docker

Name: docker
Author: avibebuilder

109stars17forks

How to install docker?

avibebuilder/claude-prime/docker

$npx -y skills add avibebuilder/claude-prime --skill docker

Installs into the current project.

Summary

ALWAYS activate when the user's query involves Docker in any way — even if it also matches other skills. If the words docker, Dockerfile, docker-compose, compose.yml, container, or image appear in the query, this skill MUST be used. Covers: writing or editing Dockerfiles and comp

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SKILL.md

1	# Docker
2
3	Project-specific containerization patterns for Dockerfile and Docker Compose.
4
5	## Architecture Decisions
6
7	### Image Building
8	1. Minimal base images — Use slim/alpine variants; pin to digest for reproducibility.
9	2. Multi-stage builds — Separate build dependencies from runtime.
10	3. Layer optimization — Combine RUN commands; place frequently changed files last.
11	4. COPY over ADD — ADD only for tar extraction or remote URLs.
12
13	### Security
14	5. Non-root users — Always use UID >10000; never run as root in production.
15	6. No secrets in images — Use Docker secrets or runtime env injection.
16	7. .dockerignore required — Exclude .git, .env, node_modules, build artifacts.
17
18	### Runtime
19	8. One process per container — Single responsibility principle.
20	9. Healthchecks required — Define HEALTHCHECK in Dockerfile or Compose.
21	10. Resource limits — Always set mem_limit and cpus in production.
22
23	### Compose
24	11. Network segmentation — Dedicated networks per service group.
25	12. Named volumes — Never use anonymous volumes in production.
26	13. depends_on with healthchecks — Use `condition: service_healthy`.
27	14. Environment separation — Use override files for dev/staging/prod.
28
29	## Gotchas
30
31	- `COPY . .` before `RUN npm install` busts the cache on EVERY code change. Copy `package*.json` first, install, THEN copy source.
32	- Alpine uses musl libc, not glibc. Python packages with C extensions (numpy, pandas, cryptography) may fail to install or need `apk add` build dependencies. Consider `-slim` variants if you hit this.
33	- `ENTRYPOINT ["python", "app.py"]` (exec form) handles signals correctly. `ENTRYPOINT python app.py` (shell form) wraps in `/bin/sh -c` and PID 1 won't receive SIGTERM — containers take 10s to stop.
34	- Docker layer cache is invalidated from the FIRST changed layer downward. A changed `COPY` near the top rebuilds everything below it.
35	- `depends_on` without `condition: service_healthy` only waits for container START, not readiness. Your app will crash connecting to a database that's still initializing.
36	- `host.docker.internal` works on Docker Desktop (Mac/Windows) but NOT on Linux. Use `--network host` or explicit container networking on Linux.
37	- Build args (`ARG`) are NOT available after `FROM` in multi-stage builds unless re-declared. Each stage starts fresh.
38	- `docker compose up` reuses existing containers. After changing `Dockerfile`, you need `docker compose up --build` or `docker compose build` first.
39	- Volume mounts override the container's filesystem — if your `node_modules` are built inside the container but you mount `.:/app`, the host's (possibly empty) `node_modules` shadows them. Use a named volume for `node_modules`.
40	- `EXPOSE` is documentation only — it does NOT publish the port. You still need `-p 8080:8080` or `ports:` in compose.
41	- Docker's default bridge network does NOT provide DNS resolution between containers. Use a custom network or compose's default network.
42
43	## References
44
45	\| When you need... \| Read \|
46	\|------------------\|------\|
47	\| Dockerfile patterns, CMD vs ENTRYPOINT \| [dockerfile.md](./references/dockerfile.md) \|
48	\| Compose services, networks, volumes \| [compose.md](./references/compose.md) \|
49	\| Security hardening \| [security.md](./references/security.md) \|
50	\| Production deployment \| [production.md](./references/production.md) \|

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6 picks

Type

docker

109stars17forks

View on GitHub

How to install docker?

avibebuilder/claude-prime/docker

$npx -y skills add avibebuilder/claude-prime --skill docker

Installs into the current project.

Summary

Files · 1

View on GitHub

SKILL.md

1	# Docker
2
3	Project-specific containerization patterns for Dockerfile and Docker Compose.
4
5	## Architecture Decisions
6
7	### Image Building
8	1. Minimal base images — Use slim/alpine variants; pin to digest for reproducibility.
9	2. Multi-stage builds — Separate build dependencies from runtime.
10	3. Layer optimization — Combine RUN commands; place frequently changed files last.
11	4. COPY over ADD — ADD only for tar extraction or remote URLs.
12
13	### Security
14	5. Non-root users — Always use UID >10000; never run as root in production.
15	6. No secrets in images — Use Docker secrets or runtime env injection.
16	7. .dockerignore required — Exclude .git, .env, node_modules, build artifacts.
17
18	### Runtime
19	8. One process per container — Single responsibility principle.
20	9. Healthchecks required — Define HEALTHCHECK in Dockerfile or Compose.
21	10. Resource limits — Always set mem_limit and cpus in production.
22
23	### Compose
24	11. Network segmentation — Dedicated networks per service group.
25	12. Named volumes — Never use anonymous volumes in production.
26	13. depends_on with healthchecks — Use `condition: service_healthy`.
27	14. Environment separation — Use override files for dev/staging/prod.
28
29	## Gotchas
30
31	- `COPY . .` before `RUN npm install` busts the cache on EVERY code change. Copy `package*.json` first, install, THEN copy source.
32	- Alpine uses musl libc, not glibc. Python packages with C extensions (numpy, pandas, cryptography) may fail to install or need `apk add` build dependencies. Consider `-slim` variants if you hit this.
33	- `ENTRYPOINT ["python", "app.py"]` (exec form) handles signals correctly. `ENTRYPOINT python app.py` (shell form) wraps in `/bin/sh -c` and PID 1 won't receive SIGTERM — containers take 10s to stop.
34	- Docker layer cache is invalidated from the FIRST changed layer downward. A changed `COPY` near the top rebuilds everything below it.
35	- `depends_on` without `condition: service_healthy` only waits for container START, not readiness. Your app will crash connecting to a database that's still initializing.
36	- `host.docker.internal` works on Docker Desktop (Mac/Windows) but NOT on Linux. Use `--network host` or explicit container networking on Linux.
37	- Build args (`ARG`) are NOT available after `FROM` in multi-stage builds unless re-declared. Each stage starts fresh.
38	- `docker compose up` reuses existing containers. After changing `Dockerfile`, you need `docker compose up --build` or `docker compose build` first.
39	- Volume mounts override the container's filesystem — if your `node_modules` are built inside the container but you mount `.:/app`, the host's (possibly empty) `node_modules` shadows them. Use a named volume for `node_modules`.
40	- `EXPOSE` is documentation only — it does NOT publish the port. You still need `-p 8080:8080` or `ports:` in compose.
41	- Docker's default bridge network does NOT provide DNS resolution between containers. Use a custom network or compose's default network.
42
43	## References
44
45	\| When you need... \| Read \|
46	\|------------------\|------\|
47	\| Dockerfile patterns, CMD vs ENTRYPOINT \| [dockerfile.md](./references/dockerfile.md) \|
48	\| Compose services, networks, volumes \| [compose.md](./references/compose.md) \|
49	\| Security hardening \| [security.md](./references/security.md) \|
50	\| Production deployment \| [production.md](./references/production.md) \|

People who liked this also viewed

6 picks

Type