Incorrect ELASTICSEARCH_URL Environment Variable Causing bad URI (is not URI?) Error in Rails with Searchkick

Question

I'm working on a Rails application using Searchkick with Elasticsearch running inside a Docker container.

When I try to start my Rails server, I get the following error:

bad URI (is not URI?): <"http://\"http:0">

However, when I run the search command inside the Rails console, it works fine:

DoctorRegister.search("Ali")

Code Setup

1. Searchkick Configuration (config/initializers/searchkick.rb)

   Searchkick.client =
     Elasticsearch::Client.new(
       url: ENV.fetch("ELASTICSEARCH_URL", "http://localhost:9200"),
       retry_on_failure: 3,
       transport_options: { request: { timeout: 20 } }
     )
   

2. .env File

   - ELASTICSEARCH_URL= http://host.docker.internal:9200
   

3. Docker-compose.yml file

   web:
     build:
       context: .
       dockerfile: Dockerfile
     container_name: rails_app
     command: ["/bin/sh", "-c", "rails db:migrate && foreman start -f Procfile.dev"]
     extra_hosts:
       - "host.docker.internal:host-gateway"
     external_links:
       - "http://localhost:9200/"
     volumes:
       - .:/app:delegated
       - /app/node_modules
     depends_on:
       db:
         condition: service_healthy
       redis:
         condition: service_healthy
       elasticsearch:
         condition: service_healthy
     environment:
       DATABASE_URL: "postgres://${POSTGRES_USER}:${POSTGRES_PASSWORD}@db:5432/${POSTGRES_DB}"
       CLOUD_NAME: ${CLOUD_NAME}
       API_KEY: ${API_KEY}
       API_SECRET: ${API_SECRET}
       URL: ${URL}
       ELASTICSEARCH_URL: ${ELASTICSEARCH_URL}
     ports:
       - "3000:3000"
     networks:
       - app_network
     env_file:
       - .env
   
   elasticsearch:
     image: docker.elastic.co/elasticsearch/elasticsearch:7.17.11
     container_name: elasticsearch
     ports:
       - 9200:9200
     healthcheck:
       # test: ["CMD-SHELL", "curl -s http://localhost:9200/_cluster/health | grep -q '\"status\":\"green\"'"]
       # test: curl -s http://localhost:9200/_cluster/health > /dev/null | exit 1
       test:
         [
           "CMD-SHELL",
           "curl -s http://localhost:9200/_cluster/health?pretty | grep status | grep -q '\\(green\\|yellow\\)'"
         ]
       interval: 1m
       timeout: 30s
       retries: 5
     environment:
       - discovery.type=single-node
       - xpack.security.enabled=false