In a single Ansible playbook, you may wish to apply some roles to all hosts, while limiting other roles to only certain groups. While it is certainly possible to apply a role to all hosts and then use a ‘when’ to filter down to the desired group like below: – hosts: all gather_facts: yes roles: … Ansible: applying roles to certain groups in a single playbook
awk is a powerful utility for text processing, but the command itself is surrounded by single quotes and unfortunately does not allow you to escape single quotes within the output. To workaround this, you can represent the single quote as its hexidecimal escape code “\x27”. $ echo -e “name=Ben\nname=Jerry” | awk -F’=’ ‘{ printf(“insert into … Linux: Outputting single quotes in awk output
If you are looking for basic HTTP file uploading using Flask, you can use the code in my python-flask-upload-files project on github as an example. This project exercises multiple scenarios: Upload a single file in chunked mode (not forced to save entirety to disk) Upload a single file Upload multiple files Error message shown when … Python: Using Flask to upload files
The typical usage for xargs is feeding it multiple lines of input, and having it run commands using each line as an argument. But there are other cases when you have a single line separated by a delimiter or even a list of optionally quoted args, and I’ll show in this article how to handle … Bash: Running command on quoted list of parameters using xargs
If you have to ssh to a remote system to produce a block of json, it may be preceded and suffixed with login and system messages. Or you may have a program that sends json as the main part of its output, but also sends debug type messages to stdout that need to be cleaned. … Linux: sed to cleanup json that has errant text surrounding it
With the modern mantra of “everything is code”, operations and network teams must come to terms with how they want to work with source control in a team environment. Imagine a repository that contains configuration templates and scripts for maintaining an application or appliance. For a multi-member operations team who shares the responsibility for this … Git: Sharing a single git controlled folder among a group under Linux
The two most common logging implementations used in conjunction with Spring/Spring Boot are Logback and Log4j2. In the recent past, a developer had a great deal of discretion on the format and files used for logging. But in the modern world of container deployment and scale, these logs typically feed enterprise logging solutions which requires … Java: Collapsing multiline stack traces into a single log event using Spring backed by Logback or Log4j2
An issue that keeps coming up on the mailing lists as well as Stackoverflow[1,2] is how to merge multiple pillar files for use with a single state. The problem is that pillars using the same key overwrite each other, and there is no easy way to express the desire to merge instead. There are various workarounds, but all … SaltStack: Combine multiple pillar files under a single key