Improve the docker entrypoint and dockerfile

Dockerfile

@@ -1,12 +1,15 @@
-FROM alpine
+FROM alpine:3.5
 
-RUN apk add --no-cache git ansible mysql-client curl openssh-client
-RUN curl -L https://github.com/ansible-semaphore/semaphore/releases/download/v2.2.0/semaphore_linux_amd64 > /usr/bin/semaphore && chmod +x /usr/bin/semaphore && mkdir -p /etc/semaphore/playbooks
+ENV SEMAPHORE_VERSION="2.2.0" SEMAPHORE_ARCH="linux_amd64"
 
-ADD semaphore-startup.sh /usr/bin/semaphore-startup.sh
-RUN chmod +x /usr/bin/semaphore-startup.sh
+RUN apk add --no-cache git ansible mysql-client curl openssh-client && \
+    curl -sSfL "https://github.com/ansible-semaphore/semaphore/releases/download/v$SEMAPHORE_VERSION/semaphore_$SEMAPHORE_ARCH" > /usr/bin/semaphore && \
+    chmod +x /usr/bin/semaphore && mkdir -p /etc/semaphore/playbooks
 
 EXPOSE 3000
+
+ADD semaphore-startup.sh /usr/bin/semaphore-startup.sh
+
 ENTRYPOINT ["/usr/bin/semaphore-startup.sh"]
 
 CMD ["/usr/bin/semaphore", "-config", "/etc/semaphore/semaphore_config.json"]

semaphore-startup.sh

@@ -2,21 +2,44 @@
 
 echoerr() { printf "%s\n" "$*" >&2; }
 
+SEMAPHORE_PLAYBOOK_PATH="${SEMAPHORE_PLAYBOOK_PATH:-/semaphore}"
+# Semaphore database env config
+SEMAPHORE_DB_HOST="${SEMAPHORE_DB_HOST:-127.0.0.1}"
+SEMAPHORE_DB_PORT="${SEMAPHORE_DB_PORT:-3306}"
+SEMAPHORE_DB="${SEMAPHORE_DB:-semaphore}"
+SEMAPHORE_DB_USER="${SEMAPHORE_DB_USER:-semaphore}"
+SEMAPHORE_DB_PASS="${SEMAPHORE_DB_PASS:-semaphore}"
+# Semaphore Admin env config
+SEMAPHORE_ADMIN="${SEMAPHORE_ADMIN:-admin}"
+SEMAPHORE_ADMIN_EMAIL="${SEMAPHORE_ADMIN_EMAIL:-admin@localhost}"
+SEMAPHORE_ADMIN_NAME="${SEMAPHORE_ADMIN_NAME:-Semaphore Admin}"
+SEMAPHORE_ADMIN_PASSWORD="${SEMAPHORE_ADMIN_PASSWORD:-semaphorepassword}"
+
+# create semaphore playbook directory
+mkdir -p "${SEMAPHORE_PLAYBOOK_PATH}" || {
+    echo "Can't create Semaphore playbook path '$SEMAPHORE_PLAYBOOK_PATH'."
+    exit 1
+}
+
 # wait on db to be up
-echoerr "Attempting to connect to database ${SEMAPHORE_DB} on ${SEMAPHORE_DB_HOST} with user:pass ${SEMAPHORE_DB_USER}:${SEMAPHORE_DB_PASS}"
-until mysql -h ${SEMAPHORE_DB_HOST} -u ${SEMAPHORE_DB_USER} --password=${SEMAPHORE_DB_PASS} ${SEMAPHORE_DB} -e "select version();" &>/dev/null;
-do
-    echoerr "waiting";
-    sleep 3;
+echoerr "Attempting to connect to database ${SEMAPHORE_DB} on ${SEMAPHORE_DB_HOST}:${SEMAPHORE_DB_PORT} with user ${SEMAPHORE_DB_USER} ..."
+TIMEOUT=30
+while ! mysqladmin ping -h"$SEMAPHORE_DB_HOST" -P "$SEMAPHORE_DB_PORT" -u "$SEMAPHORE_DB_USER" --password="$SEMAPHORE_DB_PASS" --silent >/dev/null 2>&1; do
+    TIMEOUT=$(expr $TIMEOUT - 1)
+    if [ $TIMEOUT -eq 0 ]; then
+        echoerr "Could not connect to database server. Exiting."
+        exit 1
+    fi
+    echo -n "."
+    sleep 1
 done
 
-# generate stdin
-if [ -f ${SEMAPHORE_PLAYBOOK_PATH}/config.stdin ]
-then
-    echoerr "already generated stdin"
-else
-    echoerr "generating ${SEMAPHORE_PLAYBOOK_PATH}/config.stdin"
-    cat << EOF > ${SEMAPHORE_PLAYBOOK_PATH}/config.stdin
+if [ -f "${SEMAPHORE_PLAYBOOK_PATH}/semaphore_config.json" ]; then
+    ln -s "${SEMAPHORE_PLAYBOOK_PATH}/semaphore_config.json" /etc/semaphore/semaphore_config.json
+fi
+if [ ! -f /etc/semaphore/semaphore_config.json ]; then
+    echoerr "Generating ${SEMAPHORE_PLAYBOOK_PATH}/config.stdin ..."
+    cat << EOF > "${SEMAPHORE_PLAYBOOK_PATH}/config.stdin"
 ${SEMAPHORE_DB_HOST}:${SEMAPHORE_DB_PORT}
 ${SEMAPHORE_DB_USER}
 ${SEMAPHORE_DB_PASS}
@@ -27,17 +50,8 @@ ${SEMAPHORE_ADMIN}
 ${SEMAPHORE_ADMIN_EMAIL}
 ${SEMAPHORE_ADMIN_NAME}
 ${SEMAPHORE_ADMIN_PASSWORD}
-n
 EOF
-fi
-
-# test to see if initialzation is needed
-if [ -f ${SEMAPHORE_PLAYBOOK_PATH}/semaphore_config.json ]
-then
-    echoerr "already initialized"
-else
-    echoerr "Initializing semaphore"
-    /usr/bin/semaphore -setup < ${SEMAPHORE_PLAYBOOK_PATH}/config.stdin
+    /usr/bin/semaphore -setup < "${SEMAPHORE_PLAYBOOK_PATH}/config.stdin"
 fi
 
 # run our command