{"id":391714,"date":"2024-06-29T09:59:22","date_gmt":"2024-06-29T09:59:22","guid":{"rendered":"http:\/\/savepearlharbor.com\/?p=391714"},"modified":"-0001-11-30T00:00:00","modified_gmt":"-0001-11-29T21:00:00","slug":"","status":"publish","type":"post","link":"https:\/\/savepearlharbor.com\/?p=391714","title":{"rendered":"Modern COBOL: Microservice Tutorial<\/span>"},"content":{"rendered":"
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You will learn and implement a microservice in COBOL without Mainframe. You will structure the project, manage dependencies, implement automatic tests and build virtualized execution environment. Finally, you will publish the microservice on GitHub under Continuous Integration workflow.<\/p>\n

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Preconditions<\/h3>\n

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You have learned basic principles, methods and standards of COBOL. In this tutorial we\u2019ll use GnuCOBOL<\/strong> \u2014 a free COBOL compiler which implements a substantial part of the COBOL 85, COBOL 2002 and COBOL 2014 standards and X\/Open COBOL, as well as many extensions included in other COBOL compilers.<\/p>\n

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You are familiar with HTTP protocol<\/strong> \u2014 request and response formats.<\/p>\n

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You have Docker<\/strong>, a command-line virtualization tool, installed.<\/p>\n

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You have NPM<\/strong>, a package manager for JavaScript programming language, installed.<\/p>\n

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You have Git<\/strong>, an open source distributed version control client, installed.<\/p>\n

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You have GitHub<\/strong> account for publishing of the microservice.<\/p>\n

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You may use any text editor you like, but I recommend Visual Studio Code<\/strong> (or its open-source version VSCodium<\/strong>) with COBOL-syntax extension bitlang.cobol<\/em> installed.<\/p>\n

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TLDR<\/h3>\n

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Complete source-code of this tutorial you can see on GitHub<\/a>.<\/p>\n

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Specifications<\/h2>\n

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One of strengths of COBOL is a decimal mathematics. In this tutorial we\u2019ll create a high-precision currency exchange microservice that exposes HTTP API and returns EUR amount in JSON format.<\/p>\n

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Let\u2019s say, the microservice awaits HTTP request GET \/currency\/amount<\/em> on port 8000<\/em> and respond JSON {«amount»: amount}<\/em>, where<\/p>\n

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