diff --git a/.rubocop.yml b/.rubocop.yml
index 8e9fdae..9667367 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -15,3 +15,6 @@ Layout/LineLength:
 
 Style/Documentation:
   Enabled: false
+
+Metrics/BlockLength:
+  IgnoredMethods: ['describe', 'context']
diff --git a/lib/rumbda/function.rb b/lib/rumbda/function.rb
index 9b6404c..f5d8d6e 100644
--- a/lib/rumbda/function.rb
+++ b/lib/rumbda/function.rb
@@ -30,9 +30,9 @@ class Command < Thor
                    desc: "Lambda functions to package and deploy. Defaults to the functions list configured in the service configuration file"
 
       class_option :ecr_registry,
-                   required: false,
+                   required: true,
                    aliases: "-ecr",
-                   desc: "Name of the ECR registry to push to. Defaults to the ecr_registry value configured for the given environment"
+                   desc: "Name of the ECR registry to push to."
 
       class_option :image_tag,
                    required: true,
diff --git a/lib/rumbda/function/config.rb b/lib/rumbda/function/config.rb
index 0ce1122..973ad00 100644
--- a/lib/rumbda/function/config.rb
+++ b/lib/rumbda/function/config.rb
@@ -15,11 +15,11 @@ def initialize(options)
       end
 
       def image_uri
-        @__image_uri ||= "#{ecr_registry}/#{environment}-#{service}:#{image_tag}"
+        @image_uri ||= "#{ecr_registry}/#{service}:#{image_tag}"
       end
 
       def functions
-        @__functions ||= function_names.map do |function_name|
+        @functions ||= function_names.map do |function_name|
           "#{environment}-#{service}-#{function_name}"
         end
       end
@@ -85,15 +85,6 @@ def parse_dockerfile!
 
       def parse_ecr_registry!
         @ecr_registry = options[:ecr_registry]
-        return unless ecr_registry.blank?
-
-        current_environment_config = yaml_content[:environments][environment]
-        if current_environment_config.blank?
-          raise ::Rumbda::Function::ConfigError,
-                "environments block in config file is missing options for the environment called '#{environment}'"
-        end
-
-        @ecr_registry = current_environment_config[:ecr_registry]
         raise ::Rumbda::Function::ConfigError, "ecr_registry parameter not provided" if ecr_registry.blank?
       end
     end
diff --git a/spec/rumbda/function/config_spec.rb b/spec/rumbda/function/config_spec.rb
index 06ca4d3..5ec2be6 100644
--- a/spec/rumbda/function/config_spec.rb
+++ b/spec/rumbda/function/config_spec.rb
@@ -6,11 +6,11 @@
   subject { described_class.new(options) }
 
   let(:config_file) { "spec/support/rumbda.yml" }
-  let(:environment) { :test }
-  let(:service) { "test-service" }
-  let(:functions) { %w[one two three] }
-  let(:ecr_registry) { "test-registry" }
-  let(:image_tag) { "test-tag" }
+  let(:environment) { "testenv" }
+  let(:service) { "petshop" }
+  let(:functions) { %w[order purchase cancel] }
+  let(:ecr_registry) { "ecr-petshop-registry" }
+  let(:image_tag) { "SOMETAG" }
   let(:dockerfile) { "spec/support/test_repository/Dockerfile" }
   let(:options) do
     {
@@ -24,8 +24,8 @@
     }
   end
 
-  let(:formatted_image_uri) { "#{ecr_registry}/#{environment}-#{service}:#{image_tag}" }
-  let(:formatted_functions) { functions.map { |f| "#{environment}-#{service}-#{f}" } }
+  let(:formatted_image_uri) { "#{ecr_registry}/#{service}:#{image_tag}" }
+  let(:formatted_functions) { functions.map { |function| "#{environment}-#{service}-#{function}" } }
 
   describe "#image_uri" do
     it "returns a correctly formatted image uri" do
@@ -182,34 +182,9 @@
       end
 
       context "when the ecr registry is not in the options" do
-        context "and it is in the config file" do
-          let(:ecr_registry) { nil }
-          it "loads the value from the config file" do
-            expect { subject }.to_not raise_error
-            expect(subject.ecr_registry).to eq(parsed_service_yaml[:environments][environment][:ecr_registry])
-          end
-        end
-
-        context "and the environment is not in the config file" do
-          before do
-            allow(YAML).to receive(:load_file).and_return({ environments: {} })
-          end
-          let(:ecr_registry) { nil }
-          it "throws an error" do
-            expect { subject }.to raise_error(::Rumbda::Function::ConfigError, /environments/)
-          end
-        end
-
-        context "and the registry is not in the config file" do
-          before do
-            allow(YAML).to receive(:load_file).and_return({
-                                                            environments: { environment => { ecr_registry: nil } }
-                                                          })
-          end
-          let(:ecr_registry) { nil }
-          it "throws an error" do
-            expect { subject }.to raise_error(::Rumbda::Function::ConfigError, /ecr_registry/)
-          end
+        let(:ecr_registry) { nil }
+        it "throws an error" do
+          expect { subject }.to raise_error(::Rumbda::Function::ConfigError, /ecr_registry/)
         end
       end
     end
diff --git a/spec/rumbda/function/deploy_spec.rb b/spec/rumbda/function/deploy_spec.rb
index 15663db..e607e61 100644
--- a/spec/rumbda/function/deploy_spec.rb
+++ b/spec/rumbda/function/deploy_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 
 RSpec.describe Rumbda::Function::Deploy do
diff --git a/spec/support/rumbda.yml b/spec/support/rumbda.yml
index 13dfdca..80937f3 100644
--- a/spec/support/rumbda.yml
+++ b/spec/support/rumbda.yml
@@ -4,12 +4,3 @@ functions:
 - pets
 - stores
 - users
-environments:
-  production:
-    ecr_registry: 123456789012.dkr.ecr.eu-west-1.amazonaws.com
-  staging:
-    ecr_registry: 210987654321.dkr.ecr.eu-west-1.amazonaws.com
-  hello:
-    ecr_registry: 210987654321.dkr.ecr.eu-west-1.amazonaws.com
-  test:
-    ecr_registry: 210987654321.dkr.ecr.eu-west-1.amazonaws.com