Fix & imporve postgres backup/restore scripts

{{cookiecutter.project_slug}}/compose/production/postgres/Dockerfile

@@ -1,10 +1,6 @@
-FROM postgres:{{ cookiecutter.postgresql_version }}
+FROM postgres:10.3
 
-COPY ./compose/production/postgres/backup.sh /usr/local/bin/backup
+COPY ./compose/production/postgres/maintenance /usr/local/bin/maintenance
-RUN chmod +x /usr/local/bin/backup
+RUN chmod +x /usr/local/bin/maintenance/*
-
+RUN mv /usr/local/bin/maintenance/* /usr/local/bin \
-COPY ./compose/production/postgres/restore.sh /usr/local/bin/restore
+    && rmdir /usr/local/bin/maintenance
-RUN chmod +x /usr/local/bin/restore
-
-COPY ./compose/production/postgres/list-backups.sh /usr/local/bin/list-backups
-RUN chmod +x /usr/local/bin/list-backups

{{cookiecutter.project_slug}}/compose/production/postgres/backup.sh

@@ -1,25 +0,0 @@
-#!/usr/bin/env bash
-
-set -o errexit
-set -o pipefail
-set -o nounset
-
-
-# we might run into trouble when using the default `postgres` user, e.g. when dropping the postgres
-# database in restore.sh. Check that something else is used here
-if [ "$POSTGRES_USER" == "postgres" ]
-then
-    echo "creating a backup as the postgres user is not supported, make sure to set the POSTGRES_USER environment variable"
-    exit 1
-fi
-
-# export the postgres password so that subsequent commands don't ask for it
-export PGPASSWORD=$POSTGRES_PASSWORD
-
-echo "creating backup"
-echo "---------------"
-
-FILENAME=backup_$(date +'%Y_%m_%dT%H_%M_%S').sql.gz
-pg_dump -h postgres -U $POSTGRES_USER | gzip > /backups/$FILENAME
-
-echo "successfully created backup $FILENAME"

{{cookiecutter.project_slug}}/compose/production/postgres/list-backups.sh

@@ -1,10 +0,0 @@
-#!/usr/bin/env bash
-
-set -o errexit
-set -o pipefail
-set -o nounset
-
-
-echo "listing available backups"
-echo "-------------------------"
-ls /backups/

{{cookiecutter.project_slug}}/compose/production/postgres/maintenance/_sourced/constants.sh

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+
+
+BACKUP_DIR_PATH='/backups'
+BACKUP_FILE_PREFIX='backup'

{{cookiecutter.project_slug}}/compose/production/postgres/maintenance/_sourced/countdown.sh

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+
+
+countdown() {
+    declare desc="A simple countdown. Source: https://superuser.com/a/611582"
+    local seconds="${1}"
+    local d=$(($(date +%s) + "${seconds}"))
+    while [ "$d" -ge `date +%s` ]; do
+        echo -ne "$(date -u --date @$(($d - `date +%s`)) +%H:%M:%S)\r";
+        sleep 0.1
+    done
+}

{{cookiecutter.project_slug}}/compose/production/postgres/maintenance/_sourced/messages.sh

@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+
+
+message_newline() {
+    echo
+}
+
+message_debug()
+{
+    echo -e "DEBUG: ${@}"
+}
+
+message_welcome()
+{
+    echo -e "\e[1m${@}\e[0m"
+}
+
+message_warning()
+{
+    echo -e "\e[33mWARNING\e[0m: ${@}"
+}
+
+message_error()
+{
+    echo -e "\e[31mERROR\e[0m: ${@}"
+}
+
+message_info()
+{
+    echo -e "\e[37mINFO\e[0m: ${@}"
+}
+
+message_suggestion()
+{
+    echo -e "\e[33mSUGGESTION\e[0m: ${@}"
+}
+
+message_success()
+{
+    echo -e "\e[32mSUCCESS\e[0m: ${@}"
+}

{{cookiecutter.project_slug}}/compose/production/postgres/maintenance/_sourced/yes_no.sh

@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+
+
+yes_no() {
+    declare desc="Prompt for confirmation. \$\"\{1\}\": confirmation message."
+    local arg1="${1}"
+
+    local response=
+    read -r -p "${arg1} (y/[n])? " response
+    if [[ "${response}" =~ ^[Yy]$ ]]
+    then
+        exit 0
+    else
+        exit 1
+    fi
+}

{{cookiecutter.project_slug}}/compose/production/postgres/maintenance/backup

@@ -0,0 +1,38 @@
+#!/usr/bin/env bash
+
+
+### Create a database backup.
+###
+### Usage:
+###     $ docker-compose -f <environment>.yml (exec |run --rm) postgres backup
+
+
+set -o errexit
+set -o pipefail
+set -o nounset
+
+
+working_dir="$(dirname ${0})"
+source "${working_dir}/_sourced/constants.sh"
+source "${working_dir}/_sourced/messages.sh"
+
+
+message_welcome "Backing up the '${POSTGRES_DB}' database..."
+
+
+if [[ "${POSTGRES_USER}" == "postgres" ]]; then
+    message_error "Backing up as 'postgres' user is not supported. Assign 'POSTGRES_USER' env with something else and try again."
+    exit 1
+fi
+
+export PGPASSWORD="${POSTGRES_PASSWORD}"
+
+backup_filename="${BACKUP_FILE_PREFIX}_$(date +'%Y_%m_%dT%H_%M_%S').sql.gz"
+pg_dump \
+    --host=postgres \
+    --dbname="${POSTGRES_DB}" \
+    --username="${POSTGRES_USER}" \
+    | gzip > "${BACKUP_DIR_PATH}/${backup_filename}"
+
+
+message_success "'${POSTGRES_DB}' database backup '${backup_filename}' has been created and placed in '${BACKUP_DIR_PATH}'."

{{cookiecutter.project_slug}}/compose/production/postgres/maintenance/backups

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+
+
+### View backups.
+###
+### Usage:
+###     $ docker-compose -f <environment>.yml (exec |run --rm) postgres backups
+
+
+set -o errexit
+set -o pipefail
+set -o nounset
+
+
+working_dir="$(dirname ${0})"
+source "${working_dir}/_sourced/constants.sh"
+source "${working_dir}/_sourced/messages.sh"
+
+
+message_welcome "These are the backups you have got:"
+
+ls -lht "${BACKUP_DIR_PATH}"

{{cookiecutter.project_slug}}/compose/production/postgres/maintenance/restore

@@ -0,0 +1,76 @@
+#!/usr/bin/env bash
+
+
+### Restore database from a backup.
+###
+### Parameters:
+###     <1> filename of an existing backup.
+###
+### Usage:
+###     $ docker-compose -f <environment>.yml (exec |run --rm) postgres restore <1>
+
+
+set -o errexit
+set -o pipefail
+set -o nounset
+
+
+working_dir="$(dirname ${0})"
+source "${working_dir}/_sourced/constants.sh"
+source "${working_dir}/_sourced/messages.sh"
+
+
+if [[ -z ${1+x} ]]; then
+    message_error "Backup filename is not specified."
+    exit 1
+fi
+backup_filename="${BACKUP_DIR_PATH}/${1}"
+if [[ ! -f "${backup_filename}" ]]; then
+    message_error "No backup with the specified filename found."
+    exit 1
+fi
+
+message_welcome "Restoring the '${POSTGRES_DB}' database from the '${backup_filename}' backup..."
+
+if [[ "${POSTGRES_USER}" == "postgres" ]]; then
+    message_error "Restoring as 'postgres' user is not supported."
+    exit 1
+fi
+
+export PGPASSWORD="${POSTGRES_PASSWORD}"
+
+message_info "Dropping all connections to the database..."
+# Source: http://dba.stackexchange.com/a/11895
+drop_postgres_connections_sql='UPDATE pg_database'
+drop_postgres_connections_sql+=" SET datallowconn = 'false'"
+drop_postgres_connections_sql+=" WHERE datname = '${POSTGRES_DB}';"
+drop_postgres_connections_sql+='SELECT pg_terminate_backend(pid)'
+drop_postgres_connections_sql+=' FROM pg_stat_activity'
+drop_postgres_connections_sql+=" WHERE datname = '${POSTGRES_DB}';"
+psql \
+    --host=localhost \
+    --username=postgres \
+    --dbname=postgres \
+    --command="${drop_postgres_connections_sql}"
+
+message_info "Dropping the database..."
+dropdb \
+    --host=postgres \
+    --username="${POSTGRES_USER}" \
+    "${POSTGRES_DB}"
+
+message_info "Creating a new database..."
+createdb \
+    --host=postgres \
+    --username="${POSTGRES_USER}" \
+    --owner="${POSTGRES_USER}" \
+    "${POSTGRES_DB}"
+
+message_info "Applying the backup to the new database..."
+gunzip -c "${backup_filename}" \
+    | psql \
+        --host=postgres \
+        --username="${POSTGRES_USER}" \
+        "${POSTGRES_DB}"
+
+message_success "The '${POSTGRES_DB}' database has been restored from the '${backup_filename}' backup."

{{cookiecutter.project_slug}}/compose/production/postgres/restore.sh

@@ -1,58 +0,0 @@
-#!/usr/bin/env bash
-
-set -o errexit
-set -o pipefail
-set -o nounset
-
-
-# we might run into trouble when using the default `postgres` user, e.g. when dropping the postgres
-# database in restore.sh. Check that something else is used here
-if [ "$POSTGRES_USER" == "postgres" ]
-then
-    echo "restoring as the postgres user is not supported, make sure to set the POSTGRES_USER environment variable"
-    exit 1
-fi
-
-# export the postgres password so that subsequent commands don't ask for it
-export PGPASSWORD=$POSTGRES_PASSWORD
-
-# check that we have an argument for a filename candidate
-if [[ $# -eq 0 ]] ; then
-    echo 'usage:'
-    echo '    docker-compose -f production.yml run postgres restore <backup-file>'
-    echo ''
-    echo 'to get a list of available backups, run:'
-    echo '    docker-compose -f production.yml run postgres list-backups'
-    exit 1
-fi
-
-# set the backupfile variable
-BACKUPFILE=/backups/$1
-
-# check that the file exists
-if ! [ -f $BACKUPFILE ]; then
-    echo "backup file not found"
-    echo 'to get a list of available backups, run:'
-    echo '    docker-compose -f production.yml run postgres list-backups'
-    exit 1
-fi
-
-echo "beginning restore from $1"
-echo "-------------------------"
-
-# delete the db
-# deleting the db can fail. Spit out a comment if this happens but continue since the db
-# is created in the next step
-echo "deleting old database $POSTGRES_USER"
-if dropdb -h postgres -U $POSTGRES_USER $POSTGRES_USER
-then echo "deleted $POSTGRES_USER database"
-else echo "database $POSTGRES_USER does not exist, continue"
-fi
-
-# create a new database
-echo "creating new database $POSTGRES_USER"
-createdb -h postgres -U $POSTGRES_USER $POSTGRES_USER -O $POSTGRES_USER
-
-# restore the database
-echo "restoring database $POSTGRES_USER"
-gunzip -c $BACKUPFILE | psql -h postgres -U $POSTGRES_USER