refactor!: require the builder pattern for module initalisation (#161)

This PR makes sure that the way structs are constructed is consistent
and encourages the builder pattern.
It is based on this question:
#156 (comment)

For the changelog:

We now require you to use the builder pattern (instead of some structs
being [unit structs](https://doc.rust-lang.org/std/keyword.struct.html))
for all modules.
This ensures that if we add a field in the future that this will not
break your existing code.

This change is breaking for these modules:

| Module | before | after |
|--------|--------|--------|
| `cncf_distribution::CncfDistribution` | `CncfDistribution.start()` |
`CncfDistribution::default().start()` |
| `dynamodb_local::DynamoDb` | `DynamoDb.start()` |
`DynamoDb::default().start()` |
| `elasticmq::ElasticMq` | `ElasticMq.start()` |
`ElasticMq::default().start()` |
| ~`mongo::Mongo`~ (see #143) | ~`Mongo.start()`~ |
~`Mongo::default().start()`~ |
| `kwok::KwokCluster` | `KwokCluster.start()` |
`KwokCluster::default().start()` |
| `rabbitmq::RabbitMq` | `RabbitMq.start()` |
`RabbitMq::default().start()` |
| `redis::stack::RedisStack` | `RedisStack.start()` |
`RedisStack::default().start()` |
| `redis::standalone::Redis` | `Redis.start()` |
`Redis::default().start()` |
| `victoria_metrics::VictoriaMetrics` | `VictoriaMetrics.start()` |
`VictoriaMetrics::default().start()` |

src/cncf_distribution/mod.rs

@@ -11,7 +11,9 @@ const TAG: &str = "2";
 /// ```
 /// use testcontainers_modules::{cncf_distribution, testcontainers::runners::SyncRunner};
 ///
-/// let registry = cncf_distribution::CncfDistribution.start().unwrap();
+/// let registry = cncf_distribution::CncfDistribution::default()
+///     .start()
+///     .unwrap();
 ///
 /// let image_name = "test";
 /// let image_tag = format!(
@@ -25,7 +27,12 @@ const TAG: &str = "2";
 ///
 /// [`CNCF Distribution`]: https://distribution.github.io/distribution/
 #[derive(Debug, Default, Clone)]
-pub struct CncfDistribution;
+pub struct CncfDistribution {
+    /// (remove if there is another variable)
+    /// Field is included to prevent this struct to be a unit struct.
+    /// This allows extending functionality (and thus further variables) without breaking changes
+    _priv: (),
+}
 
 impl Image for CncfDistribution {
     fn name(&self) -> &str {
@@ -56,7 +63,9 @@ mod tests {
     #[tokio::test]
     async fn distribution_push_pull_image() -> Result<(), Box<dyn std::error::Error + 'static>> {
         let _ = pretty_env_logger::try_init();
-        let distribution_node = cncf_distribution::CncfDistribution.start().await?;
+        let distribution_node = cncf_distribution::CncfDistribution::default()
+            .start()
+            .await?;
         let docker = bollard::Docker::connect_with_local_defaults().unwrap();
         let image_tag = format!(
             "localhost:{}/test:latest",

src/dynamodb_local/mod.rs

@@ -5,7 +5,12 @@ const TAG: &str = "2.0.0";
 const DEFAULT_WAIT: u64 = 3000;
 
 #[derive(Default, Debug, Clone)]
-pub struct DynamoDb;
+pub struct DynamoDb {
+    /// (remove if there is another variable)
+    /// Field is included to prevent this struct to be a unit struct.
+    /// This allows extending functionality (and thus further variables) without breaking changes
+    _priv: (),
+}
 
 impl Image for DynamoDb {
     fn name(&self) -> &str {
@@ -46,7 +51,7 @@ mod tests {
     #[tokio::test]
     async fn dynamodb_local_create_table() -> Result<(), Box<dyn std::error::Error + 'static>> {
         let _ = pretty_env_logger::try_init();
-        let node = DynamoDb.start().await?;
+        let node = DynamoDb::default().start().await?;
         let host = node.get_host().await?;
         let host_port = node.get_host_port_ipv4(8000.tcp()).await?;
 

src/elastic_search/mod.rs

@@ -23,6 +23,9 @@ pub const ELASTICSEARCH_INTER_NODE_PORT: ContainerPort = ContainerPort::Tcp(9300
 
 #[derive(Debug, Default, Clone)]
 pub struct ElasticSearch {
+    /// (remove if there is another variable)
+    /// Field is included to prevent this struct to be a unit struct.
+    /// This allows extending functionality (and thus further variables) without breaking changes
     _priv: (),
 }
 

src/elasticmq/mod.rs

@@ -4,7 +4,12 @@ const NAME: &str = "softwaremill/elasticmq";
 const TAG: &str = "1.5.2";
 
 #[derive(Debug, Default, Clone)]
-pub struct ElasticMq;
+pub struct ElasticMq {
+    /// (remove if there is another variable)
+    /// Field is included to prevent this struct to be a unit struct.
+    /// This allows extending functionality (and thus further variables) without breaking changes
+    _priv: (),
+}
 
 impl Image for ElasticMq {
     fn name(&self) -> &str {
@@ -31,7 +36,7 @@ mod tests {
 
     #[tokio::test]
     async fn sqs_list_queues() -> Result<(), Box<dyn std::error::Error + 'static>> {
-        let node = ElasticMq.start().await?;
+        let node = ElasticMq::default().start().await?;
         let host_ip = node.get_host().await?;
         let host_port = node.get_host_port_ipv4(9324).await?;
         let client = build_sqs_client(host_ip, host_port).await;

src/kwok/mod.rs

@@ -33,7 +33,12 @@ pub const KWOK_CLUSTER_PORT: ContainerPort = ContainerPort::Tcp(8080);
 ///
 /// [`Kwok Cluster`]: https://kwok.sigs.k8s.io/
 #[derive(Debug, Default, Clone)]
-pub struct KwokCluster;
+pub struct KwokCluster {
+    /// (remove if there is another variable)
+    /// Field is included to prevent this struct to be a unit struct.
+    /// This allows extending functionality (and thus further variables) without breaking changes
+    _priv: (),
+}
 
 impl Image for KwokCluster {
     fn name(&self) -> &str {
@@ -82,7 +87,7 @@ mod test {
                 .expect("Error initializing rustls provider");
         }
 
-        let node = KwokCluster.start().await?;
+        let node = KwokCluster::default().start().await?;
         let host_port = node.get_host_port_ipv4(8080.tcp()).await?;
 
         // Create a custom Kubeconfig

src/localstack/mod.rs

@@ -26,6 +26,9 @@ const DEFAULT_WAIT: u64 = 3000;
 /// No environment variables are required.
 #[derive(Default, Debug, Clone)]
 pub struct LocalStack {
+    /// (remove if there is another variable)
+    /// Field is included to prevent this struct to be a unit struct.
+    /// This allows extending functionality (and thus further variables) without breaking changes
     _priv: (),
 }
 

src/mariadb/mod.rs

@@ -27,6 +27,9 @@ const TAG: &str = "11.3";
 /// [`MariaDB docker image`]: https://hub.docker.com/_/mariadb
 #[derive(Debug, Default, Clone)]
 pub struct Mariadb {
+    /// (remove if there is another variable)
+    /// Field is included to prevent this struct to be a unit struct.
+    /// This allows extending functionality (and thus further variables) without breaking changes
     _priv: (),
 }
 

src/mosquitto/mod.rs

@@ -28,6 +28,9 @@ const TAG: &str = "2.0.18";
 
 #[derive(Debug, Default, Clone)]
 pub struct Mosquitto {
+    /// (remove if there is another variable)
+    /// Field is included to prevent this struct to be a unit struct.
+    /// This allows extending functionality (and thus further variables) without breaking changes
     _priv: (),
 }
 

src/mysql/mod.rs

@@ -27,6 +27,9 @@ const TAG: &str = "8.1";
 /// [`MySQL docker image`]: https://hub.docker.com/_/mysql
 #[derive(Debug, Default, Clone)]
 pub struct Mysql {
+    /// (remove if there is another variable)
+    /// Field is included to prevent this struct to be a unit struct.
+    /// This allows extending functionality (and thus further variables) without breaking changes
     _priv: (),
 }
 

src/oracle/free.rs

@@ -42,6 +42,9 @@ pub const FREE_PORT: ContainerPort = ContainerPort::Tcp(1521);
 /// [`gvenzl/oracle-free:23-slim-faststart`]: https://hub.docker.com/r/gvenzl/oracle-free
 #[derive(Debug, Default, Clone)]
 pub struct Oracle {
+    /// (remove if there is another variable)
+    /// Field is included to prevent this struct to be a unit struct.
+    /// This allows extending functionality (and thus further variables) without breaking changes
     _priv: (),
 }
 

src/orientdb/mod.rs

@@ -7,6 +7,9 @@ const TAG: &str = "3.2.19";
 
 #[derive(Debug, Default, Clone)]
 pub struct OrientDb {
+    /// (remove if there is another variable)
+    /// Field is included to prevent this struct to be a unit struct.
+    /// This allows extending functionality (and thus further variables) without breaking changes
     _priv: (),
 }
 

src/parity_parity/mod.rs

@@ -7,6 +7,9 @@ const TAG: &str = "v2.5.0";
 
 #[derive(Debug, Default, Clone)]
 pub struct ParityEthereum {
+    /// (remove if there is another variable)
+    /// Field is included to prevent this struct to be a unit struct.
+    /// This allows extending functionality (and thus further variables) without breaking changes
     _priv: (),
 }
 

src/rabbitmq/mod.rs

@@ -14,7 +14,7 @@ const TAG: &str = "3.8.22-management";
 /// ```
 /// use testcontainers_modules::{rabbitmq, testcontainers::runners::SyncRunner};
 ///
-/// let rabbitmq_instance = rabbitmq::RabbitMq.start().unwrap();
+/// let rabbitmq_instance = rabbitmq::RabbitMq::default().start().unwrap();
 ///
 /// let amqp_url = format!(
 ///     "amqp://{}:{}",
@@ -30,7 +30,12 @@ const TAG: &str = "3.8.22-management";
 /// [`RabbitMQ Management HTTP API`]: https://www.rabbitmq.com/management.html#http-api
 /// [`RabbitMQ docker image`]: https://hub.docker.com/_/rabbitmq
 #[derive(Debug, Default, Clone)]
-pub struct RabbitMq;
+pub struct RabbitMq {
+    /// (remove if there is another variable)
+    /// Field is included to prevent this struct to be a unit struct.
+    /// This allows extending functionality (and thus further variables) without breaking changes
+    _priv: (),
+}
 
 impl Image for RabbitMq {
     fn name(&self) -> &str {
@@ -68,7 +73,7 @@ mod tests {
     async fn rabbitmq_produce_and_consume_messages(
     ) -> Result<(), Box<dyn std::error::Error + 'static>> {
         let _ = pretty_env_logger::try_init();
-        let rabbit_node = rabbitmq::RabbitMq.start().await?;
+        let rabbit_node = rabbitmq::RabbitMq::default().start().await?;
 
         let amqp_url = format!(
             "amqp://{}:{}",

src/redis/stack.rs

@@ -15,7 +15,7 @@ const TAG: &str = "7.2.0-v8";
 /// use serde_json::json;
 /// use testcontainers_modules::{testcontainers::runners::SyncRunner, redis::{RedisStack, REDIS_PORT}};
 ///
-/// let redis_instance = RedisStack.start().unwrap();
+/// let redis_instance = RedisStack::default().start().unwrap();
 /// let host_ip = redis_instance.get_host().unwrap();
 /// let host_port = redis_instance.get_host_port_ipv4(REDIS_PORT).unwrap();
 ///
@@ -32,7 +32,12 @@ const TAG: &str = "7.2.0-v8";
 /// [`Redis reference guide`]: https://redis.io/docs/interact/
 /// [`REDIS_PORT`]: super::REDIS_PORT
 #[derive(Debug, Default, Clone)]
-pub struct RedisStack;
+pub struct RedisStack {
+    /// (remove if there is another variable)
+    /// Field is included to prevent this struct to be a unit struct.
+    /// This allows extending functionality (and thus further variables) without breaking changes
+    _priv: (),
+}
 
 impl Image for RedisStack {
     fn name(&self) -> &str {
@@ -61,7 +66,7 @@ mod tests {
     #[test]
     fn redis_fetch_an_integer_in_json() -> Result<(), Box<dyn std::error::Error + 'static>> {
         let _ = pretty_env_logger::try_init();
-        let node = RedisStack.start()?;
+        let node = RedisStack::default().start()?;
         let host_ip = node.get_host()?;
         let host_port = node.get_host_port_ipv4(REDIS_PORT)?;
         let url = format!("redis://{host_ip}:{host_port}");

src/redis/standalone.rs

@@ -34,7 +34,12 @@ const TAG: &str = "5.0";
 /// [`Redis reference guide`]: https://redis.io/docs/interact/
 /// [`REDIS_PORT`]: super::REDIS_PORT
 #[derive(Debug, Default, Clone)]
-pub struct Redis;
+pub struct Redis {
+    /// (remove if there is another variable)
+    /// Field is included to prevent this struct to be a unit struct.
+    /// This allows extending functionality (and thus further variables) without breaking changes
+    _priv: (),
+}
 
 impl Image for Redis {
     fn name(&self) -> &str {
@@ -59,7 +64,7 @@ mod tests {
     #[test]
     fn redis_fetch_an_integer() -> Result<(), Box<dyn std::error::Error + 'static>> {
         let _ = pretty_env_logger::try_init();
-        let node = Redis.start()?;
+        let node = Redis::default().start()?;
         let host_ip = node.get_host()?;
         let host_port = node.get_host_port_ipv4(6379)?;
         let url = format!("redis://{host_ip}:{host_port}");

src/solr/mod.rs

@@ -32,6 +32,9 @@ const TAG: &str = "9.5.0-slim";
 /// [`Solr reference guide`]: https://solr.apache.org/guide/solr/latest/
 #[derive(Debug, Default, Clone)]
 pub struct Solr {
+    /// (remove if there is another variable)
+    /// Field is included to prevent this struct to be a unit struct.
+    /// This allows extending functionality (and thus further variables) without breaking changes
     _priv: (),
 }
 

src/victoria_metrics/mod.rs

@@ -13,7 +13,9 @@ const TAG: &str = "v1.96.0";
 /// ```
 /// use testcontainers_modules::{testcontainers::runners::SyncRunner, victoria_metrics};
 ///
-/// let victoria_metrics_instance = victoria_metrics::VictoriaMetrics.start().unwrap();
+/// let victoria_metrics_instance = victoria_metrics::VictoriaMetrics::default()
+///     .start()
+///     .unwrap();
 ///
 /// let import_url = format!(
 ///     "http://127.0.0.1:{}/api/v1/import",
@@ -31,7 +33,12 @@ const TAG: &str = "v1.96.0";
 /// [`VictoriaMetrics API examples`]: https://docs.victoriametrics.com/url-examples.html#victoriametrics-api-examples
 /// [`VictoriaMetrics Docker image`]: https://hub.docker.com/r/victoriametrics/victoria-metrics
 #[derive(Debug, Default, Clone)]
-pub struct VictoriaMetrics;
+pub struct VictoriaMetrics {
+    /// (remove if there is another variable)
+    /// Field is included to prevent this struct to be a unit struct.
+    /// This allows extending functionality (and thus further variables) without breaking changes
+    _priv: (),
+}
 
 impl Image for VictoriaMetrics {
     fn name(&self) -> &str {
@@ -61,7 +68,7 @@ mod tests {
 
     #[test]
     fn query_buildinfo() -> Result<(), Box<dyn std::error::Error + 'static>> {
-        let node = VictoriaMetricsImage.start()?;
+        let node = VictoriaMetricsImage::default().start()?;
         let host_ip = node.get_host()?;
         let host_port = node.get_host_port_ipv4(8428)?;
         let url = format!("http://{host_ip}:{host_port}/api/v1/status/buildinfo");

src/zookeeper/mod.rs

@@ -40,6 +40,9 @@ const TAG: &str = "3.9.0";
 /// [Zookeeper documentation]: https://zookeeper.apache.org/documentation.html
 #[derive(Debug, Default, Clone)]
 pub struct Zookeeper {
+    /// (remove if there is another variable)
+    /// Field is included to prevent this struct to be a unit struct.
+    /// This allows extending functionality (and thus further variables) without breaking changes
     _priv: (),
 }