", file=sys.stderr)
+    sys.exit(1)
+
+tpl = env.get_template(template_path)
+print(tpl.render(**variables))