CircleCI: add some info steps, and re-group jobs

This patch:

- Combines the shellcheck and lint stages. Free CircleCI plans allow a maximum
  of 4 concurrent jobs, and from the timing, the "lint" and "shellcheck" stages
  combined would still take less time than the other stages, so combining them
  keeps the same overall duration, but saving one machine "slot".
- Splits some steps, so that their output can be found more easily in the CI
  results. For example, separating building of Docker images from running them.
- Adds a "Docker info" step, because information about the environment can be
  useful when debugging.
- Adds the "Docker info" and "Docker version" steps to all stages, so that it's
  possible to get that information without having to find the stage in which
  it's printed.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit 937e65cac5)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

circle.yml

@@ -14,11 +14,27 @@ jobs:
           reusable: true
           exclusive: false
       - run:
+          name: "Docker version"
           command: docker version
+      - run:
+          name: "Docker info"
+          command: docker info
+      - run:
+          name: "Shellcheck - build image"
+          command: |
+            docker build --progress=plain -f dockerfiles/Dockerfile.shellcheck --tag cli-validator:$CIRCLE_BUILD_NUM .
+      - run:
+          name: "Shellcheck"
+          command: |
+            docker run --rm cli-validator:$CIRCLE_BUILD_NUM \
+                make shellcheck
+      - run:
+          name: "Lint - build image"
+          command: |
+            docker build --progress=plain -f dockerfiles/Dockerfile.lint --tag cli-linter:$CIRCLE_BUILD_NUM .
       - run:
           name: "Lint"
           command: |
-            docker build --progress=plain -f dockerfiles/Dockerfile.lint --tag cli-linter:$CIRCLE_BUILD_NUM .
             docker run --rm cli-linter:$CIRCLE_BUILD_NUM
 
   cross:
@@ -34,9 +50,18 @@ jobs:
           reusable: true
           exclusive: false
       - run:
-          name: "Cross"
+          name: "Docker version"
+          command: docker version
+      - run:
+          name: "Docker info"
+          command: docker info
+      - run:
+          name: "Cross - build image"
           command: |
             docker build --progress=plain -f dockerfiles/Dockerfile.cross --tag cli-builder:$CIRCLE_BUILD_NUM .
+      - run:
+          name: "Cross"
+          command: |
             name=cross-$CIRCLE_BUILD_NUM-$CIRCLE_NODE_INDEX
             docker run \
                 -e CROSS_GROUP=$CIRCLE_NODE_INDEX \
@@ -60,10 +85,19 @@ jobs:
           reusable: true
           exclusive: false
       - run:
-          name: "Unit Test with Coverage"
+          name: "Docker version"
+          command: docker version
+      - run:
+          name: "Docker info"
+          command: docker info
+      - run:
+          name: "Unit Test with Coverage - build image"
           command: |
             mkdir -p test-results/unit-tests
             docker build --progress=plain -f dockerfiles/Dockerfile.dev --tag cli-builder:$CIRCLE_BUILD_NUM .
+      - run:
+          name: "Unit Test with Coverage"
+          command: |
             docker run \
                 -e GOTESTSUM_JUNITFILE=/tmp/junit.xml \
                 --name \
@@ -98,30 +132,23 @@ jobs:
           reusable: true
           exclusive: false
       - run:
-          name: "Validate Vendor, Docs, and Code Generation"
+          name: "Docker version"
+          command: docker version
+      - run:
+          name: "Docker info"
+          command: docker info
+      - run:
+          name: "Validate - build image"
           command: |
             rm -f .dockerignore # include .git
             docker build --progress=plain -f dockerfiles/Dockerfile.dev --tag cli-builder-with-git:$CIRCLE_BUILD_NUM .
+      - run:
+          name: "Validate Vendor, Docs, and Code Generation"
+          command: |
             docker run --rm cli-builder-with-git:$CIRCLE_BUILD_NUM \
                 make ci-validate
           no_output_timeout: 15m
-  shellcheck:
+
-    working_directory: /work
-    docker: [{image: 'docker:18.09-git'}]
-    environment:
-      DOCKER_BUILDKIT: 1
-    steps:
-      - checkout
-      - setup_remote_docker:
-          version: 18.09.3
-          reusable: true
-          exclusive: false
-      - run:
-          name: "Run shellcheck"
-          command: |
-            docker build --progress=plain -f dockerfiles/Dockerfile.shellcheck --tag cli-validator:$CIRCLE_BUILD_NUM .
-            docker run --rm cli-validator:$CIRCLE_BUILD_NUM \
-                make shellcheck
 workflows:
   version: 2
   ci:
@@ -130,4 +157,3 @@ workflows:
       - cross
       - test
       - validate
-      - shellcheck