diff --git a/content/posts/digging-through-docker-volumes/index.md b/content/posts/digging-through-docker-volumes/index.md index 9dc3f0f..be64f67 100644 --- a/content/posts/digging-through-docker-volumes/index.md +++ b/content/posts/digging-through-docker-volumes/index.md @@ -14,11 +14,11 @@ showFullContent: false This article is only relevant if you know about and use Docker volumes and have some fluency in bash. I'll explain the code as I go, if it helps. ## The Problem -Over the lifetime of a Docker host machine, it's like that orphaned volumes ( and other detritus ) will accumulate over time. You might also find yourself fumbling a configuration and orphaning a volume yourself. +Over the lifetime of a Docker host machine, it's likely that orphaned volumes and other detritus will accumulate over time. You might find yourself fumbling a configuration and orphaning a volume yourself. However we got here, we have a bunch of volumes and we need to know if any of them are important. In a perfect world, they'll have decent names. -However we got here, we have a bunch of volumes and we need to know if any of them are important. In a perfect world, they'll have decent names. We don't live in a perfect world. +We don't live in a perfect world. ## Make a list -Luckily, we have tools at our disposal to handle this. My thought process almost always starts with "Can I turn a list of the things I care about into a newline separated list?" If I can do that, I can start automating my troubleshooting. +Luckily, we have tools at our disposal to handle this. My thought process almost always starts with "Can I make a newline separated list of the things I care about?" If I can do that, I can start automating my troubleshooting. Let's start with `docker volume ls`. This is how we list volumes, but the default output isn't quite what I'm looking for: ``` @@ -29,7 +29,7 @@ local grafana-storage local plausible_db-data local plausible_event-data ``` -This is human readable, and we could even do some slicing with `cut` or `awk`, but Docker gives us a flag that will take us exactly where we need to go: `--format`. Generally, Docker uses Go's `text/template` library to back this feature, and more specifically, individual flags (usually) [document](https://docs.docker.com/reference/cli/docker/volume/ls/#format) the template verbs available. Here, we want `Name`. +This is human readable, and we could even do some slicing with `cut` or `awk`, but Docker gives us a flag that will take us exactly where we need to go: `--format`. Docker uses Go's `text/template` library to power this feature and individual flags (usually) [document](https://docs.docker.com/reference/cli/docker/volume/ls/#format) the template verbs available. Here, we want `Name`. ``` docker volume ls --format "{{.Name}}" d35fce052fbce42b94b2f9b2957be0f77090fa006b1a192030eff07db3675af2 @@ -38,7 +38,7 @@ plausible_db-data plausible_event-data ``` -And now we have a newline separated list of volume names. +We now have a newline separated list of volume names. ## Process of elimination The next part is fairly straightforward. We loop over this list and ask Docker to create a temporary container based on alpine, with a single volume mounted at `/test/`. ```