adding docs for init-wrapper script

14-minimal/README.md

@@ -316,6 +316,47 @@ Below is an example _package.json_ file with the _main_ attribute and _start_ sc
 #### Note:
 `oc rsync` is only available in versions 3.1+ of OpenShift.
 
+## init-wrapper
+
+init-wrapper script is located on `/usr/libexec/s2i/init-wrapper` and is used for preventing below circumstances:
+
+- Proper signal handling and propagation, as Node.js was not designed to run as PID 1.
+- Reaping zombie child processes
+- Avoiding use of npm, more information on [reference architecture](https://github.com/nodeshift/nodejs-reference-architecture/blob/e4c4dc1fd20c2cac392e862859aaad27f85d504f/docs/development/building-good-containers.md#avoiding-using-npm-to-start-application)
+
+A detailed explanation on how the init-wrapper script works is avalable on [this url](http://veithen.io/2014/11/16/sigterm-propagation.html).
+
+Example of using init-wrapper:
+
+**During image build**
+```
+s2i -e INIT_WRAPPER=true build . buildImage  node-app
+docker run node-app
+```
+**During container start**
+```
+s2i build . buildImage  node-app
+docker run -e INIT_WRAPPER=true  node-app
+```
+
+`init-wrapper` script can be disabled by setting the `INIT_WRAPPER` env variable to `false`.
+
+```
+docker run -e INIT_WRAPPER=false node-app
+```
+`NODE_CMD` can be used during the build process or container start, in order to have more control on the command that `init-wrapper` script will wrap.
+
+For example:
+
+**during container build**
+```
+s2i -e INIT_WRAPPER=true -e NODE_CMD="node index.js" build . buildImage  node-app
+
+```
+**during container start** 
+```
+docker run -e INIT_WRAPPER=false -e NODE_CMD="node index.js" node-app
+```
 
 See also
 --------

14/README.md

@@ -143,7 +143,7 @@ Application developers can use the following environment variables to configure
        Select an alternate / custom runtime mode, defined in your `package.json` file's [`scripts`](https://docs.npmjs.com/misc/scripts) section (default: npm run "start"). These user-defined run-scripts are unavailable while `DEV_MODE` is in use.
 
 **`NODE_CMD`**  
-       When specified (e.g.Specify `NODE_CMD="node server.js"`) the `NODE_CMD` is executed by the `init-wrapper` script, which handles reaping zombie processes and signal forwarding (SIGINT, SIGTERM) to Node.js application.
+       When specified e.g. `NODE_CMD="node server.js"` the application will start by using the command `node server.js`.
 
 **`HTTP_PROXY`**  
        Use an npm proxy during assembly
@@ -154,6 +154,10 @@ Application developers can use the following environment variables to configure
 **`NPM_MIRROR`**  
        Use a custom NPM registry mirror to download packages during the build process
 
+**`INIT_WRAPPER`**  
+       When set to "true", it will look for the files `server.js`, `index.js` or `main.js` in the aforementioned order and in case any of these files are available, it will wrap the command `node $file_found`, by using the `init-wrapper` script.
+       It can also be used in conjuction with `NODE_CMD` option where in that case, `init-wrapper` will wrap the value of `NODE_CMD`.
+
 One way to define a set of environment variables is to include them as key value pairs in your repo's `.s2i/environment` file.
 
 Example: DATABASE_USER=sampleUser
@@ -244,6 +248,47 @@ Below is an example _package.json_ file with the _main_ attribute and _start_ sc
 #### Note:
 `oc rsync` is only available in versions 3.1+ of OpenShift.
 
+## init-wrapper
+
+init-wrapper script is located on `/usr/libexec/s2i/init-wrapper` and is used for preventing below circumstances:
+
+- Proper signal handling and propagation, as Node.js was not designed to run as PID 1.
+- Reaping zombie child processes
+- Avoiding use of npm, more information on [reference architecture](https://github.com/nodeshift/nodejs-reference-architecture/blob/e4c4dc1fd20c2cac392e862859aaad27f85d504f/docs/development/building-good-containers.md#avoiding-using-npm-to-start-application)
+
+A detailed explanation on how the init-wrapper script works is avalable on [this url](http://veithen.io/2014/11/16/sigterm-propagation.html).
+
+Example of using init-wrapper:
+
+**During image build**
+```
+s2i -e INIT_WRAPPER=true build . buildImage  node-app
+docker run node-app
+```
+**During container start**
+```
+s2i build . buildImage  node-app
+docker run -e INIT_WRAPPER=true  node-app
+```
+
+`init-wrapper` script can be disabled by setting the `INIT_WRAPPER` env variable to `false`.
+
+```
+docker run -e INIT_WRAPPER=false node-app
+```
+`NODE_CMD` can be used during the build process or container start, in order to have more control on the command that `init-wrapper` script will wrap.
+
+For example:
+
+**during container build**
+```
+s2i -e INIT_WRAPPER=true -e NODE_CMD="node index.js" build . buildImage  node-app
+
+```
+**during container start** 
+```
+docker run -e INIT_WRAPPER=false -e NODE_CMD="node index.js" node-app
+```
 
 See also
 --------

16-minimal/README.md

@@ -317,6 +317,47 @@ Below is an example _package.json_ file with the _main_ attribute and _start_ sc
 #### Note:
 `oc rsync` is only available in versions 3.1+ of OpenShift.
 
+## init-wrapper
+
+init-wrapper script is located on `/usr/libexec/s2i/init-wrapper` and is used for preventing below circumstances:
+
+- Proper signal handling and propagation, as Node.js was not designed to run as PID 1.
+- Reaping zombie child processes
+- Avoiding use of npm, more information on [reference architecture](https://github.com/nodeshift/nodejs-reference-architecture/blob/e4c4dc1fd20c2cac392e862859aaad27f85d504f/docs/development/building-good-containers.md#avoiding-using-npm-to-start-application)
+
+A detailed explanation on how the init-wrapper script works is avalable on [this url](http://veithen.io/2014/11/16/sigterm-propagation.html).
+
+Example of using init-wrapper:
+
+**During image build**
+```
+s2i -e INIT_WRAPPER=true build . buildImage  node-app
+docker run node-app
+```
+**During container start**
+```
+s2i build . buildImage  node-app
+docker run -e INIT_WRAPPER=true  node-app
+```
+
+`init-wrapper` script can be disabled by setting the `INIT_WRAPPER` env variable to `false`.
+
+```
+docker run -e INIT_WRAPPER=false node-app
+```
+`NODE_CMD` can be used during the build process or container start, in order to have more control on the command that `init-wrapper` script will wrap.
+
+For example:
+
+**during container build**
+```
+s2i -e INIT_WRAPPER=true -e NODE_CMD="node index.js" build . buildImage  node-app
+
+```
+**during container start** 
+```
+docker run -e INIT_WRAPPER=false -e NODE_CMD="node index.js" node-app
+```
 
 See also
 --------

16/README.md

@@ -244,6 +244,47 @@ Below is an example _package.json_ file with the _main_ attribute and _start_ sc
 #### Note:
 `oc rsync` is only available in versions 3.1+ of OpenShift.
 
+## init-wrapper
+
+init-wrapper script is located on `/usr/libexec/s2i/init-wrapper` and is used for preventing below circumstances:
+
+- Proper signal handling and propagation, as Node.js was not designed to run as PID 1.
+- Reaping zombie child processes
+- Avoiding use of npm, more information on [reference architecture](https://github.com/nodeshift/nodejs-reference-architecture/blob/e4c4dc1fd20c2cac392e862859aaad27f85d504f/docs/development/building-good-containers.md#avoiding-using-npm-to-start-application)
+
+A detailed explanation on how the init-wrapper script works is avalable on [this url](http://veithen.io/2014/11/16/sigterm-propagation.html).
+
+Example of using init-wrapper:
+
+**During image build**
+```
+s2i -e INIT_WRAPPER=true build . buildImage  node-app
+docker run node-app
+```
+**During container start**
+```
+s2i build . buildImage  node-app
+docker run -e INIT_WRAPPER=true  node-app
+```
+
+`init-wrapper` script can be disabled by setting the `INIT_WRAPPER` env variable to `false`.
+
+```
+docker run -e INIT_WRAPPER=false node-app
+```
+`NODE_CMD` can be used during the build process or container start, in order to have more control on the command that `init-wrapper` script will wrap.
+
+For example:
+
+**during container build**
+```
+s2i -e INIT_WRAPPER=true -e NODE_CMD="node index.js" build . buildImage  node-app
+
+```
+**during container start** 
+```
+docker run -e INIT_WRAPPER=false -e NODE_CMD="node index.js" node-app
+```
 
 See also
 --------

18-minimal/README.md

@@ -316,6 +316,47 @@ Below is an example _package.json_ file with the _main_ attribute and _start_ sc
 #### Note:
 `oc rsync` is only available in versions 3.1+ of OpenShift.
 
+## init-wrapper
+
+init-wrapper script is located on `/usr/libexec/s2i/init-wrapper` and is used for preventing below circumstances:
+
+- Proper signal handling and propagation, as Node.js was not designed to run as PID 1.
+- Reaping zombie child processes
+- Avoiding use of npm, more information on [reference architecture](https://github.com/nodeshift/nodejs-reference-architecture/blob/e4c4dc1fd20c2cac392e862859aaad27f85d504f/docs/development/building-good-containers.md#avoiding-using-npm-to-start-application)
+
+A detailed explanation on how the init-wrapper script works is avalable on [this url](http://veithen.io/2014/11/16/sigterm-propagation.html).
+
+Example of using init-wrapper:
+
+**During image build**
+```
+s2i -e INIT_WRAPPER=true build . buildImage  node-app
+docker run node-app
+```
+**During container start**
+```
+s2i build . buildImage  node-app
+docker run -e INIT_WRAPPER=true  node-app
+```
+
+`init-wrapper` script can be disabled by setting the `INIT_WRAPPER` env variable to `false`.
+
+```
+docker run -e INIT_WRAPPER=false node-app
+```
+`NODE_CMD` can be used during the build process or container start, in order to have more control on the command that `init-wrapper` script will wrap.
+
+For example:
+
+**during container build**
+```
+s2i -e INIT_WRAPPER=true -e NODE_CMD="node index.js" build . buildImage  node-app
+
+```
+**during container start** 
+```
+docker run -e INIT_WRAPPER=false -e NODE_CMD="node index.js" node-app
+```
 
 See also
 --------

18/README.md

@@ -244,6 +244,47 @@ Below is an example _package.json_ file with the _main_ attribute and _start_ sc
 #### Note:
 `oc rsync` is only available in versions 3.1+ of OpenShift.
 
+## init-wrapper
+
+init-wrapper script is located on `/usr/libexec/s2i/init-wrapper` and is used for preventing below circumstances:
+
+- Proper signal handling and propagation, as Node.js was not designed to run as PID 1.
+- Reaping zombie child processes
+- Avoiding use of npm, more information on [reference architecture](https://github.com/nodeshift/nodejs-reference-architecture/blob/e4c4dc1fd20c2cac392e862859aaad27f85d504f/docs/development/building-good-containers.md#avoiding-using-npm-to-start-application)
+
+A detailed explanation on how the init-wrapper script works is avalable on [this url](http://veithen.io/2014/11/16/sigterm-propagation.html).
+
+Example of using init-wrapper:
+
+**During image build**
+```
+s2i -e INIT_WRAPPER=true build . buildImage  node-app
+docker run node-app
+```
+**During container start**
+```
+s2i build . buildImage  node-app
+docker run -e INIT_WRAPPER=true  node-app
+```
+
+`init-wrapper` script can be disabled by setting the `INIT_WRAPPER` env variable to `false`.
+
+```
+docker run -e INIT_WRAPPER=false node-app
+```
+`NODE_CMD` can be used during the build process or container start, in order to have more control on the command that `init-wrapper` script will wrap.
+
+For example:
+
+**during container build**
+```
+s2i -e INIT_WRAPPER=true -e NODE_CMD="node index.js" build . buildImage  node-app
+
+```
+**during container start** 
+```
+docker run -e INIT_WRAPPER=false -e NODE_CMD="node index.js" node-app
+```
 
 See also
 --------