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https://issues.apache.org/jira/browse/HBASE-28977?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17898667#comment-17898667
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Dávid Paksy commented on HBASE-28977:
-------------------------------------
h2. In short
*It does not work with our way of shading of JAX-RS libraries.* Maybe we could
make it work if we would add swagger-core to our
[https://github.com/apache/hbase-thirdparty] repository and shade it as well.
But this may be too much effort compared to the value.
h2. What is OpenAPI / Swagger
{quote}*OpenAPI Specification* (formerly Swagger Specification) is an API
description format for REST APIs. An OpenAPI file allows you to describe your
entire API
{quote}
[https://swagger.io/docs/specification/v3_0/about/]
Interesting parts for us:
- [Swagger Core|https://github.com/swagger-api/swagger-core] – Java-related
libraries for creating, consuming, and working with OpenAPI definitions.
- [Swagger UI|https://github.com/swagger-api/swagger-ui] – renders OpenAPI
definitions as interactive documentation.
h2. Value
Having the OpenAPI JSON / YAML file would allow:
* developers to import the file to PostMan (REST client) and try HBase REST
API quickly.
* to generate REST API clients in the supported programming languages:
[https://swagger.io/tools/open-source/open-source-integrations/]
* render OpenAPI definitions as interactive (playground) web documentation
page.
h2. Manually create OpenAPI
One option is to write the JSON / YAML file based on the
[specification|https://swagger.io/docs/specification/v3_0/basic-structure/] but
this is time consuming and then the file will have to maintained later when
there are changes to the REST API (and likely to be forgotten).
h2. Runtime integration
If you add it to the JAX-RS Java project, it will add a servlet which can serve
the OpenAPI JSON (or YAML) file based on the automatically detected the JAX-RS
annotations (Path, GET, POST, DELETE, Produces, etc) in the application.
(The OpenAPI JSON file could be used with [Swagger
UI|https://github.com/swagger-api/swagger-ui] to render the interactive
documentation.)
Integration was based on:
*
[https://github.com/swagger-api/swagger-core/wiki/Swagger-2.X---Getting-started]
*
[https://github.com/swagger-api/swagger-core/wiki/Swagger-2.X---Integration-and-Configuration]
*
[https://anirtek.github.io/java/jetty/swagger/openapi/2021/06/12/Hooking-up-OpenAPI-with-Jetty.html]
It can be seen in this PR how it is integrated:
[https://github.com/PDavid/hbase/pull/1]
Problem: When we add OpenAPI library and the servlet, we face with this:
{code:java}
2024-11-15T15:32:33,436 WARN [qtp1989332276-50 {}] server.HttpChannel: /openapi
java.lang.NoClassDefFoundError: javax/ws/rs/Path
at io.swagger.v3.jaxrs2.Reader.read(Reader.java:285)
~[swagger-jaxrs2-2.2.25.jar:2.2.25]
at io.swagger.v3.jaxrs2.Reader.read(Reader.java:199)
~[swagger-jaxrs2-2.2.25.jar:2.2.25]
at io.swagger.v3.jaxrs2.Reader.read(Reader.java:228)
~[swagger-jaxrs2-2.2.25.jar:2.2.25]
at
io.swagger.v3.oas.integration.GenericOpenApiContext.read(GenericOpenApiContext.java:693)
~[swagger-integration-2.2.25.jar:2.2.25]
at
io.swagger.v3.jaxrs2.integration.OpenApiServlet.doGet(OpenApiServlet.java:55)
~[swagger-jaxrs2-2.2.25.jar:2.2.25]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
~[javax.servlet-api-3.1.0.jar:3.1.0]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
~[javax.servlet-api-3.1.0.jar:3.1.0]
at
org.apache.hbase.thirdparty.org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:799)
~[hbase-shaded-jetty-4.1.9.jar:?]
at
org.apache.hbase.thirdparty.org.eclipse.jetty.servlet.ServletHandler$ChainEnd.doFilter(ServletHandler.java:1656)
~[hbase-shaded-jetty-4.1.9.jar:?]
...
at
org.apache.hbase.thirdparty.org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1034)
~[hbase-shaded-jetty-4.1.9.jar:?]
at java.lang.Thread.run(Thread.java:840) ~[?:?]
Caused by: java.lang.ClassNotFoundException: javax.ws.rs.Path
at
jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
~[?:?]
at
jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
~[?:?]
at java.lang.ClassLoader.loadClass(ClassLoader.java:525) ~[?:?]
... 44 more
{code}
The OpenAPI / Swagger code directly depends on JAX-RS classes such as
{{javax.ws.rs.Path}} but HBase REST uses shaded thirdparty version of these
({{{}org.apache.hbase.thirdparty.javax.ws.rs.Path{}}}).
Even if we add the {{javax.ws.rs:javax.ws.rs-api}} library to the HBase REST
project, the generated openapi JSON file will not contain, just the metadata
(without any useful endpoints) because the OpenAPI / Swagger code only
considers JAX-RS annotations.
Also tried to add some Swagger annotations based on
https://github.com/swagger-api/swagger-core/wiki/Swagger-2.X—Annotations but
this did not help.
Maybe we could make it work if we would add swagger-core to our
[https://github.com/apache/hbase-thirdparty] repository and shade it as well.
This I did not yet tried.
h2. Build-time integration
There is a Swagger Maven plugin which can be added to the build which builds
the file:
{{swagger-maven-plugin}} ({*}since 2.0.5{*}): provides a maven plugin to
resolve an OpenAPI definition at build time (using {{{}swagger-jaxrs2{}}}).
Please see [module
readme|https://github.com/swagger-api/swagger-core/tree/master/modules/swagger-maven-plugin/README.md]
However adding it requires also adding the {{javax.ws.rs:javax.ws.rs-api}}
library to the HBase REST project otherwise the build will fail:
{code:java}
[ERROR] Failed to execute goal
io.swagger.core.v3:swagger-maven-plugin:2.2.25:resolve (default-cli) on project
hbase-rest: Execution default-cli of goal
io.swagger.core.v3:swagger-maven-plugin:2.2.25:resolve failed: A required class
was missing while executing
io.swagger.core.v3:swagger-maven-plugin:2.2.25:resolve: javax/ws/rs/Path {code}
If the JAX-RS library is added, then the build will be successful but the same
problem: the generated openapi JSON file will not contain, just the metadata
(without any useful endpoints) because the OpenAPI / Swagger code only
considers JAX-RS annotations.
Also tried to add some Swagger annotations based on
https://github.com/swagger-api/swagger-core/wiki/Swagger-2.X—Annotations but
this did not help.
> Investigate integrating OpenAPI / Swagger to hbase-rest
> -------------------------------------------------------
>
> Key: HBASE-28977
> URL: https://issues.apache.org/jira/browse/HBASE-28977
> Project: HBase
> Issue Type: Improvement
> Components: REST
> Reporter: Dávid Paksy
> Assignee: Dávid Paksy
> Priority: Major
>
> Using OpenAPI / Swagger it would be possible to generate a schema file of
> HBase REST API.
> In theory the generated schema file could be used as documentation /
> generating API clients.
> Even Swagger UI could be used to have an interactive playground for the HBase
> REST API.
> Check how much HBase could gain having this.
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