feat: allow Pact Broker to run on Heroku

README.md

@@ -31,13 +31,14 @@ If you want to run the container as a standalone instance, then the `dius/pact-b
 
 For a postgres or mysql database:
 
+You can either set the PACT_BROKER_DATABASE_URL in the format `driver://username:password@host:port/database` (eg. `postgres://user1:pass1@myhost/mydb`) or, you can set the credentials individually using the following environment variables:
+
     * PACT_BROKER_DATABASE_ADAPTER (optional, defaults to 'postgres', see note below.)
     * PACT_BROKER_DATABASE_USERNAME
     * PACT_BROKER_DATABASE_PASSWORD
     * PACT_BROKER_DATABASE_HOST
     * PACT_BROKER_DATABASE_NAME
     * PACT_BROKER_DATABASE_PORT (optional, defaults to the default port for the specified adapter)
-    * PACT_BROKER_DATABASE_SSLMODE (optional, possible values: 'disable', 'allow', 'prefer', 'require', 'verify-ca', or 'verify-full' to choose how to treat SSL (only respected if using the postgres database adapter). See https://www.postgresql.org/docs/9.1/libpq-ssl.html for more information.)
 
 Adapter can be 'postgres' (recommended) or 'mysql2' (please note that future JSON search features may not be supported on mysql).
 
@@ -46,6 +47,10 @@ For an sqlite database (only recommended for investigation/spikes, as it will be
   * PACT_BROKER_DATABASE_ADAPTER (set to 'sqlite')
   * PACT_BROKER_DATABASE_NAME (arbitrary name eg. pact_broker.sqlite)
 
+You can additionally set:
+
+    * PACT_BROKER_DATABASE_SSLMODE (optional, possible values: 'disable', 'allow', 'prefer', 'require', 'verify-ca', or 'verify-full' to choose how to treat SSL (only respected if using the postgres database adapter). See https://www.postgresql.org/docs/9.1/libpq-ssl.html for more information.)
+
 3. Test the pact broker environment by executing [script/test.sh][test-script]
 
 ## Notes
@@ -130,6 +135,10 @@ See [pact-broker-openshift][pact-broker-openshift] for an example config file.
 
 Don't call your service "pact_broker" as it will create an environment called `PACT_BROKER_PORT` which will clash with the docker images own environment variables. See this issue: https://github.com/pact-foundation/pact-broker-docker/issues/7
 
+## Running on Heroku
+
+Heroku provides the database connection string as the environment variable `$DATABASE_URL`. To tell the Pact Broker to use this environment variable rather than `$PACT_BROKER_DATABASE_URL`, set the environment variable `PACT_BROKER_DATABASE_URL_ENVIRONMENT_VARIABLE_NAME=DATABASE_URL`.
+
 ## Database migrations
 
 The Pact Broker auto migrates on startup, and will always do so in a way that is backwards compatible, to support architectures that run multiple instances of the application at a time (eg. AWS auto scaling).

docker-compose.yml

@@ -22,11 +22,14 @@ services:
     depends_on:
       - postgres
     environment:
-      PACT_BROKER_DATABASE_USERNAME: postgres
-      PACT_BROKER_DATABASE_PASSWORD: password
-      PACT_BROKER_DATABASE_HOST: postgres
-      PACT_BROKER_DATABASE_NAME: postgres
+      PACT_BROKER_DATABASE_URL_ENVIRONMENT_VARIABLE_NAME: DATABASE_URL
+      DATABASE_URL: "postgres://postgres:password@postgres/postgres"
+      # PACT_BROKER_DATABASE_USERNAME: postgres
+      # PACT_BROKER_DATABASE_PASSWORD: password
+      # PACT_BROKER_DATABASE_HOST: postgres
+      # PACT_BROKER_DATABASE_NAME: postgres
       PACT_BROKER_PORT: "9292"
+      PACT_BROKER_LOG_LEVEL: INFO
 
   # Nginx is not necessary, but demonstrates how
   # one might use a reverse proxy in front of the broker,

pact_broker/database_connection.rb

@@ -1,24 +1,41 @@
 require 'sequel'
 require_relative 'database_logger'
 
-def create_database_connection(logger)
-  database_adapter = ENV.fetch('PACT_BROKER_DATABASE_ADAPTER','') != '' ? ENV['PACT_BROKER_DATABASE_ADAPTER'] : 'postgres'
+DB_ENV_VAR_NAME = ENV.fetch('PACT_BROKER_DATABASE_URL_ENVIRONMENT_VARIABLE_NAME', 'PACT_BROKER_DATABASE_URL')
+URL = ENV[DB_ENV_VAR_NAME]
+SSL_MODE = ENV.fetch('PACT_BROKER_DATABASE_SSLMODE','')
+ADAPTER = ENV.fetch('PACT_BROKER_DATABASE_ADAPTER','') != '' ? ENV['PACT_BROKER_DATABASE_ADAPTER'] : 'postgres'
+USERNAME = ENV['PACT_BROKER_DATABASE_USERNAME']
+PASSWORD = ENV['PACT_BROKER_DATABASE_PASSWORD']
+HOST = ENV['PACT_BROKER_DATABASE_HOST']
+NAME = ENV['PACT_BROKER_DATABASE_NAME']
+PORT = ENV['PACT_BROKER_DATABASE_PORT']
 
-  config = {
-    adapter: database_adapter,
-    user: ENV['PACT_BROKER_DATABASE_USERNAME'],
-    password: ENV['PACT_BROKER_DATABASE_PASSWORD'],
-    host: ENV['PACT_BROKER_DATABASE_HOST'],
-    database: ENV['PACT_BROKER_DATABASE_NAME'],
-    encoding: 'utf8'
+def create_database_connection(logger)
+  non_credential_options = {
+    encoding: 'utf8',
+    logger: DatabaseLogger.new(logger)
   }
+  non_credential_options[:sslmode] = SSL_MODE if SSL_MODE != ''
 
-  if ENV.fetch('PACT_BROKER_DATABASE_SSLMODE','') != ''
-    config[:sslmode] = ENV['PACT_BROKER_DATABASE_SSLMODE']
-  end
+  connection = if URL
+    uri = URI(URL)
+    uri.password = "*****"
+    logger.info "Connecting to database #{uri} with config: #{non_credential_options}"
+    Sequel.connect(URL, non_credential_options)
+  else
+    config = {
+      adapter: ADAPTER,
+      user: USERNAME,
+      password: PASSWORD,
+      host: HOST,
+      database: NAME,
+    }.merge(non_credential_options)
 
-  if ENV['PACT_BROKER_DATABASE_PORT'] =~ /^\d+$/
-    config[:port] = ENV['PACT_BROKER_DATABASE_PORT'].to_i
+    config[:port] = PORT.to_i if PORT =~ /^\d+$/
+
+    logger.info "Connecting to database with config: #{config.merge(password: "*****")}"
+    Sequel.connect(config)
   end
 
   ##
@@ -38,9 +55,7 @@ def create_database_connection(logger)
   # -1 means that connections will be validated every time, which avoids errors
   # when databases are restarted and connections are killed.  This has a performance
   # penalty, so consider increasing this timeout if building a frequently accessed service.
-  logger.info "Connecting to database with config: #{config.merge(password: "*****")}"
-  config[:logger] = DatabaseLogger.new(logger)
-  connection = Sequel.connect(config)
+
   connection.extension(:connection_validator)
   connection.pool.connection_validation_timeout = -1
   connection