Installing the psycopg2 Python package for PostgreSQL database

If you are using PostgreSQL as a backend database for Hue on CDP Private Cloud Base 7, then you must install a version of the psycopg2 package to be at least 2.9.5 on all Hue hosts. The psycopg2 package is automatically installed as a dependency of Cloudera Manager Agent, but the version installed is often lower than 2.9.3.

Before you begin, you must disable the postgresql10 section from the cloudera-manager.repo file as follows:

SSH in to the Cloudera Manager host as an Administrator.
Change to the directory where you had downloaded the cloudera-manager.repo file. On RHEL, the file is present under the /etc/yum.repos.d directory.

Open the file for editing and update the value of the enabled property to 0 as follows:

[postgresql10]
name=Postgresql 10
baseurl=https://archive.cloudera.com/postgresql10/redhat8/
gpgkey=https://archive.cloudera.com/postgresql10/redhat8/RPM-GPG-KEY-PGDG-10
enabled=0 
gpgcheck=1
module_hotfixes=true

Save the file and exit.

CentOS RHEL OEL 7 8
RHEL 9
SLES
Ubuntu

The following steps apply to CentOS 7, RHEL 7, and OEL 7, CentOS 8, RHEL 8, OEL 8:

SSH into the Hue server host as a root user.
Before you install psycopg2-binary package, run the following pip command to install dependencies and to ensure smooth psycopg2 installation:
```
yum install -y python39-pip
```

Install the psycopg2-binary package as follows:

Python 3.9

python3.9 -m pip install psycopg2-binary
python3.9 -m pip show psycopg2-binary

Python 3.8

python3.8 -m pip install psycopg2-binary
python3.8 -m pip show psycopg2-binary

Repeat these steps on all the Hue server hosts.

If you get the "Error: pg_config executable not found" error while installing the psycopg2-binary package, then run the following commands to install the postgresql, postgresql-devel, python-devel packages:

yum install postgresql postgresql-devel python-devel

The following steps apply to RHEL 9, as the minimum version of Python is 3.9:

SSH into the Hue server host as a root user.
Install pip for Python as follows:
```
yum install python3-pip -y
```
Add the /usr/local/bin path to the PATH environment variable:
```
export PATH=$PATH:/usr/local/bin
echo $PATH
```
Install the psycopg2-binary package as follows:
```
pip3 install psycopg2-binary
```
Repeat these steps on all the Hue server hosts.

yum install postgresql postgresql-devel python-devel

SSH into the Hue host as a root user.
Install the psycopg2 package dependencies for SLES by running the following commands:
```
zypper install xmlsec1
zypper install xmlsec1-devel
zypper install xmlsec1-openssl-devel
```
Install the postgresql-devel package corresponding to your database version by running the following command:
```
zypper -n postgresql[***DB-VERSION***]-devel
```
Add the location of the installed postgresql-devel package to the PATH environment variable by running the following command:
```
export PATH=$PATH:/usr/local/bin
```
Install the psycopg2 package by running the following command:
```
pip3.8 install psycopg2==2.9.3 --ignore-installed
```

SSH into the Hue host as a root user.

Install the psycopg2 package dependencies for Ubuntu by running the following commands:

apt-get install -y xmlsec1
apt-get install libxmlsec1-openssl
apt-get install libpq-dev python3-pip -y

Install the python3-dev and libpq-dev packages by running the following command:
```
apt install python3-dev libpq-dev
```
Add the location of the installed postgresql-devel package to the PATH environment variable by running the following command:
```
export PATH=$PATH:/usr/local/bin
```
Install the psycopg2 package by running the following command:
```
pip3.8 install psycopg2==2.9.3 --ignore-installed
```