Single container with a service and Postgres main

4 files changed, 48 insertions, 0 deletions

diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..3f3de0f
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,14 @@
+FROM alpine:latest AS build
+WORKDIR /build
+RUN apk update && \
+    apk add --no-cache gcc musl-dev postgresql-dev
+
+COPY service.c .
+RUN gcc -o service service.c -lpq
+
+FROM postgres:alpine
+
+COPY script.sh .
+COPY --from=build /build/service .
+
+ENTRYPOINT ["./script.sh"]
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..511c3c3
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,8 @@
+.PHONY: build-image run-container
+.DEFAULT_GOAL := run-container
+
+build-image:
+	docker build -t onecontainer .
+
+run-container: build-image
+	docker run -e POSTGRES_HOST_AUTH_METHOD=trust -it --rm onecontainer
diff --git a/script.sh b/script.sh
new file mode 100755
index 0000000..3a6e0f5
--- /dev/null
+++ b/script.sh
@@ -0,0 +1,4 @@
+#!/bin/bash
+
+/usr/local/bin/docker-entrypoint.sh postgres &
+./service
diff --git a/service.c b/service.c
new file mode 100644
index 0000000..edc6fd0
--- /dev/null
+++ b/service.c
@@ -0,0 +1,22 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <libpq-fe.h>
+
+int main() {
+    PGconn *conn;
+    for (int i = 0; i < 100; i++) {
+	printf("trying to connect...\n");
+        conn = PQconnectdb("host=localhost dbname=postgres user=postgres password=");
+        if (PQstatus(conn) == CONNECTION_OK) {
+            printf("connected :)\n");
+	    break;
+        } else {
+            fprintf(stderr, "connection failed: %s", PQerrorMessage(conn));
+	    sleep(2);
+        }
+    }
+
+    PQfinish(conn);
+}
+