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//! A single-node PostgreSQL container. Defaults to a `test`/`test`/`test`
//! user/password/database trio so [`PostgresGuard::connection_string`] is usable with
//! zero configuration; call [`PostgresContainer::with_username`]/
//! [`PostgresContainer::with_password`]/[`PostgresContainer::with_database`] before
//! `start()` to override any of them.
use rightsize::{Container, ContainerGuard, Result, Wait};
/// A single-node PostgreSQL container.
pub struct PostgresContainer {
container: Container,
username: String,
password: String,
database: String,
}
impl PostgresContainer {
const PORT: u16 = 5432;
/// Builds a container from the pinned default image (`postgres:18-alpine`) —
/// 18.4 was current stable at the time of that pin.
pub fn new() -> Self {
Self::with_image("postgres:18-alpine")
}
/// Builds a container from a caller-chosen image.
pub fn with_image(image: &str) -> Self {
let username = "test".to_string();
let password = "test".to_string();
let database = "test".to_string();
let container = Container::new(image)
.with_exposed_ports(&[Self::PORT])
.with_env("POSTGRES_USER", &username)
.with_env("POSTGRES_PASSWORD", &password)
.with_env("POSTGRES_DB", &database)
// The official postgres:*-alpine image bakes DOCKER_PG_LLVM_DEPS into its
// manifest with a literal tab character in the value (a package list built
// with `\t\t` continuation). msb 0.6.2's krun VMM builder panics with
// InvalidAscii on that boot-env value before the guest ever starts
// (reproduced with zero rightsize-set env vars — it's the image, not us).
// Docker is unaffected. Overriding the var here wins over the
// image default in both backends' env-merge order and is a no-op for the
// build the image already baked, so it's a safe, backend-portable fix
// rather than an msb-only special case.
.with_env("DOCKER_PG_LLVM_DEPS", "")
// The postgres entrypoint starts the server once to run initdb scripts
// against it, shuts it down, then starts it again for real — printing
// "database system is ready to accept connections" BOTH times. Waiting
// for the first occurrence races that restart: a client can connect to
// the init-time server just before it's torn down. times=2 waits for the
// second, durable listen.
.waiting_for(Wait::for_log_message(
".*database system is ready to accept connections.*",
2,
));
Self {
container,
username,
password,
database,
}
}
/// Overrides `POSTGRES_USER` (default `test`).
pub fn with_username(mut self, username: &str) -> Self {
self.username = username.to_string();
self.container = self.container.with_env("POSTGRES_USER", username);
self
}
/// Overrides `POSTGRES_PASSWORD` (default `test`).
pub fn with_password(mut self, password: &str) -> Self {
self.password = password.to_string();
self.container = self.container.with_env("POSTGRES_PASSWORD", password);
self
}
/// Overrides `POSTGRES_DB` (default `test`).
pub fn with_database(mut self, database: &str) -> Self {
self.database = database.to_string();
self.container = self.container.with_env("POSTGRES_DB", database);
self
}
/// Boots the container.
pub async fn start(self) -> Result<PostgresGuard> {
crate::register_default_backends();
let guard = self.container.start().await?;
Ok(PostgresGuard {
guard,
username: self.username,
password: self.password,
database: self.database,
})
}
}
impl Default for PostgresContainer {
fn default() -> Self {
Self::new()
}
}
/// The running guard for a [`PostgresContainer`].
pub struct PostgresGuard {
guard: ContainerGuard,
username: String,
password: String,
database: String,
}
impl PostgresGuard {
/// The configured database user (default `test`).
pub fn username(&self) -> &str {
&self.username
}
/// The configured database password (default `test`).
pub fn password(&self) -> &str {
&self.password
}
/// The configured database name (default `test`).
pub fn database_name(&self) -> &str {
&self.database
}
/// A `postgres://` connection string for the running container's
/// [`Self::database_name`].
pub fn connection_string(&self) -> String {
format!(
"postgres://{}:{}@{}:{}/{}",
self.username,
self.password,
self.guard.host(),
self.guard.get_mapped_port(PostgresContainer::PORT).unwrap(),
self.database,
)
}
/// Stops and removes the container, releasing its host port.
pub async fn stop(self) -> Result<()> {
self.guard.stop().await
}
}
impl std::ops::Deref for PostgresGuard {
type Target = ContainerGuard;
fn deref(&self) -> &ContainerGuard {
&self.guard
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn defaults_are_the_test_trio() {
let c = PostgresContainer::new();
assert_eq!(c.username, "test");
assert_eq!(c.password, "test");
assert_eq!(c.database, "test");
}
#[test]
fn builders_override_the_defaults() {
let c = PostgresContainer::new()
.with_username("alice")
.with_password("s3cret")
.with_database("app");
assert_eq!(c.username, "alice");
assert_eq!(c.password, "s3cret");
assert_eq!(c.database, "app");
}
}