Updating ghost
A reminder that Docker isn't just "set it and forget it"
In a previous post, I discussed setting up this blog, around a year and a half ago. In that time, much has changed in my life and much has changed on the Ghost github repository.
TryGhostThese past few days, I've got loads more time than before and I suddenly got the urge to post on my blog again, when I was greeted with a message to the tune of "You are running an outdated version of Ghost, which is very vulnerable. Update immediately!". At first I ignored the message and went on writing a post, but it kept nagging me. In the end, I conceded and went to fix the issue - it's just a docker container, I thought to myself, it should be simple.
It wasn't that simple.
The first issue I ran into was that I couldn't find the docker-compose file anywhere on my server. Then I realized I hadn't yet used docker-compose at that time, and realized I stored all my docker run commands in text files on my laptop... :/
Fortunately, it was easy enough to find on my laptop, and I decided to place it directly on the server next to ghost's files, named docker-config.sh. Now whenever I need to change anything in the config, it's as easy as stopping, deleting the container and running bash docker-config.sh. (now that I think about it, the first two tasks could be automated as well...)
So, everything solved, let's just run docker pull ghost:latest and start the container, and it should just work, right? I reloaded the webpage in anticipation, but nothing happened... I checked the container's status with docker ps -a and saw it was returning a "Restart (2)" error. After a tiny amount of googling I found this very neat command that allows me to see what's going on in the container's logs. sudo docker logs --tail 50 --follow --timestamps ghost
Balessan
I quickly discovered the issue: ghost had gone through multiple major versions in the time I was busy, and it couldn't migrate to the latest version. I somehow "forgot" Docker is just an abstraction layer, and underneath it is still a living, breathing, in development app, that has its own quirks and peculiarities.
The solution: cautiously update from one version to the next. To find the versions I was going to need, I used a feature of docker hub I just discovered, looking up all the possible tags in the tags tab. I first began with the last 3.x.x version, it being 3.42.9. After it successfully spun up, I shut it down and moved to the next version by date (4.3.3), then the last 4.0 version (4.48.2) and then to the latest version (5.2.3). I used the above log tracing command each time to check that it updated properly.
I also learned that using the latest tag isn't the best idea and that it's probably safer to always specify a version. ;)