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#!/bin/bash |
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# BASH COMMAND CHEATSHEET |
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cat /etc/*release # find Linux distribution version |
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cat /etc/*-release | uniq -u | grep 'release' # show Linux release |
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sudo fuser -k 80/tcp # kill all processes using port 80 (useful if nginx won't stop/restart gracefully) |
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alias cdwww="cd /var/www/html/" # add to ~/.bashrc for shortcut to webroot |
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# ansible |
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ansible-playbook <playbook>.yml --private-key ~/.ssh/<key>.pem # specify a private key to use to connect when running playbooks on EC2 instances |
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# apt |
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apt list --installed # list all installed packages |
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apt-cache policy |grep http |awk '{print $2 $3}' |sort -u # list apt sources |
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apt-get install <package name>=<version> # install a specific version of a package |
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# AWS motd banner |
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sudo vim /etc/update-motd.d/30-banner # edit motd banner on AWS Amazon Linux AMI systems |
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sudo /usr/sbin/update-motd # update motd banner from contents of /etc/update-motd.d/ on AWS Amazon Linux AMI systems |
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# cron |
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sudo crontab -l -u <user> # view cron jobs for a specific user |
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sudo crontab -e -u <user> # edit cron jobs for a specific user |
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sudo sh -c 'tail -n +1 /var/spool/cron/*' # list crontab for all users |
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# cron time string format: |
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* * * * * # cron time string character positions |
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└─│─│─│─│── minute # run cron job (0-59) minutes past the hour, or * for every minute |
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└─│─│─│── hour # run cron job (0-23) hours past midnight, or * for every hour |
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└─│─│── day of month # run cron job on day (1-31) of the month, or * for every day |
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└─│── month # run cron job during month (1-12) of the year, or * for every month |
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└── day of week # run cron job every (0-6) days past Sunday, or * for every day of the week |
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# cron time special characters: |
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* (asterisk) # cron time: any/every |
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, (comma) # cron time: value list separator |
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- (hyphen) # cron time: defines range of values |
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/ (forward slash) # cron time: step value |
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# cron time examples: |
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* * * * * # run cron job every minute |
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0 0-6,18-23 * * * # run cron job hourly from 18:00 through 06:00 |
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10 */2 * * * # run cron job 10 minutes past the hour, every other hour |
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# See http://crontab.guru for more interactive cron examples |
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# docker |
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docker --version # check Docker version |
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docker images # list Docker images |
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docker search # search the Docker Hub for images |
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docker pull <image> # pull an image or a repository from Docker Hub or another registry |
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docker create <image> # create a writeable container from an image and prepare it to run |
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docker run <image> # creates container from an image and runs it (similar to docker create + docker start) |
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docker run -it centos:latest /bin/bash # run a CentOS container, start bash and attach to to terminal |
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docker run -d centos:latest /bin/bash # run a CentOS container in detached mode |
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docker start <container> # start a stopped container |
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docker inspect <image or container> # show low-level information on Docker objects |
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docker exec <container> <command> # pass command to running container |
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docker exec -it <container> /bin/bash # start a bash prompt in a running container and attach it to terminal |
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docker stop <container name> # stop a running container |
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docker ps # list running containers |
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docker ps -a # list all containers, running or stopped |
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docker rm <container> # remove container |
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docker rm `docker ps -a -q` # remove all containers |
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docker rmi <image> # remove image |
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docker rmi -f <image> # remove image (force) |
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# git |
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git init # initialize empty git repo in .git/ |
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git status # show current branch, list changes to be committed, untracked files, etc. |
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git add <file> # add untracked file to staging area |
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git add '*.txt' # add all new .txt files to staging area |
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git --git-dir=/my/path/.git/ --work-tree=/my/path/ add <file> # add file in another directory to staging area |
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git commit -m "<message>" # store staged changes |
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git --git-dir=/my/path/.git/ --work-tree=/my/path/ commit -m "<comment>" # commit changes in another directory |
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git log # list changes committed so far |
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git remote add origin <https://some.repo.com> # add remote repository |
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git push -u origin master # push local changes to remote repo origin (-u stores params so only 'git push' is needed next time) |
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git pull origin master # check for changes on remote origin repo and pull them down |
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git diff HEAD # check what is different from most recent commit |
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git diff --staged # show changes within files that have already been staged |
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git reset <file> # unstage <file> |
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git branch # show branches and highlight which branch is currently being used |
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git branch <branch> # create branch called <branch> |
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git branch -d <branch> # delete <branch> branch |
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git checkout -- <file> # get rid of changes since last commit for <file> |
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git checkout <branch> # switch to branch <branch> |
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git checkout -b <branch> # create and switch to branch <branch> |
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git rm '*.txt' # deletes .txt files from disk and stages removal of the files in the repo |
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git merge <branch> # merge changes from <branch> branch into current branch |
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git clone <repo> . # clone repository in current local directory |
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# grep |
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grep -rli --exclude-dir={dir1,dir2,dir3} keyword /search/path # search path for pattern with exceptions |
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grep "^[^#;]" file.name # show only non-commented lines (ignore comments) |
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grep '^[[:blank:]]*[^[:blank:]#;]' file.name # show only non-commented non-blank lines (ignore comments and blank lines) |
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# history (bash) |
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HISTCONTROL=ignorespace # tell bash not to record commands starting with space to history (add to .bashrc to make persistent) |
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history -d <number> # delete command <number> from bash history |
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# kubernetes |
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kubectl exec -it <pod name> -n <namespace> -- /bin/bash # accesh shell in a container running in a kubernetes/EKS pod (see https://kubernetes.io/docs/tasks/debug-application-cluster/get-shell-running-container/) |
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# ln |
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ln -s <target> <name> # creates a symbolic link (symlink) to <target> called <name> |
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# magento |
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php bin/magento admin:user:create --admin-user='<user>' --admin-password='<password>' --admin-email='<[email protected]>' --admin-firstname='<first>' --admin-lastname='<last>' # create admin user |
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rm -rf var/di/* var/generation/* var/cache/* var/log/* var/page_cache/* var/session/* var/view_preprocessed/* pub/static/* # clear out magento cache and temp directories |
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magento setup:install # install Magento software |
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magento setup:upgrade # update the Magento software |
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magento setup:di:compile # run single-tenant compiler |
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magento setup:static-content:deploy # deploy static content |
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magento cache:clean # clean cache type(s) |
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magento cache:flush # flush cache storage used by cache type(s) |
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magento module:{enable|disable} # enable or disable modules |
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magento setup:db:status # check if the database is up-to-date with the code |
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export PATH=$PATH:/var/www/html/bin # add to ~/.bashrc to add magento commands to $PATH |
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# mysql |
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mysql -u db_username -p db_name < db_file.sql # import database 'db_name' from 'db_file.sql' into mysql (use gunzip if file.sql.gz) |
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SELECT User FROM mysql.user; # mysql > show all database users |
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SHOW DATABASES; # mysql > show all databases |
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sed -e 's/DEFINER[ ]*=[ ]*[^*]*\*/\*/' file.sql > newfile.sql # make a mysql dump ready to import without SUPER permissions error |
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# dump mysql database 'db_name' on server 'db_server' to file: |
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mysqldump -h <db_server> -u <db_username> -p <db_name> --single-transaction | sed -e 's/DEFINER[ ]*=[ ]*[^*]*\*/\*/' | gzip > <db_file>.sql.gz |
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# netstat |
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sudo netstat -tulpn | grep :80 # find out what is running/listening on port 80 |
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sudo netstat | grep http | wc -l # check how many http connections are open |
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# nginx |
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sudo nginx -s reload # reload nginx config |
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sudo nginx -s quit # gracefully shutdown nginx |
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sudo nginx -s stop # terminates nginx process |
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sudo nginx -t # nginx config syntax check (pre-load) |
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sudo nginx -T # displays currently running configs |
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sudo nginx -v # checks nginx version |
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ps aux | grep "[n]ginx" # check running nginx processes |
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service nginx status # check nginx service status |
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# rsync |
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rsync -havz --stats --progress -e "ssh -i /path/to/sshkey.pem" /path/to/local/file user@remotehost:~/ # transfer local file to home directory on remote server |
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rsync -havz --stats --progress -e "ssh -i /path/to/sshkey.pem" user@remotehost:~/file ~/ # transfer file from home directory on remote server to local home directory |
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# screen |
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screen # start screen |
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<ctrl-a> c # creat new screen window |
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<ctrl-a> n # go to next screen window |
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<ctrl-a> p # go to previous screen window |
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<ctrl-a> " " # show list of screen windows (allows you to select a window to change to) |
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<ctrl-a> w # show screen window bar |
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<ctrl-a> m # monitor current screen window for activity, alert when active |
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<ctrl-a> _ # monitor current screen window for silence or no activity, alert when inactive |
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<ctrl-a> d # detach from current screen |
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screen -ls # list screen sessions |
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screen -r [pid.session.name] # re-attach to screen session |
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https://www.howtoforge.com/linux_screen # decent screen tutorial |
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# ssh |
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ssh-keygen -t rsa # generate ssh keys |
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find ~/.ssh -type f -exec chmod -R 600 {} \; && find ~/.ssh -type d -exec chmod -R 700 {} \; # fix permissions on ssh folder and keys |
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ssh-keygen -R hostname # remove a host from known_hosts file |
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# tar |
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tar xvzf file.tar.gz # extract entire .tar.gz archive |
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tar tvf file.tar.gz # view a table of contents by listing all files in achieve |
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tar xvjf file.tar.bz2 # extract file which was compressed using a bZip2 compressor |
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tar zcvf archive-name.tar.gz directory-name # compress entire directory |
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# tmux |
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tmux new -s session_name # creates a new tmux session named session_name |
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tmux attach -t session_name # attaches to an existing tmux session named session_name |
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tmux switch -t session_name # switches to an existing session named session_name |
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tmux list-sessions # lists existing tmux sessions |
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tmux kill-session -t :0-9 # kill tmux session |
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tmux detach # detach the currently attached session |
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tmux new-window # create a new window |
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tmux select-window -t :0-9 # move to the window based on index |
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tmux rename-window # rename the current window |
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tmux split-window # splits the window into two vertical panes |
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tmux split-window -h # splits the window into two horizontal panes |
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tmux swap-pane -[UDLR] # swaps pane with another in the specified direction |
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tmux select-pane -t :.+ # selects the next pane in numerical order |
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tmux list-keys # lists out every bound key and the tmux command it runs |
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tmux list-commands # lists out every tmux command and its arguments |
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tmux info # lists out every session, window, pane, its pid, etc. |
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tmux source-file ~/.tmux.conf # reloads the current tmux configuration (based on a default tmux config) |
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# tmux shortcuts: |
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<ctrl-b> d # tmux detach |
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<ctrl-b> c # tmux new-window |
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<ctrl-b> 0-9 # tmux select-window |
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<ctrl-b> , # tmux rename-window |
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<ctrl-b> " " # tmux split-window |
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<ctrl-b> % # tmux split-window -h |
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<ctrl-b> { or } # tmux swap-pane -[UDLR] |
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# tmux crash course: |
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https://robots.thoughtbot.com/a-tmux-crash-course |
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# user and group management |
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useradd -s /sbin/nologin dbuser # add a user without a valid login shell (to establish SSH tunnels for DB access, for example) |
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groups <user> # list groups <user> is in |
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sudo usermod -a -G <group> <user> # add user to group |
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# varnish |
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varnishlog -g request -q 'ReqMethod eq "PURGE"' # view logged varnish purge requsts |
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# yum |
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yum list all # list all installed and available packages |
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yum list installed # list all installed packages |
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yum list available # list all available packages |
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yum repolist all # list all yum repositories and their status |
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yum repolist enabled # list only enabled yum repositories |
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yum repolist disabled # list disabled yum repositories |
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yum --disablerepo=* --enablerepo=repo_name install [packages] # only install packages from the 'repo_name' repository |
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# zip, gzip |
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gunzip file.gz # extract .gz file without tar |
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gzcat <filename> # look at gzipped file contents without extracting it |
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