How to Install Exalate for ServiceNow on Docker

You can host Exalate for Servicenow on your own server. To do so, you need to install Exalate on Docker.

How to Install Exalate for ServiceNow

1. Create directory and create docker-compose.yml file

Create a directory to hold the docker-compose file:

cd ~
mkdir exalate-snownode

Create or download a docker-compose.yml file.

services:
  database:
    restart: unless-stopped
    image: postgres:15.12
    volumes:
      - ./persist/db:/var/lib/postgresql/data
      - ./createdb.sh:/docker-entrypoint-initdb.d/init-user-db.sh
    environment:
      - POSTGRES_PASSWORD=exalate
      - DB_NAME=snownode
      - DB_USER=exalate
      - DB_PASS=exalate
    networks:
      - dbnet

  snownode:
    restart: unless-stopped
    ports:
      - 9000:9000

    #
    # Change the image tag to the required version
    # Check Release History on docs.exalate.com for an overview
    #
    image: idalko/snownode:5.23.0
    depends_on:
      - database #wait for postgres to be started, not for ready
    volumes:
      - ./persist/home:/opt/snownode/data
    environment:
      # Add your environment settings here
      - SNOWNODE_PG_HOST=database
      - SNOWNODE_PG_DB=snownode?gssEncMode=disable
      - SNOWNODE_PG_USER=exalate
      - SNOWNODE_PG_PWD=exalate
      - SNOWNODE_PORT=9000     
     #As part of the security improvements, Exalate 5.6.0 and above validates the origin header
     #that the browser is sending upon every request to Exalate.
     #In order to validate the origin header, Exalate needs to know what is the URL 
     #leading to it.
     #When you deploy Exalate onto a server, you configure a DNS rule such that 
     #whenever people navigate to foo.com, they reach your server's Exalate. 
     #You set up SSL so that https://foo.com leads to your Exalate on your server. once this is      done you need to set an environment variable NODE_SELF_URL=https://foo.com 
     #for your Exalate docker container.
      - NODE_SELF_URL=https://foo.com
     # You can use following variables to link the node with nginx proxy
     # Replace exa-snow.exalate.biz with the appropriate FQDN
     # - LETSENCRYPT_HOST=exa-snow.exalate.biz
     # - VIRTUAL_HOST=exa-snow.exalate.biz
     # - VIRTUAL_PORT=9002
     # To hanlde SSL termination we suggest following this article https://docs.exalate.com/docs/scripts-how-to-bring-up-a-reverse-proxy-using-the-jwildernginx-proxy
      
     # CACHE_EXPIRY_DURATION_HOURS variable defines how long the cache will remain in the app.
     # The default value of 8 hours can be changed by specifying the number of hours.
     # - CACHE_EXPIRY_DURATION_HOURS=20

    networks:
      - dbnet
      - default

networks:
  dbnet:
    driver: bridge
  default:
    driver: bridge

Note: the - SNOWNODE_PG_DB= and - DB_NAME= must match in order to start the db correctly.

Connecting to Postgres 10 or Higher

For unencrypted connections from Exalate to a Postgres version 10 or higher, you need to disable gssEncMode with the following setting:

# in this example "exalate" is the name of the database on the postgres instance
#
SNOWNODE_PG_DB=exalate?gssEncMode=disable

2. Ensure that a correct database is setup using a createdb.sh

Create or download a createdb.sh file (referenced from docker-compose.yml):

The file must be executable (you can use the command: chmod +x createdb.sh to make the file executable)and should contain the following information:

#!/bin/bash
 
TEST=`psql -U postgres <<-EOSQL
   SELECT 1 FROM pg_database WHERE datname='$DB_NAME';
EOSQL`
 
echo "******CREATING DOCKER DATABASE******"
if [[ $TEST == "1" ]]; then
    # database exists
    # $? is 0
    exit 0
else
psql -U postgres <<-EOSQL
   CREATE ROLE $DB_USER WITH LOGIN ENCRYPTED PASSWORD '${DB_PASS}' SUPERUSER;
EOSQL
 
psql -U postgres <<-EOSQL
   CREATE DATABASE $DB_NAME WITH OWNER $DB_USER ENCODING 'UNICODE' LC_COLLATE 'C' LC_CTYPE 'C' TEMPLATE template0;
EOSQL
 
psql -U postgres <<-EOSQL
   GRANT ALL PRIVILEGES ON DATABASE $DB_NAME TO $DB_USER;
EOSQL
fi
 
echo ""
echo "******DOCKER DATABASE CREATED******"

Ensure that the volumes are included in your backup strategy:

• persist

3. Set Environment Variables if necessary

Below, you can find the environment variables used for the app container. All of them are optional, and in the given example, we've overridden snownode_PG_DB, snownode_PG_USER, and snownode_PG_PWD just to show how to pass different credentials to the Exalate application.

    ports:
      - 9000:9000

    ports:
      - 80:80

Using a Proxy for Outgoing Connections

Whenever Exalate needs to use a proxy to establish outgoing connections, use the following parameters in the environment (naming should be obvious):

• PROXY_HTTP_HOST
• PROXY_HTTP_PORT
• PROXY_HTTPS_HOST
• PROXY_HTTPS_PORT

4. Start the Application

cd ~/exalate-snownode
docker-compose up -d

Verify your instance

After starting Exalate for ServiceNow you need to verify your instance. For more information on how to verify your Exalate for ServiceNow, please this article.

How to Manage the Application on Docker

Run Queries to the Application's Database

You can find all tables using PSQLs \dt+ command:

\dt+

All the Postgres SQL queries are permitted

To exit the application's DB:

\q
# \q exits the psql 
exit
# exits the postgres user session
exit
# exits the exalatesnownode_database_1 bash session

Inspect the Application's Filesystem

cd ~/exalate-snownode
docker exec -it exalatesnownode_snownode_1 bash

Remove the Application

cd ~/exalate-snownode
docker-compose rm

Remove the Application Data

cd ~/exalate-snownode
# docker volume ls | grep exalatesnownode_vol |  awk '{ print $2 }' | xargs docker volume rm
docker volume rm exalatesnownode_voldatabase
docker volume rm exalatesnownode_volsnownode

System Administration Tasks

When Exalate for ServiceNow is running on your environment, you are also required to do the mandatory system administration tasks

• Backup (& restore tests)
• Disaster recovery procedure
• Upgrades whenever needed

Upgrading Exalate on Docker

If you need to upgrade Exalate on Docker, here are the steps to follow:

1. Edit the YAML File:

   Open the docker-compose.yml file in a text editor and modify the image tag for the service you wish to upgrade.

   # use the latest version https://hub.docker.com/r/idalko/snownode
   image: idalko/snownode:latest
   depends_on:
   - database #wait for postgres to be started, not for ready
   

   Replace latest with the latest or desired version tag.

2. Pull the Latest Image:

   From the directory containing your docker-compose.yml file, pull the latest image.

   docker-compose pull
   

3. Recreate the Container:

   Using Docker Compose, you can easily recreate the container with the new image.

   docker-compose up -d
   

   The -d flag runs the containers in detached mode. Docker Compose automatically stops the old container and start a new one based on the updated image.

4. Post-Upgrade Checks:

   After starting the upgraded container, check to make sure everything is running as expected:

• Log into the Exalate interface and verify that all your configurations, connections are intact.
• Test out a few synchronizations to make sure they work as expected.
• Check for any errors in the Docker logs or the Exalate logs.

Troubleshooting

Problems during the installation of the Exalate server for Snownode

If you have problems during the installation of the Exalate app for Servicenow you can find logs describing possible problems inside /tmp.

The name for the file is generated randomly and automatically by the OS, but you can find the file by the creation date.

Problems while running the Exalate server for Snownode

Logs are generated under the directory: /opt/snownode/data/logs.

Refer to these logs to get more information about possible problems and communicate with our support if you need any assistance.

Support

Please read our Support options.