# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/.*(fstype="[^"]*").*?(instance="[^"]*").*?(mountpoint="[^"]*").*/$1 $2 $3/gm;t' <<< "{container=\"node-exporter\", device=\"/dev/mapper/ubuntu--vg-ubuntu--lv\", endpoint=\"http-metrics\", fstype=\"ext4\", instance=\"172.20.32.10:9100\", job=\"node-exporter\", mountpoint=\"/\", namespace=\"prometheus\", pod=\"prometheus-prometheus-node-exporter-xvz7v\", service=\"prometheus-prometheus-node-exporter\"}
{container=\"node-exporter\", device=\"/dev/mapper/ubuntu--vg-ubuntu--lv\", endpoint=\"http-metrics\", fstype=\"ext4\", instance=\"172.20.32.11:9100\", job=\"node-exporter\", mountpoint=\"/\", namespace=\"prometheus\", pod=\"prometheus-prometheus-node-exporter-w8cqq\", service=\"prometheus-prometheus-node-exporter\"}
{container=\"node-exporter\", device=\"/dev/mapper/ubuntu--vg-ubuntu--lv\", endpoint=\"http-metrics\", fstype=\"ext4\", instance=\"172.20.32.12:9100\", job=\"node-exporter\", mountpoint=\"/\", namespace=\"prometheus\", pod=\"prometheus-prometheus-node-exporter-4wfhq\", service=\"prometheus-prometheus-node-exporter\"}
{container=\"node-exporter\", device=\"/dev/mapper/ubuntu--vg-ubuntu--lv\", endpoint=\"http-metrics\", fstype=\"ext4\", instance=\"172.20.32.13:9100\", job=\"node-exporter\", mountpoint=\"/\", namespace=\"prometheus\", pod=\"prometheus-prometheus-node-exporter-zfskj\", service=\"prometheus-prometheus-node-exporter\"}
{container=\"node-exporter\", device=\"/dev/mapper/ubuntu--vg-ubuntu--lv\", endpoint=\"http-metrics\", fstype=\"ext4\", instance=\"172.20.32.15:9100\", job=\"node-exporter\", mountpoint=\"/\", namespace=\"prometheus\", pod=\"prometheus-prometheus-node-exporter-cllnv\", service=\"prometheus-prometheus-node-exporter\"}"
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for SED, please visit: https://www.gnu.org/software/sed/manual/html_node/The-_0022s_0022-Command.html