openapi-merge-cli

openapi-merge-cli

This tool is based on the library. Please read that README for more details.

This library is intended to be used for merging multiple OpenAPI 3.0 files together. The most common reason that developers want to do this is because they have multiple services that they wish to expose underneath a single API Gateway. Therefore, even though this merging logic is sufficiently generic to be used for most use cases, some of the feature decisions are tailored for that specific use case.

Getting started

In order to use this merging cli tool you need to have one or more OpenAPI 3.0 files that you wish to merge. Then you need to create a configuration file, called openapi-merge.json by default, in your current directory. It should look something like this:

{
  "inputs": [
    {
      "inputFile": "./gateway.swagger.json"
    },
    {
      "inputFile": "./jira.swagger.json",
      "pathModification": {
        "stripStart": "/rest",
        "prepend": "/jira"
      },
      "operationSelection": {
        "includeTags": ["included"]
      }
    },
    {
      "inputFile": "./confluence.swagger.json",
      "disputePrefix": "Confluence",
      "pathModification": {
        "prepend": "/confluence"
      },
      "operationSelection": {
        "excludeTags": ["excluded"]
      }
    }
  ], 
  "output": "./output.swagger.json"
}

In this configuration you specify your inputs and your output file. For each input you have the following parameters:

• inputFile: the relative path, from the openapi-merge.json, to the OpenAPI schema file for that input.
• disputePrefix: if two inputs both define a component with the same name then, in order to prevent incorrect overlaps, we will attempt to use the dispute prefix to come up with a unique name for that component.
• pathModification.stripStart: When copying over the paths from your OpenAPI specification for this input, it will strip this string from the start of the path if it is found.
• pathModification.prepend: When copying over the paths from your OpenAPI specification for this input, it will prepend this string to the start of the path if it is found. prepend will always run after stripStart so that it is deterministic.
• operationSelection.includeTags: Only operations that are tagged with the tags configured here will be extracted from the OpenAPI file and merged with the others.
• operationSelection.excludeTags: Only operations that are NOT tagged with the tags configured here will be extracted from the OpenAPI file and merged with the others. Also, these tags will also be removed from the top level tags element for this file before being merged. If a single REST API operation has an includeTags reference and an excludeTags reference then the exclusion rule will take precidence.

And then, once you have your Inputs in place and your configuration file you merely run the following in the directory that has your configuration file:

npx openapi-merge-cli

And the merge should be run and complete! Congratulations and enjoy!

If you experience any issues then please raise them in the bug tracker.