There is no need to explicitly list variables in envsubst

[sadiqkhoja]

central/files/service/scripts/start-odk.sh

Line 7 in f09c50b

envsubst '$DOMAIN $BASE_URL $SYSADMIN_EMAIL $ENKETO_API_KEY $DB_HOST $DB_USER $DB_PASSWORD $DB_NAME $DB_SSL $EMAIL_FROM $EMAIL_HOST $EMAIL_PORT $EMAIL_SECURE $EMAIL_IGNORE_TLS $EMAIL_USER $EMAIL_PASSWORD $SENTRY_ORG_SUBDOMAIN $SENTRY_KEY $SENTRY_PROJECT' \

[alxndrsn]

This won't work for files which contain other strings of the form $name, e.g. nginx config:

$ envsubst <<< 'proxy_set_header Host $host;'
proxy_set_header Host ;

Given this limitation, here are some options:

double-escape dollars which should be preserved:

$ envsubst <<< 'proxy_set_header Host $${W}host;'
proxy_set_header Host $host;

add second conversion layer

$ envsubst <<< 'host={{host}} shell=$SHELL' | sed 's/{{\([^}]*\)}}/$\1/'
host=$host shell=/bin/bash

automatically generate SHELL-FORMAT

printenv

$ envsubst "$(printenv | awk -F= '{ printf "$%s", $1 }')" <<< 'host=$host shell=$SHELL'
host=$host shell=/bin/bash

compgen

$ envsubst "$(compgen -v | awk '{ printf "$%s", $1 }')" <<< 'host=$host shell=$SHELL'
host=$host shell=/bin/bash

use perl in place of envsubst

...and require substituted vars to take the form ${CAPS_AND_UNDERSCORES_ONLY}

$ perl -pe 's/\$\{([A-Z_]*)\}/$ENV{$1}/g' <<< 'host=$host shell=${SHELL}'
host=$host shell=/bin/bash