Added TrueCharts db tools

Copied from here:
https://truecharts.org/manual/SCALE/guides/sql-export/

Link to source of page:
https://github.com/truecharts/website/blame/main/docs/manual/SCALE/guides/sql-export.md#L13

Permalink in space/time:
30484d04f7/docs/manual/SCALE/guides/sql-export.md (L13)

tcdbbackup.sh

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+#!/bin/bash
+# create backup folder
+folder="./dumps/"
+mkdir -p "$folder"
+
+# get namespaces with postgres database pod
+namespaces=$(k3s kubectl get pods -A | grep postgres | awk '{print $1}')
+
+for ns in $namespaces; do
+  # extract application name
+  app=$(echo "$ns" | sed 's/^ix-//')
+
+  echo "Creating database backup for $app."
+
+  file="$app.sql"
+  
+  # Scale down deployment to avoid inconsistencies in DB
+  k3s kubectl scale deploy "$app" -n "$ns" --replicas=0
+  while true; do k3s kubectl get pods -n "$ns" | grep -i -q terminating || break; done;
+
+  k3s kubectl exec -n "$ns" -c "$app"-postgresql "$app"-postgresql-0 -- bash -c 'PGPASSWORD=$POSTGRES_PASSWORD pg_dump -Fc -U $POSTGRES_USER -d $POSTGRES_DB -f /tmp/'$file
+  k3s kubectl cp -n "$ns" -c "$app"-postgresql "$app-postgresql-0:tmp/$file" $folder$file
+
+  # Scale deployment back up
+  k3s kubectl scale deploy "$app" -n "$ns" --replicas=1
+  
+  if [ ! -f "$folder$file" ]; then
+    >&2 echo "$folder$file does not exist."
+    exit 1
+  fi
+
+  echo "File $file created."
+
+done
+
+exit 0
+