1# see images available on your hosts 2docker image list 3 4# equal to above 5docker images 6REPOSITORY TAG IMAGE ID CREATED SIZE 7httpd latest 6fa26f20557b 45 hours ago 164MB 8hello-world latest 75280d40a50b 4 months ago 1.69kB 9 10# give sha 11docker images --no-trunc=true 12 13# delete unused images 14docker rmi $(docker images -q) 15# delete images without tags 16docker rmi $(docker images | grep "^<none>" | awk '{print $3}')
The Basics 1sed -e '…' -e '…' # Several execution 2sed -i # Replace in place 3sed -r # Play with REGEX 4 5# The most usefull 6sed -e '/^[ ]*#/d' -e '/^$/d' <fich.> # openfile without empty or commented lines 7sed 's/ -/\n -/g' # replace all "-" with new lines 8sed 's/my_match.*/ /g' # remove from the match till end of line 9sed -i '4048d;3375d' ~/.ssh/known_hosts # delete lines Number 10 11# Buffer 12s/.*@(.*)/$1/; # keep what is after @ put it in buffer ( ) and reuse it with $1. 13sed -e '/^;/! s/.*-reserv.*/; Reserved: &/' file.txt # resuse search with & 14 15# Search a line 16sed -e '/192.168.130/ s/^/#/g' -i /etc/hosts # Comment a line 17sed -re 's/^;(r|R)eserved:/; Reserved:/g' file.txt # Search several string 18 19# Insert - add two lines below a match pattern 20sed -i '/.*\"description\".*/s/$/ \n \"after\" : \"network.target\"\,\n \"requires\" : \"network.target\"\,/g' my_File 21 22# Append 23sed '/WORD/ a Add this line after every line with WORD' 24 25# if no occurence, then add it after "use_authtok" 26sed -e '/remember=10/!s/use_authtok/& remember=10/' -i /etc/pam.d/system-auth-permanent
CUE stands for Configure, Unify, Execute
Basics Installation 1# Install GO 2GO_VERSION="1.21.0" 3wget https://go.dev/dl/go${GO_VERSION}.linux-amd64.tar.gz 4sudo tar -C /usr/local -xzf go${GO_VERSION}.linux-amd64.tar.gz 5export PATH=$PATH:/usr/local/go/bin 6 7go install cuelang.org/go/cmd/cue@latest 8sudo cp -pr ./go /usr/local/. 9 10# or use Container 11printf "\e[1;34m[INFO]\e[m Install CUElang:\n"; 12podman pull docker.io/cuelang/cue:latest concepts top -> schema -> constraint -> data -> bottom
Command 1# import a file 2cue import imageset-config.yaml 3 4# Validate 5cue vet imageset-config.cue imageset-config.yaml 6 7 8* Some basics example 9 10```go 11// This is a comment 12_greeting: "Welcome" // Hidden fields start with "_" 13#project: "CUE" // Definitions start with "#" 14 15message: "\(_greeting) to \(#project)!" // Regular fields are exported 16 17#Person: { 18 age: number // Mandatory condition and must be a number 19 hobbies?: [...string] // non mandatory but if present must be a list of string 20} 21 22// Constrain which call #Person and check if age 23#Adult: #Person & { 24 age: >=18 25} 26 27// =~ match a regular expression 28#Phone: string & =~ "[0-9]+" 29 30// Mapping 31instanceType: { 32 web: "small" 33 app: "medium" 34 db: "large" 35} 36 37server1: { 38 role: "app" 39 instance: instanceType[role] 40} 41 42// server1.instance: "medium" Scripting 1# executable have extension name "_tool.cue" 2 3# usage 4cue cmd prompter 1package foo 2 3import ( 4 "tool/cli" 5 "tool/exec" 6 "tool/file" 7) 8 9// moved to the data.cue file to show how we can reference "pure" Cue files 10city: "Amsterdam" 11 12// A command named "prompter" 13command: prompter: { 14 15 // save transcript to this file 16 var: { 17 file: *"out.txt" | string @tag(file) 18 } // you can use "-t flag=filename.txt" to change the output file, see "cue help injection" for more details 19 20 // prompt the user for some input 21 ask: cli.Ask & { 22 prompt: "What is your name?" 23 response: string 24 } 25 26 // run an external command, starts after ask 27 echo: exec.Run & { 28 // note the reference to ask and city here 29 cmd: ["echo", "Hello", ask.response + "!", "Have you been to", city + "?"] 30 stdout: string // capture stdout, don't print to the terminal 31 } 32 33 // append to a file, starts after echo 34 append: file.Append & { 35 filename: var.file 36 contents: echo.stdout // because we reference the echo task 37 } 38 39 // also starts after echo, and concurrently with append 40 print: cli.Print & { 41 text: echo.stdout // write the output to the terminal since we captured it previously 42 } 43} Sources Offical Documentation
Interesting example from justfile documentation:
where it create mktemp and set it in variable then by concatenation you get a full path to the tar.gz.
Then the Recipe “publish” create the artifact again and push it to a server.
1tmpdir := `mktemp` # Create a tmp file 2version := "0.2.7" 3tardir := tmpdir / "awesomesauce-" + version 4tarball := tardir + ".tar.gz" # use tmpfile path to create a tarball 5 6publish: 7 rm -f {{tarball}} 8 mkdir {{tardir}} 9 cp README.md *.c {{tardir}} 10 tar zcvf {{tarball}} {{tardir}} 11 scp {{tarball}} me@server.com:release/ 12 rm -rf {{tarball}} {{tardir}} This one can be really usefull to define a default value which can be redefine with env variable:
Shell Variable $$var $$( python -c ‘import sys; print(sys.implementation.name)’ )
Make Variable T ?= foo # give a default value T := $(shell whoami) # execute shell immediately to put in the var
PHONY to execute several makefile Example 1
1SUBDIRS = foo bar baz 2 3## dir is a Shell variables 4## SUBDIR and MAKE are Internal make variables 5subdirs: 6 for dir in $(SUBDIRS); do \ 7 $(MAKE) -C $$dir; \ 8 done Example 2
1SUBDIRS = foo bar baz 2 3.PHONY: subdirs $(SUBDIRS) 4subdirs: $(SUBDIRS) 5$(SUBDIRS): 6 $(MAKE) -C $@ 7foo: baz Idea for a testing tools 1git clone xxx /tmp/xxx&& make -C !$/Makefile 2make download le conteneur 3make build le binaire 4make puts it in /usr/local/bin 5make clean 6make help Sources: Tutorials
Deploy a Nexus3 in container on VM Load the image
1podman pull sonatype/nexus3:3.59.0 2podman save sonatype/nexus3:3.59.0 -o nexus3.tar 3podman load < nexus3.tar Create a service inside /etc/systemd/system/container-nexus3.service with content below:
1[Unit] 2Description=Nexus Podman container 3Wants=syslog.service 4 5[Service] 6User=nexus-system 7Group=nexus-system 8Restart=always 9ExecStart=/usr/bin/podman run \ 10 --log-level=debug \ 11 --rm \ 12 -ti \ 13 --publish 8081:8081 \ 14 --name nexus \ 15 sonatype/nexus3:3.59.0 16 17ExecStop=/usr/bin/podman stop -t 10 nexus 18 19[Install] 20WantedBy=multi-user.target
Pypi Repo for airgap env Let’s take as an example py dependencies for Netbox
1# Tools needed 2dnf install -y python3.11 3pip install --upgrade pip setuptool python-pypi-mirror twine 4 5# init mirror 6python3.11 -m venv mirror 7mkdir download 8 9# Get list of Py packages needed 10curl raw.githubusercontent.com/netbox-community/netbox/v3.7.3/requirements.txt -o requirements.txt 11echo pip >> requirements.txt 12echo setuptools >> requirements.txt 13echo uwsgi >> requirements.txt 14 15# Make sure repository CA is installed 16curl http://pki.server/pki/cacerts/ISSUING_CA.pem -o /etc/pki/ca-trust/source/anchors/issuing.crt 17curl http://pki.server/pki/cacerts/ROOT_CA.pem -o /etc/pki/ca-trust/source/anchors/root.crt 18update-ca-trust 19 20 21source mirror/bin/activate 22pypi-mirror download -b -d download -r requirements.tx 23twine upload --repository-url https://nexus3.server/repository/internal-pypi/ download/*.whl --cert /etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem 24twine upload --repository-url https://nexus3.server/repository/internal-pypi/ /download/*.tar.gz --cert /etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem Then on target host inside /etc/pip.conf :
General concern If you want to move VMs to an another Storage Domain, you need to copy the template from it as well!
Remove a disk:
1# IF RHV does not use anymore disk those should appear empty in lsblk: 2lsblk -a 3sdf 8:80 0 4T 0 disk 4└─36001405893b456536be4d67a7f6716e3 253:38 0 4T 0 mpath 5sdg 8:96 0 4T 0 disk 6└─36001405893b456536be4d67a7f6716e3 253:38 0 4T 0 mpath 7sdh 8:112 0 4T 0 disk 8└─36001405893b456536be4d67a7f6716e3 253:38 0 4T 0 mpath 9sdi 8:128 0 0 disk 10└─360014052ab23b1cee074fe38059d7c94 253:39 0 100G 0 mpath 11sdj 8:144 0 0 disk 12└─360014052ab23b1cee074fe38059d7c94 253:39 0 100G 0 mpath 13sdk 8:160 0 0 disk 14└─360014052ab23b1cee074fe38059d7c94 253:39 0 100G 0 mpath 15 16# find all disks from LUN ID 17LUN_ID="360014054ce7e566a01d44c1a4758b092" 18list_disk=$(dmsetup deps -o devname ${LUN_ID}| cut -f 2 |cut -c 3- |tr -d "()" | tr " " "\n") 19echo ${list_disk} 20 21# Remove from multipath 22multipath -f "${LUN_ID}" 23 24# remove disk 25for i in ${list_disk}; do echo ${i}; blockdev --flushbufs /dev/${i}; echo 1 > /sys/block/${i}/device/delete; done 26 27# You can which disk link with which LUN on CEPH side 28ls -l /dev/disk/by-* NFS for OLVM/oVirt Since oVirt need a shared stockage, we can create a local NFS to bypass this point if no Storage bay.
Manuals for commands man <cmd> : Open man page of command.
space : go ahead page by page. b : go back page by page. q : quit. Enter : go line by line. /<word> : search a word in man. n : go to the next expression that you search. N : go back to search expression. man -k <key word> : look for in all man for your key words.
man -k <word1>.*<word2> : “.*” allow to search several words. whatis <cmd> : give short explaination about the command.
Oracle DB Diagram --- config: theme: forest layout: elk --- flowchart TD subgraph s1["Instance DB"] style s1 fill:#E8F5E9,stroke:#388E3C,stroke-width:2px subgraph s1a["Background Processes"] style s1a fill:#FFF9C4,stroke:#FBC02D,stroke-width:1px n5["PMON (Process Monitor)"] n6["SMON (System Monitor)"] n10["RECO (Recoverer Process)"] end subgraph s1b["PGA (Process Global Area)"] style s1b fill:#E3F2FD,stroke:#1976D2,stroke-width:1px n1["Processes"] end subgraph s1c["SGA (System Global Area)"] style s1c fill:#FFEBEE,stroke:#D32F2F,stroke-width:1px subgraph n7["Shared Pool (SP)"] style n7 fill:#F3E5F5,stroke:#7B1FA2,stroke-width:1px n7a["DC (Dictionary Cache)"] n7b["LC (Library Cache)"] n7c["RC (Result Cache)"] end n8["DB Cache (DBC)"] n9["Redo Buffer"] n3["DBWR (DB Writer)"] n4["LGWR (Log Writer)"] n5["PMON (Process Monitor)"] n6["SMON (System Monitor)"] n10["RECO (Recoverer Process)"] end end subgraph s2["Database: Physical Files"] style s2 fill:#FFF3E0,stroke:#F57C00,stroke-width:2px n11["TBS (Tablespaces, files in .DBF)"] n12["Redo Log Files"] n13["Control Files"] n14["SPFILE (Binary Authentication File)"] n15["ArchiveLog files"] end subgraph s3["Operating System"] style s3 fill:#E0F7FA,stroke:#00796B,stroke-width:2px n16["Listener (Port 1521)"] end n3 --> n11 n3 --> n7c n4 --> n12 n6 --> n7a s3 --> s1 s1c <--> n12 s1c <--> n13 s1c <--> n14 n7b <--> n7c classDef Aqua stroke-width:1px, stroke-dasharray:none, stroke:#0288D1, fill:#B3E5FC, color:#01579B classDef Yellow stroke-width:1px, stroke-dasharray:none, stroke:#FBC02D, fill:#FFF9C4, color:#F57F17 classDef Green stroke-width:1px, stroke-dasharray:none, stroke:#388E3C, fill:#C8E6C9, color:#1B5E20 classDef Red stroke-width:1px, stroke-dasharray:none, stroke:#D32F2F, fill:#FFCDD2, color:#B71C1C class n11,n12,n13,n14,n15 Aqua class n5,n6,n10 Yellow class n1 Green class n7,n8,n9,n3,n4 Red Explanation An Oracle server includes an Oracle Instance and an Oracle Database.
What is Cert-Manager cert-manager automates the management of X.509 certificates inside Kubernetes via CRDs — it requests, issues, renews and rotates certificates automatically.
Key concepts Issuer — a namespaced certificate signer. ClusterIssuer — a cluster-wide signer. Certificate — asks cert-manager to obtain a cert for a name. Supported backends: ACME (Let’s Encrypt), self-signed, CA, Vault, Venafi, …
Install (helm) 1helm repo add jetstack https://charts.jetstack.io 2helm repo update 3helm upgrade --install cert-manager jetstack/cert-manager \ 4 --namespace cert-manager --create-namespace \ 5 --set installCRDs=true Example: self-signed issuer 1apiVersion: cert-manager.io/v1 2kind: ClusterIssuer 3metadata: 4 name: selfsigned 5spec: 6 selfSigned: {} 1apiVersion: cert-manager.io/v1 2kind: Certificate 3metadata: 4 name: example-tls 5spec: 6 secretName: example-tls 7 dnsNames: 8 - example.com 9 issuerRef: 10 name: selfsigned 11 kind: ClusterIssuer Useful commands 1kubectl get certificate -A 2kubectl get certificaterequest -A 3kubectl describe certificate <name> -n <ns> 4 5# manual renewal (normally automatic) 6cmctl renew <name> -n <ns> Ops notes Cert-Manager stores the TLS key/cert in a <name> secret, ready for Ingress. kubectl get challenges is the first place to look for ACME/Let’s Encrypt failures.
Tar - “tape archiver” Preserve files permissions and ownership.
The Basics
1# Archive 2tar cvf my_archive.tar <file1> <file2> </dir/folder/> 3 4## Archive and compress with zstd everything in the current dir and push to /target/dir 5tar -I zstd -vcf archive.tar.zstd -C /target/dir . 6 7# Extract 8tar xvf my_archive.tar 9 10# Extract and push to target dir 11tar -zxvf new.tar.gz -C /target/dir Other useful options • t : list archive’s content. • T : archive list given by a file. • P : preserve absolute path (useful for backing up /etc). • X : exclude. • z : gunzip compression. • j : bzip2 compression. • J : lzma compression.
