Problem
You want to use the pgp encryption when using Terraform to create an AWS IAM user, and you have the secret access token returned as an output but encoded.
Solution
Use the following to get the actual secret key decoded (after copying your encoded key to a file encrypted_key.txt:
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$ cat encrypted_key.txt | base64 --decode | gpg -d |
To install megtools (command line utilities for Mega.nz), in your raspberry with ubuntu installed follow the steps below (thanks to the instructions from here: https://www.instructables.com/id/Descarga-archivos-de-Mega-con-Raspberry-Pi/)
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sudo apt-get -y install build-essential libglib2.0-dev libssl-dev libcurl4-openssl-dev libgirepository1.0-dev |
You may also need to add some additional packages if there is an error about the documentation.
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wget https://megatools.megous.com/builds/megatools-1.10.3.tar.gz |
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tar xvfz megatools-1.10.3.tar.gz cd megatools-1.10.3 ./configure make sudo make install sudo ldconfig |
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[Login] Username = my_mega@email Password = mypassword |
After installing an image of the Ubuntu server on the Raspberry 4, the wifi is not automatically configured after the initial book.
In order to be able to use the WiFi follow the steps described below for setting up your wifi in your SD card, and then reboot your raspberry (make sure that the indentation in the yaml file is correct, and also your WiFi access point is enclosed in quotes):
https://ubuntu.com/tutorials/how-to-install-ubuntu-on-your-raspberry-pi#3-wifi-or-ethernet
You would like to have a list of IPs or MAC address for the device in your network
Use the ARP protocol’s command:
$ arp -a
dv1.home (192.168.1.102) at 48:xx:xx:xx:xx:xx [ether] on wlp4s0
dv2.home (192.168.1.127) at a4:xx:xx:xx:xx:xx [ether] on wlp4s0
...
You would like to find out your public IP from the command line without using an online service
Use dig like the following line (taken from https://www.cyberciti.biz/faq/how-to-find-my-public-ip-address-from-command-line-on-a-linux/):
dig +short myip.opendns.com @resolver1.opendns.comyou could also add it as an alias:
alias myip=”dig +short myip.opendns.com @resolver1.opendns.com”
To get a list of all the installed crontab jobs on a server use the following (taken from https://stackoverflow.com/a/134944)
for user in $(cut -f1 -d: /etc/passwd); do echo $user; crontab -u $user -l; doneProblem
You would like to be able to automatically send some emails (ie reports) from a linux server, using a bash script that runs in cronjob, without installing an email server on the linux server.
Solution
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#!/bin/bash # Email setup SENDGRID_API_KEY="your_sendgrid_api_key" FILENAME_ATTACH="title_of_your_attachment" FILENAME_ZIP="the_path_to_your_zip_file" FILENAME_BASE64_TMP="the_path_to_temporary_base64_encoding" EMAIL_TO="email_to_address" EMAIL_SUBJECT="email_subject" EMAIL_FROM="email_from_address" EMAIL_MESSAGE="your_email_message" function email_exports() { FILENAME_BASE64=$(base64 -w0 $FILENAME_ZIP); REQUEST_DATA='{"personalizations": [{ "to": [{ "email": "'"$EMAIL_TO"'" }], "subject": "'"$EMAIL_SUBJECT"'" }], "from": { "email": "'"$EMAIL_FROM"'" }, "content": [{ "type": "text/plain", "value": "'"$EMAIL_MESSAGE"'" }], "attachments": [{ "content": "'"$FILENAME_BASE64"'", "filename": "'"$FILENAME_ATTACH"'" }] }'; # We need to store the base64 locally as the text # is too big for sending directly with curl echo $REQUEST_DATA > $FILENAME_BASE64_TMP curl -X "POST" "https://api.sendgrid.com/v3/mail/send" \ -H "Authorization: Bearer $SENDGRID_API_KEY" \ -H "Content-Type: application/json" \ -d "@$FILENAME_BASE64_TMP"; rm $FILENAME_BASE64_TMP } email_exports |
Problem
Using docker-compose up (or build), displays the following error message (even though the same command used to work previously):
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ERROR: Couldn't connect to Docker daemon at http+docker://localunixsocket - is it running? |
Solution
This is quite possible caused by permissions issue, as one of the folders files that docker is trying to use is owned by a different user/group from the one trying to use the docker-compose commands. Try to find the file/folder with the different permissions and change it to your user name and group, or use change the files by using something like:
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chown -R me:me . |
Problem
You would like to copy the contents of a source directory to a destination directory without overwriting existing files on the destination.
Solution
You can use
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rsync -a -v --ignore-existing source_dir/ dest_dir/ |
and you can also use the –dry-run option to test before running it.