Skip to content

Instantly share code, notes, and snippets.

Nils Meyer nilsmeyer

  • Freelancer
  • Hamburg, Germany
Block or report user

Report or block nilsmeyer

Hide content and notifications from this user.

Learn more about blocking users

Contact Support about this user’s behavior.

Learn more about reporting abuse

Report abuse
View GitHub Profile
View gist:dcb2cf17b4d8347e0ef0561e0c9b544e
MariaDB [test]> create table t1 (id int unsigned not null auto_increment primary key);
Query OK, 0 rows affected (0.027 sec)
MariaDB [test]> create table t2 (id int unsigned not null auto_increment primary key, t1_id int unsigned not null, foreign key(t1_id) references t1(id));
Query OK, 0 rows affected (0.040 sec)
MariaDB [test]> insert into t2 (t1_id) values (1);
ERROR 1452 (23000): Cannot add or update a child row: a foreign key constraint fails (`test`.`t2`, CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`t1_id`) REFERENCES `t1` (`id`))
MariaDB [test]> set foreign_key_checks=0;
Query OK, 0 rows affected (0.000 sec)
@nilsmeyer
nilsmeyer / fragment.json
Created Jul 29, 2019
CentOS 7 source ami filter
View fragment.json
"source_ami_filter": {
"filters": {
"virtualization-type": "hvm",
"name": "CentOS Linux 7 x86_64 HVM EBS ENA 1901*",
"root-device-type": "ebs"
},
"owners": [
"679593333241"
],
"most_recent": true
@nilsmeyer
nilsmeyer / gist:1444eec126046f4fc9b204ef7828b50c
Created Jun 16, 2019
XFS docker volume from sparse file
View gist:1444eec126046f4fc9b204ef7828b50c
root@ip-172-18-21-22:~# dd if=/dev/zero of=myxfs bs=1 count=0 seek=2G
0+0 records in
0+0 records out
0 bytes copied, 0.000199112 s, 0.0 kB/s
root@ip-172-18-21-22:~# mkfs.xfs myxfs
meta-data=myxfs isize=512 agcount=4, agsize=131072 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=1, sparse=0, rmapbt=0, reflink=0
data = bsize=4096 blocks=524288, imaxpct=25
= sunit=0 swidth=0 blks
@nilsmeyer
nilsmeyer / volumes.txt
Created May 10, 2019
root device is getting attached at different locations
View volumes.txt
----------52.48.95.74--------
total 0
lrwxrwxrwx 1 root root 13 May 10 16:25 nvme-Amazon_Elastic_Block_Store_vol01f9d4a5c1497535d -> ../../nvme0n1
lrwxrwxrwx 1 root root 13 May 10 16:25 nvme-Amazon_Elastic_Block_Store_vol0c83712f171fc4151 -> ../../nvme1n1
lrwxrwxrwx 1 root root 15 May 10 16:25 nvme-Amazon_Elastic_Block_Store_vol0c83712f171fc4151-part1 -> ../../nvme1n1p1
lrwxrwxrwx 1 root root 13 May 10 16:25 nvme-nvme.1d0f-766f6c3031663964346135633134393735333564-416d617a6f6e20456c617374696320426c6f636b2053746f7265-00000001 -> ../../nvme0n1
lrwxrwxrwx 1 root root 13 May 10 16:25 nvme-nvme.1d0f-766f6c3063383337313266313731666334313531-416d617a6f6e20456c617374696320426c6f636b2053746f7265-00000001 -> ../../nvme1n1
lrwxrwxrwx 1 root root 15 May 10 16:25 nvme-nvme.1d0f-766f6c3063383337313266313731666334313531-416d617a6f6e20456c617374696320426c6f636b2053746f7265-00000001-part1 -> ../../nvme1n1p1
----------34.254.163.177--------
total 0
@nilsmeyer
nilsmeyer / userdata.yml
Created May 10, 2019
when the nvme devices schanges
View userdata.yml
#cloud-config
fs_setup:
- label: docker
device: /dev/nvme0n1
filesystem: xfs
partition: none
overwrite: false
extra_opts: ['-n', 'ftype=1', '-l', 'size=256m', '-b', 'size=4096',
'-s', 'size=4096', '-m', 'crc=1,finobt=1,rmapbt=1,reflink=1',
'-i', 'sparse=1']
@nilsmeyer
nilsmeyer / gist:1b703dd4b54157f7cb71b0ff913a5b6f
Created Mar 29, 2019
check if url is reachable in ansible
View gist:1b703dd4b54157f7cb71b0ff913a5b6f
- name: check metadata endpoint
uri:
url: http://169.254.169.254/latest/meta-data/
timeout: 1
return_content: yes
register: _nmiac_metadata
changed_when: no
check_mode: no
failed_when: no
@nilsmeyer
nilsmeyer / volumes.yml
Created Mar 25, 2019
volume configuration example
View volumes.yml
volumes:
docker:
type: xfs
mount: /srv/docker
mount_options : defaults
mkfs_options: -s size=4096 -b size=4096 -m crc=1,finobt=1,rmapbt=1,reflink=1 -l size=128m -i sparse=1
devices:
- 'volume:docker-enc'
docker-enc:
type: luks2
View ssh-keygen sign keys with private key stored in agent
ssh-add -t 300 $ca_private_key_file # key will be available in agent for 5m
ssh-keygen -s $ca_private_key_file -U -I $host_identity_sring -n $hostname -h -V +52w $public_host_key
View gist:2e1396fe5e504b2af20dd54054b3dca5
$database would be the database/schema...
SELECT c.TABLE_NAME, CONSTRAINT_NAME, SUM(CHARACTER_OCTET_LENGTH) AS length FROM KEY_COLUMN_USAGE kcu INNER JOIN COLUMNS c ON c.TABLE_SCHEMA = kcu.TABLE_SCHEMA AND c.TABLE_NAME = kcu.TABLE_NAME AND c.COLUMN_NAME = kcu.COLUMN_NAME WHERE kcu.TABLE_SCHEMA='$database' GROUP BY CONSTRAINT_NAME, c.TABLE_NAME ORDER BY length;
View gist:b4da931f9907a00cdca872e589cb026f
- name: enrich partition data
set_fact:
_partitions: >
{{
_partitions|combine({_partuuids[item.0.device + '_' + item.1.num|string]:
_partitions[_partuuids[item.0.device + '_' + item.1.num|string]]|combine(item.1)})
}}
with_subelements:
- "{{ layout }}"
- partitions
You can’t perform that action at this time.