docs: add more example in cookbook (#2977)

Author: Codelax

docs/cookbook.md

@@ -3,13 +3,87 @@
 This file regroups some useful combinations of different commands to efficiently manage your Scaleway resources.
 Do not hesitate to open a PR and share your favorite recipes.
 
+## General
+
+### Retrieve specific field
+
+```bash
+## Retrieve all available instance type names
+
+# Using jq
+scw -o json instance server-type list | jq -r '.[].name'
+# Using CLI templates
+scw instance server-type list -o template="{{ .Name }}"
+```
+
+### Filter output using jq
+
+```bash
+# Retrieve all available instance type with GPUs
+scw -o json instance server-type list | jq '.[] | select (.gpu > 0)'```
+```
+
+### Parallelize actions using xargs
+
+```bash
+## Reboot all listed servers at the same time, 8 max concurrent actions
+
+# Using jq
+scw -o json instance server list | jq -r '.[].id' | xargs -L1 -P8 scw instance server reboot
+# Using CLI templates
+scw instance server list -o template="{{ .ID }}" | xargs -L1 -P8 scw instance server reboot
+```
+
+### Create arguments for a cli command and use it in xargs
+
+```bash
+## List private-nics of all listed servers
+
+# Using jq
+scw -o json instance server list | jq -r '.[] | "server-id=\(.id)"' | xargs -L1 scw instance private-nic list
+# Using CLI templates
+scw instance server list -o template="server-id={{ .ID }}" | xargs -L1 scw instance private-nic list
+```
+
 ## Instance
 
 ### Start/Stop a group of servers based on a tag
 ```bash
 # Start all servers with tag staging
-scw -o json instance server list tags.0=staging | jq -r .[].id | xargs scw instance server start -w
+scw -o json instance server list tags.0=staging | jq -r '.[].id' | xargs scw instance server start -w
 
 # Stop all servers with tag staging
-scw -o json instance server list tags.0=staging | jq -r .[].id | xargs scw instance server stop -w
+scw -o json instance server list tags.0=staging | jq -r '.[].id' | xargs scw instance server stop -w
+```
+
+### Servers and private networks
+
+```bash
+# Add all listed servers to a given private network
+scw -o json instance server list tags.0=staging | jq '.[].id' | xargs -t -I{} scw instance private-nic create private-network-id=<pn-id> server-id={}
+
+# List all servers in a specific private network
+scw instance server list -ojson | jq 'map(select (.private_nics | map(select (.private_network_id == "<pn-id>")) | length == 1))'
+# List all servers not in a specific private network
+scw instance server list -ojson | jq 'map(select (.private_nics | map(select (.private_network_id == "<pn-id>")) | length == 0))'
+```
+
+### Action on servers across multiple zones
+
+```bash
+## Reboot all servers across all zones, 8 server at a time
+
+# Using jq
+scw -o json instance server list zone=all | jq -r '.[] | "\(.id) zone=\(.zone)"' | xargs -P8 -L1 scw instance server reboot
+# Using CLI templates
+scw instance server list zone=all -o template="{{.ID}} zone={{.Zone}}" | xargs -P8 -L1 scw instance server reboot
+```
+
+## Database
+
+### Filter backups by date
+
+```bash
+# Get all backup older than 7 days
+scw rdb backup list -ojson | jq --arg d "$(date -d "7 days ago" --utc --iso-8601=ns)" '.[] | select (.created_at < $d)'
 ```