To find your current resolution in a Linux shell you can use:
xdpyinfo | grep dim
dimensions: 3840×3600 pixels (1015×951 millimeters)
Find your screen resolution in Linux shell
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Using OR in a grep search
To use OR when you are doing a grep search use the \| characters to separate the items you are searching for.
cat text_to_search_in | grep 'first\|second\|third'
Kubectl using -l a=something -l b=other or -l a=something,b=other
When you have two pods with different labels, let’s say one with two labels a=something and b=other, and the second one with label b=other, when you use kubectl to get them there is a difference in the way that the -l selector is used.
So using kubectl -n namespace get pods -l a=something -l b=other it will give you back both pods as it works as an OR operator.
If you wanted to get only the first one that has both labels, but not the second, you would need to use it as in kubectl -n namespace get pods -l a=something,b=other.
In other words the comma separator acts as a logical AND operator in selecting the labels.
PostgreSQL json difference of -> and ->> operators
There are different ways of using the json(b) operators in a PostgreSQL column.
The differences between two of them (->) and (->>) are described below:
‘[1,2,3]’::json->2 returns “2”
‘[1,2,3]’::json->>2 returns 2
Checking MX records with Google Admin Toolbox
There is a google Admin toolbox that lets you check your domain’s MX records.
This can be found here: https://toolbox.googleapps.com/apps/checkmx/
Flushing dns caching in linux
Problem
You want to update your dns resolution locally after some change in DNS.
You want to do this because your local dns cache still holds the old information about the domain. For example using your local dns and the google one returns two different results
host changed_domain.com returns the old ip host changed_domain.com 8.8.8.8 returns the new ip.
Solution
Check your systemd-resolved is active:
sudo systemctl is-active systemd-resolved active
Get some statistics:
sudo systemd-resolve --statistics
Transactions
Current Transactions: 0
Total Transactions: 38818
Cache
Current Cache Size: 73
Cache Hits: 21120
Cache Misses: 19745
DNSSEC Verdicts
Secure: 0
Insecure: 0
Bogus: 0
Indeterminate: 0
Flush the cache (make the Current Cache Size above 0)
sudo systemd-resolve --flush-caches
Check the cache again (should be 0 now):
sudo systemd-resolve --statistics
ransactions
Current Transactions: 0
Total Transactions: 38818
Cache
Current Cache Size: 0
Cache Hits: 21120
Cache Misses: 19745
DNSSEC Verdicts
Secure: 0
Insecure: 0
Bogus: 0
Indeterminate: 0Information taken from https://www.techrepublic.com/article/how-to-flush-the-dns-cache-on-linux/
Show events ordered by creation date in kubernetes namespace
To show all events on a specific kubernetes namespace ordered by date use the following:
kubectl -n namespace_name get events --sort-by='.metadata.creationTimestamp'
Using exo cli to display your vm templates in Exoscale
To display your vm templates, as opposed to all available templates in Exoscale using the exo CLI, use the following (you should have already the environment variables set up to be able to use exo):
exo vm template list --mine ????????????????????????????????????????????????????????????????????????????????????????????????????????? ? ID ? NAME ? CREATION DATE ? ZONE ? DISK SIZE ? ????????????????????????????????????????????????????????????????????????????????????????????????????????? ? a58f0180-689d-4663-aa53-91111111111 ? my-ubuntu ? 2020-08-12T13:44:01+0000 ? ch-dk-2 ? 50 GiB ? ?????????????????????????????????????????????????????????????????????????????????????????????????????????
WARNING: Pulling GitLab Runner helper image from Docker Hub. Helper image is migrating to registry.gitlab.com, for more information see https://docs.gitlab.com/runner/configuration/advanced-configuration.html#migrating-helper-image-to-registrygitlabcom
To change this in your gitlab-runner configuration, depends on the version of your gitlab-runner as described in https://docs.gitlab.com/runner/configuration/feature-flags.html
If you version is 13.9.0 (gitlab-runner –version), then add the following in ~/.gitlab-runner/config.toml
[[runners]] name = "gitlab-runner-name" request_concurrency = 1 url = "https://git.url.test/" token = "xckaxxxxxxxx" executor = "kubernetes" environment = ["FF_GITLAB_REGISTRY_HELPER_IMAGE=1"]
Error: Invalid provider configuration (terraform plan locally with TerraformCloud)
Problem
You are trying to run locally the terraform plan, while using the Terraform’s Cloud remote backend, before commiting your changes to your repo and running it through Terraform’s Cloud UI, and you are getting the previous error message:
Error: Invalid provider configuration
Solution
Remember to add the environment variables needed for your provider (AWS, Google, Exoscale etc) in the Variables section of your Terraform Cloud setup.
Even you have added them before, using a new Workspace means you will need to add them to each new workspace.