Hello and welcome to the forum. Is there any reason why you wish to feed Royal Canin? I cannot find Midi on the Dog Food Directory but have a look to check out the various varieties. You will see that the nutritional ratings are not good. The Directory is here.
When searching for a suitable food you need to look at the ingredient list and it should be crystal clear so that you understand exactly what it contains. The first ingredient should always be the named meat source. Avoid anything with the word 'derivatives' in it. We have a thread here
which might be helpful.
Regarding the anal glands, we have a number of useful threads about this. You can find them using the search box at the top left, search term 'anal'. I have found some here for you:Help my dog with anal gland issueAnal gland impactionHi new member.....Can anyone offer advice please?.....Anal gland issues
The stool needs to be firm so that it compresses the anal glands as it passes through. This can be achieved be giving food that has good fibre content. Brown rice is a good source of fibre, as is sweet potato. Another helpful source of fibre is suitable cooked, mashed vegetables. The leafy green ones such as broccoli, cabbage are useful and these can be added to dry dog food as an enhancement.
I am sorry that I can't recommend any particular food - there are so many. Also, it is best for you to learn a little about the key features to look out for when choosing food. This always pays off in the long run. If looking for dry food, I would be inclined to look for ones containing the aforementioned brown rice/sweet potato. Cold pressed foods tend to be high in fibre and may be worth looking at.
Please post back if you need further advice or require help with the Dog Food Directory.