Install node canvas on AWS EC2 with Bitnami image

I am trying to install node canvas on my server AWS EC2 with Bitnami image.
I think I have installed correctly Cairo (after few attempts).
Now, when I run `sudo npm install canvas` I get the following error:

```
> node-gyp rebuild

Package cairo was not found in the pkg-config search path.
Perhaps you should add the directory containing `cairo.pc'
to the PKG_CONFIG_PATH environment variable
No package 'cairo' found
gyp: Call to './util/has_lib.sh freetype' returned exit status 0. while trying to load binding.gyp
```

if I run `dpkg-query -S cairo.pc` I see the following answer:

```
libcairo2-dev: /usr/lib/x86_64-linux-gnu/pkgconfig/cairo.pc
libpango1.0-dev: /usr/lib/x86_64-linux-gnu/pkgconfig/pangocairo.pc
```

which makes me think cairo has been installed.
If I run `pkg-config --cflags cairo` I get

```
Package cairo was not found in the pkg-config search path.
Perhaps you should add the directory containing `cairo.pc'
to the PKG_CONFIG_PATH environment variable
No package 'cairo' found
```

Can anybody help?
Thanks in advance