Update June 3, 2017: The team has revised the docker image and the bash file is gone, presumably with its logic broken up in to various locations. Still I’m glad I grabbed this when I did to satisfy my curiosity!

Microsoft has created 4 official Docker images for SQL Server: SQL Server for Linux, SQL Server Developer Edition, SQL Server Express and (windows) SQL Server vNext) . They can be found on the Docker hub (e.g. https://hub.docker.com/r/microsoft/mssql-server-linux/) and there is also a Github repository for them at github.com/Microsoft/mssql-docker. Some of the files that go along with that image are not on Github. The Dockerfile files for each image run some type of startup script. The Windows images have a PowerShell script called start.ps1. You can see those in the Github repo. The Linux image runs a bash file called sqlservr.sh. That’s not included in the repo though and I was curious what it did.

Note: I wrote a blog post about using the SQL Server for Linux container (Mashup: SQL Server on Linux in Docker on a Mac with Visual Studio Code)  and I’m also writing an article about using the containers for my July MSDN Magazine Data Points column (watch this space).

Still a bit of a bash noob, I learned how to read a file from a docker container on ..you guessed it…StackOverflow.  Following those instructions, I created a snapshot of my running container

➜ MySqlServerLinuImage git:(master) docker commit juliesqllinux  mysnapshot

sha256:9b552a1e24df7652af0c6c265ae5e2d7cb7832586c431d4b480c30663ab713f0

and ran the snapshot with bash:

➜  MySqlServerLinuImage git:(master) docker run -t -i mysnapshot bin/bash

[email protected]:/# 

Then at the new prompt (#), used ls to get the listing

[email protected]:/# ls

SqlCmdScript.sql  SqlCmdStartup.sh  bin  boot  dev  entrypoint.sh  etc  home  install.sh  lib  lib64  media  mnt  opt  proc  root  run  sbin  srv  sys  tmp  usr  var

then navigated to  folder where the bash file is and listed its contents:

[email protected]:/opt/mssql/bin# ls

compress-dump.sh  generate-core.sh  mssql-conf  paldumper  sqlpackage  sqlservr  sqlservr.sh

Once I was there I used the cat command to list out the contents of the sqlservr.sh file and see what it does. Here is the secret sauce in case, like me, you NEED to know what’s going on under the covers!

[email protected]:/opt/mssql/bin# cat sqlservr.sh 

#!/bin/bash

#

# Microsoft(R) SQL Server(R) launch script for Docker

#

ACCEPT_EULA=${ACCEPT_EULA:-}

SA_PASSWORD=${SA_PASSWORD:-}

#COLLATION=${COLLATION:-SQL_Latin1_General_CP1_CI_AS}

have_sa_password=""

#have_collation=""

sqlservr_setup_prefix=""

configure=""

reconfigure=""

# Check system memory

#

let system_memory="$(awk '/MemTotal/ {print $2}' /proc/meminfo) / 1024"

if [ $system_memory -lt 3250 ]; then

    echo "ERROR: This machine must have at least 3.25 gigabytes of memory to install Microsoft(R) SQL Server(R)."

    exit 1

fi

# Create system directories

#

mkdir -p /var/opt/mssql/data

mkdir -p /var/opt/mssql/etc

mkdir -p /var/opt/mssql/log

# Check the EULA

#

if [ "$ACCEPT_EULA" != "Y" ] && [ "$ACCEPT_EULA" != "y" ]; then

 echo "ERROR: You must accept the End User License Agreement before this container" > /dev/stderr

 echo "can start. The End User License Agreement can be found at " > /dev/stderr

 echo "http://go.microsoft.com/fwlink/?LinkId=746388." > /dev/stderr

 echo ""

 echo "Set the environment variable ACCEPT_EULA to 'Y' if you accept the agreement." > /dev/stderr

 exit 1

fi

# Configure SQL engine

#

if [ ! -f /var/opt/mssql/data/master.mdf ]; then

 configure=1

 if [ ! -z "$SA_PASSWORD" ] || [ -f /var/opt/mssql/etc/sa_password ]; then

 have_sa_password=1

 fi

# if [ ! -z "$COLLATION" ] || [ -f /var/opt/mssql/etc/collation ]; then

# have_collation=1

# fi

 if [ -z "$have_sa_password" ]; then

        echo "ERROR: The system administrator password is not configured. You can set the" > /dev/stderr

        echo "password via environment variable (SA_PASSWORD) or configuration file" > /dev/stderr

        echo "(/var/opt/mssql/etc/sa_password)." > /dev/stderr

 exit 1

 fi

fi

# If user wants to reconfigure, set reconfigure flag

#

if [ -f /var/opt/mssql/etc/reconfigure ]; then

 reconfigure=1

fi

# If we need to configure or reconfigure, run through configuration

# logic

#

if [ "$configure" == "1" ] || [ "$reconfigure" == "1" ]; then

 sqlservr_setup_options=""

# if [ -f /var/opt/mssql/etc/collation ]; then

# sqlservr_setup_options+="-q $(cat /var/opt/mssql/etc/collation)"

# else

# if [ ! -z "$COLLATION" ]; then

# sqlservr_setup_options+="-q $COLLATION "

# fi

# fi

 set +e

 cd /var/opt/mssql

 echo 'Configuring Microsoft(R) SQL Server(R)...'

 if [ -f /var/opt/mssql/etc/sa_password ]; then

 SQLSERVR_SA_PASSWORD_FILE=/var/opt/mssql/etc/sa_password /opt/mssql/bin/sqlservr --setup $sqlservr_setup_options 2>&1 > /var/opt/mssql/log/setup-$(date +%Y%m%d-%H%M%S).log

 elif [ ! -z "$SA_PASSWORD" ]; then

 SQLSERVR_SA_PASSWORD_FILE=<(echo -n "$SA_PASSWORD") /opt/mssql/bin/sqlservr --setup $sqlservr_setup_options 2>&1 > /var/opt/mssql/log/setup-$(date +%Y%m%d-%H%M%S).log

 else

 if [ ! -z '$sqlservr_setup_options' ]; then

 /opt/mssql/bin/sqlservr --setup $sqlservr_setup_options 2>&1 > /var/opt/mssql/log/setup-$(date +%Y%m%d-%H%M%S).log

 fi

 fi

 retcode=$?

 if [ $retcode != 0 ]; then

 echo "Microsoft(R) SQL Server(R) setup failed with error code $retcode. Please check the setup log in /var/opt/mssql/log for more information." > /dev/stderr

 exit 1

 fi

 set -e

 rm -f /var/opt/mssql/etc/reconfigure

 rm -f /var/opt/mssql/etc/sa_password

 echo "Configuration complete."

fi

# Start SQL Server

#

exec /opt/mssql/bin/sqlservr $*