re-arranged for faster builds

[rlc4]

A few changes to the dockerfile to improve the cache hits on subsequent builds for most development changes.
If you are doing development without adding any new node modules or touching package.json, this will remove 2-3 minutes of waiting time for every time you rebuild the docker image.

Previous timing:

First build

❯ time docker build -f Dockerfile -t antest .
[+] Building 151.8s (13/13) FINISHED
=> [internal] load build definition from Dockerfile 0.0s
=> => transferring dockerfile: 359B 0.0s
=> [internal] load .dockerignore 0.0s
=> => transferring context: 34B 0.0s
=> [internal] load metadata for docker.io/library/node:16 0.0s
=> [internal] load build context 0.0s
=> => transferring context: 16.27kB 0.0s
=> CACHED [1/8] FROM docker.io/library/node:16 0.0s
=> [2/8] WORKDIR /src 0.0s
=> [3/8] COPY nav-app/ /src/nav-app/ 0.1s
=> [4/8] COPY layers/*.md /src/layers/ 0.0s
=> [5/8] COPY .md /src/ 0.0s
=> [6/8] WORKDIR /src/nav-app 0.0s
=> [7/8] RUN chown -R node:node ./ 0.6s
=> [8/8] RUN npm install --unsafe-perm 138.6s
=> exporting to image 12.3s
=> => exporting layers 12.3s
=> => writing image sha256:581813171f1b146d7116bad96e9f25459a4f63277e9acbec61e79e3034c069d4 0.0s
=> => naming to docker.io/library/antest 0.0s
docker build -f Dockerfile -t antest . 0.55s user 0.37s system 0% cpu 2:32.35 total

Subsequent builds:

❯ time docker build -f Dockerfile -t antest .
[+] Building 141.9s (13/13) FINISHED
=> [internal] load build definition from Dockerfile 0.0s
=> => transferring dockerfile: 37B 0.0s
=> [internal] load .dockerignore 0.0s
=> => transferring context: 34B 0.0s
=> [internal] load metadata for docker.io/library/node:16 0.0s
=> [internal] load build context 0.0s
=> => transferring context: 16.66kB 0.0s
=> [1/8] FROM docker.io/library/node:16 0.0s
=> CACHED [2/8] WORKDIR /src 0.0s
=> [3/8] COPY nav-app/ /src/nav-app/ 0.2s
=> [4/8] COPY layers/.md /src/layers/ 0.0s
=> [5/8] COPY *.md /src/ 0.0s
=> [6/8] WORKDIR /src/nav-app 0.0s
=> [7/8] RUN chown -R node:node ./ 0.6s
=> [8/8] RUN npm install --unsafe-perm 128.3s
=> exporting to image 12.6s
=> => exporting layers 12.5s
=> => writing image sha256:c8e704cfef0a3947107243b6fab894582c3d587df4e821299ce3500401282714 0.0s
=> => naming to docker.io/library/antest 0.0s
docker build -f Dockerfile -t antest . 0.51s user 0.37s system 0% cpu 2:22.40 total%

Timing after re-arranging the Dockerfile:

First build:

❯ time docker build -f Dockerfile.new -t antest .
[+] Building 189.4s (15/15) FINISHED
=> [internal] load build definition from Dockerfile.new 0.0s
=> => transferring dockerfile: 492B 0.0s
=> [internal] load .dockerignore 0.0s
=> => transferring context: 54B 0.0s
=> [internal] load metadata for docker.io/library/node:16 0.0s
=> [internal] load build context 0.3s
=> => transferring context: 5.90MB 0.2s
=> [ 1/10] FROM docker.io/library/node:16 0.3s
=> [ 2/10] WORKDIR /src/nav-app 0.0s
=> [ 3/10] COPY nav-app/package*.json nav-app/patch-webpack.js . 0.0s
=> [ 4/10] RUN npm install --unsafe-perm 64.5s
=> [ 5/10] RUN chown -R node:node ./ 107.9s
=> [ 6/10] COPY nav-app/ ./ 0.1s
=> [ 7/10] WORKDIR /src 0.0s
=> [ 8/10] COPY layers/.md ./layers/ 0.0s
=> [ 9/10] COPY .md ./ 0.1s
=> [10/10] WORKDIR /src/nav-app 0.0s
=> exporting to image 16.2s
=> => exporting layers 16.2s
=> => writing image sha256:57599cd9b25158cdfb27a8beefafb66324540932cc169fa1065753b89bebd558 0.0s
=> => naming to docker.io/library/antest 0.0s
docker build -f Dockerfile.new -t antest . 0.63s user 0.44s system 0% cpu 3:09.90 total

Subsequent builds:

❯ time docker build -f Dockerfile.new -t antest .
[+] Building 0.5s (15/15) FINISHED
=> [internal] load build definition from Dockerfile.new 0.0s
=> => transferring dockerfile: 41B 0.0s
=> [internal] load .dockerignore 0.0s
=> => transferring context: 34B 0.0s
=> [internal] load metadata for docker.io/library/node:16 0.0s
=> [ 1/10] FROM docker.io/library/node:16 0.0s
=> [internal] load build context 0.0s
=> => transferring context: 16.66kB 0.0s
=> CACHED [ 2/10] WORKDIR /src/nav-app 0.0s
=> CACHED [ 3/10] COPY nav-app/package.json nav-app/patch-webpack.js . 0.0s
=> CACHED [ 4/10] RUN npm install --unsafe-perm 0.0s
=> CACHED [ 5/10] RUN chown -R node:node ./ 0.0s
=> [ 6/10] COPY nav-app/ ./ 0.1s
=> [ 7/10] WORKDIR /src 0.0s
=> [ 8/10] COPY layers/.md ./layers/ 0.0s
=> [ 9/10] COPY *.md ./ 0.0s
=> [10/10] WORKDIR /src/nav-app 0.0s
=> exporting to image 0.1s
=> => exporting layers 0.1s
=> => writing image sha256:b5bd0a4ad4c7d9bb168f98c69b0b299eb002a7089584d7b69fbe0452eea01075 0.0s
=> => naming to docker.io/library/antest 0.0s
docker build -f Dockerfile.new -t antest . 0.19s user 0.13s system 32% cpu 0.982 total%

[sergiuser1]

@jondricek ping

[jondricek]

@seansica would you mind looking into this? Seems possibly fine but I'm just not focusing on Navigator a lot at the moment

[seansica]

Ran some tests yesterday evening to validate your work, @sergiuser1.

Using the current Dockerfile:

1. Using the current Dockerfile image and no cached layers (including the base node:16 image), it took 10m8s.
2. When all layers are cached and the image is rebuilt, it took 14s.
3. When I add a test.md file to the root directory and rebuild, layer 5 is a cache-miss, causing the npm install layer to cache-miss as well. The build took 2m42s.

Using your modified Dockerfile:

1. With layer 1 (FROM node:16) cached and all other layers un-cached, the build took 4m7s.
2. When I perform the same test previously mentioned (Step 3: add a test.md file to the root directory), the npm install layer did not cache-miss as it previously did. The build took 20s.

This change looks like a solid improvement and is reasonable to merge. The team will review your PR next week and, assuming no objections arise, should approve your pull request.

[clemiller]

Thank you for your contributions!

[rlc4]

Glad to have helped! Hopefully this makes development more enjoyable and efficient.