add files for building containter artifacts

Lifted in large parts from version 9.5 of the SCL postgresql container.

https://github.com/sclorg/postgresql-container

root/usr/bin/cgroup-limits

@@ -0,0 +1,92 @@
+#!/usr/bin/python
+
+"""
+Script for parsing cgroup information
+
+This script will read some limits from the cgroup system and parse
+them, printing out "VARIABLE=VALUE" on each line for every limit that is
+successfully read. Output of this script can be directly fed into
+bash's export command. Recommended usage from a bash script:
+
+    set -o errexit
+    export_vars=$(cgroup-limits) ; export $export_vars
+
+Variables currently supported:
+    MAX_MEMORY_LIMIT_IN_BYTES
+        Maximum possible limit MEMORY_LIMIT_IN_BYTES can have. This is
+        currently constant value of 9223372036854775807.
+    MEMORY_LIMIT_IN_BYTES
+        Maximum amount of user memory in bytes. If this value is set
+        to the same value as MAX_MEMORY_LIMIT_IN_BYTES, it means that
+        there is no limit set. The value is taken from
+        /sys/fs/cgroup/memory/memory.limit_in_bytes
+    NUMBER_OF_CORES
+        Number of detected CPU cores that can be used. This value is
+        calculated from /sys/fs/cgroup/cpuset/cpuset.cpus
+    NO_MEMORY_LIMIT
+        Set to "true" if MEMORY_LIMIT_IN_BYTES is so high that the caller
+        can act as if no memory limit was set. Undefined otherwise.
+"""
+
+from __future__ import print_function
+import sys
+
+
+def _read_file(path):
+    try:
+        with open(path, 'r') as f:
+            return f.read().strip()
+    except IOError:
+        return None
+
+
+def get_memory_limit():
+    """
+    Read memory limit, in bytes.
+    """
+
+    limit = _read_file('/sys/fs/cgroup/memory/memory.limit_in_bytes')
+    if limit is None or not limit.isdigit():
+        print("Warning: Can't detect memory limit from cgroups",
+              file=sys.stderr)
+        return None
+    return int(limit)
+
+
+def get_number_of_cores():
+    """
+    Read number of CPU cores.
+    """
+
+    core_count = 0
+
+    line = _read_file('/sys/fs/cgroup/cpuset/cpuset.cpus')
+    if line is None:
+        print("Warning: Can't detect number of CPU cores from cgroups",
+              file=sys.stderr)
+        return None
+
+    for group in line.split(','):
+        core_ids = list(map(int, group.split('-')))
+        if len(core_ids) == 2:
+            core_count += core_ids[1] - core_ids[0] + 1
+        else:
+            core_count += 1
+
+    return core_count
+
+
+if __name__ == "__main__":
+    env_vars = {
+        "MAX_MEMORY_LIMIT_IN_BYTES": 9223372036854775807,
+        "MEMORY_LIMIT_IN_BYTES": get_memory_limit(),
+        "NUMBER_OF_CORES": get_number_of_cores()
+    }
+
+    env_vars = {k: v for k, v in env_vars.items() if v is not None}
+
+    if env_vars.get("MEMORY_LIMIT_IN_BYTES", 0) >= 92233720368547:
+        env_vars["NO_MEMORY_LIMIT"] = "true"
+
+    for key, value in env_vars.items():
+        print("{0}={1}".format(key, value))

root/usr/bin/container-entrypoint

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+exec "$@"

root/usr/bin/run-postgresql

@@ -0,0 +1,28 @@
+#!/bin/bash
+
+export ENABLE_REPLICATION=${ENABLE_REPLICATION:-false}
+
+set -eu
+export_vars=$(cgroup-limits) ; export $export_vars
+
+source "${CONTAINER_SCRIPTS_PATH}/common.sh"
+
+set_pgdata
+check_env_vars
+generate_passwd_file
+generate_postgresql_config
+
+if [ ! -f "$PGDATA/postgresql.conf" ]; then
+  initialize_database
+  NEED_TO_CREATE_USERS=yes
+fi
+
+pg_ctl -w start -o "-h ''"
+if [ "${NEED_TO_CREATE_USERS:-}" == "yes" ]; then
+  create_users
+fi
+set_passwords
+pg_ctl stop
+
+unset_env_vars
+exec postgres "$@"

root/usr/bin/run-postgresql-master

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+export ENABLE_REPLICATION=true
+
+exec run-postgresql "$@"

root/usr/bin/run-postgresql-slave

@@ -0,0 +1,36 @@
+#!/bin/bash
+
+export ENABLE_REPLICATION=true
+
+set -eu
+export_vars=$(cgroup-limits) ; export $export_vars
+
+source "$CONTAINER_SCRIPTS_PATH"/common.sh
+
+set_pgdata
+
+function initialize_replica() {
+  echo "Initializing PostgreSQL slave ..."
+  # TODO: Validate and reuse existing data?
+  rm -rf $PGDATA
+  PGPASSWORD="${POSTGRESQL_MASTER_PASSWORD}" pg_basebackup -x --no-password --pgdata ${PGDATA} --host=${MASTER_FQDN} --port=5432 -U "${POSTGRESQL_MASTER_USER}"
+
+  # PostgreSQL recovery configuration.
+  generate_postgresql_recovery_config
+  cat >> "$PGDATA/recovery.conf" <<EOF
+
+# Custom OpenShift recovery configuration:
+include '${POSTGRESQL_RECOVERY_FILE}'
+EOF
+}
+
+check_env_vars
+generate_passwd_file
+generate_postgresql_config
+
+wait_for_postgresql_master
+export MASTER_FQDN=$(postgresql_master_addr)
+initialize_replica
+
+unset_env_vars
+exec postgres "$@"