diff --git a/docs/index.html b/docs/index.html index 78614e90..91af20c0 100644 --- a/docs/index.html +++ b/docs/index.html @@ -2590,6 +2590,509 @@ https://hub.docker.com/r/jpetazzo/dockercoins_worker/tags/) --- +# Scripting image building and pushing + +- Earlier, we used some rather crude shell loops to build and push images + +- Compose (and clever environment variables) can help us to make that easier + +- When using Compose file version 2, you can specify *both* `build` and `image`: + +```yaml +version: "2" + +services: + + webapp: + build: src/ + image: jpetazzo/webapp:${TAG} +``` + +Note: Compose tolerates empty (or unset) environment variables, but in this example, +`TAG` *must* be set, because `jpetazzo/webapp:` is not a valid image name. + +--- + +## Updating the Compose file to specify image tags + +- Let's update the Compose file for DockerCoins to make it easier to push it to our registry + +.exercise[ + +- Go back to the `dockercoins` directory: + ```bash + cd ~/orchestration-workshop/dockercoins + ``` + +- Edit `docker-compose.yml`, and update each service to add an `image` directive as follows: + ```yaml + rng: + build: rng + `image: ${REGISTRY_SLASH}rng${COLON_TAG}` + ``` + +] + +You can also directly use the file `docker-compose.yml-images`. + +--- + +## Use the new Compose file + +- We need to set `REGISTRY_SLASH` and `COLON_TAG` variables + +- Then we can use Compose to `build` and `push` + +.exercise[ + +- Set environment variables: + ```bash + export REGISTRY_SLASH=localhost:5000/ + export COLON_TAG=:v0.01 + ``` + +- Build and push with Compose: + ```bash + docker-compose build + docker-compose push + ``` + +] + +--- + +## Why the weird variable names? + +- It would be more intuitive to have: + ```bash + REGISTRY=localhost:5000 + TAG=v0.01 + ``` + +- But then, when the variables are not set, the image names would be invalid + + (they would look like .red[`/rng:`]) + +- Putting the slash and the colon in the variables allows to use the Compose file + even when the variables are not set + +- The variable names (might) remind you that you have to put the trailing slash and heading colon + +--- + +# Integration with Compose + +- The previous section showed us how to streamline image build and push + +- We will now see how to streamline service creation + + (i.e. get rid of the `for SERVICE in ...; do docker service create ...` part) + +--- + +## Compose file version 3 + +(New in Docker Engine 1.13) + +- Almost identical to version 2 + +- Can be directly used by a Swarm cluster through `docker stack ...` commands + +- Introduces a `deploy` section to pass Swarm-specific parameters + +- Resource limits are moved to this `deploy` section + +- See [here](https://github.com/aanand/docker.github.io/blob/8524552f99e5b58452fcb1403e1c273385988b71/compose/compose-file.md#upgrading) for the complete list of changes + +- Supersedes *Distributed Application Bundles* + + (JSON payload describing an application; could be generated from a Compose file) + +--- + +## Removing everything + +- Before deploying using "stacks," let's get a clean slate + +.exercise[ + +- Remove *all* the services: + ```bash + docker service ls -q | xargs docker service rm + ``` + +] + +--- + +## Our first stack + +We need a registry to move images around. + +Before, we deployed it with the following command: + +```bash +docker service create --publish 5000:5000 registry:2 +``` + +Now, we are going to deploy it with the following stack file: + +```yaml +version: "3" + +services: + registry: + image: registry:2 + ports: + - "5000:5000" +``` + +--- + +## Checking our stack files + +- All the stack files that we will use are in the `stacks` directory + +.exercise[ + +- Go to the `stacks` directory: + ```bash + cd ~/orchestration-workshop/stacks + ``` + +- Check `registry.yml`: + ```bash + cat registry.yml + ``` + +] + +--- + +## Deploying our first stack + +- All stack manipulation commands start with `docker stack` + +- Under the hood, they map to `docker service` commands + +- Stacks have a *name* (which also serves as a namespace) + +- Stacks are specified with the aforementioned Compose file format version 3 + +.exercise[ + +- Deploy our local registry: + ```bash + docker stack deploy registry --compose-file registry.yml + ``` + +] + +--- + +## Inspecting stacks + +- `docker stack ps` shows the detailed state of all services of a stack + +.exercise[ + +- Check that our registry is running correctly: + ```bash + docker stack ps registry + ``` + +- Confirm that we get the same output with the following command: + ```bash + docker service ps registry_registry + ``` + +] + +--- + +## Specifics of stack deployment + +Our registry is not *exactly* identical to the one deployed with `docker service create`! + +- Each stack gets its own overlay network + +- Services of the task are connected to this network +
(unless specified differently in the Compose file) + +- Services get network aliases matching their name in the Compose file +
(just like when Compose brings up an app specified in a v2 file) + +- Services are explicitly named `_` + +- Services and tasks also get an internal label indicating which stack they belong to + +--- + +## Building and pushing stack services + +- We are going to use the `build` + `image` trick that we showed earlier: + + ```bash + docker-compose -f my_stack_file.yml build + docker-compose -f my_stack_file.yml push + docker stack deploy my_stack --compose-file my_stack_file.yml + ``` + +.exercise[ + +- Try it: + ```bash + docker-compose -f dockercoins.yml build + ``` + +] + +-- + +If it doesn't work, make sure that you have Compose 1.10. + +--- + +## Upgrading Compose + +- This is only necessary if you have an older version of Compose + +.exercise[ + +- Upgrade Compose, using the `master` branch: + ```bash + pip install git+git://github.com/docker/compose + ``` + +- Re-hash our `$PATH`: + ```bash + hash docker-compose + ``` + +] + +--- + +## Trying again + +- We can now build and push our container images + +.exercise[ + +- Build our application: + ```bash + docker-compose -f dockercoins.yml build + ``` + +- Push the images to our registry: + ```bash + docker-compose -f dockercoins.yml push + ``` + +] + +Let's have a look at the `dockercoins.yml` file while this is building and pushing. + +--- + +```yaml +version: "3" + +services: + rng: + build: dockercoins/rng + image: ${REGISTRY_SLASH-localhost:5000/}rng${COLON_TAG-:latest} + deploy: + mode: global + ... + redis: + image: redis + ... + worker: + build: dockercoins/worker + image: ${REGISTRY_SLASH-localhost:5000/}worker${COLON_TAG-:latest} + ... + deploy: + replicas: 10 +``` + +??? + +## What's this `logging` section? + +- This application stack is setup to send logs to a local GELF receiver + +- We will use another "ready-to-use" Compose file to deploy an ELK stack + +- We won't give much more details about the ELK stack right now + + (But there is a chapter dedicated to it in another part!) + +- A given container can have only one logging driver at a time (for now) + +- As a result, the `gelf` driver is superseding the default `json-file` driver + +- ... Which means that the output of these containers won't show up in `docker logs` + +--- + +## Deploying the application + +- Now that the images are on the registry, we can deploy our application stack + +.exercise[ + +- Create the application stack: + ```bash + docker stack deploy dockercoins --compose-file dockercoins.yml + ``` + +] + +We can now connect to any of our nodes on port 8000, and we will see the familiar hashing speed graph. + +??? + +## Deploying the logging stack + +- We are going to deploy an ELK stack + +- We won't tell you much more about ELK (for now!) + +.exercise[ + +- Deploy the logging stack: + ```bash + docker stack deploy elk --compose-file elk.yml + ``` + +] + +??? + +## Accessing the logging stack + +- At the end of `elk.yml`, we have: + +```yaml + kibana: + image: kibana:4 + ports: + - "5601:5601" + environment: + ELASTICSEARCH_URL: http://elasticsearch:9200 +``` + +- Kibana (the web frontend for the logging stack) is exposed on port 5601 + +.exercise[ + +- With your web browser, connect to port 5601 + +- Click around until you see your containers' logs! + +] + +??? + +.exercise[ + +- Deploy Prometheus, cAdvisor, and the node exporter, just like we deployed DockerCoins: + ```bash + docker-compose -f prometheus.yml build + docker-compose -f prometheus.yml push + docker stack deploy prometheus --compose-file prometheus.yml + ``` + +] + +Look at `prometheus.yml` while it's building and pushing. + +??? + +```yaml +version: "3" + +services: + + prometheus: + build: ../prom + image: localhost:5000/prom + ports: + - "9090:9090" + + node: + ... + + cadvisor: + image: google/cadvisor + deploy: + mode: global + volumes: + - "/:/rootfs" + - "/var/run:/var/run" + - "/sys:/sys" + - "/var/lib/docker:/var/lib/docker" +``` + +??? + +## Accessing our new metrics stack + +.exercise[ + +- Go to any node, port 9090 + +- Check that data scraping works (click on "status", then "targets") + +- Select a metric from the "insert metric at cursor" dropdown + +- Execute! + +] + +--- + +## Maintaining multiple environments + +There are many ways to handle variations between environments. + +- Compose loads `docker-compose.yml` and (if it exists) `docker-compose.override.yml` + +- Compose can load alternate file(s) by setting the `-f` flag or the `COMPOSE_FILE` environment variable + +- Compose files can *extend* other Compose files, selectively including services: + + ```yaml + web: + extends: + file: common-services.yml + service: webapp + ``` + +See [this documentation page](https://docs.docker.com/compose/extends/) for more details about these techniques. + + +--- + +## Good to know ... + +- Compose file version 3 adds the `deploy` section + +- Compose file version 3.1 adds support for secrets + +- You can re-run `docker stack deploy` to update a stack + +- ... But unsupported features will be wiped each time you redeploy (!) + + (This will likely be fixed/improved soon) + +- `extends` doesn't work with `docker stack deploy` + + (But you can use `docker-compose config` to "flatten" your configuration) + +--- + ## Summary - We've seen how to set up a Swarm @@ -2602,6 +3105,8 @@ https://hub.docker.com/r/jpetazzo/dockercoins_worker/tags/) - We've deployed and scaled our application +- We've seen how to use Compose to streamline deployments + - Awesome job, team! --- @@ -2614,9 +3119,46 @@ Part 2 --- -class: title +## Before we start ... -# Operating the Swarm +The following exercises assume that you have a 5-nodes Swarm cluster. + +If you come here from a previous tutorial and still have your cluster: great! + +Otherwise: check [part 1](#part-1) to learn how to setup your own cluster. + +We pick up exactly where we left you, so we assume that you have: + +- a five nodes Swarm cluster, + +- a self-hosted registry, + +- DockerCoins up and running. + +The next slide has a cheat sheet if you need to set that up in a pinch. + +--- + +## Catching up + +Assuming you have 5 nodes provided by +[Play-With-Docker](http://www.play-with-docker/), do this from `node1`: + +```bash +docker swarm init --advertise-addr eth0 +TOKEN=$(docker swarm join-token -q manager) +for N in $(seq 2 5); do + DOCKER_HOST=tcp://node$N:2375 docker swarm join --token $TOKEN node1:2377 +done +git clone git://github.com/jpetazzo/orchestration-workshop +cd orchestration-workshop/stacks +docker stack deploy --compose-file registry.yml registry +docker-compose -f dockercoins.yml build +docker-compose -f dockercoins.yml push +docker stack deploy --compose-file dockercoins.yml dockercoins +``` + +You should now be able to connect to port 8000 and see the DockerCoins web UI. --- @@ -2652,7 +3194,7 @@ class: title - Start a "do nothing" container using our favorite Swiss-Army distro: ```bash - docker service create --network dockercoins --name debug --mode global \ + docker service create --network dockercoins_default --name debug --mode global \ alpine sleep 1000000000 ``` @@ -2817,7 +3359,7 @@ This should list 5 IP addresses. - Open another window, and stop the workers, to test in isolation: ```bash - docker service update worker --replicas 0 + docker service update dockercoins_worker --replicas 0 ``` ] @@ -3067,7 +3609,7 @@ WHY?!? Seeing tons of HTTP request? Shutdown your DockerCoins workers: ```bash -docker service update worker --replicas=0 +docker service update dockercoins_worker --replicas=0 ``` --- @@ -3173,8 +3715,8 @@ However, when you run the second one, only `#` will show up. - Build the new image: ```bash - IMAGE=localhost:5000/dockercoins_worker:v0.01 - docker build -t $IMAGE worker + IMAGE=localhost:5000/worker:v0.01 + docker build -t $IMAGE ~/orchestration-workshop/dockercoins/worker ``` - Push it to the registry: @@ -3218,12 +3760,12 @@ Note how the build and push were fast (because caching). - In the other window, bring back the workers (if you had stopped them earlier): ```bash - docker service update worker --replicas 10 + docker service update dockercoins_worker --replicas 10 ``` - Then, update the service to the new image: ```bash - docker service update worker --image $IMAGE + docker service update dockercoins_worker --image $IMAGE ``` ] @@ -3242,7 +3784,8 @@ By default, SwarmKit does a rolling upgrade, one instance at a time. - Change the parallelism to 2 and the delay to 5 seconds: ```bash - docker service update worker --update-parallelism 2 --update-delay 5s + docker service update dockercoins_worker \ + --update-parallelism 2 --update-delay 5s ``` ] @@ -3259,12 +3802,13 @@ The current upgrade will continue at a faster pace. - Rollback to the previous image: ```bash - docker service update worker --image $DOCKER_REGISTRY/dockercoins_worker:v0.1 + docker service update dockercoins_worker \ + --image $DOCKER_REGISTRY/dockercoins_worker:v0.1 ``` - With Docker 1.13, we can also revert to the previous service specification: ```bash - docker service update worker --rollback + docker service update dockercoins_worker --rollback ``` ] @@ -3594,7 +4138,7 @@ Wait for the service to be fully updated with e.g. `watch docker service ps dumm docker service update ... --secret-rm foo.M --secret-add source=foo.N,target=foo ``` -- For more details and examples, [check the upcoming documentation](https://github.com/docker/docker.github.io/pull/568) +- For more details and examples, [check the documentation](https://docs.docker.com/engine/swarm/secrets/) --- @@ -3934,10 +4478,7 @@ What we will do: docker service ps logstash ``` -- Log into that node: - ```bash - ssh nodeX - ``` +- Connect to that node ] @@ -4043,9 +4584,15 @@ You can also set `--restart-delay`, `--restart-max-attempts`, and `--restart-win - The Kibana web UI is exposed on cluster port 5601 -- Open the UI in your browser: http://instance-address:5601/ +.exercise[ - (Remember: you can use any instance address!) +- Connect to port 5601 of your cluster + + - if you're using Play-With-Docker, click on the (5601) badge above the terminal + + - otherwise, open http://(any-node-address):5601/ with your browser + +] --- @@ -4083,7 +4630,7 @@ You can also set `--restart-delay`, `--restart-max-attempts`, and `--restart-win - Enable GELF logging for all our *stateless* services: ```bash for SERVICE in hasher rng webui worker; do - docker service update $SERVICE \ + docker service update dockercoins_$SERVICE \ --log-driver gelf --log-opt gelf-address=udp://127.0.0.1:12201 done ``` @@ -4537,6 +5084,23 @@ To exit, hit `^C` ## Running Snap itself on every node +- Snap runs in the foreground, so you need to use `&` or start it in tmux + +.exercise[ + +- Run the following command *on every node:* + ```bash + snapd -t 0 -l 1 --tribe --tribe-seed node1:6000 + ``` + +] + +If you're *not* using Play-With-Docker, there is another way to start Snap! + +--- + +## Starting a daemon through SSH + .warning[Hackety hack ahead!] - We will create a *global service* @@ -4569,6 +5133,8 @@ To exit, hit `^C` ] +Remember: this *does not work* with Play-With-Docker (which doesn't have SSH). + --- ## Viewing the members of our tribe @@ -4703,7 +5269,7 @@ this breaks a few things.] .exercise[ -- Connect to http://any.node.address:8083/ +- Open port 8083 with your browser - Enter the following query in the query box: ``` @@ -4846,7 +5412,7 @@ the task (it will delete+re-create on all nodes). .exercise[ -- Go to http://any.node.address:3000/ +- Open port 3000 with your browser - Identify with "admin" as the username and password @@ -4869,7 +5435,7 @@ Fill the form exactly as follows: - Type = "InfluxDB" In HTTP settings, fill as follows: -- Url = "http://any.node.address:8086" +- Url = "http://(IP.address.of.any.node):8086" - Access = "direct" - Leave HTTP Auth untouched @@ -5147,7 +5713,7 @@ scrape_configs: .exercise[ -- Connect to `http://:9090` +- Open port 9090 with your browser - Click on "status", then "targets" @@ -5324,7 +5890,7 @@ We see the same input form that we filled earlier to connect to InfluxDB. - Select "Prometheus" as the source type -- Enter http://(node IP address):9090 in the Url field +- Enter http://(IP.address.of.any.node):9090 in the Url field - Select "direct" as the access method @@ -5723,466 +6289,6 @@ Note: we could keep the volume around if we wanted. --- -# Scripting image building and pushing - -- Earlier, we used some rather crude shell loops to build and push images - -- Compose (and clever environment variables) can help us to make that easier - -- When using Compose file version 2, you can specify *both* `build` and `image`: - -```yaml -version: "2" - -services: - - webapp: - build: src/ - image: jpetazzo/webapp:${TAG} -``` - -Note: Compose tolerates empty (or unset) environment variables, but in this example, -`TAG` *must* be set, because `jpetazzo/webapp:` is not a valid image name. - ---- - -## Updating the Compose file to specify image tags - -- Let's update the Compose file for DockerCoins to make it easier to push it to our registry - -.exercise[ - -- Go back to the `dockercoins` directory: - ```bash - cd ~/orchestration-workshop/dockercoins - ``` - -- Edit `docker-compose.yml`, and update each service to add an `image` directive as follows: - ```yaml - rng: - build: rng - `image: ${REGISTRY_SLASH}rng${COLON_TAG}` - ``` - -] - -You can also directly use the file `docker-compose.yml-images`. - ---- - -## Use the new Compose file - -- We need to set `REGISTRY_SLASH` and `COLON_TAG` variables - -- Then we can use Compose to `build` and `push` - -.exercise[ - -- Set environment variables: - ```bash - export REGISTRY_SLASH=localhost:5000/ - export COLON_TAG=:v0.01 - ``` - -- Build and push with Compose: - ```bash - docker-compose build - docker-compose push - ``` - -] - ---- - -## Why the weird variable names? - -- It would be more intuitive to have: - ```bash - REGISTRY=localhost:5000 - TAG=v0.01 - ``` - -- But then, when the variables are not set, the image names would be invalid - - (they would look like .red[`/rng:`]) - -- Putting the slash and the colon in the variables allows to use the Compose file - even when the variables are not set - -- The variable names (might) remind you that you have to put the trailing slash and heading colon - ---- - -# Integration with Compose - -- The previous section showed us how to streamline image build and push - -- We will now see how to streamline service creation - - (i.e. get rid of the `for SERVICE in ...; do docker service create ...` part) - -.warning[This is experimental and subject to change!] - ---- - -## Compose file version 3 - -(New in Docker Engine 1.13) - -- Almost identical to version 2 - -- Can be directly used by a Swarm cluster through `docker stack ...` commands - -- Introduces a `deploy` section to pass Swarm-specific parameters - -- Resource limits are moved to this `deploy` section - -- See [here](https://github.com/aanand/docker.github.io/blob/8524552f99e5b58452fcb1403e1c273385988b71/compose/compose-file.md#upgrading) for the complete list of changes - -- Supersedes *Distributed Application Bundles* - - (JSON payload describing an application; could be generated from a Compose file) - ---- - -## Removing everything - -- Before deploying using "stacks," let's get a clean slate - -.exercise[ - -- Remove *all* the services: - ```bash - docker service ls -q | xargs docker service rm - ``` - -] - ---- - -## Our first stack - -We need a registry to move images around. - -Before, we deployed it with the following command: - -```bash -docker service create --publish 5000:5000 registry:2 -``` - -Now, we are going to deploy it with the following stack file: - -```yaml -version: "3" - -services: - registry: - image: registry:2 - ports: - - "5000:5000" -``` - ---- - -## Checking our stack files - -- All the stack files that we will use are in the `stacks` directory - -.exercise[ - -- Go to the `stacks` directory: - ```bash - cd ~/orchestration-workshop/stacks - ``` - -- Check `registry.yml`: - ```bash - cat registry.yml - ``` - -] - ---- - -## Deploying our first stack - -- All stack manipulation commands start with `docker stack` - -- Under the hood, they map to `docker service` commands - -- Stacks have a *name* (which also serves as a namespace) - -- Stacks are specified with the aforementioned Compose file format version 3 - -.exercise[ - -- Deploy our local registry: - ```bash - docker stack deploy registry --compose-file registry.yml - ``` - -] - ---- - -## Inspecting stacks - -- `docker stack ps` shows the detailed state of all services of a stack - -.exercise[ - -- Check that our registry is running correctly: - ```bash - docker stack ps registry - ``` - -- Confirm that we get the same output with the following command: - ```bash - docker service ps registry_registry - ``` - -] - ---- - -## Specifics of stack deployment - -Our registry is not *exactly* identical to the one deployed with `docker service create`! - -- Each stack gets its own overlay network - -- Services of the task are connected to this network -
(unless specified differently in the Compose file) - -- Services get network aliases matching their name in the Compose file -
(just like when Compose brings up an app specified in a v2 file) - -- Services are explicitly named `_` - -- Services and tasks also get an internal label indicating which stack they belong to - ---- - -## Building and pushing stack services - -- We are going to use the `build` + `image` trick that we showed earlier: - - ```bash - docker-compose -f my_stack_file.yml build - docker-compose -f my_stack_file.yml push - docker stack deploy my_stack --compose-file my_stack_file.yml - ``` - -.exercise[ - -- Try it: - ```bash - docker-compose -f dockercoins.yml build - ``` - -] - --- - -If it doesn't work, make sure that you have Compose 1.10. - ---- - -## Upgrading Compose - -- This is only necessary if you have an older version of Compose - -.exercise[ - -- Upgrade Compose, using the `master` branch: - ```bash - pip install git+git://github.com/docker/compose - ``` - -- Re-hash our `$PATH`: - ```bash - hash docker-compose - ``` - -] - ---- - -## Trying again - -- We can now build and push our container images - -.exercise[ - -- Build our application: - ```bash - docker-compose -f dockercoins.yml build - ``` - -- Push the images to our registry: - ```bash - docker-compose -f dockercoins.yml push - ``` - -] - -Let's have a look at the `dockercoins.yml` file while this is building and pushing. - ---- - -```yaml -version: "3" - -services: - rng: - build: dockercoins/rng - image: ${REGISTRY_SLASH-localhost:5000/}rng${COLON_TAG-:latest} - logging: - driver: gelf - options: - gelf-address: udp://localhost:12201 - deploy: - mode: global - ... - redis: - image: redis - ... - worker: - build: dockercoins/worker - image: ${REGISTRY_SLASH-localhost:5000/}worker${COLON_TAG-:latest} - ... - deploy: - replicas: 10 -``` - ---- - -## Deploying the application - -- Now that the images are on the registry, we can deploy our application stack - -.exercise[ - -- Create the application stack: - ```bash - docker stack deploy dockercoins --compose-file dockercoins.yml - ``` - -] - -We can now connect to any of our nodes on port 8000, and we will see the familiar hashing speed graph. - ---- - -## Deploying the metrics stack - -- Remember these super long obscure `docker service create` commands we did earlier? - --- - -- Neither do I! - --- - -.exercise[ - -- Deploy Prometheus, cAdvisor, and the node exporter, just like we deployed DockerCoins: - ```bash - docker-compose -f prometheus.yml build - docker-compose -f prometheus.yml push - docker stack deploy prometheus --compose-file prometheus.yml - ``` - -] - -Look at `prometheus.yml` while it's building and pushing. - ---- - -```yaml -version: "3" - -services: - - prometheus: - build: ../prom - image: localhost:5000/prom - ports: - - "9090:9090" - - node: - ... - - cadvisor: - image: google/cadvisor - deploy: - mode: global - volumes: - - "/:/rootfs" - - "/var/run:/var/run" - - "/sys:/sys" - - "/var/lib/docker:/var/lib/docker" -``` - ---- - -## Accessing our new metrics stack - -.exercise[ - -- Go to any node, port 9090 - -- Check that data scraping works (click on "status", then "targets") - -- Select a metric from the "insert metric at cursor" dropdown - -- Execute! - -] - ---- - -## Caveats - -- Compose file format v3 is very new, and not written in the stone yet - -- It exists because nobody wants to maintain redundant files if they can avoid it - -- Some features are not fully supported yet: - - - logging, see [#29116](https://github.com/docker/docker/issues/29116) - - - secrets - -- You can re-run `docker stack deploy` to update a stack - -- ... But unsupported features will be wiped each time you redeploy (!) - - (This will likely be fixed/improved soon) - ---- - -## Maintaining multiple environments - -There are many ways to handle variations between environments. - -- Compose loads `docker-compose.yml` and (if it exists) `docker-compose.override.yml` - -- Compose can load alternate file(s) by setting the `-f` flag or the `COMPOSE_FILE` environment variable - -- Compose files can *extend* other Compose files, selectively including services: - - ```yaml - web: - extends: - file: common-services.yml - service: webapp - ``` - -See [this documentation page](https://docs.docker.com/compose/extends/) for more details about these techniques. - ---- - # Controlling Docker from a container - In a local environment, just bind-mount the Docker control socket: @@ -6431,7 +6537,7 @@ It makes it easy to come back later and check what has changed since you did it! class: title -# Thanks!
Questions? +# Thanks!