feat(ci): specific build branch name under travis

Signed-off-by: Lorenzo Fontana <lo@linux.com>

.travis.yml

@@ -8,5 +8,4 @@ services:
 - docker
 script:
 - make _output/bin/kubectl-trace
-after_success:
 - ./hack/release-image.sh

Makefile

@@ -5,9 +5,10 @@ DOCKER ?= docker
 
 COMMIT_NO := $(shell git rev-parse HEAD 2> /dev/null || true)
 GIT_COMMIT := $(if $(shell git status --porcelain --untracked-files=no),${COMMIT_NO}-dirty,${COMMIT_NO})
-GIT_BRANCH := $(shell git rev-parse --abbrev-ref HEAD 2>/dev/null)
+GIT_BRANCH ?= $(shell git rev-parse --abbrev-ref HEAD 2>/dev/null)
 GIT_BRANCH_CLEAN := $(shell echo $(GIT_BRANCH) | sed -e "s/[^[:alnum:]]/-/g")
 
+
 IMAGE_BPFTRACE_BRANCH := quay.io/fntlnz/kubectl-trace-bpftrace:$(GIT_BRANCH_CLEAN)
 IMAGE_BPFTRACE_COMMIT := quay.io/fntlnz/kubectl-trace-bpftrace:$(GIT_COMMIT)
 IMAGE_BPFTRACE_LATEST := quay.io/fntlnz/kubectl-trace-bpftrace:latest

hack/release-image.sh

@@ -7,14 +7,18 @@ set -xeo pipefail
 make=$(command -v make)
 docker=$(command -v docker)
 
-$make image/build
+makeopts=""
+if [[ ! -z "$TRAVIS_PULL_REQUEST_BRANCH" ]]; then
+  makeopts="-e GIT_BRANCH=$TRAVIS_PULL_REQUEST_BRANCH image/build"
+fi
+
+$make $makeopts image/build
 
 if [[ ! -z "$QUAY_TOKEN" ]]; then
   $docker login -u="fntlnz+travisci" -p="$QUAY_TOKEN" quay.io
-  $make image/push
-
-  if [[ "$TRAVIS_BRANCH" = "master" ]]; then
-    $make image/latest
-  fi
+  $make $makeopts image/push
 fi
 
+if [[ "$TRAVIS_BRANCH" = "master" && "$TRAVIS_PULL_REQUEST_BRANCH" = "" ]]; then
+  $make $makeopts image/latest
+fi