Web app and remote access

Build Status

Introduction

Containerized web app running in Azure App Service configured so that you can remote to it using SSH.

You can connect via Web SSH Console e.g. https://yoursitenamehere.scm.azurewebsites.net/webssh/host

Or using az CLI:

# Create tunnel
az webapp create-remote-connection --name $appSvcName --resource-group $resourceGroup --port 9000
# Connect via tunnel
ssh root@localhost -p 9000

Summary of changes to enable SSH in your custom container

Inside your dockerfile do these changes:

# SSH Configuration->
EXPOSE 2222
ENV SSH_PORT 2222
RUN apt-get update -qq && \
    apt-get dist-upgrade --no-install-recommends -y && \
    apt-get install -y --no-install-recommends openssh-server && \
    echo "root:Docker!" | chpasswd

COPY init_container.sh /bin/
RUN chmod 755 /bin/init_container.sh

COPY sshd_config /etc/ssh/
RUN mkdir -p /var/run/sshd
# <-SSH Configuration

And then change the entrypoint to be custom script:

ENTRYPOINT ["/bin/init_container.sh", "dotnet", "WebApp.dll"]

Custom script should start ssh server and then of course your application after that:

# ...
service ssh start

# Run the main application
$@

How to deploy to App Service

Deploy published image to the Azure CLI way:

# Variables
appSvcName="mywebappremoteaccessdemo"
appSvcPlanName="webAppPlan"
resourceGroup="rg-webappremote-dev"
location="westeurope"
image="jannemattila/webapp-remote-access:1.0.14"

# Login to Azure
az login

# *Explicitly* select your working context
az account set --subscription <YourSubscriptionName>

# Create new resource group
az group create --name $resourceGroup --location $location

# Create App Service Plan
az appservice plan create --name $appSvcPlanName --resource-group $resourceGroup --is-linux --sku B1

# Create App Service
az webapp create --name $appSvcName --plan $appSvcPlanName --deployment-container-image-name $image --resource-group $resourceGroup

# Create SSH tunnel
az webapp create-remote-connection --name $appSvcName --resource-group $resourceGroup --port 9000

# Now you can connect via your SSH client using the tunnel
ssh root@localhost -p 9000

# Wipe out the resources
az group delete --name $resourceGroup -y

Bonus content - CRON

This demo also show how you can use cron to run some background tasks.

Inside your dockerfile do these changes:

# CRON Configuration->
RUN apt-get install -y --no-install-recommends cron
COPY mycron /etc/cron.d
RUN chmod 0744 /etc/cron.d/mycron
# <-CRON Configuration

Custom script should start cron:

echo Start CRON
service cron start

You can verify that cron is running by opening the web app and then navigating to the cron.txt which is then updated every minute by the background job.

Links

SSH support for Azure App Service on Linux