{ "date": "2020-02-08T22:25:42", "slug": "running-sql-server-on-the-oracle-free-tier", "link": "https://www.dbi-services.com/blog/running-sql-server-on-the-oracle-free-tier/", "title": { "rendered": "Running SQL Server on the Oracle Free tier" }, "content": { "rendered": "

By Franck Pachot

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The Oracle Cloud is not only for Oracle Database. You can create a VM running Oracle Linux with full root access to it, even in the free tier: a free VM that will be always up, never expires, with full ssh connectivity to a sudoer user, where you are able to tunnel any port. Of course, there are some limits that I’ve detailed in a previous post. But that is sufficient to run a database, given that you configure a low memory usage. For Oracle Database XE, Kamil Stawiarski mentions that you can just hack the memory test in the RPM shell script.
\nBut for Microsoft SQL Server, that’s a bit more complex because this test is hardcoded in the sqlservr binary and the solution I propose here is to intercept the call to the sysinfo() system call.
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\nCreating a VM in the Oracle Cloud is very easy, here are the steps in one picture:
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I’m connecting to the public IP Address with ssh (the public key is uploaded when creating the VM) and I’ll will run everything as root:

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ssh opc@129.213.138.34\nsudo su -\ncat /etc/oracle-release
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I install docker engine (version 19.3 there)

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yum install -y docker-engine
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I start docker

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\nsystemctl start docker\ndocker info
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\nI’ll use the latest SQL Server 2019 image built on RHEL

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docker pull mcr.microsoft.com/mssql/rhel/server:2019-latest\ndocker images
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5 minutes to download a 1.5GB image. Now trying to start it.
\nThe nice thing (when I compare to Oracle) is that we don’t have to manually accept the license terms with a click-through process. I just mention that I have read and accepted them with: ACCEPT_EULA=Y

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I try to run it:

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docker run \\\n -e \"ACCEPT_EULA=Y\" \\\n -e 'MSSQL_PID=Express' \\\n -p 1433:1433 \\\n -e 'SA_PASSWORD=**P455w0rd**' \\\n --name mssql \\\n mcr.microsoft.com/mssql/rhel/server:2019-latest
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There’s a hardcoded prerequisite verification to check that the system has at least 2000 MB of RAM. And I have less than one GB here in this free tier:

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\nawk '/^Mem/{print $0,$2/1024\" MB\"}' /proc/meminfo\n
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Fortunately, there’s always a nice geek on the internet with an awesome solution: hack the sysinfo() system call with a LD_PRELOAD’ed wrapper : A Slightly Liberated Microsoft SQL Server Docker image

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Let’s get it:

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git clone https://github.com/justin2004/mssql_server_tiny.git\ncd mssql_server_tiny
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I changed the FROM to build from the 2019 RHEL image and I preferred to use /etc/ld.so.preload rather than overriding the CMD command with LD_LIBRARY:

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\nFROM oraclelinux:7-slim AS build0\nWORKDIR /root\nRUN yum update -y && yum install -y binutils gcc\nADD wrapper.c /root/\nRUN gcc -shared  -ldl -fPIC -o wrapper.so wrapper.c\nFROM mcr.microsoft.com/mssql/rhel/server:2019-latest\nCOPY --from=build0 /root/wrapper.so /root/\nADD wrapper.c /root/\nUSER root\nRUN echo \"/root/wrapper.so\" > /etc/ld.so.preload\nUSER mssql\n
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I didn’t change the wrapper for the sysinfo function:

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#define _GNU_SOURCE\n#include \n#include \n#include\nint sysinfo(struct sysinfo *info){\n    // clear it\n    //dlerror();\n    void *pt=NULL;\n    typedef int (*real_sysinfo)(struct sysinfo *info);\n    // we need the real sysinfo function address\n    pt = dlsym(RTLD_NEXT,\"sysinfo\");\n    //printf(\"pt: %x\\n\", *(char *)pt);\n    // call the real sysinfo system call\n    int real_return_val=((real_sysinfo)pt)(info);\n    // but then modify its returned totalram field if necessary\n    // because sqlserver needs to believe it has \"2000 megabytes\"\n    // physical memory\n    if( info->totalram totalram = 1000l * 1000l * 1000l * 2l ;\n    }\n    return real_return_val;\n}\n
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I build the image from there:

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docker build -t mssql .
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\nI run it:

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docker run -d \\\n -e \"ACCEPT_EULA=Y\" \\\n -e 'MSSQL_PID=Express' \\\n -p 1433:1433 \\\n -e 'SA_PASSWORD=**P455w0rd**' \\\n --name mssql \\\n mssql
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I wait until it is ready:

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until docker logs mssql  | grep -C10 \"Recovery is complete.\" ; do sleep 1 ; done
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All is ok and I connect and check the version:

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Well… as you can see my first attempt failed. I am running with very low memory here, and then many memory allocation problems can be expected. If you look at the logs after a while, many automatic system tasks fail. But that’s sufficient for a minimal lab and you can tweak some Linux and SQL Server parameters if you need it. Comments are welcome here for feedback and ideas…

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The port 1433 is exposed here locally and it can be tunneled through ssh. This is a free lab environment always accessible from everywhere to do small tests in MS SQL, running on the Oracle free tier. Here is how I connect with DBeaver from my laptop, just mentioning the public IP address, private ssh key and connection information:

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