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Comment by ram_rar | Hacker News Reader

When I was @ yahoo! in mid 2000s, I used to argue with my principal engineer to great lengths on why he should consider Python for DevOps. Writing code in perl felt like a pissing contest on who can obfuscate and make the code do insane things with least amount of characters.

Now, I have barely seen anyone use anything but Python (Golang maybe...) for this. Bottom line - readability matters! people have moved on and perl has outlived its purpose.

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I feel the same way with Bash.

It's great for one liners, but it breaks down when doing simple things like checking if a variable is a string or integer.

Ugh. If I have to write Bash, I try to enforce some level of basic sanity with:

    set -euo pipefail

I've seen way too many scripts catastrophically fail because of unbound variables or one side of a pipe failing and the script continuing anyways, etc.

+1 to this.

-e Abort at the first failed line

-u Abort when undefined variable is used

-o pipefail Piped commands return the status of the last failed command, rather than the status of the last command

You are a wonderful person for doing this. As an ops guy, I tip my hat.

I use the verbose version for readability:

    set -o errexit
    set -o nounset
    set -o pipefail

Some commands need custom error handling, which means turning off -e:

    set +o errexit

    ansible-playbook ...

    if [[ "$?" != "0" ]]; then
        echo -e "\e[1;31m""Error when executing ansible!""\e[0m"
        exit 1
    fi

    set -o errexit

And if you use -e , you will probably need the default value helper to validate input arguments:

    # the :- operator means "use the right side value if the left side ($1) is not set"
    env=${1:-}
    
    inventoryFile="${baseDir}/env/${env}/inventory"

    if [[ -f "${inventoryFile}" ]]; then
        echo -e "\e[1;31m""Invalid environment specified!""\e[0m"
        exit 1
    fi

I feel your first example is better written like this:

    if ! ansible-playbook ... ; then 
        echo -e "\e[1;31m""Error when executing ansible!""\e[0m"
        exit 1
    fi

But generally when I need to work around errexit, I tend to add something like " || true" or " || xyz_failed=true" to the end of the command line instead of turning it off and on again.

I'm mostly using ansible instead of bash noawadays.

Does all the same with more commands and better error handling.

Same here, but Ansible forces a basic knowledge of Python if you want to use it really well.

There are limits for sure, but actually it's quite possible to write bash code at scale, but it requires some discipline and practice. It's hard to avoid it.

One reason I still use perl for is its better regexes. In particular, I tend to use `perl -pe 's/regex/replacement/g'` instead of `sed 's/regex/replacement/g'` when I need to replace something. sed's regexes are just not good enough for some tasks.

So like, Puppet & Chef are pretty big Ruby devops communities. And Ruby is fairly obviously inspired by Perl.

Ruby's name was inspired by Perl, but I'm curious to know which language structures you think were inspired by Perl.

The regular expression syntax; sigils on (some) variables; shortcuts like `bar if foo`; optional parenthesis on function calls; `chomp()` and `chop()`; those are just a few things that come to mind.

Read up on Matz's account of how he developed Ruby and what were his influences. Larry Wall was top his list.

Ruby has since forever been described as a cross between Perl and Smalltalk (and some other languages), including by its creator (Matz).

> I have barely seen anyone use anything but Python (Golang maybe...) for this

Odd. I see almost entirely Ruby. Especially with tools like Chef.

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