Add detection for latest Postgres and limit CI

.github/workflows/docker-build.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        postgres_version: ["18", "17", "17.6", "16", "16.10"]
+        postgres_version: ["latest", "18", "17", "17.6", "16", "16.10"]
       fail-fast: false
 
     steps:

.github/workflows/pr-test.yml

@@ -14,8 +14,8 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        postgres_version: ["18", "17", "17.6", "16", "16.10"]
-        platform: ["linux/amd64", "linux/arm64"]
+        postgres_version: ["latest", "18", "17", "17.6", "16", "16.10"]
+        platform: ["linux/amd64"]
       fail-fast: false
 
     steps:

Dockerfile

@@ -1,4 +1,4 @@
-ARG POSTGRES_VERSION=17.5
+ARG POSTGRES_VERSION=latest
 
 # Builder stage: compile the Rust binary
 FROM rust:slim AS builder

src/common.rs

@@ -11,3 +11,20 @@ pub fn run(cmd: &str) {
         panic!("Command failed: {}", cmd);
     }
 }
+
+/// Run a shell command and return its stdout as a trimmed String.
+/// Panics if the command fails to execute or returns a non-zero exit code.
+pub fn run_output(cmd: &str) -> String {
+    let output = Command::new("sh")
+        .arg("-c")
+        .arg(cmd)
+        .output()
+        .expect("Failed to execute command");
+
+    if !output.status.success() {
+        let stderr = String::from_utf8_lossy(&output.stderr);
+        panic!("Command failed: {}\nstderr: {}", cmd, stderr);
+    }
+
+    String::from_utf8_lossy(&output.stdout).trim().to_string()
+}

src/main.rs

@@ -1,6 +1,6 @@
 use std::env;
 
-use crate::common::run;
+use crate::common::{run, run_output};
 
 mod common;
 mod extensions;
@@ -14,7 +14,25 @@ async fn main() {
         panic!("Insert PostgreSQL version as argument");
     }
 
-    let pg_version = &args[1];
+    // If user passed "latest", detect the numeric version from the installed postgres binary.
+    // Otherwise use the provided version string (e.g. "15.3" or "15").
+    let mut pg_version = args[1].clone();
+    if pg_version.eq_ignore_ascii_case("latest") {
+        println!("🔎 Detecting PostgreSQL version from the base image (requested: latest)...");
+        // Try `postgres --version`. This requires that the base image already provides the postgres binary.
+        let ver_output = run_output("postgres --version");
+        // Typical output: "postgres (PostgreSQL) 15.3"
+        // We take the last whitespace-separated token as the numeric version.
+        let numeric_version = ver_output
+            .split_whitespace()
+            .last()
+            .expect("Failed to parse postgres --version output")
+            .to_string();
+
+        println!("ℹ️ Detected PostgreSQL version: {}", numeric_version);
+        pg_version = numeric_version;
+    }
+
     let pg_major = pg_version.split(".").next().unwrap();
 
     println!(