initial

Author: justin2004

Dockerfile

@@ -0,0 +1,15 @@
+FROM debian:stretch-slim AS build0
+WORKDIR /root
+
+RUN apt-get update && apt-get install -y binutils gcc
+
+ADD wrapper.c /root/
+RUN gcc -shared  -ldl -fPIC -o wrapper.so wrapper.c
+
+
+
+FROM mcr.microsoft.com/mssql/server
+COPY --from=build0 /root/wrapper.so /root/
+
+
+CMD LD_PRELOAD=/root/wrapper.so /opt/mssql/bin/sqlservr

wrapper.c

@@ -0,0 +1,28 @@
+#define _GNU_SOURCE
+#include <sys/sysinfo.h>
+#include <dlfcn.h>
+#include <stdio.h>
+
+int sysinfo(struct sysinfo *info){
+    // clear it
+    //dlerror();
+    void *pt=NULL;
+    typedef int (*real_sysinfo)(struct sysinfo *info);
+
+    // we need the real sysinfo function address
+    pt = dlsym(RTLD_NEXT,"sysinfo");
+    //printf("pt: %x\n", *(char *)pt);
+    
+    // call the real sysinfo system call
+    int real_return_val=((real_sysinfo)pt)(info);
+
+    // but then modify its returned totalram field if necessary
+    // because sqlserver needs to believe it has 2GiB physical 
+    // memory
+    if( info->totalram < 1024l * 1024l * 1024l * 2l){ // 2GiB
+        info->totalram = 1024l * 1024l * 1024l * 2l ;
+    }
+
+    return real_return_val;
+}
+