Make checking for duplicate IDs optional about wiremock

[holomekc]

Seems like the features also creates issues, if mappings are created from a config map in k8s: holomekc#269

[jrs666666]

Kubernetes mounts a ConfigMap containing just 2 unique stub mappings like this:

root@wiremock-66dc8ccf9b-2z8m2:/home/wiremock/mappings# ls -laR
.:
total 0
drwxrwxrwx. 3 root root 152 Jul  5 13:51 .
drwxr-xr-x. 1 root root  25 Jul  5 13:52 ..
drwxr-xr-x. 2 root root  98 Jul  5 13:51 ..2024_07_05_13_51_53.2567708330
lrwxrwxrwx. 1 root root  32 Jul  5 13:51 ..data -> ..2024_07_05_13_51_53.2567708330
lrwxrwxrwx. 1 root root  23 Jul  5 13:51 jwks.json -> ..data/jwks.json
lrwxrwxrwx. 1 root root  31 Jul  5 13:51 webhook-test.json -> ..data/webhook-test.json

./..2024_07_05_13_51_53.2567708330:
total 12
drwxr-xr-x. 2 root root   98 Jul  5 13:51 .
drwxrwxrwx. 3 root root  152 Jul  5 13:51 ..
-rw-r--r--. 1 root root  264 Jul  5 13:51 jwks.json
-rw-r--r--. 1 root root  432 Jul  5 13:51 webhook-test.json

Wiremock detects soft-linked files as well as the 'real' files inside the hierarchy as duplicates regardless of the file type and identical MD5 checksum:

MB-79-P16:wiremock $ md5sum mappings/..2024_07_05_13_51_53.2567708330/webhook-test.json mappings/webhook-test.json 

eb58ef4b72a411579d764c4d540ca1ae  mappings/..2024_07_05_13_51_53.2567708330/webhook-test.json
eb58ef4b72a411579d764c4d540ca1ae  mappings/webhook-test.json

Exception in thread "main" com.github.tomakehurst.wiremock.common.InvalidInputException: {
  "errors" : [ {
    "code" : 109,
    "title" : "Duplicate stub mapping ID",
    "detail" : "ID of the provided stub mapping '64c23b4a-5f94-427b-8b6e-f8c43ed5529d' is already taken by another stub mapping"
  } ]
}
        at com.github.tomakehurst.wiremock.stubbing.AbstractStubMappings.addMapping(AbstractStubMappings.java:169)
        at com.github.tomakehurst.wiremock.standalone.JsonFileMappingsSource.loadMappingsInto(JsonFileMappingsSource.java:120)
        at com.github.tomakehurst.wiremock.core.WireMockApp.loadMappingsUsing(WireMockApp.java:288)
        at com.github.tomakehurst.wiremock.core.WireMockApp.loadDefaultMappings(WireMockApp.java:282)
        at com.github.tomakehurst.wiremock.core.WireMockApp.<init>(WireMockApp.java:143)
        at com.github.tomakehurst.wiremock.WireMockServer.<init>(WireMockServer.java:74)
        at com.github.tomakehurst.wiremock.standalone.WireMockServerRunner.run(WireMockServerRunner.java:71)
        at wiremock.Run.main(Run.java:23)

My current work-around is using an init-container which find and copy just all real files from the k8s mounted directory to the mappings directory (find /home/wiremock/configmap-mappings/ -type f -exec cp '{}' /home/wiremock/mappings/ \;), which is somehow cumbersome.