#format wiki
#language en
= linux docker notes =
 * 2021 - replaced single use container with [[podman]]
 * Links [[https://www.docker.com/blog/containers-are-not-vms/]] , [[docker/Dockerfile]] , [[docker-compose]] , [[https://blogs.oracle.com/developers/official-docker-image-for-oracle-java-and-the-openjdk-roadmap-for-containers|Docker&Oracle-java]] , [[Containers]] , [[Azure]] , [[https://medium.com/@betz.mark/ten-tips-for-debugging-docker-containers-cde4da841a1d]] , [[https://blog.docker.com/2014/06/why-you-dont-need-to-run-sshd-in-docker/|No ssh needed]]
    * [[https://itnext.io/shift-your-ci-scripts-to-docker-build-92453bca9f75|2019-Multi-Container-Docker-Build]]
    * [[https://learnk8s.io/blog/smaller-docker-images|2020 smaller docker images]] - alpine - google distroless

== Docker login ===
=== Azure cli ===
{{{ az acr login -n <name> }}}

=== Azure ACR SP ===
 * Azure ACR - Docker login with service principal
   * https://docs.microsoft.com/en-us/azure/container-registry/container-registry-auth-service-principal {{{
#!/bin/bash
#!/bin/bash
ACR_NAME=<container-registry-name>
SERVICE_PRINCIPAL_NAME=acr-service-principal
ACR_SUBSCRIPTION="<subscription>"
#
ACR_REGISTRY_ID=$(az acr show --subscription $ACR_SUBSCRIPTION --name $ACR_NAME --query id --output tsv)
SP_PASSWD=$(az ad sp create-for-rbac --name http://$SERVICE_PRINCIPAL_NAME --scopes $ACR_REGISTRY_ID --role acrpull --query password --output tsv)
SP_APP_ID=$(az ad sp show --id http://$SERVICE_PRINCIPAL_NAME --query appId --output tsv)
echo "Service principal ID: $SP_APP_ID"
echo "Service principal password: $SP_PASSWD"
echo "#  docker login $ACR_NAME.azurecr.io -u $SP_APP_ID -p $SP_PASSWD"
}}}
   * $ $ docker login <acr>.azurecr.io -u <SP-ID> -p <SP-P>
   * Or directly using Microsoft credentials with $ az acr login --name <container-registry-name (no azurecr.io>

 * On Ubuntu
   * install docker
   * add user to docker group, logout and log in again
     {{{ adduser Me docker }}}
  
   * Flags
     * -t pseudo-TTY
     * -i --interactive
     * --name "!NameContainer"
     * --publish=[]  format ip:hostPort:containerPort | ip::containerPort | hostPort:containerPort | containerPort
     * -e, --env=[] Set environment variables
     * --add-host=[] Add a custom host-to-IP mapping (host:ip)
     * --rm Automatically remove the container when it exits

== Docker scratch/empty image ==
 * Very small, usually used with go apps(self contained)
 * View content with docker save -o tar  e.g. https://www.mgasch.com/post/scratch/

== Cleanup old docker images ==
   * docker rmi $(docker images | grep "none" | awk '/ / { print $3 }')

   * docker search ubuntu:14.04
     {{{ $ docker search ubuntu:14.04 }}}
     {{{ $ docker search --no-trunc --stars=1 etcd }}}

   * downloaded images
     {{{ docker images }}}

   * run interactively 
     {{{ $ docker run -it ubuntu:14.04 }}} 

     {{{ $ docker run -it -v ~/docker:/docker ubuntu:14.04 }}}

     {{{ $ docker run -it -v ~/docker:/docker -v /dev/log:/dev/log ubuntu:14.04 }}}

   * view running images and historic
     {{{ $ docker ps -a }}}

   * connect to a running docker attache to main terminal. (attach or exec new app)
     {{{ docker exec -it <<docker ps #id>> /bin/bash }}}
   
   * Find docker details e.g. ip 
     {{{ docker inspect <container id>  }}}

   * set default resolve.conf dns servers.
     * create/edit  $ sudo gvim /etc/docker/daemon.json
       {{{
       {
	"dns": ["8.8.8.8", "8.8.4.4"]
       }
       }}}

  * commit a new image
    1. run and make changes.
    2. exit
    3. commit and save as new image
       {{{
       $ docker commit -m "My Image Test01" -a "My Name" 37bf99224fce myimg01
       sha256:4b439bc2347b744a405ae6a60862906442e461eddd33d0496dff322060fe837b
       }}}
    4. run new image. $ docker run -it -v ~/docker:/docker myimg01

 * re-run exited image.
   * docker start  xxxxxx
   * docker exec   xxxxxx   /bin/bash

 * Get logs from container {{{
docker logs --tail=50 <container id>
   }}}