How to login to a running Docker container as root?

-----------------------------------------------

TL DR:

docker exec -it --user root <container> bash

-----------------------------------------------

Most of the times the application would run in a different user. as specified in the docker file. Such a docker file is mentioned below.

FROM openjdk:17-alpine
RUN apk update && apk add --no-cache gcompat && apk add curl bash
RUN addgroup -S appuser && adduser -S appuser -G appuser
USER appuser:appuser
# some custom code to run an app

In this Dockerfile the line "USER appuser:appuser" specifies the user and group which the application should run. Also, any commands following this line will run as the same user, and if you login the container without specifying the user explicitly, it will be the default user.

eg:

Docker exec accepts another parameter to specify the user. With that we can login as root or any user we want.

Login to a running container with specific user

Comments

Install Docker on Windows 11 with WSL Ubuntu 22.04

This is to install Docker within Ubuntu WSL without using the Windows Docker application. Follow the below steps. Install Ubuntu 22.04 WSL 1. Enable Windows Subsystem for Linux and Virtual Machine platform Go to Control Panel -> Programs -> Programs and Features -> Turn Windows features on or off 2. Switch to WSL 2 Open Powershell and type in the below command. wsl --set-default-version 2 If you don't have WSL 2, download the latest WSL 2 package and install it. 3. Install Ubuntu Open Microsoft Store and search for Ubuntu. Select the version you intend to install. I'd use the latest LTS version Ubuntu 22.04. Click on the Get button. It will take a couple of minutes to download and install. 4. Open up the installed Ubuntu version that was installed. If you get an error like the below image, make sure to install the WSL2 Kernel update . If it's an older Ubuntu version the error message would be something like the image below. Error: WSL 2 requires an update to its ...

How to fix SSLHandshakeException PKIX path building failed in Java

TL ; DR 1. Extract the public certificate of the website/API that you are trying to connect from your Java application. Steps are mentioned in this post 2. Use the Java keytool to install the extracted certificate into the "cacerts" file (Trust store) keytool -import -trustcacerts -alias <domain name> -file <public certificate>.cert -keystore /path_to_java_home/jre/lib/security/cacerts -storepass changeit 3. Restart your Java application Exception A typical exception stack trace would look like below. javax.net.ssl. SSLHandshakeException : sun.security.validator.ValidatorException: PKIX path building failed : sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target at sun.security.ssl.Alerts.getSSLException(Alerts.java:192) at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1959) at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:302) at sun.security.ssl.Handshake...

Automatically open Chrome developer tools in a new tab

Sometimes we need to check the console or the network transactions of a link that opens up in a new tab. By default, the Chrome developer tools are not opening in a new tab. So, by the time when we hit F12 and open the dev tools, part of the information we needed could be already gone. There's a setting in dev tools where you can keep the dev tools open automatically in a new tab. To enable that, hit F12 and open up the dev tools. Click on the settings icon in the top right corner. In the Preferences section, scroll down to the bottom. You'll be able to find the option to Auto-open DevTools for popups. Select the checkbox and we're good to go!

TJ is Blogging!

Search This Blog