From db996b1839df9fbd5a905fec3fc11bd7c883a7b1 Mon Sep 17 00:00:00 2001
From: "Alexander A. Klimov" <alexander.klimov@icinga.com>
Date: Thu, 23 Sep 2021 18:14:07 +0200
Subject: [PATCH] Document Postgres support

refs #136
---
 README.md               |  5 +++--
 doc/01-About.md         |  5 +++--
 doc/02-Installation.md  | 40 ++++++++++++++++++++++++++++++++++++++--
 doc/03-Configuration.md |  1 +
 4 files changed, 45 insertions(+), 6 deletions(-)

diff --git a/README.md b/README.md
index e7e5342e..b57623ff 100644
--- a/README.md
+++ b/README.md
@@ -13,9 +13,10 @@
 
 ## About
 
-Icinga DB serves as a synchronisation daemon between Icinga 2 (Redis) and Icinga Web 2 (MySQL). It synchronises configuration, state and history of an Icinga 2 environment using checksums.
+Icinga DB serves as a synchronisation daemon between Icinga 2 (Redis) and Icinga Web 2 (MySQL/MariaDB/PostgreSQL database).
+It synchronises configuration, state and history of an Icinga 2 environment using checksums.
 
-Icinga DB also supports reading from multiple environments and writing into a single MySQL instance.
+Icinga DB also supports reading from multiple environments and writing into a single database.
 
 ## License
 
diff --git a/doc/01-About.md b/doc/01-About.md
index 29229dec..3c3e8903 100644
--- a/doc/01-About.md
+++ b/doc/01-About.md
@@ -2,6 +2,7 @@
 
 ![Icinga DB Context](images/about/icinga-db-in-icinga-context.png)
 
-Icinga DB serves as a synchronisation daemon between Icinga 2 (Redis) and Icinga Web 2 (MySQL). It synchronises configuration, volatile states and history of an Icinga 2 environment using checksums.
+Icinga DB serves as a synchronisation daemon between Icinga 2 (Redis) and Icinga Web 2 (MySQL/MariaDB/PostgreSQL database).
+It synchronises configuration, volatile states and history of an Icinga 2 environment using checksums.
 
-Icinga DB also supports reading from multiple environments and writing into a single MySQL instance.
\ No newline at end of file
+Icinga DB also supports reading from multiple environments and writing into a single database.
diff --git a/doc/02-Installation.md b/doc/02-Installation.md
index 58712867..30c67730 100644
--- a/doc/02-Installation.md
+++ b/doc/02-Installation.md
@@ -3,7 +3,7 @@
 ## Requirements <a id="installation-requirements"></a>
 
 * Local Redis instance (Will be installed during this documentation)
-* MySQL/MariaDB database `icingadb`, user and schema imports (Will be set up during this documentation)
+* MySQL/MariaDB/PostgreSQL database `icingadb`, user and schema imports (Will be set up during this documentation)
 
 ## Setting up Icinga DB <a id="setting-up-icingadb"></a>
 
@@ -133,7 +133,11 @@ Debian/Ubuntu:
 apt-get install icingadb-redis
 ```
 
-### Setting up the MySQL database <a id="setting-up-mysql-db"></a>
+### Setting up the Database <a id="setting-up-db"></a>
+
+A MySQL/MariaDB or PostgreSQL database is required.
+
+#### MySQL/MariaDB <a id="setting-up-mysql-db"></a>
 
 Note that if you're using a version of MySQL < 5.7 or MariaDB < 10.2, the following server options must be set:
 
@@ -159,6 +163,38 @@ After creating the database, you can import the Icinga DB schema using the follo
 mysql -u root -p icingadb </usr/share/icingadb/schema/mysql/schema.sql
 ```
 
+#### PostgreSQL <a id="setting-up-pgsql-db"></a>
+
+Set up a PostgreSQL database for Icinga DB:
+
+```
+# su -l postgres
+
+createuser -P icingadb
+createdb -E UTF8 -O icingadb icingadb
+```
+
+Edit `pg_hba.conf`, insert the following before everything else:
+
+```
+local all icingadb           md5
+host  all icingadb 0.0.0.0/0 md5
+host  all icingadb      ::/0 md5
+```
+
+To apply those changes, run `systemctl reload postgresql`.
+(On RHEL/CentOS 7 the service is called "rh-postgresql95-postgresql".)
+
+After creating the database you can import the Icinga DB schema using the
+following command. Enter the password when asked.
+
+```
+psql -U icingadb icingadb < /usr/share/icingadb/schema/pgsql/schema.sql
+```
+
+On RHEL/CentOS 7 prefix "createuser", "createdb" and "psql" with
+"/opt/rh/rh-postgresql95/root/usr/bin/".
+
 ### Running Icinga DB <a id="running-icingadb"></a>
 
 Foreground:
diff --git a/doc/03-Configuration.md b/doc/03-Configuration.md
index da018de9..7d9ed2e1 100644
--- a/doc/03-Configuration.md
+++ b/doc/03-Configuration.md
@@ -25,6 +25,7 @@ Configuration of the database used by Icinga DB.
 
 Option                   | Description
 -------------------------|-----------------------------------------------
+type                     | **Optional.** Either `mysql` (default) or `pgsql`.
 host                     | **Required.** Database host or absolute Unix socket path.
 port                     | **Required.** Database port.
 database                 | **Required.** Database database.