apiVersion: v1
data:
  postgres_backup.sh: |
    #!/bin/bash

    DEBUG_LOG="/tmp/pg_backup_`date +%F`.log"
    echo "Plz check $DEBUG_LOG for debugging purpose. EVERY output will be redirected!"
    # fgoerz DEV-1029
    # pipe all output to file for debugging purpose
    exec 2>&1 1>$DEBUG_LOG

    function log
    {
        echo "$(date "+%Y-%m-%d %H:%M:%S.%3N") - $0 - $*"
    }

    [[ -z $1 ]] && echo "Usage: $0 PGDATA" && exit 1

    log "I was called as: $0 $*"


    readonly PGDATA=$1
    DAYS_TO_RETAIN=$BACKUP_NUM_TO_RETAIN

    readonly IN_RECOVERY=$(psql -tXqAc "select pg_is_in_recovery()")
    if [[ $IN_RECOVERY == "f" ]]; then
        [[ "$WALG_BACKUP_FROM_REPLICA" == "true" ]] && log "Cluster is not in recovery, not running backup" && exit 0
    elif [[ $IN_RECOVERY == "t" ]]; then
        [[ "$WALG_BACKUP_FROM_REPLICA" != "true" ]] && log "Cluster is in recovery, not running backup" && exit 0
    else
        log "ERROR: Recovery state unknown: $IN_RECOVERY" && exit 1
    fi

    # leave at least 2 days base backups before creating a new one
    [[ "$DAYS_TO_RETAIN" -lt 2 ]] && DAYS_TO_RETAIN=2

    if [[ "$USE_WALG_BACKUP" == "true" ]]; then
        readonly WAL_E="wal-g"
        [[ -z $WALG_BACKUP_COMPRESSION_METHOD ]] || export WALG_COMPRESSION_METHOD=$WALG_BACKUP_COMPRESSION_METHOD
        export PGHOST=/var/run/postgresql
    else
        readonly WAL_E="wal-e"

        # Ensure we don't have more workes than CPU's
        POOL_SIZE=$(grep -c ^processor /proc/cpuinfo 2>/dev/null || 1)
        [ "$POOL_SIZE" -gt 4 ] && POOL_SIZE=4
        POOL_SIZE=(--pool-size "$POOL_SIZE")
    fi

    BEFORE=""
    LEFT=0

    readonly NOW=$(date +%s -u)
    while read -r name last_modified rest; do
        last_modified=$(date +%s -ud "$last_modified")
        if [ $(((NOW-last_modified)/86400)) -ge $DAYS_TO_RETAIN ]; then
            if [ -z "$BEFORE" ] || [ "$last_modified" -gt "$BEFORE_TIME" ]; then
                BEFORE_TIME=$last_modified
                BEFORE=$name
            fi
        else
            # count how many backups will remain after we remove everything up to certain date
            ((LEFT=LEFT+1))
        fi
    done < <($WAL_E backup-list 2> /dev/null | sed '0,/^name\s*\(last_\)\?modified\s*/d')

    # we want keep at least N backups even if the number of days exceeded
    if [ ! -z "$BEFORE" ] && [ $LEFT -ge $DAYS_TO_RETAIN ]; then
        if [[ "$USE_WALG_BACKUP" == "true" ]]; then
            $WAL_E delete before FIND_FULL "$BEFORE" --confirm
        else
            $WAL_E delete --confirm before "$BEFORE"
        fi
    fi

    # push a new base backup
    log "producing a new backup"
    # We reduce the priority of the backup for CPU consumption
    exec nice -n 5 $WAL_E backup-push "$PGDATA" "${POOL_SIZE[@]}"
kind: ConfigMap
metadata:
  name: pg-backup-script