From c5c36f6b7afefacb421243b746e94b0cbdf2e3f3 Mon Sep 17 00:00:00 2001 From: darksun Date: Sat, 18 Aug 2018 11:53:04 +0800 Subject: [PATCH] =?UTF-8?q?=E9=80=89=E9=A2=98:=20Cloudgizer:=20An=20introd?= =?UTF-8?q?uction=20to=20a=20new=20open=20source=20web=20development=20too?= =?UTF-8?q?l?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- ... a new open source web development tool.md | 282 ++++++++++++++++++ 1 file changed, 282 insertions(+) create mode 100644 sources/tech/20180817 Cloudgizer- An introduction to a new open source web development tool.md diff --git a/sources/tech/20180817 Cloudgizer- An introduction to a new open source web development tool.md b/sources/tech/20180817 Cloudgizer- An introduction to a new open source web development tool.md new file mode 100644 index 0000000000..3692ad05c5 --- /dev/null +++ b/sources/tech/20180817 Cloudgizer- An introduction to a new open source web development tool.md @@ -0,0 +1,282 @@ +Cloudgizer: An introduction to a new open source web development tool +====== + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/bus_cloud_database.png?itok=lhhU42fg) + +[Cloudgizer][1] is a free open source tool for building web applications. It combines the ease of scripting languages with the performance of [C][2], helping manage the development effort and run-time resources for cloud applications. + +Cloudgizer works on [Red Hat][3]/[CentOS][4] Linux with the [Apache web server][5] and [MariaDB database][6]. It is licensed under [Apache License version 2][7]. + +### Hello World + +In this example, we output an [HTTP][8] header and Hello World, followed by a horizontal line: +``` +#include "cld.h" + +void home() +{ +   /*< +   output-http-header + +   Hello World! +   
+   >*/ +} +``` + +Cloudgizer code is written as a C comment with `/*<` and `>*/` at the beginning and ending, respectively. + +Writing output to the web client is as simple as directly writing [HTML][9] code in your source. There are no API calls or special markups for that—simplicity is good because HTML (or [JavaScript][10], [CSS][11], etc.) will probably comprise a good chunk of your code. + +### How it works + +Cloudgizer source files (with a `.v` extension) are translated into C code by the `cld` command-line tool. C code is then compiled and linked with the web server and your application is ready to be used. For instance, generated code for the source file named `home.v` would be `__home.c`, if you'd like to examine it. + +Much of your code will be written as "markups," small snippets of intuitive and descriptive code that let you easily do things like the following: + + * database queries + * web programming + * encoding and encryption + * executing programs + * safe string manipulation + * file operations + * sending emails + + + +and other common tasks. For less common tasks, there is an API that covers broader functionality. And ultimately, you can write any C code and use any libraries you wish to complete your task. + +The `main()` function is generated by Cloudgizer and is a part of the framework, which provides Apache and database integration and other services. One such service is tracing and debugging (including memory garbage collection, underwrite/overwrite detection, run-time HTML linting, etc.). A program crash produces a full stack, including the source code lines, and the crash report is emailed to you the moment it happens. + +A Cloudgizer application is linked with the Apache server as an Apache module in a pre-fork configuration. This means the Apache web server will pre-fork a number of processes and direct incoming requests to them. The Apache module mechanism provides high-performance request handling for applications. + +All Cloudgizer applications run under the same Linux user, with each application separated under its own application directory. This user is also the Apache user; i.e., the user running the web server. + +Each application has its own database with the name matching that of the application. Cloudgizer establishes and maintains database connections across requests, increasing performance. + +### Development process + +The process of compiling your source code and building an installation file is automated. By using the `cldpackapp` script, you’ll transform your code into pure C code and create an installation file (a [.tar.gz file][12]). The end user will install this file with the help of a configuration file called `appinfo`, producing a working web application. This process is straightforward: + +![](https://opensource.com/sites/default/files/uploads/process_cloudgizer.jpg) + +The deployment process is designed to be automated if needed, with configurable parameters. + +### Getting started + +The development starts with installing [the Example application][13]. This sets up the development environment; you start with a Hello World and build up your application from there. + +The Example application also serves as a smoke test because it has a number of code snippets that test various Cloudgizer features. It also gives you a good amount of example code (hence the name). + +There are two files to be aware of as you start: + + * `cld_handle_request.v` is where incoming requests (such as `GET`, `POST`, or a command-line execution) are processed. + * `sourcelist` lists all your source code so that Cloudgizer can make your application. + + + +In addition to `cld_handle_request.v`, `oops.v` implements an error handler, and `file_too_large.v` implements a response to an upload that's too large. These are already implemented in the Example application, and you can keep them as they are or tweak them. + +Use `cldbuild` to recompile source-file (`.v`) changes, and `cldpackapp` to create an installer file for testing or release delivery via `cldgoapp`: + +![](https://opensource.com/sites/default/files/uploads/how_0_0.jpg) + +Deployment via `cldgoapp` lets you install an application from scratch or update from one version to another. + +### Example + +Here's a stock-ticker application that updates and reports on ticker prices. It is included in the Example application. + +#### The code + +The request handler checks the URL query parameter page, and if it's `stock`, it calls `function stock()`: +``` +#include "cld.h" + +void cld_handle_request() +{ +  /*< +  input-param page +  +  if-string page="stock" +      c stock (); +  else +      report-error "Unrecognized page %s", page +  end-if +  >*/ +} +``` + +The implementation of function `stock()` would be in file `stock.v`. The code adds a stock ticker if the URL query parameter action is `add` or shows all stock tickers if it is `show`. +``` +#include "cld.h" + +void stock() +{ +   /*< + +   output-http-header + +    +        +       input-param action + +       if-string action="add" +           input-param stock_name +           input-param stock_price + +           run-query#add_data = "insert into stock \ +               (stock_name, stock_price) values \ +               (, ) \ +               on duplicate key update \ +               stock_price=" + +               query-result#add_data, error as \ +                   define err + +               if atoi(err) != 0 +                   report-error "Cannot update \ +                       stock price, error [%s]",err +               end-if +           end-query + +           
+               Stock price updated! +           
+       else-if-string action="show" +            +                +                    +                    +                +           run-query#show_data = "select stock_name, \ +               stock_price from stock" + +                +                    +                    +                +           end-query +           
Stock nameStock price
+                   query-result#show_data, stock_name +                    +                   query-result#show_data, stock_price +                   
+       else +           
Unrecognized request!
+       end-if +        +    +   >*/ +} +``` + +#### The database table + +The SQL table used would be: +``` +create table stock (stock_name varchar(100) primary key, stock_price bigint); +``` + +#### Making and packaging + +To include `stock.v` in your Cloudgizer application, simply add it to the sourcelist file: +``` +SOURCE_FILES=stock.v .... +... +stock.o : stock.v $(CLDINCLUDE)/cld.h $(HEADER_FILES) +... +``` + +To recompile changes to your code, use: +``` +cldbuild +``` + +To package your application for deployment, use: +``` +cldpackapp +``` + +When packaging an application, all additional objects you create (other than source code files), should be included in the `create.sh` file. This file sets up anything that the Cloudgizer application installer doesn't do; in this case, create the above SQL table. For example, the following code in your `create.sh` might suffice: +``` +echo -e "drop table if exists stock;\ncreate table stock (stock_name varchar(100) primary key, stock_price bigint);" | mysql -u root -p$CLD_DB_ROOT_PWD -D $CLD_APP_NAME +``` + +In `create.sh`, you can use any variables from the `appinfo` file (an installation configuration file). Those variables always include `CLD_DB_ROOT_PWD` (the root password database, which is always automatically cleared after installation for security), `CLD_APP_NAME` (the application and database name), `CLD_SERVER` (the URL of the installation server), `CLD_EMAIL` (the administration and notification email address), and others. You also have `CLD_APP_HOME_DIR` (the application's home directory) and `CLD_APP_INSTALL_DIR` (the location where the installation .tar.gz file had been unzipped so you can copy files from it). You can include any other variables in the `appinfo` file that you find useful. + +#### Using the application + +If your application name is 'myapp' running on myserver.com, then the URL to update a stock ticker would be this: +``` +https://myserver.com/go.myapp?page=stock&action=add&stock_name=RHT&stock_price=500 +``` + +and the URL to show all stock tickers would be this: +``` +https://myserver.com/go.myapp?page=stock&action=show +``` + +(The URL path for all Cloudgizer applications always starts with `go.`; in this case, `go.myapp`.) + +### Download and more examples + +For more examples or download and installation details, visit [Zigguro.org/cloudgizer][14]. You'll also find the above example included in the installation (see [the Example application source code][15]). + +For a much larger real-world example, check out the [source code][16] for [Rentomy][17], a free open source cloud application for rental property managers, written entirely in Cloudgizer and consisting of over 32,000 lines of code. + +### Why use Cloudgizer? + +Here's why Rentomy is written in Cloudgizer: + +Originally, the goal was to use one of the popular [scripting languages][18] or [process virtual machines][19] like [Java][20], and to host Rentomy as a [Software-as-a-Service][21] (Saas) free of charge. + +Since there are nearly 50 million rental units in the US alone, a free service like this needs superior software performance. + +So squeezing more power from CPUs and using less RAM became very important. And with [Moore's Law slowing down][22], the bloat of popular web languages is costing more computing resources—we're talking about process-virtual machines, interpreters, [p-code generators][23], etc. + +Debugging can be a pain because more layers of abstraction exist between you and what's really going on. Not every library can be easily used, so some functional and interoperability limitations remain. + +On the other hand, in terms of big performance and a small footprint, there is no match for C. Most libraries are written in C for the same reason, so virtually any library you need is available, and debugging is straightforward. + +However, C has issues with memory and overall safety (overwrites, underwrites, garbage collection, etc.), usability (it is low-level), application packaging, etc. And equally important, much of the development cost lies in the ease of writing and debugging the code and in its accessibility to novices. + +From this perspective, Cloudgizer was born. Greater performance and a smaller footprint mean cheaper computing power. Easy, stable coding brings Zen to the development process, as does the ability to manage it better. + +In hindsight, using Cloudgizer to build Rentomy was like using a popular scripting language without the issues. + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/18/8/cloudgizer-intro + +作者：[Sergio Mijares][a] +选题：[lujun9972](https://github.com/lujun9972) +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:https://opensource.com/users/sergio-mijares +[1]:https://zigguro.org/cloudgizer/ +[2]:https://en.wikipedia.org/wiki/C_%28programming_language%29 +[3]:https://www.redhat.com/en +[4]:https://www.centos.org/ +[5]:http://httpd.apache.org/ +[6]:https://mariadb.com/ +[7]:http://www.apache.org/licenses/LICENSE-2.0 +[8]:https://en.wikipedia.org/wiki/Hypertext_Transfer_Protocol +[9]:https://en.wikipedia.org/wiki/HTML +[10]:https://en.wikipedia.org/wiki/JavaScript +[11]:https://en.wikipedia.org/wiki/Cascading_Style_Sheets +[12]:https://opensource.com/article/17/7/how-unzip-targz-file +[13]:https://zigguro.org/cloudgizer/#install +[14]:https://zigguro.org/cloudgizer +[15]:https://bitbucket.org/zigguro/cloudgizer_example/src +[16]:https://bitbucket.org/zigguro/rentomy/src +[17]:https://zigguro.org/rentomy/ +[18]:https://en.wikipedia.org/wiki/Scripting_language +[19]:https://en.wikipedia.org/wiki/Virtual_machine +[20]:https://www.java.com/en/ +[21]:https://en.wikipedia.org/wiki/Software_as_a_service +[22]:https://www.engineering.com/ElectronicsDesign/ElectronicsDesignArticles/ArticleID/17209/DARPAs-100-Million-Programs-for-a-Silicon-Compiler-and-a-New-Open-Hardware-Ecosystem.aspx +[23]:https://en.wikipedia.org/wiki/P-code_machine