asdf and terraform (or vault or packer)

Posted on 7 April 2021 by kosmas

Using the asdf version manager to manage versions of various binaries like terraform, vault or packer is easily done by following the instructions below:

Download and install asdf if you haven’t got it already (https://asdf-vm.com/#/core-manage-asdf)
If you want to install the latest version of terraform for example do the following:

asdf plugin add terraform
asdf install terraform latest
asdf global terraform 0.14.9
asdf list
terraform
  0.14.9
terraform --version
Terraform v0.14.9

				
					
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						asdf plugin add terraform
asdf install terraform latest
asdf global terraform 0.14.9
asdf list
terraform
  0.14.9
terraform --version
Terraform v0.14.9

					

			

Renaming multiple files in linux

Posted on 18 March 2021 by kosmas

Problem

You would like to rename multiple files, replacing some text with something else (like replacing Pixies_The with Pixies).

Solution

Install the rename utility

sudo apt install rename

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						sudo apt install rename

and replace the text as follows

cd folder_to_rename_files
rename 's/Pixies_The/Pixies/g' **

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						cd folder_to_rename_files
rename 's/Pixies_The/Pixies/g' **

Get/Set platform information

Posted on 15 March 2021 by kosmas

To get or set in environment variables the platform information of a system you can use the following:

export ARCH=$(case $(arch) in x86_64) echo -n amd64 ;; aarch64) echo -n arm64 ;; *) echo -n $(arch) ;; esac)
export OS=$(uname | awk '{print tolower($0)}')

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						export ARCH=$(case $(arch) in x86_64) echo -n amd64 ;; aarch64) echo -n arm64 ;; *) echo -n $(arch) ;; esac)
export OS=$(uname | awk '{print tolower($0)}')

Taken from the installation instructions of the Operator SKD here: https://master.sdk.operatorframework.io/docs/installation/

Upgrading node and yarn

Posted on 11 March 2021 by kosmas

Problem

You are getting the following error when trying to use yarn:

$ yarn
yarn install v1.21.1
[1/5] Validating package.json...
error xxxxx@: The engine &quot;node&quot; is incompatible with this module. Expected version &quot;^10.0.0&quot;. Got &quot;8.10.0&quot;
error Found incompatible module.
info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.

				
					
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						$ yarn
yarn install v1.21.1
[1/5] Validating package.json...
error xxxxx@: The engine &quot;node&quot; is incompatible with this module. Expected version &quot;^10.0.0&quot;. Got &quot;8.10.0&quot;
error Found incompatible module.
info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.

					

			

Solution

Upgrade yarn

$ curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add -
[sudo] password for username: 
OK

$ echo &quot;deb https://dl.yarnpkg.com/debian/ stable main&quot; | sudo tee /etc/apt/sources.list.d/yarn.list
deb https://dl.yarnpkg.com/debian/ stable main

$ sudo apt-get update
$ sudo apt-get upgrade

				
					
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						$ curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add -
[sudo] password for username: 
OK
 
$ echo &quot;deb https://dl.yarnpkg.com/debian/ stable main&quot; | sudo tee /etc/apt/sources.list.d/yarn.list
deb https://dl.yarnpkg.com/debian/ stable main
 
$ sudo apt-get update
$ sudo apt-get upgrade

					

			

Which should give the updated yarn version:

$ yarn
yarn install v1.22.5
[1/5] Validating package.json...
error xxxxx@: The engine &quot;node&quot; is incompatible with this module. Expected version &quot;^10.0.0&quot;. Got &quot;8.10.0&quot;
error Found incompatible module.
info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.

				
					
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						$ yarn
yarn install v1.22.5
[1/5] Validating package.json...
error xxxxx@: The engine &quot;node&quot; is incompatible with this module. Expected version &quot;^10.0.0&quot;. Got &quot;8.10.0&quot;
error Found incompatible module.
info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.

					

			

Upgrade node version with the correct version from above (ie 10.0.0)

$ curl -fsSL https://deb.nodesource.com/setup_10.x | sudo -E bash -

$ sudo apt-get install -y nodejs
....
The following packages will be upgraded:
  nodejs
...

				
					
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						$ curl -fsSL https://deb.nodesource.com/setup_10.x | sudo -E bash -
 
$ sudo apt-get install -y nodejs
....
The following packages will be upgraded:
  nodejs
...

					

			

And then the needed versions would have been installed:

$ yarn
yarn install v1.22.5
[1/5] Validating package.json...
[2/5] Resolving packages...
success Already up-to-date.
Done in 0.90s.

				
					
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						$ yarn
yarn install v1.22.5
[1/5] Validating package.json...
[2/5] Resolving packages...
success Already up-to-date.
Done in 0.90s.

					

			

Forcing https with wordpress on dreamhost

Posted on 24 February 2021 by kosmas

In order to be able to force the http to https redirection when using wordpress in dreamhost use the following (taken from https://help.dreamhost.com/hc/en-us/articles/215747758-Force-your-site-to-load-securely-with-an-htaccess-file) :

RewriteEngine On
RewriteCond %{HTTPS} !=on
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301,NE]
Header always set Content-Security-Policy &quot;upgrade-insecure-requests;&quot;

# BEGIN WordPress
.....
# END WordPress

				
					
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						RewriteEngine On
RewriteCond %{HTTPS} !=on
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301,NE]
Header always set Content-Security-Policy &quot;upgrade-insecure-requests;&quot;
 
# BEGIN WordPress
.....
# END WordPress

					

			

Linux disabling a service on bootup

Posted on 12 February 2021 by kosmas

To stop having a service automatically start after bootup in a Linux system with systemctl use the following to stop and then disable the service:

sudo systemctl stop service_name
sudo systemctl disable service_name

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						sudo systemctl stop service_name
sudo systemctl disable service_name

Using port number in Terraform output

Posted on 10 February 2021 by kosmas

Problem

You would like to output some additional information (ie port number) in addition to the variable provided by Terraform.

Solution

Use interpolation of the Terraform variable using ${var} together with the rest of the string you would like to output, like:

output &quot;kibana_endpoint&quot; {
  value       = &quot;http://${aws_instance.elasticsearch.public_ip}:5601&quot;
  description = &quot;The Kibana endpoint&quot;
}

				
					
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						output &quot;kibana_endpoint&quot; {
  value       = &quot;http://${aws_instance.elasticsearch.public_ip}:5601&quot;
  description = &quot;The Kibana endpoint&quot;
}

					

			

More information about the language https://learn.hashicorp.com/tutorials/terraform/outputs?in=terraform/configuration-language

docker rmi image_name V docker image rm image_name

Posted on 8 February 2021 by kosmas

There is a newer way of using the command, as it is also the case in a few other docker commands.

Even though both the command can be used to remove a docker image, the command using docker image rm is the most recent way of using it.

Creating two types of IAM users in AWS using the CLI

Posted on 29 January 2021 by kosmas

To create a user in AWS IAM using the CLI (after you have configured it), use the following:

Create a user with programmatic access (access key ID and secret access key):

$ aws iam create-user \
  --user-name User_Prog_Access

Response: 
{
    "User": {
        "Path": "/",
        "UserName": "User_Prog_Access",
        "UserId": "AIDExampleUserId",
        "Arn": "arn:aws:iam::123333333:user/User_Prog_Access",
        "CreateDate": "2021-01-29T12:20:43+00:00"
    }
}

$ aws iam create-access-key \
  --user-name User_Prog_Access

Response:
{
    "AccessKey": {
        "UserName": "User_Prog_Access",
        "AccessKeyId": "AKIExampleAccessKeyID",
        "Status": "Active",
        "SecretAccessKey": "ttExampleSecretAccessKey",
        "CreateDate": "2021-01-29T12:21:22+00:00"
    }
}

$ aws iam create-user \

--user-name User_Prog_Access

Response:

{

"User": {

"Path": "/",

"UserName": "User_Prog_Access",

"UserId": "AIDExampleUserId",

"Arn": "arn:aws:iam::123333333:user/User_Prog_Access",

"CreateDate": "2021-01-29T12:20:43+00:00"

}

$ aws iam create-access-key \

--user-name User_Prog_Access

Response:

{

"AccessKey": {

"UserName": "User_Prog_Access",

"AccessKeyId": "AKIExampleAccessKeyID",

"Status": "Active",

"SecretAccessKey": "ttExampleSecretAccessKey",

"CreateDate": "2021-01-29T12:21:22+00:00"

}

And for a user with console access:

$ aws iam create-user \
  --user-name User_Console_Access

Response:
{
    "User": {
        "Path": "/",
        "UserName": "User_Console_Access",
        "UserId": "AIExampleUserId",
        "Arn": "arn:aws:iam::933323111111:user/User_Console_Access",
        "CreateDate": "2021-01-29T12:31:46+00:00"
    }
}

$ aws iam create-login-profile \
  --user-name User_Console_Access \
  --password Temp_Password4 \
  --password-reset-required

Response:
{
    "LoginProfile": {
        "UserName": "User_Console_Access",
        "CreateDate": "2021-01-29T12:35:28+00:00",
        "PasswordResetRequired": true
    }
}

$ aws iam create-user \

--user-name User_Console_Access

Response:

{

"User": {

"Path": "/",

"UserName": "User_Console_Access",

"UserId": "AIExampleUserId",

"Arn": "arn:aws:iam::933323111111:user/User_Console_Access",

"CreateDate": "2021-01-29T12:31:46+00:00"

}

$ aws iam create-login-profile \

--user-name User_Console_Access \

--password Temp_Password4 \

--password-reset-required

Response:

{

"LoginProfile": {

"UserName": "User_Console_Access",

"CreateDate": "2021-01-29T12:35:28+00:00",

"PasswordResetRequired": true

}

Failed to start docker.service: Unit is masked

Posted on 27 January 2021 by kosmas

Problem

Trying to start the docker service after some upgrades fails with the following message:

Failed to start docker.service: Unit is masked.

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						Failed to start docker.service: Unit is masked.

Solution

It turns out that after upgrading or more specifically removing and then upgrading the docker installation in ubuntu (in this particular case in raspberry 4 with Ubuntu 20.04 installed), results in this error.

A search brings up the following:

https://forums.docker.com/t/failed-to-start-docker-service-unit-is-masked/67413

and from that the following bug post:

https://bugs.launchpad.net/ubuntu/+source/docker.io/+bug/1844894

So the solution is to run the following to be able to start the docker service (described in the first link above):

sudo systemctl unmask docker
sudo systemctl start docker

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						sudo systemctl unmask docker
sudo systemctl start docker

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Web notebook about thoughts and discoveries in DevOps, SRE, Software Engineering….

asdf and terraform (or vault or packer)

Renaming multiple files in linux

Get/Set platform information

Upgrading node and yarn

Problem

Solution

Forcing https with wordpress on dreamhost

Linux disabling a service on bootup

Using port number in Terraform output

Problem

Solution

docker rmi image_name V docker image rm image_name

Creating two types of IAM users in AWS using the CLI

Failed to start docker.service: Unit is masked

Problem

Solution