Run the linter only in Docker (closes #20)

script/lint now builds only the lint stage of the Dockerfile, without
the build cache, so every run executes the linter; the image is tagged
simplelog-lint. The lint stage calls golangci-lint directly, since make
lint is itself a docker build of that stage. script/cibuild and
script/docker also build without the cache, so their check steps always
run. script/fmt no longer runs golangci-lint --fix, and script/bootstrap
no longer installs it. golangci-lint config verify is left out, on the
owner's ruling. The README, TODO.md and the script/cibuild comment say
what now runs.

Model: opus-5-5

script/bootstrap

@@ -54,12 +54,7 @@ main() {
     if missing git; then pkg_install git git git git; fi
 
     if missing go; then pkg_install go golang go go; fi
-    # golangci-lint is packaged in nix, brew, and apk; there is no apt
-    # package (on apt hosts, install it from a hash-verified GitHub
-    # release archive manually, never curl | sh).
-    if missing golangci-lint; then
-        pkg_install golangci-lint golangci-lint golangci-lint golangci-lint
-    fi
+    # golangci-lint is not installed: it runs only in docker (script/lint).
 
     go mod download
 

script/cibuild

@@ -1,13 +1,15 @@
 #!/bin/sh
-# script/cibuild: run the CI build. The Dockerfile runs script/check, so
-# a successful build implies all checks pass.
+# script/cibuild: run the CI build. The Dockerfile runs the format check,
+# the linter and the tests, so a successful build means they all pass.
+# --no-cache because a cached check step is a check that did not run.
 set -eu
 
-ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
+ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    docker build .
+    docker build --no-cache -t "$("$SCRIPT_DIR/projectname")" .
 }
 
 main "$@"

script/docker

@@ -1,6 +1,7 @@
 #!/bin/sh
 # script/docker: build the Docker image tagged with the project name.
 # Identical in all repos; the tag comes from script/projectname.
+# --no-cache because a cached check step is a check that did not run.
 set -eu
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
@@ -8,7 +9,7 @@ ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    docker build -t "$("$SCRIPT_DIR/projectname")" .
+    docker build --no-cache -t "$("$SCRIPT_DIR/projectname")" .
 }
 
 main "$@"

script/fmt

@@ -7,7 +7,6 @@ ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
 main() {
     cd "$ROOT"
     goimports -l -w .
-    golangci-lint run --fix
 }
 
 main "$@"

script/lint

@@ -1,12 +1,19 @@
 #!/bin/sh
-# script/lint: run the linter.
+# script/lint: run the linter, in docker only, by building the lint stage
+# of the Dockerfile and nothing else; the build fails on any finding.
+# --no-cache makes every run execute the linter: a cached build of an
+# unchanged tree succeeds without linting anything. The tag makes each
+# build replace the previous image instead of leaving an untagged one.
 set -eu
 
-ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
+ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    golangci-lint run
+    docker build --no-cache \
+        --target lint \
+        -t "$("$SCRIPT_DIR/projectname")-lint" .
 }
 
 main "$@"