feat: elasticsearch exporter

[csatib02]

Adds support for the elasticsearch exporter.

The current handling of secrets, such as credentials from basicAuth or bearerAuth extension were stored as plaintext in config. I've adjusted it in a non breaking way.

• The secrets can be mounted from a secret just as before.
• The operator manages a secret/collector, that contains the same values, but under different keys.
• The keys are mounted as env-vars in the collector, essentially hiding them.

Manually tested with the commited demo.

curl -sk -u elastic:qG6N8rDL80QYLuZp -X POST "https://localhost:9200/logs-generic-default/_search?pretty" \
  -H 'Content-Type: application/json' \
  -d '{"size": 5, "sort": [{"@timestamp": {"order": "desc"}}]}'

{
  "took" : 965,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 2007,
      "relation" : "eq"
    },
    "max_score" : null,
    "hits" : [
      {
        "_index" : ".ds-logs-generic-default-2026.03.04-000001",
        "_id" : "9TFluZwBSf2q5Fw9J94V",
        "_score" : null,
        "_source" : {
          "@timestamp" : "2026-03-04T15:08:59.889076097Z",
          "agent" : {
            "name" : "otlp"
          },
          "data_stream" : {
            "dataset" : "generic",
            "namespace" : "default",
            "type" : "logs"
          },
          "exporter" : "elasticsearch/tenant-es-demo_elasticsearch",
          "k8s" : {
            "container" : {
              "restart_count" : "0"
            },
            "pod" : {
              "labels" : {
                "app" : {
                  "kubernetes" : {
                    "io/instance" : "log-generator",
                    "io/name" : "log-generator"
                  }
                },
                "pod-template-hash" : "988b67d7c"
              },
              "start_time" : "2026-03-04T14:07:27Z"
            }
          },
          "kubernetes" : {
            "container" : {
              "name" : "log-generator"
            },
            "deployment" : {
              "name" : "log-generator"
            },
            "namespace" : "tenant-es-demo",
            "node" : {
              "name" : "kind-control-plane"
            },
            "pod" : {
              "name" : "log-generator-988b67d7c-gdx4b",
              "uid" : "8819071a-0246-4f1a-bb38-f779b3faf56e"
            }
          },
          "log" : {
            "file" : {
              "path" : "/var/log/pods/tenant-es-demo_log-generator-988b67d7c-gdx4b_8819071a-0246-4f1a-bb38-f779b3faf56e/log-generator/0.log"
            },
            "iostream" : "stdout"
          },
          "logtag" : "F",
          "message" : "112.222.204.97 - - [04/Mar/2026:15:08:59 +0000] \"GET /blog HTTP/1.1\" 404 15589 \"-\" \"Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:52.0) Gecko/20100101 Firefox/52.0\" \"-\"",
          "subscription" : "all-logs",
          "tenant" : "es-demo",
          "time" : "2026-03-04T15:08:59.889076097Z"
        },
        "sort" : [
          1772636939889
        ]
      },
      {
        "_index" : ".ds-logs-generic-default-2026.03.04-000001",
        "_id" : "9DFluZwBSf2q5Fw9J94V",
        "_score" : null,
        "_source" : {
          "@timestamp" : "2026-03-04T15:08:58.888422097Z",
          "agent" : {
            "name" : "otlp"
          },
          "data_stream" : {
            "dataset" : "generic",
            "namespace" : "default",
            "type" : "logs"
          },
          "exporter" : "elasticsearch/tenant-es-demo_elasticsearch",
          "k8s" : {
            "container" : {
              "restart_count" : "0"
            },
            "pod" : {
              "labels" : {
                "app" : {
                  "kubernetes" : {
                    "io/instance" : "log-generator",
                    "io/name" : "log-generator"
                  }
                },
                "pod-template-hash" : "988b67d7c"
              },
              "start_time" : "2026-03-04T14:07:27Z"
            }
          },
          "kubernetes" : {
            "container" : {
              "name" : "log-generator"
            },
            "deployment" : {
              "name" : "log-generator"
            },
            "namespace" : "tenant-es-demo",
            "node" : {
              "name" : "kind-control-plane"
            },
            "pod" : {
              "name" : "log-generator-988b67d7c-gdx4b",
              "uid" : "8819071a-0246-4f1a-bb38-f779b3faf56e"
            }
          },
          "log" : {
            "file" : {
              "path" : "/var/log/pods/tenant-es-demo_log-generator-988b67d7c-gdx4b_8819071a-0246-4f1a-bb38-f779b3faf56e/log-generator/0.log"
            },
            "iostream" : "stdout"
          },
          "logtag" : "F",
          "message" : "137.16.94.135 - - [04/Mar/2026:15:08:58 +0000] \"PUT /index.html HTTP/1.1\" 404 19314 \"-\" \"Mozilla/5.0 (Linux; Android 8.0.0; Pixel XL Build/OPR6.170623.012) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.107 Mobile Safari/537.36\" \"-\"",
          "subscription" : "all-logs",
          "tenant" : "es-demo",
          "time" : "2026-03-04T15:08:58.888422097Z"
        },
        "sort" : [
          1772636938888
        ]
      },
      {
        "_index" : ".ds-logs-generic-default-2026.03.04-000001",
        "_id" : "8zFluZwBSf2q5Fw9J94V",
        "_score" : null,
        "_source" : {
          "@timestamp" : "2026-03-04T15:08:57.886356304Z",
          "agent" : {
            "name" : "otlp"
          },
          "data_stream" : {
            "dataset" : "generic",
            "namespace" : "default",
            "type" : "logs"
          },
          "exporter" : "elasticsearch/tenant-es-demo_elasticsearch",
          "k8s" : {
            "container" : {
              "restart_count" : "0"
            },
            "pod" : {
              "labels" : {
                "app" : {
                  "kubernetes" : {
                    "io/instance" : "log-generator",
                    "io/name" : "log-generator"
                  }
                },
                "pod-template-hash" : "988b67d7c"
              },
              "start_time" : "2026-03-04T14:07:27Z"
            }
          },
          "kubernetes" : {
            "container" : {
              "name" : "log-generator"
            },
            "deployment" : {
              "name" : "log-generator"
            },
            "namespace" : "tenant-es-demo",
            "node" : {
              "name" : "kind-control-plane"
            },
            "pod" : {
              "name" : "log-generator-988b67d7c-gdx4b",
              "uid" : "8819071a-0246-4f1a-bb38-f779b3faf56e"
            }
          },
          "log" : {
            "file" : {
              "path" : "/var/log/pods/tenant-es-demo_log-generator-988b67d7c-gdx4b_8819071a-0246-4f1a-bb38-f779b3faf56e/log-generator/0.log"
            },
            "iostream" : "stdout"
          },
          "logtag" : "F",
          "message" : "15.45.109.46 - - [04/Mar/2026:15:08:57 +0000] \"GET / HTTP/1.1\" 403 5749 \"-\" \"Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Firefox/38.0 Iceweasel/38.2.1\" \"-\"",
          "subscription" : "all-logs",
          "tenant" : "es-demo",
          "time" : "2026-03-04T15:08:57.886356304Z"
        },
        "sort" : [
          1772636937886
        ]
      },
      {
        "_index" : ".ds-logs-generic-default-2026.03.04-000001",
        "_id" : "8jFluZwBSf2q5Fw9J94V",
        "_score" : null,
        "_source" : {
          "@timestamp" : "2026-03-04T15:08:56.886040804Z",
          "agent" : {
            "name" : "otlp"
          },
          "data_stream" : {
            "dataset" : "generic",
            "namespace" : "default",
            "type" : "logs"
          },
          "exporter" : "elasticsearch/tenant-es-demo_elasticsearch",
          "k8s" : {
            "container" : {
              "restart_count" : "0"
            },
            "pod" : {
              "labels" : {
                "app" : {
                  "kubernetes" : {
                    "io/instance" : "log-generator",
                    "io/name" : "log-generator"
                  }
                },
                "pod-template-hash" : "988b67d7c"
              },
              "start_time" : "2026-03-04T14:07:27Z"
            }
          },
          "kubernetes" : {
            "container" : {
              "name" : "log-generator"
            },
            "deployment" : {
              "name" : "log-generator"
            },
            "namespace" : "tenant-es-demo",
            "node" : {
              "name" : "kind-control-plane"
            },
            "pod" : {
              "name" : "log-generator-988b67d7c-gdx4b",
              "uid" : "8819071a-0246-4f1a-bb38-f779b3faf56e"
            }
          },
          "log" : {
            "file" : {
              "path" : "/var/log/pods/tenant-es-demo_log-generator-988b67d7c-gdx4b_8819071a-0246-4f1a-bb38-f779b3faf56e/log-generator/0.log"
            },
            "iostream" : "stdout"
          },
          "logtag" : "F",
          "message" : "4.31.78.98 - - [04/Mar/2026:15:08:56 +0000] \"PUT /products HTTP/1.1\" 403 6241 \"-\" \"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.99 Safari/537.36\" \"-\"",
          "subscription" : "all-logs",
          "tenant" : "es-demo",
          "time" : "2026-03-04T15:08:56.886040804Z"
        },
        "sort" : [
          1772636936886
        ]
      },
      {
        "_index" : ".ds-logs-generic-default-2026.03.04-000001",
        "_id" : "8TFluZwBSf2q5Fw9J94V",
        "_score" : null,
        "_source" : {
          "@timestamp" : "2026-03-04T15:08:55.884651970Z",
          "agent" : {
            "name" : "otlp"
          },
          "data_stream" : {
            "dataset" : "generic",
            "namespace" : "default",
            "type" : "logs"
          },
          "exporter" : "elasticsearch/tenant-es-demo_elasticsearch",
          "k8s" : {
            "container" : {
              "restart_count" : "0"
            },
            "pod" : {
              "labels" : {
                "app" : {
                  "kubernetes" : {
                    "io/instance" : "log-generator",
                    "io/name" : "log-generator"
                  }
                },
                "pod-template-hash" : "988b67d7c"
              },
              "start_time" : "2026-03-04T14:07:27Z"
            }
          },
          "kubernetes" : {
            "container" : {
              "name" : "log-generator"
            },
            "deployment" : {
              "name" : "log-generator"
            },
            "namespace" : "tenant-es-demo",
            "node" : {
              "name" : "kind-control-plane"
            },
            "pod" : {
              "name" : "log-generator-988b67d7c-gdx4b",
              "uid" : "8819071a-0246-4f1a-bb38-f779b3faf56e"
            }
          },
          "log" : {
            "file" : {
              "path" : "/var/log/pods/tenant-es-demo_log-generator-988b67d7c-gdx4b_8819071a-0246-4f1a-bb38-f779b3faf56e/log-generator/0.log"
            },
            "iostream" : "stdout"
          },
          "logtag" : "F",
          "message" : "195.78.147.249 - - [04/Mar/2026:15:08:55 +0000] \"POST / HTTP/1.1\" 404 11170 \"-\" \"Mozilla/5.0 (Linux; Android 8.0.0; Pixel XL Build/OPR6.170623.012) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.107 Mobile Safari/537.36\" \"-\"",
          "subscription" : "all-logs",
          "tenant" : "es-demo",
          "time" : "2026-03-04T15:08:55.88465197Z"
        },
        "sort" : [
          1772636935884
        ]
      }
    ]
  }
}