Rglpk is an R library that links the GLPK package with R interface. This package is required by the igraph package to perform cluster optimization tasks. Due to some CRAN policy update, the embedded GLPK in igraph (and Rglpk) is removed, and users can not longer get GLPK installed with a simple R installation command.
So here is the solution from stackoverflow:
Install GLPK in a local directory:
wget http://ftp.gnu.org/gnu/glpk/glpk-4.54.tar.gz
tar xfzv glpk-4.54.tar.gz
mkdir GLPK
cd glpk-4.54
./configure --prefix=/home/<username>/GLPK
make
make install
Install Rglpk (0.6-3):
cd ~
wget http://cran.r-project.org/src/contrib/Rglpk_0.6-4.tar.gz
export LIBRARY_PATH=/home/<username>/GLPK/lib
export LD_LIBRARY_PATH=/home/<username>/GLPK/lib
export CPATH=/home/<username>/GLPK/include
R CMD INSTALL Rglpk_0.6-4.tar.gz