From 02cda05012e12e3284b28cfe2bacf343e634dadc Mon Sep 17 00:00:00 2001
From: Marc Tamsky <tamsky@users.noreply.github.com>
Date: Sat, 16 Sep 2017 02:41:38 -0700
Subject: [PATCH 1/3] add shellcheck linter to Makefile, add package to
 .travis.yml

---
 .travis.yml | 10 ++++++++++
 Makefile    | 13 +++++++++++--
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index f0bb1e296..42bdbbf0c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,6 +4,13 @@ services:
 language: go
 go:
 - '1.9'
+addons:
+  apt:
+    sources:
+    - debian-sid # Grab ShellCheck from the Debian repo
+    packages:
+    - shellcheck
+
 # Make sure we have p2 and the postgres client.
 before_install:
 - go get -v github.com/mattn/goveralls
@@ -19,6 +26,7 @@ script:
 - make test-integration
 - make cover.out
 - $HOME/gopath/bin/goveralls -coverprofile=cover.out -service=travis-ci
+
 after_success:
 - docker login -e $DOCKER_EMAIL -u $DOCKER_USER -p $DOCKER_PASS
 # Push a tagged build if a tag is found.
@@ -28,11 +36,13 @@ after_success:
   fi
 # Push a latest version
 - if [ "$TRAVIS_BRANCH" == "master" ]; then docker push wrouesnel/postgres_exporter ; fi
+
 env:
   global:
   - secure: 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
   - secure: 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
   - secure: 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
+
 deploy:
   skip_cleanup: true
   provider: releases
diff --git a/Makefile b/Makefile
index 26ccb8a65..d186cf666 100644
--- a/Makefile
+++ b/Makefile
@@ -14,8 +14,14 @@ LINTER_DEADLINE ?= 30s
 
 export PATH := $(TOOLDIR)/bin:$(PATH)
 SHELL := env PATH=$(PATH) /bin/bash
+# We may want to move shell scripts to have a common *.sh suffix, 
+# allowing us to use 'find *.sh', like we do for GO_SRC.
+hash := \#
+SHELL_SRC := $(shell grep -l '$(hash)!/bin/bash' -r . \
+                          --exclude-dir 'tools' \
+                          --exclude Makefile)
 
-all: style lint test postgres_exporter
+all: style lint shellcheck test postgres_exporter
 
 # Cross compilation (e.g. if you are on a Mac)
 cross: docker-build docker
@@ -35,6 +41,9 @@ docker: postgres_exporter
 style: tools
 	gometalinter --disable-all --enable=gofmt --vendor
 
+shellcheck:
+	shellcheck $(SHELL_SRC)
+
 lint: tools
 	@echo Using $(CONCURRENT_LINTERS) processes
 	gometalinter -j $(CONCURRENT_LINTERS) --deadline=$(LINTER_DEADLINE) --disable=gotype --disable=gocyclo $(GO_DIRS)
@@ -76,4 +85,4 @@ tools:
 clean:
 	rm -f postgres_exporter postgres_exporter_integration_test
 
-.PHONY: tools docker-build docker lint fmt test vet push cross clean
+.PHONY: tools docker-build docker lint shellcheck fmt test vet push cross clean

From 1604b72e051290d06f640dafc68f54c52078edc7 Mon Sep 17 00:00:00 2001
From: Marc Tamsky <tamsky@users.noreply.github.com>
Date: Sat, 16 Sep 2017 02:42:33 -0700
Subject: [PATCH 2/3] update shell scripts to address new linter's findings and
 harmonize styles across scripts.

---
 postgres_exporter_integration_test_script     |   8 +-
 postgres_metrics_added_and_removed            |   4 +-
 postgres_metrics_parse_script                 |   5 +-
 .../docker-entrypoint.sh                      |   8 +-
 .../setup-replication.sh                      |  10 +-
 tests/test-smoke                              | 204 +++++++++++-------
 6 files changed, 141 insertions(+), 98 deletions(-)

diff --git a/postgres_exporter_integration_test_script b/postgres_exporter_integration_test_script
index 03f2945af..d6a5ee35e 100755
--- a/postgres_exporter_integration_test_script
+++ b/postgres_exporter_integration_test_script
@@ -7,9 +7,9 @@ shift
 output_cov=$1
 shift
 
-echo "mode: count" > $output_cov
+echo "mode: count" > "${output_cov}"
 
 test_cov=$(mktemp)
-$test_binary -test.coverprofile=$test_cov $@
-tail -n +2 $test_cov >> $output_cov
-rm -f $test_cov
+${test_binary} -test.coverprofile="${test_cov}" "$@"
+tail -n +2 "${test_cov}" >> "${output_cov}"
+rm -f "${test_cov}"
diff --git a/postgres_metrics_added_and_removed b/postgres_metrics_added_and_removed
index d33618904..f3e1684ce 100755
--- a/postgres_metrics_added_and_removed
+++ b/postgres_metrics_added_and_removed
@@ -7,5 +7,5 @@ version=$2
 old_version=$3
 new_version=$4
 
-comm -23 $old_version $new_version > .metrics.${type}.${version}.removed
-comm -13 $old_version $new_version > .metrics.${type}.${version}.added
+comm -23 "${old_version}" "${new_version}" > ".metrics.${type}.${version}.removed"
+comm -13 "${old_version}" "${new_version}" > ".metrics.${type}.${version}.added"
diff --git a/postgres_metrics_parse_script b/postgres_metrics_parse_script
index 393e39a1a..a499fb668 100755
--- a/postgres_metrics_parse_script
+++ b/postgres_metrics_parse_script
@@ -7,10 +7,9 @@
 
 for raw_prom in $(echo .*.prom) ; do
     # Strip, sort and deduplicate the label names
-    cat $raw_prom | grep -v '#' | \
+    grep -v "#" "${raw_prom}" | \
         rev | cut -d' ' -f2- | \
         rev | cut -d'{' -f1 | \
         sort | \
-        uniq > ${raw_prom}.unique
-    
+        uniq > "${raw_prom}.unique"
 done
diff --git a/tests/docker-postgres-replication/docker-entrypoint.sh b/tests/docker-postgres-replication/docker-entrypoint.sh
index 0203e4b79..0b085514d 100755
--- a/tests/docker-postgres-replication/docker-entrypoint.sh
+++ b/tests/docker-postgres-replication/docker-entrypoint.sh
@@ -36,12 +36,12 @@ if [ "$1" = 'postgres' ]; then
 	    if [ "x$REPLICATE_FROM" == "x" ]; then
 		eval "gosu postgres initdb $POSTGRES_INITDB_ARGS"
 	    else
-            	until ping -c 1 -W 1 ${REPLICATE_FROM}
+            	until ping -c 1 -W 1 "${REPLICATE_FROM}"
             	do
                 	echo "Waiting for master to ping..."
                 	sleep 1s
             	done
-            	until gosu postgres pg_basebackup -h ${REPLICATE_FROM} -D ${PGDATA} -U ${POSTGRES_USER} -vP -w
+            	until gosu postgres pg_basebackup -h "${REPLICATE_FROM}" -D "${PGDATA}" -U "${POSTGRES_USER}" -vP -w
             	do
                 	echo "Waiting for master to connect..."
                 	sleep 1s
@@ -84,10 +84,13 @@ if [ "$1" = 'postgres' ]; then
 			-o "-c listen_addresses='localhost'" \
 			-w start
 
+                # shellcheck disable=SC2086
 		: ${POSTGRES_USER:=postgres}
+                # shellcheck disable=SC2086
 		: ${POSTGRES_DB:=$POSTGRES_USER}
 		export POSTGRES_USER POSTGRES_DB
 
+                # shellcheck disable=SC2191
 		psql=( psql -v ON_ERROR_STOP=1 )
 
 		if [ "$POSTGRES_DB" != 'postgres' ]; then
@@ -112,6 +115,7 @@ if [ "$1" = 'postgres' ]; then
 		psql+=( --username "$POSTGRES_USER" --dbname "$POSTGRES_DB" )
 
 		echo
+                # shellcheck disable=SC1090
 		for f in /docker-entrypoint-initdb.d/*; do
 			case "$f" in
 				*.sh)     echo "$0: running $f"; . "$f" ;;
diff --git a/tests/docker-postgres-replication/setup-replication.sh b/tests/docker-postgres-replication/setup-replication.sh
index 460c54891..ea3a794b2 100755
--- a/tests/docker-postgres-replication/setup-replication.sh
+++ b/tests/docker-postgres-replication/setup-replication.sh
@@ -1,8 +1,8 @@
 #!/bin/bash
 
-if [ "x$REPLICATE_FROM" == "x" ]; then
+if [[ -z "$REPLICATE_FROM" ]]; then
 
-cat >> ${PGDATA}/postgresql.conf <<EOF
+cat >> "${PGDATA}/postgresql.conf" <<EOF
 wal_level = hot_standby
 max_wal_senders = $PG_MAX_WAL_SENDERS
 wal_keep_segments = $PG_WAL_KEEP_SEGMENTS
@@ -11,12 +11,12 @@ EOF
 
 else
 
-cat > ${PGDATA}/recovery.conf <<EOF
+cat > "${PGDATA}/recovery.conf" <<EOF
 standby_mode = on
 primary_conninfo = 'host=${REPLICATE_FROM} port=5432 user=${POSTGRES_USER} password=${POSTGRES_PASSWORD}'
 trigger_file = '/tmp/touch_me_to_promote_to_me_master'
 EOF
-chown postgres ${PGDATA}/recovery.conf
-chmod 600 ${PGDATA}/recovery.conf
+chown postgres "${PGDATA}/recovery.conf"
+chmod 600 "${PGDATA}/recovery.conf"
 
 fi
diff --git a/tests/test-smoke b/tests/test-smoke
index 624a3e0bf..0a149d02e 100755
--- a/tests/test-smoke
+++ b/tests/test-smoke
@@ -1,62 +1,89 @@
-#!/bin/bash
+#!/bin/bash -x
 # Basic integration tests with postgres. Requires docker to work.
 
 SOURCE="${BASH_SOURCE[0]}"
-while [ -h "$SOURCE" ]; do # resolve $SOURCE until the file is no longer a symlink
-  DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"
-  SOURCE="$(readlink "$SOURCE")"
-  [[ $SOURCE != /* ]] && SOURCE="$DIR/$SOURCE" # if $SOURCE was a relative symlink, we need to resolve it relative to the path where the symlink file was located
+METRICS_DIR=$(pwd)
+
+# resolve $SOURCE until the file is no longer a symlink
+while [[ -h "${SOURCE}" ]]; do 
+  DIR="$( cd -P "$( dirname "${SOURCE}" )" && pwd )"
+  SOURCE="$(readlink "${SOURCE}")"
+
+  # if $SOURCE was a relative symlink, we need to resolve it relative
+  # to the path where the symlink file was located
+  [[ ${SOURCE} != /* ]] && SOURCE="${DIR}/${SOURCE}"
 done
-DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"
 
-METRICS_DIR=$(pwd)
+DIR=$( cd -P "$( dirname "${SOURCE}" )" && pwd )
+cd "${DIR}" || {
+    echo "unable to cd to ${DIR}" ;
+    exit 1 ;
+}
 
 # Read the absolute path to the exporter
-postgres_exporter=$(readlink -f $1)
-test_binary=$(readlink -f $2)
+postgres_exporter=$(readlink -f "$1")
+
+# $2 is actually multiple space-separated values,
+# we avoid quoting it here to allow argument expansion.
+#
+# readlink outputs one line per argument
+#
+# echo removes the newlines
+#
+# shellcheck disable=SC2086,SC2046,SC2005
+test_binary=$(echo $(readlink -f $2))
+
+# Confirm that the first arg is a binary we can run:
+[[ -x "${test_binary%% *}" ]] || {
+    echo "${test_binary%% *} is not an executable file" ;
+    exit 1 ;
+}
+
 export POSTGRES_PASSWORD=postgres
 exporter_port=9187
 
-cd $DIR
-
-VERSIONS=( \
-    9.1 \
-    9.2 \
-    9.3 \
-    9.4 \
-    9.5 \
-    9.6 \
+declare -a VERSIONS=(
+    9.1
+    9.2
+    9.3
+    9.4
+    9.5
+    9.6
 )
 
+# START OF FUNCTIONS
+
 wait_for_postgres(){
     local ip=$1
     local port=$2
-    if [ -z $ip ]; then
+    if [[ -z ${ip} ]]; then
         echo "No IP specified." 1>&2
         exit 1
     fi
-    
-    if [ -z $port ]; then
+
+    if [[ -z ${port} ]]; then
         echo "No port specified." 1>&2
         exit 1
     fi
-    
+
+    # shellcheck disable=SC2155
     local wait_start=$(date +%s)
     echo "Waiting for postgres to start listening..."
-    while ! pg_isready --host=$ip --port=$port &> /dev/null; do
-        if [ $(( $(date +%s) - $wait_start )) -gt $TIMEOUT ]; then
+    while ! pg_isready --host="${ip}" --port="${port}" &> /dev/null; do
+        if [[ $(( $(date +%s) - wait_start )) -gt ${TIMEOUT} ]]; then
             echo "Timed out waiting for postgres to start!" 1>&2
-            exit 1            
+            exit 1
         fi
         sleep 1
     done
 }
 
 wait_for_exporter() {
+    # shellcheck disable=SC2155
     local wait_start=$(date +%s)
     echo "Waiting for exporter to start..."
-    while ! nc -z localhost $exporter_port ; do
-        if [ $(( $(date +%s) - $wait_start )) -gt $TIMEOUT ]; then
+    while ! nc -z localhost ${exporter_port} ; do
+        if [[ $(( $(date +%s) - wait_start )) -gt ${TIMEOUT} ]]; then
             echo "Timed out waiting for exporter!" 1>&2
             exit 1            
         fi
@@ -69,92 +96,105 @@ smoketest_postgres() {
     local CONTAINER_NAME=postgres_exporter-test-smoke
     local TIMEOUT=30
     local IMAGE_NAME=postgres
-    
-    local CUR_IMAGE=$IMAGE_NAME:$version
-    
+
+    local CUR_IMAGE=${IMAGE_NAME}:${version}
+
     echo "#######################"
     echo "Standalone Postgres $version"
     echo "#######################"
-    local docker_cmd="docker run -d -e POSTGRES_PASSWORD=$POSTGRES_PASSWORD -p 127.0.0.1:55432:5432 $CUR_IMAGE"
-    echo "Docker Cmd: $docker_cmd"
-    
-    CONTAINER_NAME=$($docker_cmd)
-    trap "docker logs $CONTAINER_NAME ; docker kill $CONTAINER_NAME ; docker rm -v $CONTAINER_NAME; exit 1" EXIT INT TERM
+    local docker_cmd="docker run -d -e POSTGRES_PASSWORD=${POSTGRES_PASSWORD} -p 127.0.0.1:55432:5432 ${CUR_IMAGE}"
+    echo "Docker Cmd: ${docker_cmd}"
+
+    CONTAINER_NAME=$( ${docker_cmd} )
+    trap 'docker logs ${CONTAINER_NAME} ; 
+          docker kill ${CONTAINER_NAME} ; 
+          docker rm -v ${CONTAINER_NAME}; exit 1' EXIT INT TERM
     wait_for_postgres localhost 55432
 
     # Run the test binary.
-    DATA_SOURCE_NAME="postgresql://postgres:$POSTGRES_PASSWORD@localhost:55432/?sslmode=disable" $test_binary --log.level=debug || exit $?
+    DATA_SOURCE_NAME="postgresql://postgres:${POSTGRES_PASSWORD}@localhost:55432/?sslmode=disable" \
+                    ${test_binary} --log.level=debug || exit $?
 
     # Extract a raw metric list.
-    DATA_SOURCE_NAME="postgresql://postgres:$POSTGRES_PASSWORD@localhost:55432/?sslmode=disable" $postgres_exporter --log.level=debug --web.listen-address=:$exporter_port &
+    DATA_SOURCE_NAME="postgresql://postgres:${POSTGRES_PASSWORD}@localhost:55432/?sslmode=disable" \
+                    ${postgres_exporter} --log.level=debug --web.listen-address=:${exporter_port} &
     exporter_pid=$!
+    # shellcheck disable=SC2064
     trap "docker logs $CONTAINER_NAME ; docker kill $CONTAINER_NAME ; docker rm -v $CONTAINER_NAME; kill $exporter_pid; exit 1" EXIT INT TERM
     wait_for_exporter
 
     # Dump the metrics to a file.
-    wget -q -O - http://localhost:$exporter_port/metrics 1> $METRICS_DIR/.metrics.single.$version.prom
-    if [ "$?" != "0" ]; then
-        echo "Failed on postgres $version ($DOCKER_IMAGE)" 1>&2
-        kill $exporter_pid
-        exit 1
-    fi
-
-    kill $exporter_pid
-    docker kill $CONTAINER_NAME
-    docker rm -v $CONTAINER_NAME
+    wget -q -O - \
+         http://localhost:${exporter_port}/metrics \
+         1>"${METRICS_DIR}/.metrics.single.${version}.prom" ||
+        {
+            echo "Failed on postgres ${version} (${DOCKER_IMAGE})" 1>&2
+            kill ${exporter_pid}
+            exit 1
+        }
+
+    kill ${exporter_pid}
+    docker kill "${CONTAINER_NAME}"
+    docker rm -v "${CONTAINER_NAME}"
     trap - EXIT INT TERM
-    
+
     echo "#######################"
-    echo "Replicated Postgres $version"
+    echo "Replicated Postgres ${version}"
     echo "#######################"
     old_pwd=$(pwd)
-    cd docker-postgres-replication
+    cd docker-postgres-replication || exit 1
+
     
-    VERSION=$version p2 -t Dockerfile.p2 -o Dockerfile
-    if [ "$?" != "0" ]; then
-        echo "Templating failed" 1>&2
-        exit 1
-    fi
+    VERSION=${version} p2 -t Dockerfile.p2 -o Dockerfile || {
+        echo "Templating failed" 1>&2 ;
+        exit 1 ;
+    }
+
     trap "docker-compose logs; docker-compose down ; docker-compose rm -v; exit 1" EXIT INT TERM
-    local compose_cmd="POSTGRES_PASSWORD=$POSTGRES_PASSWORD docker-compose up -d --force-recreate --build"
-    echo "Compose Cmd: $compose_cmd"
-    eval $compose_cmd
-    
+    local compose_cmd="POSTGRES_PASSWORD=${POSTGRES_PASSWORD} docker-compose up -d --force-recreate --build"
+    echo "Compose Cmd: ${compose_cmd}"
+    eval "${compose_cmd}"
+
     master_container=$(docker-compose ps -q pg-master)
     slave_container=$(docker-compose ps -q pg-slave)
-    master_ip=$(docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' $master_container)
-    slave_ip=$(docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' $slave_container)
-    echo "Got master IP: $master_ip"
-    wait_for_postgres $master_ip 5432
-    wait_for_postgres $slave_ip 5432
-    
-    DATA_SOURCE_NAME="postgresql://postgres:$POSTGRES_PASSWORD@$master_ip:5432/?sslmode=disable" $test_binary --log.level=debug || exit $?
-    
-    DATA_SOURCE_NAME="postgresql://postgres:$POSTGRES_PASSWORD@$master_ip:5432/?sslmode=disable" $postgres_exporter --log.level=debug --web.listen-address=:$exporter_port &
+    master_ip=$(docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' "${master_container}")
+    slave_ip=$(docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' "${slave_container}")
+    echo "Got master IP: ${master_ip}"
+    wait_for_postgres "${master_ip}" 5432
+    wait_for_postgres "${slave_ip}" 5432
+
+    DATA_SOURCE_NAME="postgresql://postgres:${POSTGRES_PASSWORD}@${master_ip}:5432/?sslmode=disable" ${test_binary} --log.level=debug || exit $?
+
+    DATA_SOURCE_NAME="postgresql://postgres:${POSTGRES_PASSWORD}@${master_ip}:5432/?sslmode=disable" ${postgres_exporter} --log.level=debug --web.listen-address=:${exporter_port} &
     exporter_pid=$!
-    trap "docker-compose logs; docker-compose down ; docker-compose rm -v ; kill $exporter_pid; exit 1" EXIT INT TERM
+    # shellcheck disable=SC2064
+    trap "docker-compose logs; docker-compose down ; docker-compose rm -v ; kill ${exporter_pid}; exit 1" EXIT INT TERM
     wait_for_exporter
 
-    wget -q -O - http://localhost:$exporter_port/metrics 1> $METRICS_DIR/.metrics.replicated.$version.prom
-    if [ "$?" != "0" ]; then
-        echo "Failed on postgres $version ($DOCKER_IMAGE)" 1>&2
-        exit 1
-    fi
+    wget -q -O - \
+         http://localhost:${exporter_port}/metrics \
+         1>"${METRICS_DIR}/.metrics.replicated.${version}.prom" ||
+        {
+            echo "Failed on postgres ${version} (${DOCKER_IMAGE})" 1>&2 ;
+            exit 1 ;
+        }
 
-    kill $exporter_pid    
+    kill ${exporter_pid}
     docker-compose down
     docker-compose rm -v
     trap - EXIT INT TERM
-    
-    cd $old_pwd
+
+    cd "${old_pwd}" || exit 1
 }
 
+### START OF MAIN PROGRAM
+
 # Start pulling the docker images in advance
-for version in ${VERSIONS[@]}; do
-    docker pull postgres:$version > /dev/null &
+for version in "${VERSIONS[@]}"; do
+    docker pull "postgres:${version}" > /dev/null &
 done
 
-for version in ${VERSIONS[@]}; do
-    echo "Testing postgres version $version"
-    smoketest_postgres $version
+for version in "${VERSIONS[@]}"; do
+    echo "Testing postgres version ${version}"
+    smoketest_postgres "${version}"
 done

From e977ad3cc542b66002a8362f257598f246a916b5 Mon Sep 17 00:00:00 2001
From: Will Rouesnel <w.rouesnel@gmail.com>
Date: Sun, 11 Nov 2018 14:28:11 +1100
Subject: [PATCH 3/3] Fix bad merge syntax.

---
 cmd/postgres_exporter/tests/test-smoke | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cmd/postgres_exporter/tests/test-smoke b/cmd/postgres_exporter/tests/test-smoke
index 5695a8f48..010891afc 100755
--- a/cmd/postgres_exporter/tests/test-smoke
+++ b/cmd/postgres_exporter/tests/test-smoke
@@ -3,7 +3,7 @@
 
 SOURCE="${BASH_SOURCE[0]}"
 METRICS_DIR=$(pwd)
-done
+
 # resolve $SOURCE until the file is no longer a symlink
 while [[ -h "${SOURCE}" ]]; do 
   DIR="$( cd -P "$( dirname "${SOURCE}" )" && pwd )"