isolate-db.sh

#!/bin/bash

set -e

# Database clone script.

# ENV
# dev, staging, demo, prod
ENV=dev

CLUSTER=dms-dev-cluster-1
BACKUP_NAME=$CLUSTER-before-migration-$RANDOM

# SQL Instance
SOURCE_SQL_INSTANCE=dmsv2-dev-database
TARGET_SQL_INSTANCE=dmsv2-dev-database-$RANDOM

# If resize is not required, then set the TARGET_SQL_MEM_GB to 0 
TARGET_SQL_MEM_GB=8

# This must be an even number
TARGET_SQL_CPU=4

# Enable HA. A value of 0 means that HA will not be enabled.
SQL_ENABLE_HA=1

# Increase the MAX_CONNECTIONS. A value of 0 means that no changes will be effected
MAX_CONNECTIONS=300


function log() {
    echo ""
    echo ""
    echo  -e "\e[34m["$(date "+%Y-%m-%d %H:%M:%S")"] INFO " $1
    echo -e "\e[0m"
    echo ""
}

function log2() {
    echo -e "\e[34m["$(date "+%Y-%m-%d %H:%M:%S")"] INFO \e[34m" $1
    echo -e "\e[0m"
}


function use_prod_context() {
    kubectl config use-context gke_twigadms_us-central1-a_dms-production-cluster-1
}

function use_dev_context() {
    kubectl config use-context gke_twigadms_us-central1-a_dms-dev-cluster-1
}

function use_staging_context() {
    kubectl config use-context gke_twigadms_us-central1-a_dms-staging-cluster-1
}

function use_demo_context() {
    kubectl config use-context gke_twigait_europe-west1-b_dms-quality-cluster-1
}

function switch_env() {

    if [ "$ENV" = "dev" ]; then
        log "Using the $ENV env"
        use_dev_context

    elif [ "$ENV" = "staging"]; then
        log "Using the $ENV env"
        use_staging_context

    elif [ "$ENV" = "demo"]; then
        log "Using the $ENV env"
        use_demo_context
    elif [ "$ENV" = "prod"]; then
        log "Using the $ENV env"
        use_prod_context
    else
        log "Specify an ENV to use. Either dev, staging, demo or prod"
        exit
    fi
}

function switch_project() {
    log "Switching GCP project to $1"
    gcloud config set project $1

}

function switch_to_twigait() {
    switch_project twigait
}

function switch_to_dms() {
    switch_project twigadms
}


function create_backup() {
    backup=$1
    log "Create a backup of the cluster => $backup"
    velero backup create $backup
}

function clone_database() {
    source_db=$1
    target_db=$2
    log "Clone Database $source_db to $target_db"

    log "Available cloud sql instances"
    gcloud sql instances list

    log "Creating a new cloud instance from $target_db"
    gcloud sql instances clone $source_db $target_db

    log "Available cloud sql instances"
    gcloud sql instances list

}

function enable_query_insights() {
    target_db=$1
    log "Enabling Query insights to the database $target_db"
    gcloud sql instances patch $target_db --insights-config-query-insights-enabled --insights-config-record-application-tags --insights-config-record-client-address
}

function resize_database() {
    if [[ $TARGET_SQL_MEM_GB -eq 0 ]]; then
        log "Done with the db clone and no resize done"
        return 0
    fi

    target_db=$1
    target_mem_GB=$2
    target_cpu=$3

    log "Resize the $target_db to $target_mem_GB"
    gcloud sql instances patch $target_db --memory=$target_mem_GB --cpu=$target_cpu

}

function enable_ha() {
    if [[ $SQL_ENABLE_HA -eq 0 ]]; then
        log "HA not enabled for instance"
        return 0
    fi
    target_db=$1
    log "Enabling HA to the instance $target_db. This operation takes a few minutes. Grab a cup of coffee."
    gcloud sql instances patch $target_db --availability-type REGIONAL
}

function set_max_connections() {
    # log "TODO: Refer to this - https://cloud.google.com/sql/docs/postgres/quotas"
    # log "https://cloud.google.com/sql/docs/postgres/flags"
    if [[ $MAX_CONNECTIONS -eq 0 ]]; then
        log "Not MAX_CONNECTIONS configured."
        return 0
    fi
    target_db=$1
    connections=$2
    log "Requires a restart. Confirm before proceeding."
    gcloud sql instances patch $target_db --database-flags max_connections=$connections
}

switch_env
create_backup $BACKUP_NAME
clone_database $SOURCE_SQL_INSTANCE $TARGET_SQL_INSTANCE

enable_query_insights $TARGET_SQL_INSTANCE
resize_database $TARGET_SQL_INSTANCE $TARGET_SQL_MEM_GB $TARGET_SQL_CPU
enable_ha $TARGET_SQL_INSTANCE
set_max_connections $TARGET_SQL_INSTANCE $MAX_CONNECTIONS

log "Done"