# Dynamic configuration - setting up dynamic mapping

**URL:** <https://discuss.circleci.com/t/dynamic-configuration-setting-up-dynamic-mapping/41501>\
**Category:** Build Environment\
**Tags:** dynamic-config\
**Created:** [October 11, 2021, 3:24pm UTC](https://discuss.circleci.com/t/dynamic-configuration-setting-up-dynamic-mapping/41501 "2021-10-11T15:24:59Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![shakedk](https://sea2.discourse-cdn.com/circleci/user_avatar/discuss.circleci.com/shakedk/32/28355_2.png) [@shakedk](https://discuss.circleci.com/u/shakedk)\
**Post date:** [October 11, 2021, 3:24pm UTC](https://discuss.circleci.com/t/dynamic-configuration-setting-up-dynamic-mapping/41501/1 "2021-10-11T15:24:59Z")

</div>

We have a monorepo with new services added regularly, each one is under a new folder. I was going to use dynamic configuration to trigger workflows/jobs according to the changed path. I’ve been following this [tutorial](https://medium.com/nerd-for-tech/mastering-monorepos-with-circlecis-new-dynamic-config-2e187fe7934c).

My problem is that I don’t want developers to edit the config file every time a new service is added. In the example below 4 paths are mapped to 4 parameters that are used to trigger workflows, but I must know the paths and parameter names in advance.

```auto
workflows:
  setup:
    jobs:
      - path-filtering/filter:
          base-revision: master
          mapping: |
            data/.* config-data-modified true
            service/common/.* service-layer-modified true
            service/site-api/.* run-site-api-workflow true
            service/batch/.* run-batch-services-workflow true

```

Is there any way to generate this mapping on the fly?  
Let’s say there was a change in a file under the path ‘service/new\_service’. So I would want the setup config file to get the changed paths from git, and generate the correct mapping:

```auto
            service/new_service/.* run-new_service-workflow true

```

as if I gave it a pattern:

```auto
            service/<git-param-of-changed-folder-name->/.* run-<git-param-of-changed-folder-name->-workflow true

```

Another possible solution is that I will have a script that builds the needed continuation yaml file with the required jobs, but I still need my script to know the names of changed protocols coming from git so I can only run the needed tests.

Any ways to achieve this?

---

<div class="post-metadata">

**Author:** ![salil](https://avatars.discourse-cdn.com/v4/letter/s/c89c15/32.png) [@salil](https://discuss.circleci.com/u/salil)\
**Post date:** [October 18, 2021, 5:27pm UTC](https://discuss.circleci.com/t/dynamic-configuration-setting-up-dynamic-mapping/41501/2 "2021-10-18T17:27:18Z")

</div>

The best way to do this would be to avoid the path-filtering orb and instead use the underlying feature, [dynamic config](https://circleci.com/docs/2.0/dynamic-config/). The path-filtering filter job just does the following:

1. Use git diff to determine what has changed between the pushed SHA and the base revision
2. Using a python script that takes the `mapping`, compares against that list of changed files, and determines what pipeline parameters need to be set
3. Exports that list of pipeline parameters to a json file
4. Runs the [continuation/continue](https://circleci.com/developer/orbs/orb/circleci/continuation) command with that file.

If you create a script that does steps 1-3 with the logic you want and wrap it in a job that runs the script and the `continue` command, that should achieve your desired outcome.