apk Package Manager on Alpine Linux

apk is Alpine's package manager — short for "Alpine Package Keeper." Tiny, fast, and the right tool to know if you ever build a Dockerfile that starts with FROM alpine.

Prerequisites

• Alpine Linux 3.x with sudo or root.

Step 1: Sync and upgrade

apk update              # refresh index
apk upgrade             # upgrade everything
apk upgrade -a          # also handle replaces/swaps

Step 2: Install, remove, search

apk add nginx curl htop
apk del unused-pkg
apk search redis
apk info redis              # what is installed
apk info -L nginx | head    # files owned by nginx
apk info --who-owns /etc/nginx/nginx.conf
apk info -v | head          # everything installed with version

Step 3: Repository tags

Alpine ships main (core, supported) and community (everything else). Edit /etc/apk/repositories:

https://dl-cdn.alpinelinux.org/alpine/v3.20/main
https://dl-cdn.alpinelinux.org/alpine/v3.20/community

# Edge — bleeding edge, do not mix with stable
# https://dl-cdn.alpinelinux.org/alpine/edge/main
# https://dl-cdn.alpinelinux.org/alpine/edge/community
# https://dl-cdn.alpinelinux.org/alpine/edge/testing

After editing, apk update.

To pull a single package from edge without switching the whole system:

apk add --no-cache --repository https://dl-cdn.alpinelinux.org/alpine/edge/community new-package

Step 4: Virtual packages — group installs/removes

apk add --virtual .build-deps gcc musl-dev make
# ... build something ...
apk del .build-deps

This is the standard Dockerfile pattern — install build dependencies as one virtual package, then delete the whole group after building.

Step 5: Holds and policy

apk version              # what is installed vs available
apk version -l '<'       # only show installs that are behind
apk hold nginx           # pin nginx so upgrades skip it
apk unhold nginx
apk policy nginx         # which repo a package would come from

Step 6: Local cache and clean

apk cache clean
apk cache --purge
apk audit                 # list locally modified config files

For Docker images especially:

apk add --no-cache curl   # skip the local index cache entirely

--no-cache is the right flag in containers — it saves ~5 MB per image layer.

Verify

apk stats
apk verify
apk dot --installed | head    # dependency graph (graphviz format)

Conclusion

apk's surface area is small on purpose. apk add, apk del, apk update && apk upgrade, and --virtual for build deps — that is the full daily toolkit.

Next steps

• Install Alpine first via 5-minute install.
• See Alpine in Docker for the container patterns.
• For glibc distros see Debian Nginx.