coder/provisioner/terraform/safeenv.go

56 lines
1.2 KiB
Go

package terraform
import (
"os"
"strings"
)
// We must clean CODER_ environment variables to avoid accidentally passing in
// secrets like the Postgres connection string. See
// https://github.com/coder/coder/issues/4635.
//
// safeEnviron() is provided as an os.Environ() alternative that strips CODER_
// variables. As an additional precaution, we check a canary variable before
// provisioner exec.
//
// We cannot strip all CODER_ variables at exec because some are used to
// configure the provisioner.
const unsafeEnvCanary = "CODER_DONT_PASS"
func init() {
_ = os.Setenv(unsafeEnvCanary, "true")
}
func envName(env string) string {
parts := strings.SplitN(env, "=", 1)
if len(parts) > 0 {
return parts[0]
}
return ""
}
func isCanarySet(env []string) bool {
for _, e := range env {
if envName(e) == unsafeEnvCanary {
return true
}
}
return false
}
// safeEnviron wraps os.Environ but removes CODER_ environment variables.
func safeEnviron() []string {
env := os.Environ()
strippedEnv := make([]string, 0, len(env))
for _, e := range env {
name := envName(e)
if strings.HasPrefix(name, "CODER_") {
continue
}
strippedEnv = append(strippedEnv, e)
}
return strippedEnv
}