Commit 7845dbcf authored by Reuben Pereira's avatar Reuben Pereira Committed by Thong Kuah
Browse files

Create new Prometheus::ProxyVariableSubstitutionService

Create new service to do template variable replacement on the query
parameter of the Prometheus proxy API.
parent 25b54e73
......@@ -7,23 +7,34 @@ class Projects::Environments::PrometheusApiController < Projects::ApplicationCon
before_action :environment
 
def proxy
result = Prometheus::ProxyService.new(
variable_substitution_result =
variable_substitution_service.new(environment, permit_params).execute
if variable_substitution_result[:status] == :error
return error_response(variable_substitution_result)
end
prometheus_result = Prometheus::ProxyService.new(
environment,
proxy_method,
proxy_path,
proxy_params
variable_substitution_result[:params]
).execute
 
return continue_polling_response if result.nil?
return error_response(result) if result[:status] == :error
return continue_polling_response if prometheus_result.nil?
return error_response(prometheus_result) if prometheus_result[:status] == :error
 
success_response(result)
success_response(prometheus_result)
end
 
private
 
def query_context
Gitlab::Prometheus::QueryVariables.call(environment)
def variable_substitution_service
Prometheus::ProxyVariableSubstitutionService
end
def permit_params
params.permit!
end
 
def environment
......@@ -37,15 +48,4 @@ class Projects::Environments::PrometheusApiController < Projects::ApplicationCon
def proxy_path
params[:proxy_path]
end
def proxy_params
substitute_query_variables(params).permit!
end
def substitute_query_variables(params)
query = params[:query]
return params unless query
params.merge(query: query % query_context)
end
end
# frozen_string_literal: true
module Prometheus
class ProxyVariableSubstitutionService < BaseService
include Stepable
steps :add_params_to_result, :substitute_ruby_variables
def initialize(environment, params = {})
@environment, @params = environment, params.deep_dup
end
def execute
execute_steps
end
private
def add_params_to_result(result)
result[:params] = params
success(result)
end
def substitute_ruby_variables(result)
return success(result) unless query
# The % operator doesn't replace variables if the hash contains string
# keys.
result[:params][:query] = query % predefined_context.symbolize_keys
success(result)
rescue TypeError, ArgumentError => exception
log_error(exception.message)
Gitlab::Sentry.track_acceptable_exception(exception, extra: {
template_string: query,
variables: predefined_context
})
error(_('Malformed string'))
end
def predefined_context
@predefined_context ||= Gitlab::Prometheus::QueryVariables.call(@environment)
end
def query
params[:query]
end
end
end
......@@ -10614,6 +10614,9 @@ msgstr ""
msgid "Makes this issue confidential."
msgstr ""
 
msgid "Malformed string"
msgstr ""
msgid "Manage"
msgstr ""
 
......
......@@ -63,9 +63,7 @@ describe Projects::Environments::PrometheusApiController do
 
context 'with nil query' do
let(:params_without_query) do
params = environment_params
params.delete(:query)
params
environment_params.except(:query)
end
 
before do
......
......@@ -14,7 +14,7 @@ describe Gitlab::Prometheus::QueryVariables do
 
it do
is_expected.to include(environment_filter:
%{container_name!="POD",environment="#{slug}"})
%Q[container_name!="POD",environment="#{slug}"])
end
 
context 'without deployment platform' do
......
# frozen_string_literal: true
require 'spec_helper'
describe Prometheus::ProxyVariableSubstitutionService do
describe '#execute' do
let_it_be(:environment) { create(:environment) }
let(:params_keys) { { query: 'up{environment="%{ci_environment_slug}"}' } }
let(:params) { ActionController::Parameters.new(params_keys).permit! }
let(:result) { subject.execute }
subject { described_class.new(environment, params) }
shared_examples 'success' do
it 'replaces variables with values' do
expect(result[:status]).to eq(:success)
expect(result[:params][:query]).to eq(expected_query)
end
end
shared_examples 'error' do |message|
it 'returns error' do
expect(result[:status]).to eq(:error)
expect(result[:message]).to eq(message)
end
end
context 'does not alter params passed to the service' do
it do
subject.execute
expect(params).to eq(
ActionController::Parameters.new(
query: 'up{environment="%{ci_environment_slug}"}'
).permit!
)
end
end
context 'with predefined variables' do
it_behaves_like 'success' do
let(:expected_query) { %Q[up{environment="#{environment.slug}"}] }
end
context 'with nil query' do
let(:params_keys) { {} }
it_behaves_like 'success' do
let(:expected_query) { nil }
end
end
end
context 'ruby template rendering' do
let(:params_keys) do
{ query: 'up{env=%{ci_environment_slug},%{environment_filter}}' }
end
it_behaves_like 'success' do
let(:expected_query) do
"up{env=#{environment.slug},container_name!=\"POD\"," \
"environment=\"#{environment.slug}\"}"
end
end
context 'with multiple occurrences of variable in string' do
let(:params_keys) do
{ query: 'up{env1=%{ci_environment_slug},env2=%{ci_environment_slug}}' }
end
it_behaves_like 'success' do
let(:expected_query) { "up{env1=#{environment.slug},env2=#{environment.slug}}" }
end
end
context 'with multiple variables in string' do
let(:params_keys) do
{ query: 'up{env=%{ci_environment_slug},%{environment_filter}}' }
end
it_behaves_like 'success' do
let(:expected_query) do
"up{env=#{environment.slug}," \
"container_name!=\"POD\",environment=\"#{environment.slug}\"}"
end
end
end
context 'with unknown variables in string' do
let(:params_keys) { { query: 'up{env=%{env_slug}}' } }
it_behaves_like 'success' do
let(:expected_query) { 'up{env=%{env_slug}}' }
end
end
# This spec is needed if there are multiple keys in the context provided
# by `Gitlab::Prometheus::QueryVariables.call(environment)` which is
# passed to the Ruby `%` operator.
# If the number of keys in the context is one, there is no need for
# this spec.
context 'with extra variables in context' do
let(:params_keys) { { query: 'up{env=%{ci_environment_slug}}' } }
it_behaves_like 'success' do
let(:expected_query) { "up{env=#{environment.slug}}" }
end
it 'has more than one variable in context' do
expect(Gitlab::Prometheus::QueryVariables.call(environment).size).to be > 1
end
end
# The ruby % operator will not replace known variables if there are unknown
# variables also in the string. It doesn't raise an error
# (though the `sprintf` and `format` methods do).
context 'with unknown and known variables in string' do
let(:params_keys) do
{ query: 'up{env=%{ci_environment_slug},other_env=%{env_slug}}' }
end
it_behaves_like 'success' do
let(:expected_query) { 'up{env=%{ci_environment_slug},other_env=%{env_slug}}' }
end
end
context 'when rendering raises error' do
context 'when TypeError is raised' do
let(:params_keys) { { query: '{% a %}' } }
it_behaves_like 'error', 'Malformed string'
end
context 'when ArgumentError is raised' do
let(:params_keys) { { query: '%<' } }
it_behaves_like 'error', 'Malformed string'
end
end
end
end
end
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