Make it possible to configure example nginx server

Author: bkabrda

Diff for: examples/nginx-centos7/Dockerfile

@@ -37,6 +37,7 @@ RUN chown -R 1001:1001 /var/log/nginx
 RUN chown -R 1001:1001 /var/lib/nginx
 RUN touch /run/nginx.pid
 RUN chown -R 1001:1001 /run/nginx.pid
+RUN chown -R 1001:1001 /etc/nginx
 
 USER 1001
 

Diff for: examples/nginx-centos7/README.md

@@ -80,3 +80,15 @@ s2i build --incremental=true test/test-app nginx-centos7 nginx-app
 ---> Building and installing application from source...
 ```
 This will run the *save-artifacts* script which includes the custom code to backup the currently running application source, rebuild the application image, and then re-deploy the previously saved source using the *assemble* script.
+
+#### Configuring nginx
+It is possible to configure nginx server itself via this s2i builder image. To do so, simply provide an `nginx.conf` file in the root directory of your application. The `s2i/bin/assemble` will find this configuration file and make nginx use it. See the example configuration file in [test/test-app-redirect/](test/test-app-redirect/) directory. You can build and run it by using these commands:
+
+```
+s2i build test/test-app-redirect nginx-centos7 nginx-centos7-redirect
+docker run -d -p 8080:8080 nginx-centos7-redirect
+```
+
+Going to [http://localhost:8080](http://localhost:8080) should now redirect you to [https://openshift.com](https://openshift.com).
+
+More generally, it is possible to configure any kind of service using s2i, assuming that the provided `assemble` and/or `run` scripts support this and can recognize and use provided configuration files. It's also possible, assuming the s2i image supports it, to provide scripts that get executed by the s2i `run` script to further customize the functionality. Some more advanced examples of this can be found at https://github.com/sclorg/mongodb-container and https://github.com/sclorg/mariadb-container/.

Diff for: examples/nginx-centos7/s2i/bin/assemble

@@ -28,4 +28,9 @@ fi
 # bundle install, and anything else you need.
 
 echo "---> Building and installing application from source..."
-mv /tmp/src/* /usr/share/nginx/html/
+if [ -f /tmp/src/nginx.conf ]; then
+  mv /tmp/src/nginx.conf /etc/nginx/nginx.conf
+fi
+if [ "$(ls -A /tmp/src)" ]; then
+  mv /tmp/src/* /usr/share/nginx/html/
+fi

Diff for: examples/nginx-centos7/test/test-app-redirect/nginx.conf

@@ -0,0 +1,59 @@
+# For more information on configuration, see:
+#   * Official English Documentation: http://nginx.org/en/docs/
+#   * Official Russian Documentation: http://nginx.org/ru/docs/
+
+worker_processes auto;
+error_log /var/log/nginx/error.log;
+pid /run/nginx.pid;
+
+# Load dynamic modules. See /usr/share/doc/nginx/README.dynamic.
+include /usr/share/nginx/modules/*.conf;
+
+events {
+    worker_connections 1024;
+}
+
+http {
+    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
+                      '$status $body_bytes_sent "$http_referer" '
+                      '"$http_user_agent" "$http_x_forwarded_for"';
+
+    access_log  /var/log/nginx/access.log  main;
+
+    sendfile            on;
+    tcp_nopush          on;
+    tcp_nodelay         on;
+    keepalive_timeout   65;
+    types_hash_max_size 2048;
+
+    include             /etc/nginx/mime.types;
+    default_type        application/octet-stream;
+
+    # Load modular configuration files from the /etc/nginx/conf.d directory.
+    # See http://nginx.org/en/docs/ngx_core_module.html#include
+    # for more information.
+    include /etc/nginx/conf.d/*.conf;
+
+    server {
+        listen       8080 default_server;
+        listen       [::]:8080 default_server;
+        server_name  _;
+        root         /usr/share/nginx/html;
+
+        # Load configuration files for the default server block.
+        include /etc/nginx/default.d/*.conf;
+
+        location / {
+            return 301 http://openshift.com;
+        }
+
+        error_page 404 /404.html;
+            location = /40x.html {
+        }
+
+        error_page 500 502 503 504 /50x.html;
+            location = /50x.html {
+        }
+    }
+}
+