Base64 encoding a string may seem like a straight-forward operation, but there are a couple of gotchas even when dealing with just simple ASCII strings. Avoid embedding a new line character into the encoding If you use the most straight forward method of Base64 encoding shown below, you have to remember that echo by default … Bash: avoiding newline artifacts when Base64 encoding a string
If you need to validate your AlertManager routing configuration by sending a test alert through AlertManager, you can port-forward the AlertManager pod and send it from curl on your development host. Real alerts typically have scrape delays and then durations that must be met, so this is a way of getting almost immediate feedback on … Prometheus: sending a test alert through AlertManager
Pulling the most recent script/file/asset from a remote host may be preferable, but you would like to provide a fallback to a local file just in case the remote pull fails. This is relatively easy to do with Ansible by allowing the remote pull to ‘ignore_errors’ and then doing a local file copy if an … Ansible: preferring a pull from a URL with fallback to a local file
Once you introduce an istio sidecar proxy into your deployment, it becomes another point at which you might need to troubleshoot network connectivity to the primary container. Assuming you have deployed a pod with an app label “helloworld” in the default namespace listening on port 5000, you can use a command like the following to … Kubernetes: testing pod communication directly from istio sidecar proxy
curl has a “write-out” ability to display information after a completed transfer that can be used to support Bash scripting. In it’s simplest form, a curl request looks like this: page=”https://www.google.com” curl $page But this leaves a lot to be desired in a scripting scenario: curl does not exit with a non-zero code on failure, … Bash: Capturing HTTP status code using curl write-out
The “cf app” command will provide a brief expansion of a buildpack’s settings, but does not provide an exact buildpack name. Luckily, this can easily be pulled using “cf curl” and the CloudFoundry API. Assuming you have the jq utility for parsing/querying json output: # set name of cloudfoundry app app=”my-cf-app” # using name, pull … CloudFoundry: Determining buildpack used by application
If your ElasticSearch cluster is not healthy because of unassigned shards, there are multiple resolution paths. This datadoghq article provides an excellent walk-through of how you can analyze and resolve the situation. The simplest case is when those unassigned shards are not required anymore, and deleting them restores cluster health. In this article, I will … ELK: Deleting unassigned shards to restore cluster health
The Cloud Foundry CLI makes it easy to authenticate into a target API endpoint to consume the Cloud Controller API (CAPI). The “cf login” command allows you to pass or interactively provide the user, password, org, and space. Once logged in, if you want to run raw commands, the “cf curl” can execute a request … CloudFoundry: Authenticating and running CF API commands using curl
Once you have a Squid proxy setup as described in my article here, the next challenge is configuring your Ubuntu servers so that they use this proxy by default instead of attempting direct internet connections. There are several entities we want using Squid by default: apt package manager, interactive consoles and wget/curl, and Java applications.