Added support for msearch API to pass search pipeline name

[owaiskazi19]

Description

Added support for msearch API to pass search pipeline name.
With this change a search pipeline name can be provided while making a msearch call

{ "index": "test"}
{ "query": { "match_all": {} }, "from": 0, "size": 10, "search_pipeline": "my_pipeline"}
{ "index": "test-1", "search_type": "dfs_query_then_fetch"}
{ "query": { "match_all": {} }, "search_pipeline": "my_pipeline1" }

Related Issues

Resolves #15748

Check List

• Functionality includes testing.
• API changes companion pull request created, if applicable.
• Public documentation issue/PR created, if applicable. - Adds documentation for providing search pipeline id in the search/msearch request documentation-website#8372

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and signing off your commits, please check here.

[github-actions]

❌ Gradle check result for a6a64ee: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

[github-actions]

❕ Gradle check result for a6a64ee: UNSTABLE

Please review all flaky tests that succeeded after retry and create an issue if one does not already exist to track the flaky failure.

[codecov]

Codecov Report

Attention: Patch coverage is 70.58824% with 5 lines in your changes missing coverage. Please review.

Project coverage is 71.98%. Comparing base (1bc81d3) to head (a6a64ee).
Report is 175 commits behind head on main.

Files with missing lines	Patch %	Lines
...opensearch/search/builder/SearchSourceBuilder.java	78.57%	0 Missing and 3 partials ⚠️
...g/opensearch/action/search/MultiSearchRequest.java	0.00%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main   #15923      +/-   ##
============================================
+ Coverage     71.96%   71.98%   +0.02%     
- Complexity    64391    64418      +27     
============================================
  Files          5280     5280              
  Lines        300866   300886      +20     
  Branches      43474    43480       +6     
============================================
+ Hits         216510   216589      +79     
+ Misses        66639    66495     -144     
- Partials      17717    17802      +85     

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[owaiskazi19]

@msfroh can I get another review on this?

[msfroh]

Nice! Thanks, @owaiskazi19!

[opensearch-trigger-bot]

The backport to 2.x failed:

The process '/usr/bin/git' failed with exit code 128

To backport manually, run these commands in your terminal:

# Navigate to the root of your repository
cd $(git rev-parse --show-toplevel)
# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add ../.worktrees/OpenSearch/backport-2.x 2.x
# Navigate to the new working tree
pushd ../.worktrees/OpenSearch/backport-2.x
# Create a new branch
git switch --create backport/backport-15923-to-2.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 daf1669b7ca77c62fc82ba9162d3708702b13fce
# Push it to GitHub
git push --set-upstream origin backport/backport-15923-to-2.x
# Go back to the original working tree
popd
# Delete the working tree
git worktree remove ../.worktrees/OpenSearch/backport-2.x

Then, create a pull request where the base branch is 2.x and the compare/head branch is backport/backport-15923-to-2.x.

[owaiskazi19]

@msfroh
2.x PR: #16085
BWC version change PR to main: #16086

[msfroh]

@msfroh

2.x PR: #16085

BWC version change PR to main: #16086

@owaiskazi19 I'll merge both of these tomorrow morning. I've made the mistake of merging the first PR then going to sleep a few too many times. 😀

[dblock]

This is an API change, isn't it? It needs changes in api-specification repo please?